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333 Cards in this Set
- Front
- Back
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What is the difference between a prohormone and a phytohormone?
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A phytohormone is a plant hormone, a prohormone is a large molecule that is broken down into human hormones.
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What is the difference between a neurohormone and a neurotransmitter?
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A neurohomone is secreted from a neurosecretory cell into the blood. A neurotransmitter is produced in a nerve cell and released into the synapse.
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What is a prohormone?
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A prohormone is a large molecule, usually a peptide, which is broken down enzymatically into a hormone(s).
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Which hormone could be considered a prohormone for estrogen?
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testosterone
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Wht is the difference between a "true" hormone and a pheromone?
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True hormones are synthesized in endocrine (ductless) glands and act within the organism, pheromones are synthesized in exocrine (ducted) glands and are relased into te environment.
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Why is a nuerohormone different from a "true" hormone?
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Because it is synthesized and released from neuroendocrine cells not endocrine glands.
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What is the difference between paracrine and endocrine communication?
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Paracrine communication is short distance within the extracellular space, endocrine is long distance in blood stream.
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What is the difference between neurocrine and neuroendocrine communication?
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Neurocrine communication involves the release of neurotransmitters from neuron
into the synapse, while neuroendocrine communication involves the release of hormones from neurosecretory cells into the blood. |
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What is a parahormone?
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A hormone-like substance that is not necessarily synthesized in an endocrine gland.
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What is the difference between a neurotransmitter and a neuromodulator?
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A neurotransmitter is synthesized in a pre-synaptic nerve cell and is released into the
synapse to stimulate receptors on a post-synaptic cell. A neuromodulator, often a peptide, is secreted non-synaptically by a neuron to influence the excitability of nearby neurons. |
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What are cytokines?
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Cytokines are peptides produced in cells of the immune system (lymphocytes and monocytes) which act as immunomodulators.
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Which endocrine glands secrete the following hormones: a) calcitonin, b)melatonin, c) glucagon, d) gastrin?
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a) thyroid, b) pineal, c) alpha cells of pancreas d) stomach
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Each of the following glands secretes two primary hormones. Name the hormones from a) duodenum, b) ovary.
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a) secretin and cholecystokinin (CCK). b) estrogens and progestins.
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Name the tow parts of the adrenal gland and the two hormones secreted by each part.
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Adrenal cortex: mineralocorticoids (aldosterone) and glucocorticoids (cortisol)
Adrenal medulla: epinephrine and norepinephrine |
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Name the five steroid hormones.
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Androgens, progestins, estrogens
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Name the hormones produced in the following glands: a) testis, b) stomach, c) thyroid, d) pancreas (beta cells).
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a) androgens, inhibin.b) gastrin c) T3, T4, calcitonin. d) Insulin
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Which endocrine gland is important for the development of the immune system?
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Thymus
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Which placental hormone stimulates the ovaries to keep producing progesterone in the early stages of pregnancy?
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HCG
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Which endocrine glands secrete the following hormones: a) human placental lactogen, b) thymosin, c) aldosterone, d) adrenaline?
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a) placenta, b) Thymus, c) adrenal cortex, d) adrenal medulla
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name two hormones which are also neurotransmitters.
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Epinephrine and norepinephrine
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As well as the gonads, the sex steroids are produced in which other endocrine gland?
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Adrenal cortex
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What is the hypophysis?
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Pituitary gland
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What two pituitary hormones are neurohormones?
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Oxytocin and vasopressin
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Describe the connections between the hypothalamus and the neurohypophysis.
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Extension of hypothalamus, hormones travel down axons of PVN and SON in infundibulum to terminate in pars nervosa and stored there, to be released into hypophyseal artery.
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Which pituitary hormones serve the following functions: a) stimulating ovulation, b) stimulating corticosteroid secretion, c) stimulating milk secretion in breast, d) stimulating uterine contractions at childbirth.
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a) LH, b) ACTH, c) PRL, d) oxytocin
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Name the six hormones of the pars distalis.
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ACTH, PRL, LH, FSH, TSH, GH
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What does 'tropic' mean?
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Influences activity of a target organ.
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Which pituitary hormones have the following functions: a) cause skin colour changes in amphibia, b) stimulate T4 secretion.
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a) MSH b) TSH
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Which two pituitary hormones are primary gonadotropins?
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FSH and LH
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Give the Latin names of the 3 lobes of the pituitary gland.
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Pars distalis, pars intermedia, pars nervosa.
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Name the hormone released by the intermediate pituitary gland.
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beta-endorphin.
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Which three adenohypophyseal hormones are synthesized from the prohormone POMC?
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beta-endorphin, MSH, and ACTH.
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Name the 3 areas of the medial basal hypothalamus which arie referred to as the endocrine hypothalamus.
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VMN, ARC, median eminence
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What are the two types of neurosecretory cell in the hypothalamus and what are their functions?
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Parvocellular: release hypophysiotropic hormones into the hypophyseal portal and magnocellular: release oxytocin and vasopressin from neurons that go from the SON and PVN to posterior pituitary.
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What is the neuroendocrine transducer?
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Neurosecretory cells, neurotransmitter input, hormonal output.
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Name the 9 hypothalamic hypophysiotropic hormones hormones and describe how they influence the release of of the adenohypophyseal hormones.
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CRH stimulates ACTH; TRH stimulates TSH; GnRH stimulates stimulates FSH and LH; PRL-RH and PRL-RIH stimulate and inhibit PRL; GH-RH and GH-RIH stimulates and inhibits GH; MSH-RH and MSH-RIH stimulates and inhibits MSH
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HOw do the hormones of the hypothalamus reach the anterior pituitary?
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Through the hypophyseal portal veins
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What is the difference between tonic and cyclic GnRH secretion?
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Tonic GnRH secretion is the basal, low level of GnRH secretion that occurs in both males and females. Cyclic GnRH secretion is the estrogen-stimulated pulse of GnRH which occurs only in females and stimulates ovulation.
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What two neurotransmitters act as prolactin inhibitng factors?
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Dopamine and GABA
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Which two pituitary hormones do each of the following hypothalamic hormones affect, and are these effects stimulatory of inhibitory a) TRH; b)somatostatin; c) GnRH.
