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88 Cards in this Set
- Front
- Back
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Hormone
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long-range chemical messengers, produced by endocrine glands
-regulate cellular functions |
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Endocrine
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hormone is secreted into the blood by a gland
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Paracrine
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cell signaling in which the target cell is near ("para" = near) the signal-releasing cell
-hormones diffuse to nearby cells |
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Autocrine
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cell secretes a hormone or chemical messenger binds to autocrine receptors on the same cell, leading to changes in the cells
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What hormones are secreted from the posterior pituitary?
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-vasopressin (ADH)
-oxytocin |
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Where are vasopressin and oxytocin synthesized?
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hypothalamus
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What are the effects of vasopressin
(on kidneys, and on arterioles)? |
-kidney tubules: increases H20 reabsorption,
-Arterioles: produces vasoconstriction |
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What stimulates release of vasopressin?
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dehydration stimulates osmoreceptors in hypothalamus
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What are the effects of oxytocin (on uterus and on mammory glands)?
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Uterus: stimulates contractions of the uterus during childbirth
Mammory glands: stimulates contractions of the alveoli and ducts of the mammary glands (causes milk ejection) |
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What stimulates release of oxytocin?
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mechanoreceptors at nipple and cervix
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What hormones are produced by hypothalamus?
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-vasopressin and oxytocin
-CRH -GRH -Prolactin-inhibiting hormone -Somatostatin -TRH -GHRH |
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Corticotropin Releasing Hormone
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stimulates secretion of adrenocorticotropic hormone (ACTH)
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Gonadotropin-releasing hormone
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stimulates secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
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Prolactin-inhibiting hormone
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inhibits prolactin secretion
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Somatostatin
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inhibits growth hormone (GH) secretion
-(also known as Growth Hormone Inhibiting Hormone [GIHI]) |
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Thyrotropin-releasing hormone
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stimulates secretion of thyroid-stimulating hormone (TSH)
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Growth hormone releasing hormone
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stimulates secretion of growth hormone (GH)
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Thyroid stimulating hormone (TSH)
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stimulates T3 and T4 secretion
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Adrenocorticotropic hormone
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stimulates cortisol secretion
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Growth hormone
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essential but not solely responsible for growth,
-promotes protein synthesis and growth, -promotes lipolysis, -promotes increased blood glucose |
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Follicle stimulating hormone
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-promotes follicular growth and development;
-stimulates estrogen secretion |
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Luteinizing hormone
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males - stimulates sperm production and testosterone secretion
females - stimulates ovulation, corpus luteum development, and estrogen & progesterone secretion |
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Prolactin
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promotes breast development
-stimulates milk secretion |
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What hormones are released from the anterior pituitary?
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TSH
AcTH GH FSH LH -Prolactin |
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Where are hormones released from the anterior pituitary synthesized?
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in the anterior pituitary
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Dwarfism
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Hyposecretion of GH
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Gigantism
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Hypersecretion of Gh prior to closing of growth plates
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Acromegaly
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Hypersecrtion of GH after closing of growth plates
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What hormones are produced by the thyroid gland?
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T3 & T4
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What is the difference between T3 and T4?
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Most of thyroid hormone released from thyroid is in the form of T4. Most of the T4 is then converted (in the tissues) to T3 which is more active than T4.
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What do thyroid hormones do?
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-increases metabolic rate and heat production by enhancing sympathetic activity,
-stimulates protein synthesis and growth (through increased gene expression) |
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Cretinism
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hypothyroidism in infants and young children characterized by low metabolic rate, growth retardation, mental retardation, hypothermia
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Myxedema
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adult hypothyroidism
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Grave's disease
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thyroid stimulating immunoglobulins bind to the TSH receptor and stimulate the thyroid, -increased metabolic rate, poor heat tolerance, decreased body weight, muscle weakness, exophthalmos (bulging eyes), goiter
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Goiter
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swelling in the thyroid gland which can lead to swelling of the larynx
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2 types of Goiter
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1) Endemic Goiter: due to iodide deficiency
2) Grave's Disease Goiter: Thyroid tumor, symptom of Grave's Disease |
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Where do corticosteroids come from?
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adrenal cortex
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What is the precurser for corticosteroids?
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Cholesterol
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What are the 3 classes of corticosteroids?
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Mineralocorticoids (aldosterone)
Glucocorticoids (cortisol) Sex Hormones (DHEA) |
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aldosterone
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-helps in reabsorption of water and sodium (increase blood pressure), -controlled by amount of angiotensin II in the blood
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Cortisol
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-increases blood glucose, protein degradation and lipolysis,
-stimulated by ACTH |
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dehydroepiandrosterone (DHEA)
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-makes androgens
-leads to precocious puberty or ambiguous sex development -more is made if there is a 21-hydroxylase deficiency |
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Cushings Disease
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-too much CRH, ACTH or cortisol
-leads to *increased blood glucose, fat deposits (moon face & buffalo hump) *muscle weakness *stretch marks *poor wound healing *mental retardation in youth |
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Congenital Adrenal Hyperplasia
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increased DHEA leads to more androgens due to deficiency in 21-hydroxylase.