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TRH stimulates release of PRL and TSH; somatostatin inhibits te release of GH and TSH; GnRH stimulates release of FSH and LH
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Endocrine
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releases hormones into the bloodstream and effects target cells
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Paracrine
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Chemicals are released into the extracellular space and effect neighboring cells
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Autocrine
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Chemicals are released into extracellular space and effects itself
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Neuroendocrine
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Neurohormones are released into PNS or hypophyseal portal vessels and effect target cells or pituitary
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Neurocrine
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Chemicals are released into extracellular space and effect postsynaptic cell.
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Phytohormone
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Plant hormone
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What are the criteria for a true hormone?
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1.chemical messanger effective in minute quantities
2.synthesized in endocrine (ductless( glands 3.secreted into bloodstream and travel long-distance 4.effect specific target cell receptors 5.cause specific regulatory actions |
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What is wrong with the criterion for a true hormone "must be a chemical messanger effective in minute quantities"?
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There are physiological regulators that are not hormones (CO2, glucose, parahormones) and hormone concentrations vary.
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What is wrong with the criterion for a true hormone "synthesized in endocrine glands"?
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Angiotensin is synthesized in the bloodstream, neurohormones are synthesized in neurosecretory cells, some growth factors are not produced in endocrine glands, sytokines are produced in lymphocytes.One hormones may be produced in manhy different areas.
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What is wrong with the criterion for a true hormone "secreted into the bloodstream"?
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Paracrine and autocrine action. Synaptic action. Neurohormones, neuropeptides, and neurotransmitters may be carried bu CSF.
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What is wrong with the criterion for a true hormone "Act on a target cell at a distance"?
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Some hormones act on more than one kind of cell (GH, glucocorticoids). HMay not travel far (hypothalamic hormones, paracrine, autocrine.)
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What is wrong with the criterion for a true hormone "cause specfifc regulatory actions"?
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Hormones can cause different actions in different cells (Estrogen). There may be more than one receptor type (muscarinic/nicotinic)
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Neurohormone
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hormone that is produced and released from neurosecretory cells.
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Nuerotransmitter
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Produced and released by neurons, released into synapse.
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Pheromones
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air soluble (volatile), synthesized in exocrine glands, secreted into environement, act on other organisms, stimulate gustatory or olfactory receptors.
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Parahormone
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Hormone-like chemical not produced in endocrine glands. Histamine and prostoglandins.
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Prohormones
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Hormone precursors (POMC)
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Growth Factors
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chemical messengers synthesized in a variety of cell types and effect growth in a variety of cell types
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Cytokines
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Hormones released by immune system
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Vitamins
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Not prodcued by the body, regulate growth, development, and metabolism.
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Neuroregulators
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General term for any chemical messenger that regulates activity of a nerve cell. Includes neurotransmitters and neuromodulators and neuropeptides
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Neurotransmitter
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A chemical messenger that is released by a presynaptic cell and acts on a postsynaptic cell. Monoamine, indolamine, or catcholamine.
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Neuromodulator
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Chemical released by any cellm(neural, endocrine etc.) that acts on a neuron and effects it's response to neurotransmitters (permeability to ions). Can be a true hormone, a neurohormone, parahormone, steroids, peptide.
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Neuropeptide
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hormonal or non-hormonal peptide that acts as a neuromodulator. ACTH and Insulin are peptide hormones and neuropeptides. Can be transmitters (somatostatin, neurotensi, enkephalins)
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Where is the pineal gland, what does it realease?
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Brain, melatonin, light response, pigment.
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Where is the Thyroid gland, what does it release?
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Neck; T3, T4, calcitonin
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Where is the parathyroid and what hormones does it release?
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On surface of Thyroid, PTH
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Where is the Thymus gland and what does it release?
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Chest; Thymosin, Thymostatin
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What hormones is released by the heart?
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ANF
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What hormones is released by the stomach?
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Gastrin
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What hormones are released by the duodenum?
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Secretin, CCK
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What hormones are released by the adrenal cortex?
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Glucocorticoids, mineralcorticoids, sex steroids
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Wha hormones are released by ther adrenal medulla?
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Adrenaline, noradrenaline
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What hormones are released by the pancreas, and what types of cells?
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alpha cells release glucagon and beta cells release insulin
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What hormones are released by the testes and what types of cells?
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Leydig cells release androgens, sertoli cells release inhibin
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What hormones are released by the ovaries and from where within the ovaries?
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Follicles release estrogens, corpus luteum releases progestins, also relaxin and inhibin.
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What hormones are released by the placenta?
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HCG, HPL, also progesterone, estrogens, androgens, and relaxin/
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Melatonin
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mediates reproductive activity, light response, skin pigmentation. Pineal. Amine-trytophan
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T4
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Thyroxine, regulates cell growth (especially neural), regulates metabolism. Thyroid. Amine-tyrosine
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T3
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Triiodothyronine, regulates cell growth (especially neural), regulates metabolism. Thyroid. Amine-tyrosine
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Calcitonin
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Lowers blood calcium. Thyroid. Peptide
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PTH
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Parathyroid hormone, raises blood calcium. Parathyroid. Peptide
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ANF
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Atrial natriuretic factor, regulates blood pressue, volume, and electrolyte balance. Heart. Peptide
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Gastrin
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Stimulates HCl and increases intestinal motility in response to food. Stomach. Peptide
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Secretin
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Stimulates pancreatic juice. Duodenum. Peptide
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CCK
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Cholecystokinin. Stimulates gall bladder contractiona dn secretion of pancreatic enzymes. Duodenum. Peptide.
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Insulin
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Lowers blood glucose, promotes synthesis of fat and protein. Beta cells of pancreas. Peptide
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Glucagon
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Increases blood glucose, promotes breakdown of fat and protein. Alpha cells of pancreas. Peptide
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Glucocorticoids
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Cortisol. Convert fats and proteins to carbohydrates, anit-immune/allergy/inflammatory functions. Adrenal cortex. Steroid.
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Mineralcorticoids
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Aldosterone. Increases sodium retention and potassium loss in kidney. Adrenal cortex. Steroid.
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Adrenaline
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Epinephrine. Increases heart rate, oxygen consumpotion, glycogen mobilization. Adrenal medulla. Amine-tyrosine.
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Noradrenaline
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Norepinephrine. Increases blood pressure, concstricts blood vessels. Adrenal Medulla. Amine-tyrosine.
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Androgens
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Testrosterone. Male sex characteristics. Leydig cells of testes, adrenal cortex, placenta. Steroid.
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Inhibin
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Inhibits FHS secretion from pituitary. Sertoli cells of testes, ovaries.
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Estrogens
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Female sex charactersitics. Follicles in ovaries, adrenal medulla, placenta. Steroid
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Progesterone
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Maintains pregnancy, facilitates uterine and breat development. Corpus luteum, adrenal medulla, placenta. Steroid.
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Relaxin
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Relaxes birth canal. Ovaries, placenta. Peptide.
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HCG
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Human chorionic gonadotropin. Maintains progesterones synthesis from ovaries, acts like LH. Placenta. Peptide
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HPL
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Human placental lactogen. Mammary gland growth, acts like LH and prolactin. Placenta. Peptide.
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What are the 3 lobes of the pituitary gland?
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Anterior lobe (pars distalis), intermediate lobe (pars intermedia), and posterior lobe (pars nervosa).
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What lobes form the adenohypophysis?
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Anterior and intermediate.
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What lobes is the neurohypophysis?
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Posterior
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How are oxytocin and vasopressin released?
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Magnocellular nerves have cell bodies in the SON and the PVN, their axons extend down the infundibulum to terminate in the posterior lobe. The hormones are stored in these terminals until they are released directly into the inferior hypophyseal artery and into circulation.
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How are hormones released from the anterior pituitary?
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Parvicellular cells of the hypothalamus project axons to the median eminence where they release hypophysiotropic hormones into the primary plexus where they travel through the hypophyseal portal veins of the pars tuberalis to stimulate their target cells in the adenohypophysis to release their hormones.
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What is the primary plexus?
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The parvicellular hypothalamic cells release hormones into the primary plexus.
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What is the pars tuberalis?
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It is part of the adenohypophysis, contains the hypophyseal portal veins and carries hormones from the primary plexus to the secondary plexus.
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ADH
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Antidiuretic hormone, vasopressin. Raises blood pressure, promotes water reabsorption in kidneys. SON and PVN via the pars nervosa (neurohypophysis). Peptide
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Oxytocin
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Stimulates uterine contractions and milk ejection from mammary glands. SON and OVN via the pars nervosa (neurohypophysis). Peptide
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What makes up the neurohypophysis?
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Pars nervosa, infundibulum,
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What makes up the adenohypophysis?
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Pars distalis, pars intermedia, pars tuberalis, primary plexus, secondary plexus
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What are the 6 adenohypophyseal hormones?
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GH, ACTH, TSH, FSH, LH, PRL.
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GH
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Growth hormone, somatotropin, somatotropic hormone. Promotes protein synthesis and carbohydrate metabolism, and growth of bone and muscle. Adenohypophysis, somatotroph cells. Peptide.
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ACTH
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Adrenocorticotropic hormone. Stimulates synthesis and release of glucocorticoid hormones in adrenal cortex. Adenohypophysis, corticotroph cells. Peptide
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TSH
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Thyroid stimulating hormone, thyrotropin, thyrotropic hormone. Stimulates synthesis and release of T3 and T4 in thyroid. Adenohypophysis, thyrotroph cells
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FSH
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Follicle stimulating hormone. Promotes development of gametes and secretion of gonadal hormones, growth of primary follicle in the ovary, secretion of inhibin in in testes and sperm production. Adenohypophysis, gonadotroph cells. Peptide
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LH
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Luteinizing hormone. Stimulates ovulation, formation of corpus luteum, and progesterone secretion in females; and secretion of androgens in males. Adenohypophysis, gonadotroph cells. Peptide.
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PRL
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Prolactin Initiates milk production, stimulates gonads. Adenohypophysis, lactotroph or mammotroph cells. Peptide.
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What hormones are produced and released by the intermediate lobe of the pituitary?
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MSH and B-endorphins.
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Where is POMC produced, and what is it broken down into?
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Produced in the pars distalis, pars intermedia, and brain.
1. Broken into N-Terminal fragment, ACTH, and B-lipotropin.Occurs in both pars distalis and pars intermedia. 2. ACTH is broken into MSH and CLIP, B-lipotropin breaks into B-endorphin and g-lipotropin. Only in pars intermedia. |
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What biproducts of POMC does the anterior lobe secrete?
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ACTH and B-lipotropin
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What biproducts of POMC are secreted by the intermediate lobe?
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MSH, CLIP, B-endorphin, and g-lipotropin.
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MSH
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Melanocyte stimulating hormone, melanotropin. Pigmentation in amphibians. Pars intermedia, melanotroph cells, from POMC. Peptide.
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B-endorphin
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Neuromodulator in brain. Pars intermedia, from POMC. Peptide.
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POMC
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proopiomelanocortin. Prohormone that breaks into ACTH and B-lipotropin in anterior lobe, and into MSH, CLIP, B-endorphin, and g-lipotropin in intermediate lobe.
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What is the endocrine hypothalamus?
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It is the medial basal hypothalamus, comprised of VMN, arcuate nuclei, and the median eminence.
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What other parts of the brain is the hypothalamus connected to?
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Cerebral cortex, thalamus, limbic system, spinal cord.
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What are 6 hypothalamic functions?
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1.Regulates sympathetic and parasympathetic branches of ANS.
2. Temperature regulation 3. Biological rhythms 4. Regulates electrolyte balance 5. Emotional behaviour 6. Motivation/arousal |
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Where are magnocellular neurosecretory cells located? Where do their axons go?
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SON and PVN. Axons travel down infundibulum of neurohypophysis and terminate at the pars nervosa.
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Where are the parvocellular neurosecretory cells located? Where do they terminate?
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Found in POA, VMN, arcuate nucleus etc. Terminate at median eminence, released into primary plexus.
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What are the four areas that neuroendocrine transducers are found?