Leads to precocious puberty (males) or ambiguous sex development (females) |
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21-hydroxylase
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-converts pregenolone to cortisol
-leads to congenital adrenal hyperplasia if deficient |
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3 major secretions of pancreas
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Glucagon
Insulin Somatostatin |
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3 types of cells in islets of langerhands, and what each secretes
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Alpha: Glucagon
Beta: Insulin Delta:Somatostatin |
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actions of glucagon
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increase blood glucose levels, decreases glycogen production, increases glycogen breakdown and glucose made,
decreases fat made increases fat breakdown and ketones made, glucose from proteins, increase protein breakdown slow protein creation |
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what controls the release of glucagon?
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low blood sugar levels
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actions of insulin
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increase uptake of glucose into cells,
decrease blood glucose levels, increases glycogen production, decreases glycogen breakdown and glucose made, increases fat made and decreases fat breakdown, stop glucose from proteins, decrease protein breakdown increase protein creation (essentially, opposite of glucagon) |
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Glut-4
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increases glucose uptake
(insulin binds to receptors, releases a chemical (IRS-1 --> PI3K) that causes Glut-4 to move to and insert in cell membrane, creating passages for glucose to enter cell) |
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What triggers insulin secretion?
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High blood sugar levels
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Diabetes
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increased urine
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Diabetes Mellitus
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"sweet tasting" diabetes
-elevated fasting blood glucose -elevated urine glucose |
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Type I Diabetes
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-due to autoimmune destruction of the beta cells of the pancreatic islets
-results in insulin deficiency -patient must take insulin to survive |
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Type II Diabetes
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-90% of all diabetics
-due to insulin resistance -increased insulin secretion compensates for insensitivity in early stages, -insulin deficiency occurs in later stages leading to hyperglycemia, -average age >35, 90% are obese |
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Exercise effect
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-muscle contraction has an insulin-like effect, by stimulating Glut-4 translocation
-exercise increases insulin sensitivity of muscle |
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AMPK
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increases capacity for ATP synthesis (GLUT4 and mitochondrial enzymes) in response to endurance training
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What the three classes of hormones?
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Peptide Hormones
Amino Hormones Steroid Hormones |
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Peptide Hormones
-examples -how carried -where receptors are located |
-pituitary hormones, angiotensin, insulin, glucagon, IGF-1
-not protein bound -in membrane |
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Amino Acid Hormones
-examples -how carried -where receptors are located |
-epinephrine and thyroid hormones
-bound to carrier proteins -in nucleus |
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Steroid Hormones
-examples -how carried -where receptors are located |
-Aldosterone, Estradiol, Adrenal Cortical Hormones, Sex hormones
-bound to carrier proteins -in nucleus |
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genetic sex
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determined by X and Y chromosomes
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phenotypic sex
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determined by the presence or absence of masculinizing hormones
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5a-reductase
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changes testosterone to dihydrotestosterone
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What happens if a male is deficient in 5a reductase?
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male will have organs internally but not externally
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What happens if a male is deficient in testosterone receptors?
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genetically a male but not internal organs for either sex, and externally looks like a woman (pseudohermaphroditism)
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pseudohermaphroditism
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genetically a male but not internal organs for either sex, and externally looks like a woman
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Testes
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Produce sperm, secrete testosterone
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Epididymus/Ductus Deferens
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Path out of testes,
(epid.) site for sperm maturation (epid.) concentrate and store sperm |
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Seminal Vesicle
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-Supplies fructose,
-secretes prostglandins, semen, and precursors for semen |
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Prostate Gland
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Alkaline secretion
triggers semen clotting |
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Bulbourethral Gland
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Secretes Mucus (lubrication)
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Seminiferous Tubules
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produce sperm (inside testes)
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Ovaries
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Produce ova
secrete estrogen and progesterone |
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Oviducts
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Transport ova
site of fertilization |
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Uterus
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Maintain fetus during pregnancy
expel fetus during childbirth |
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Vagina
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Site of sperm deposit
passageway for delivery of baby during childbirth |
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Leydig Cells
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produce testosterone
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What controls testosterone release?
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-Fetal: placental hCG stimulates testosterone in leydig cells
-Puberty: GnRH is produced by hypothalamus which causes ant. pituitary to release LH which stimulates the leydig cells to produce testosterone |
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Spermatogenesis
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Spermatagonium develops in the tight junction of a sertoli cell and through several intermediates turn into spermatozoon
-occurs in between sertoli cells |
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GnRH
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-produced in hypothalamus, released from anterior pituitary
-produces LH, FSH |
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Testosterone
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-Causes Wolffian Ducts to develop
-stimulates sertoli cells to begin spermatogenisis and release inhibin -causes formation of male external genitalia |
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MIF
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-mullarian inhibiting factor
-causes mullarian ducts to degenerate in males |
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FSH
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stimulates sertoli cells
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LH
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stimulates leydig cells to produce testosterone
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Sertoli cells
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-in the seminiferous tubules
-provide nutrients and hormones for the production of sperm |
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Inhibin
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produced by sertoli cell
-inhibits production of LH and FSH, therefore inhibit spermatogenesis. and leydig production of testosterone |