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1. Magnocellular neurosecretory cells of PVN and SON
2. Parvicellular neurosecretory cells that release hormones into mediam eminence. 3. Adrenal medulla, stimulated by sypathetic nerves to secrete adrenaline and noradrenaline 4. Pineal gland, stimulated by andrenergic nerves to release melatonin. |
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TRH
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Thyrotropin Releasing Hormone, TSH-RH, thyroid stimulating hormones releasing hormones. Stimulates thyrotroph cells of anterior to produce and release TSH, neuromodulator in brain. PVN, prolactin relelase, PVa. Regulated by catecholaminergic transmitters, somatostatin, opioids.Peptide.
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CRH
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Corticotropin releasing hormone. Stimulates release of ACTH, neuromodulator in brain. PVN, PVa.Peptide.
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Gn-RH
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Gonadotropin Releasing Hormone. Stimulates release of LH and FSH from gonadotroph cells in atnerior, neuromodulator in brain, POA-AH, MBH, SCN.
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GH-RH
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Growth hormones releasing hormone, somatocrinin. Stimulates relase of GH in anterior. VMN, MBH-ARC.
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GH-RIH
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Growth hormone release inhibiting hormone, SOM, somatostatin. Inhibits release of GH, acts as neuromodulator in the brain, INHIBITS TRH. PVa.
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PRF
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Prolactin releasing factor, stimulates release of prolactin. Could be TRH, oxytocin, B-endorphins. PVN and POA-HA.
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PIF
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Prolactin inhibitng factor. Inhibits release of prolactin. Might be dopamine, also GABA. Arcuate nucleus
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MSH-RF
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Melanocyte Stimulating Hormone releasing factor. Stimulates release of MSH. PVN?
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MSH-RIF
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Melnocyte stimulating hormone release inhibitng factor. Possibly dopamine. arcuate nucleus.
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POA-AH
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Preoptic area anterior hypothalamus. Synthesis of LH-RH and TRH, stimulates LH-RH and PRL surges, regulates male sexual behaviour and female parental behaviour.
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SCN
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Suprachiasmatic nucleus, biologicl clock, rhythmic release of glucocorticoids and melatonin.
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PVa
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Periventricular Nuclei. Synthesis of CRH, TRH, and SOM
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SON
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Supraoptic nuclei. Synthesis of vasopressin and oxytocin from magnocellular division. Regulates thirst and drinking.
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PVN
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Paraventricular nuclei. Synthesis of oxytocin and vasopressin from magnocellular division. SYnthesis of TRH and CRH from parvicellular division.
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LH (nuclei not hormone)
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Lateral hypothalamus, controls hunger
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DMN
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dorsomedial nuclei. Controls aggression
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VMN
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ventromedial nuclei. Synthesis of GH-RH, somatostatin, CRH, PRF, and TRH. Detects blood glucose levels, regulates food intake, regulates female sexul behaviour.
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PH
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posterior Hypothalamus. Regulates fight or flight response
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ARC
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arcuate nucleus. Synthesis of TRH, CRH, and GH-RH. Tonic release of LH-RH. Dopamine released into portal veins from the tuberoinfundibular dopaminergic neurons.
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According to the current theory, what is LH release dependent on?
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Pulses of GnRH release and gonadal steroids.
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According to the current theory, what is FSH release deendent on?
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GnRH and activin stimulate FSH release while Estrogen, progesterone, and inhibin inhibit relase of FSH. Also follistatin inhibits activin from stimulating FSH release.
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Where are inhibin, activin, and follistatin produced?
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In the ovaries.
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What are the two older theories or gonadotrophin release?
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1. There's two hypothalamic different hypothalamic hormones, one that controls FSH and one that controls LH.
2. There's only one hormone that controls them both. |
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What are the 8 criteria for a "true" neurotransmitter?
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1. Present in presynaptic neurons
2. Synthesized in presynaptic neuron 3. Stimulation of dendrites cause release 4. Direst applicaation of substance to the synapse is the same effect as stimulating dendrites 5. Specific receptors 6. Causes increase in membrane permeability 7. inactivating mechanism exists 8. Agonists block actions |
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What are the 6 categories of neurotransmitters?
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Amino acids, cholinergic, monoamine, peptide, putative, free radicals
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What are the categories of neurotransmitters within the monoamines?
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catcholamines (andrenerghic), indolamines, others.
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What are the amino acid neurotransmitters?
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GABA, glutamic acid etc.
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What is a cholinergic neurotransmitter?
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ACh
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What are the monoamine andrenergic transmitters?
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dopamine, noradrenaline, adrenaline
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What is an indolamine neurotransmitter?
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Of the monoamines. Serotonin (5-HT)
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Wha category of neurotransmitter is histamine?
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monoamine
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What are the peptide transmitters?
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Somatostatin, CCK, endorphiins, substance P.
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What are the putative neurotransmitters?
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Don't match nt criteria. Benzodiazepenes.
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Where are excitatory and inhibitory synapses usually found on a cell?
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Ecitatory are on dendrites, inhibitory on cell body.
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What are 5 functions of synaptic vesicles?
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1. axonal transport
2. storage of transmitters 3. completion of transmitter synthesis 4. protect transmitters from deactivation 5. release of transmitter through exocytosis |
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Where does synthesis begin for amino acid, monoamine and peptide transmmitters?
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Ribosomes in cell body.
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How is ACh synthesized and broken down?
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Made from acetyl CoA and choline with choline acetyltransferase. Broken down by acetylcholinesterase to acetic acid and choline
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How is dopamine synthesized?
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Tyrosine forms dopa from tyrosine hydroxylase, which then forms dopamine from dopa decarboxylase
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How is Norepinephrine synthesized?
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Once dopamine is made dopamine B-hydroxylase turns it into norepinephrine
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How is epinephrine synthesized?
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Once norepinephrine is formed phentolamine N-methyltransferase PNMT forms epinephrine.
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How is serotonin synthesized?
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Trytophan makes 5-HTP through trytophan hydroxylase, which then makes serotonin through 5-HTP decarboxylase.
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What five factors regulate neurotransmitter synthesis?
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1. levels of enzymes required
2. neuromodulators present 3. neural input from other cells 4. Other hormones 5. availablility of amino acids |
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GABA
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Inhibitory amino acid, A and B receptors. GABA-transaminase
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Glutamate
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Excitatory amino acid. A1-4, and NMDA receptors.
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ACh
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Acetylcholine, Cholinergic. Muscarinic: sympathetic nervous system, heart, and stomach, brain. Nicotinic: skeletal muscles, autonomic ganglia, brain. Synthesized from Acetyl CoA. Degraded by Acetylcholinesterase.
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Dopamine
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Andrenergic monoamine, catecholamine. D1 and D5: brain; D2: Anterior pituitary, inhibitory effect on adenohypophyseal hormones PRL,TSH, MSH; D3 and D4: limbic system. Synthesized from tyrosine. Degraded by MAO and COMT
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Epinephrine
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Andrenergic monoamine, catecholamine. Alpha receptors: pre and post synaptic cells; Beta receptors: heart, lung, brain. Synthesized from Tyrosine. MAO
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Norepinephrine
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Andrenergic monoamine, catecholamine. Alpha receptors: pre and post synaptic cells; Beta receptors: heart, lung, brain. Excitatory effect on TSH, LH/FSH, GH. Inhibitory on oxytocin, vasopressin. Synthesized from Tyrosine. MAO
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Serotonin
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5-HT, Inoleamine, monoamine. 5-HT1-3 receptors in brain regulate contractions of blood vessels. Made from Tryptophan. MAO
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Histamine
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Monoamine. H1 and H2 receptors mediate bronchial constriction and gastric secretion. Degraded by histaminase.
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Opiate receptors
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regulate pain, reward behaviour, sedatives.
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Benzodiazepines
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Putative neurotransmitter. Typa 1 and types 2 receptors. Also GABA receptors.
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MAO
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monoamine oxidase. Enzyme that breaks down monoamines (dopamine, epinephrine, norepinaphrine, serotonin.)
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COMT
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catechol-O-methyltransferase, breakse down catecholamines.
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What is the nuclei of the Dopaminergic pathway?
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Substantia nigra. Also tuberoinfundibular pathway mediates adenohypophyseal hormones. Ventral tegmental
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What are the nuclei of the cholinergic pathway?
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Basal forebrain complex
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What are the nuclei of the norandrenergic pathway?
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locus coeruleus
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What are the nucclei of the sertonoergic pathway?
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raphe nuclei
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What are the ways that a drug can have an effect?
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1. Act as neuromodulator by influencing synthesis, storage, re-uptake, or release by presynaptic cell.
2. Alter activity of the degradative enzymes 3. Act as agonist or antagonist on receptors |
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What does an antagonist do?
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Blocks receptors
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What does an agonist do?
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Mimics the neurotransmitter
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What does Prozac do?
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Antidepressent drug that blocks presynaptic serotonin reuptake.
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Name the 3 catecholamine transmitters
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dopamine, adrenaline, and noradrenaline
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Name the 3 ways that drugs can increase the amount of neurotransmitter available at a synapse
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1. Act as a neuromodulator increases synthesis and release by presynaptic cell
2. Decrease degradative enzymes 3. Block reuptake |
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is GABA an excitatory or inhibitory neurotransmitter?
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Inhibitory
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What is the cholinergic neurotransmitter?
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Acetylcholine
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Which neurotransmitter is synthesized from dopamine by the enzyme dopamine-beta-hydroxylase?
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noradrenaline
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What is the difference between a neurotransmitter agonist and antagonist?
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An agonist mimics the neurotransmitter, and antagonist blocks the receptor.
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Which two enxymes deactivate noradrenaline?
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MAO and COMT, monoamine oxidase and catechol-O-methyltransferase
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Which neurotransmitter is synthesized from the amino acid tryptophan?
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Serotonin
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Would an antagonist for dopamine stimulate production of the second messenger cyclic AMP in a post synaptic cell?
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No
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Where are neurotransmitters stored before release and what triggers their release?
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Stored in synaptic vesicles in the nerve terminal. released by changes in membrane permeability caused by depolarization of the membrane in presence of calcium
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What two general ways can a neurotransmitter be deactivated?
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Reuptake and enzymatic dergredation
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How does a transmitter cause a postsynaptic cell to fire?
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by binding to a receptor on the postsynaptic cell causing a change in membrane permeablility and allowing sodium into the cell.
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Which neurotransmitter acts at nicotinic receptors?
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Acetylcholine
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Which neurotransmitter has its primary cell bodies in the locus ceruleus
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Noradrenaline
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What is a neuroendocrine transducer?
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A neurosecretory cell that gets input from neurotransmitters and has hormonal output.
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Give two reasone why pituitary hormones rather than hypothalamic hormones are measured in response to change in neurotransmitter levels.
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1. They are released in higher concentrations
2. They have longer half lives. |
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What are the four ways by which neurotransmitters can regulate the release of hypothalamic and pituitary hormones?
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1. Indirect. Transmitters are released into a synapse as part of a neural pathway and affect the hypothalamus via interneurons.
2. Direct. Transmitters are released into a synapse between a neuron and a the cell body of the a neurosecretory cell. 3. Axo-axonal synapse on axons of neurosecretory cells 4. Neurons directly relelase transmitters into portal veins an directly stimulate endocrine cells in the pituitary. |
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Which transmitter releases oxytocin in response to infant sucklin.
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Acetylcholine
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Which transmitter is released through the SNS to stimulate hormone release from the adrenal medulla and the pineal gland?
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Noradrenaline
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What effect would an injection of morphione, an opiate agonist, have on the electrical activity of the magnocellular neurosecretory cells of a lactating female rat during a bout of suckling?
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Reduce electrical activity, inhibit oxytocin release
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The release of prolactin and TSH is inhibited by which neurotransmitter?
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Dopamine
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Neurotransmitters can be released into the hypophyseal portal veins to stimulate or inhibit the pituitary gland. True or false?
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True.
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Why might in vitro studies of the effects of DA or LH release give different resulats than in vivo studies?
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In vitro studies are isolated and there are noe other hormones, neuropeptides, other brain areas etc.
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How do psychiatric drugs such as chlorpromazine affect prolactin levels?
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Psychiatric drugs inhibit dopamine, which inhibits prolactin, so prolactin levels increase.
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What bdetermines the amount of steroid hormones released into the bloodstream?
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The enzymes responsible for steroid synthesis also determine the amount released because they are released as the are made (not stored in secretory granules).
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Names the five steroid hormones.
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Estrogens, androgens, progestins, glucocorticoids, mineralcorticoids,
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What is the main precursor of the steroid hormones?
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Cholesterol
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What are the building blocks of the protein ans polypeptide hormones?
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Amino acids
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What is the primary mechanism for the synthesis of the small peptides?
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Cleavage of large peptides (prohormones).
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In the female, which two endocrine glands can synthesis testosterone?
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Adrenal cortex, ovaries
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Are both steroid and non-steroid hormones stored in secretory granules?
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no
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hormones are synthesized in the_________of the cell body.
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endoplasmic reticulum.
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The carrier proteins for the neurohypophyseal hormones are________.
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Neurophysin
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The contents of a secretory granule arte released into the circulation by the process of___________.
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exocytosis
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Which three pituitary hormones are synthyesized from PMC?
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ACTH, MSH, and beta-endorphin
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What controls the rate of synthesis and release of steroid hormones?
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Enzymes.
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NGF
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Nerve Growth Factor, promotes axon growth and survival of neurons in SNS and some sensory CNS
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NT-3
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Neurotrophin 3, promotes growth of hippocampal, somatosensory, cerebellar neurons
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NT-4/5
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Neurotrophin 4/5, promotes growth of sensory and motor neurons
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NT-6
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neurotrophin 6, similar to NGF, less potent, snsory and SNS nerves
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BDNF
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Nrain Dervied Neurotrophic Factor, Promotes growth of peripheral senspry neurons and CNS neurons whcih do not respond to NGF
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CNTF
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Ciliary Neurotrophic Factor, promotes growth of SNS, PNS, and sensory neurons
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GDNF
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glial cell line derived neurotrophic factor, enhances survivial of midbrain dopaminergic neurons
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EGF
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Epidermal Growth Factor, stimulates cell division in epirdermal cells
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FGFs
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Fibroblast Growth factors, stimulates proliferation of fibroblasts, endothelial cells, blood vessels, neurons, adrenal cells. Found in pituitary
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PDFG
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Platelet Derived Growth Factor, stimulates proliferation of connective tissue and neuroglial cells
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TGF-b
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Transforming Growth factor beta, inhibits response of most cells to other growth factors
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IGF-I and IGF-II
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Insulin-like growth factor I and II, somatomedins, stimulate proliferation of fat and connective tissue cells
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somatomedins
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IGFs, insulin-like growth factors
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IL-3
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Interleukin 3, stimulates stem cell differentiation. Growth Factor
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G-CSF
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Granulocyte Colony Stimulating Factor, stimulates granulocyte/macrophage progenitor cells and neutrophils
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M-CSF
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Macrophage Colony Stimulating Factor, stimulates granulocyte/macrphage progenitor cells and macrophages
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GM-CSF
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Granulocyte/Macrophage Colony Stimulating factor, stimulates granulocyte/macrophage progenitor cells
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What is the difference between growth factors and trophic factors?
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Growth factors regulate cells division, while trophic factors regulate differentiation, survival, phenootypes expression and plasticity as well as growth.
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What growth factors have the following functions?
a. promote nerve survival and axon growth in SNS neuronsn b. promotes growth of hippocampal, cerebellar, and somatosensory neurons? c. stimulates cell division in epidermal cells? d. are also called somatomedins? |
a. FNF
b. NT3 c. EGF d. IGFs |
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What is apoptosis?
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programmed cell death
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how does NGF stimulate development of a bipotential adrenal medula cell?
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FGF stimualtes the development of sympathetic neurons from a bipotential adrenal medulla cell, NGF release from the target cell promotes synaptogenesis and maturation of the neurons
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In a developing synapse, which cell releases NGF?
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The post synaptic cell
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What type of receptors do NGF and other neurotrophins bind?
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tyrosine kinase and p75
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There are at least 10 ways that neurotrophic factors could stimulate biochemical changes in their target cells. If NGF were found to elevate tyrosine hydroxylase in a cell a) what kind of cell would this be and b) what would be the result of the increased tyrosine hydroxylase?
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a. monoamine containing cell
b. more dopamine (or NA or A) being produced |
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What are 4 different ways that growth factors prevent apaptosis?
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actviating BCL-2, inhibiting p53, inhibit the endonuclease, increase metabolism
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Where would you find the testes determining factor?
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TDF is a peptide coded by the TDF gene on the SRY region of the Y chromosome
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What is Turner's Syndrome?
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45X0 chromosomal abnormality. Affected individuals are females
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Why do the Mullerian ducts not develop in a male?
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The sertoli cells begin to secrete Mullerian inhibiting substance
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Why do the wolfian ducts not develop in a female?
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A lack of mullerian inhibiting substance caueses the wolfian ducts to regress
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What is the effect of castrating a one day old rat?
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Castrating a one-day old rat feminizes and demasculinizes it
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What is alpha fetoprotein and what does it do?
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a-fetoprotein is a carrier protein which is synthesized in the liver and binds to estrogen in te blood of neonatal females. this prevents estrogen from binding to estrogen receptors and masculinizing the female
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How does testosterone masculinize the SDN-POA of rats and humans?
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Testosterone inceases the cell size and nuber of cells
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Describe the sex differences in the HPG feedback systmem
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Gonadal estrogen stimulates LH secretion in females, gonadal testosterone and estrogen inhibits LH secretion in males
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What two problems are suffered by people with Kallman's syndrome?
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Hypogonadism and lack of a sense of smell
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what is androgen insensitivity syndrome and what is the rat model of this disorder?
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AIS is otherwise known as testicular femiinization syndrome. It occurs as a result of a lack of androgen receptors. Affected individuals have testes, but female external genitals. In the rat model, castrating a male on post natal dat 1 will demonstrate the same pattern of development.
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Which pituitary hormones stimulate the Leydig cells and which stimulate the sertoli cells of the testes and which hormones are produced by each of these cells?
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Lh stimulates Leydig cells leading to testosterone release, FSH is needed to stimulate sertoli cells, leading to inhibin release
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Which two hormones re required for spermatogenesis?
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spermatogenesis requires FSH and testosterone
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In seasonally reproducing species, suc as white- tailed deer, what changes in physiology and behaviour are associtaed with the rise of testosteron in the breeding season?
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Increases testes size,spermatogenesis, increased antles growt, increased mating behaviour, increased agressive behaviour
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Describe the 3 phases of the standard hormone removal and replacement experiment
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Baseline, removal and replacement.
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Why must individual differences be considered when analyzing the efects of testosterone on sexual behaviour
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These differences are independent of testosterone levels. For example, guinea pigs which are high maters before castration are high maters after HR and low maters before are low maters after. Thus the difference is not due to hormones levels
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Why must species differences be considered when analyzing the effect of testosterone?
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Some species, such as rats, show rapid decline in sexual behaviour following castration, whereas other species, such as dogs, may not. Sexual experience may maintain behaviour in the absence of hormones.
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Discuss the effects of dominance status and female stimulation on testosterone levels of male monkeys
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Dominant males have higher testosterone than males. Testosterone levels rise in presences of a female. When confronted with dominant males, testosterone levels drop.
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Discuss the interaction of organizational and activational effects of androgens on agressive behaviour in mice.
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Female mice given testosterone on prenatal day 1 and then given testosterone injections in adulthood show high, male-like levels of aggression. Females given oil on prenatal day 1 and then given testosterone in adulthood show low levels of aggression
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What effect does taking anabolic steroids by a normal male have on spermatogenesis and why does this occur?
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Reduced spermatogenesis as a result of increased negative feedback on GnRH, LH and FSH
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Define the following:
a) primordial follicle b)Graafian follicle c)Corpus luteum d)corpus albicans |
a) primitive, undeveloped follicle
b) maturing follicle, has been stimulated by FSG c) follicle after ovulation when it is secreting progesterone d) dead, white follicle which is no longer secreting progesterone |
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What changes occur in the endometrium of the uterus during the luteal phase of the menstrual cycle?
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progesterone causes a thickening of the endometrium of the uterus and the development of glands and blood vessels to ready the endometrium for implantation.
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Which of the cells of the follicle produce estrogen and which produce progesterone?
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the granulosa cels produce estrogen and the luteal cells roduce progesterone
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Why are the vaginal secretions of rats used as a bioassay for the stages of the estrus cycle?
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the cell structure of the vagina changes over the estrus cycle from epithelial cells to cornified cells during estrus, thus the stage of the estrus cycle ad the hormone state of the female can be determined non-invasively
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What are the three aspects of female rat sexual behaviour as identified by Beach?
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attractivity, proceptivity, receptivity
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How do you determine the phases od the menstrual cycle in females?
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Follicular phase begins after menstruation and ends at ovulation and the luteal phase begins at ovulation and ends at menstruation
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How do sexual behaviour, activity levels, agression, and feeding change at estrus in female rats?
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Sexual behaviour and activity levels increase, while agression and feeding behaviour decrease.
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What is amenorrhea?
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failure to menstruate
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How do birth control pills work?
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they contain low amounts of estrogen which provides negative feedback on FSH and prevents the development of the Graafian follicle, thus there is no estrogen released by the ovary. The lack of estrogen surge inthe follicular hase eliminates the positive feedback of estrogen on LH and thus there is no LH surge. Without the LH surge, ovulation does not occur and no corpus luteum forms, so there is no progesterone secretion. The pill also contains progesterone to make up for this defecit.
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What phase of the menstrual cycle is known as the premenstrual phase and what hormonal changes ovvur during this period?
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It is the late-luteal phase and there is a rapid drop in progesterone and estrogen levels
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What phase of the human menstrual cycle is associated with the following:
a) highest level of positive feedback b) highest levek of sexual activity c) most sensitive to odours d) most sensitive to pain and cold |
a) around ovulation
b) arond ovulation and second peak premenstrually c) follicular phase d) luteal phase |
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What symptoms characterize PMS?
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tiredness, irritability, bloating, depression, inflammation, water retention, painful joints, swollen ankles
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What symptoms of PMS are the following treatments meant to "cure":
a) progesterone therapy b)MAO inhibitors c) Aspirin d) diuretics |
a) low progesterone levels
b) low NE/ high MAO levels c) elevated prostoglandin levels d) water retention and bloating |
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Infertility in women often occurs because of a failure to ovulate. In this case, ovulation is induced hormonally. What is the procedure for this?
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First PMSG is used, which acts like FSH to induce development od theGraafian follicle. Next clomiphene, which is anti estrogen and blocks estrogen receptors in the brain, inhibitng negative feedback on FSH. Next HCG is injected to induce ovulation.
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What are the 3 main problems in using Aschem-ZOndek mouse test as a pregnancy test?
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1) great possibility of false positives because the mouse is a spontaneous ovulator
2) It takes 96 hours 3) false positives can occur with high LH levels as well |
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Why s double labellin important for the most accurate immunological pregnancy test?
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Double lanelling is important as the alpha subunit is homologous to LH. By double labelling, the alpha-beta subunit of HCG can be reliably bound, along with the alpha subunit
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What two endocrine glands secrete progesterone during pregnancy?
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Corpus luteum and placenta
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What is the function of relaxin?
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relaxes the ligaments surrounding th ebirth canal, facilitating parturition
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Which hormone secreted during pregnancy inhibits the release of insulin, thus causing pregnancy related diabetes?
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HPL
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Name the four hormones secreted by the placenta during pregnancy
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HCG, HPL, progesterone and estrogen
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Describe how changes in progesterone levels stimulate parturition
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Progesterone levels remain high during pregnancy. When progesterone levels drop, parturition begins. If progesterone levels remain high for too long, parturition is delayed
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How might the feto-placental unit control the timing of parturition?
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By reducing the secretion of progesterone and by increasing the release of estrogen and or cortisol, which stimulates prostoglandin release. Prostoglandins sensitize the uterine muscles (myometirum) to oxytocin hich causes contractions at birth
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How do prolactin and oxytocin interact to control lactation?
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prolactin stimulates milk secretion from the aiveoli during lactation and oxytocin stimulates contraction of the basket cells around the alveoli to contract, ejecting milk
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What stimulates the release of prolctin during lactation?
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The pups suckling at the nipple stimulates prolactin release
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When do female rate begin to show maternal behaviour?
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Nest building begins approximately 4 days before parturition. However, broadly defined, maternal behaviour begins at conceptios
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What is post-partum estrus in the rat and what causes it?
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Ovulation that occurs quickly after birth. It arises as a result of the elevated estrogen levels that occur just before birth.
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What four hormones appear necessary to stimualte parental behaviour in female rats?
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Estrogen, progesterone, PRL and oxytocin
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In which are of the brain does estrogen stimulate maternal behaviour most rapidly and why does this occur?
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MPOA, rich in estrogen receptors. Infusion of estradiol into this brain area induces maternal behaviour. This brain region appears to be the locus of parrental behaviour
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What is lactational amenorrhea and why does it occur?
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It is a result of the suppression of the menstrual cycle during lactation. PRL inhibits GnRH, LH and FSH. It is not a reliable method of birth control
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Under what conditions does the parental behaviour shown by male mice increase pup survival?
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harsh environmental conditions.
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Describe how the 3 phases of Selye's "General Adaptation Syndrome". Explain the physiological and behavioural responses of the body to stress.
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Three phases of GAS are the alarm, resisitance and exhaustion phases. Alarm occurs to the sudden onset of the stressor. If the stress continues, the body tries to resist it and adapt, but expends energy during this adaptation process. Finally, after prolonged stress, exhaustion sets in as the body breaks down from prolonged resistance to the stressor.
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What is the difference between eustress and distress and why are both equally stressful?
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Eustress id "pleasant" stress such as a wedding or xmas, while distress in unpleasant stress, such as illness or death. both types of stress take the body away from "baseline" state and thus must be adapted to.
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What roles do the two branches of the ANS systme play in the stress response?
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Sympathetic is aroused during stress and elevates blood pressure, heart rate, etc. Parasympathetic tries to relax ANS and bring blood pressure, heart rate, etc.back to baseline.
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What is the difference between catabolic and anabolic responses to stress and how are they controlled?
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The SNS is catabolic, expending energy, while the PNS is anabolic, building energy.
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Why is adrenalin from the adrenal medulla released faster than glucocorticoids from the adrenal cortex in response to stress?
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Because adrenalin release is controlled by the nerves of the SNS. Glucocorticoids are released slowly because the depend on CRH and ACTH secretion which is slower.
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name four homrones wich are released in stress and act as catabolic hormones to provide energy in response to stress
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Adrenaline, GH, glucagon, cortisol
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Why do high levels of stress often result in illness? What is the hormonal connection between stress and illness?
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Stress elevates CRH, ACTH, and corticosteroids. Corticosteroids suppress the immune system.
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What gene on the Y chromosome is thought to be responsible for masculinization? What happens to females with this gene on the X chromosome?
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SRY gene. if on X xhromosome, female is masculinizd
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What is Turner's syndrome?
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45XO, female with ovaries that fail to secrete hormones, no barr body.
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What is mulitple X syndrome?
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47XXX or 48XXXX, mostly normal female development, may be taller nd thinner
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What is Kleinfelter's Syndrome?
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47XXY or 48XXXY, male development with barr bodies,so some feminization. testes don't secrete sperm, and there is abnormal masculinization at puberty.
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What is multiple Y syndrome?
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47XYY or 48XYYY, male development with reduced feritlity
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What is a tru hermaphrodite?
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An individual with both male and female gonads
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What is androgen insensitivity syndrome?
|
The person has a defect in the gene that codes for androgen receptors so they are genetically male but externally female. X-linked disease.
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What is congenital adrenal hypoplasia (CAH)?
|
The enzyme that converts precursor to cortisol, so no cortisol is released. It instead spills over into the adrenal androgen pathway and is converted in testosterone.Can occur in men or women. In women causes masculinization of external genitalia so they look somewhere in between.
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What is McGinnley Syndrome?
|
Does not produce 5a-reductase so testosterone is not converted to 5a-DHT. 5a-DHT is what masculinizes external genitalia, so at birth they look like girls, but develop into boys at puberty.
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What is a freemartin?
|
A calf twin that is masculinized because of influence of testosterone of the male twin
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What is Kallman's syndrome?
|
hypogonadism, there is a deficiency in GnRH. Causes delayed puberty in both ,ales and females as well as a lack of a sense of smell.
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What effect does estrogen have on LH before and after in males? On PRL? What causes the change?
|
Estrogen stimulates LH release before and then switches to negative feedback. Testosterone effects GnRH to make this change. Estrogen does not stimulate PRL, there is a low baseline level in males
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What effect does estrogen have on LH and PRL in females? How is LH released?
|
Estrogen stimulates both LH and PRL in females, stimulates cyclic relelase of LH in surges every 2834 days
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What effect does estrogen have on LH-RH when it is injected into males? Females?
|
Negative feedback in males, positive in females/
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What hormone is responsible for external masculinization?
|
5alpha-DHT
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What hormone is thought to cause masculinization of the brain during the critical period?
|
Aromatized testosterone: estrogen
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If estrogen causes masculinization of the brain, how do females avoid masculine brain development? (4 ways)
|
1. a-fetoprotein binds to estrogen to deactivate it
2. secretion of progesterone 3. Metabnolize estrogen to an inactive form 4. Have less estrogen receptors |
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What are five influences of testosterone on neural development (neonatal and adult)?
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1. Number of nerves developeing (neonatal)
2. Neurite growth (neonatal and adults) estrogen too 3. Neural size and form- increase (neonatal and adults) 4. Biochemical processes- (neonatal and adults) influence on enzyme level and nt receptors 5. Influence on steroids, alter neural sensitivity to steroids (# of receptors) |
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Wha tis the masculinization rheostat?
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levels of androgens control masculinization of brain
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What are 6 biological bases of definition for sex?
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chromosomal, internal gonads, hormonal, internal genitals,.accessory sex organs, external genitals
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What are 3 psycho-social bases for defining sex?
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Gender of rearing, gender identity, gender role
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What are the internal gonads?
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Ovaries vs. testes
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What are the internal genitals?
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vas deferens vs. fallopian tubes and uterus
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What are the accessory sex organs?
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Prostate gland, seminal vesicles, ejaculatory ducts vs. skene's gland, bartholin's gland
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