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78 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Endo |
Within |
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Crine |
To secrete |
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Hypothalamus |
Neuroendocrine |
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Neuroendocrine |
Along with neural functions, produces and releases hormones |
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Autocrines |
Chemicals that exert their effects on the same cell that secrete them |
Certain prostaglandins released by smooth muscle cells cause those smooth muscle cells to contract |
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Amino acid-based hormones |
Amino acid derivatives, peptides and proteins |
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Steroids |
Synthesized from cholesterol Gonadal and adrenocortical hormones |
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Arachidonic acid |
Eicosanoids, including leukotrienes and prostaglandins derive from this |
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Target cell |
Cell that has receptors for a given hormone |
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Hormones typically produce changes in what |
Membrane potential Stimulate synthesis of proteins or regulatory molecules Active or deactivate enzymes Introduce secretory activity Stimulate mitosis |
5 things |
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Water-soluble hormones |
Exert their effects through an intracellular second messenger that is activated when a hormone binds to a membrane receptor |
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Lipid-soluble hormones |
Steroid and thyroid hormone * diffuse into cell, bind to intracellular receptors, migrate to the nucleus, & activate specific genes |
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Second messenger system |
Signaled by most amino acid-based hormones, causes generation of an intracellular second messenger when a hormone binds to a membrane receptor |
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Cyclic AMP |
Signaling mechanism Involves G protein Mediated activation of enzymes that results in the activation of protein kinases |
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Direct gene activation |
Occurs when a Lipid-soluble hormone or thyroid hormone binds to an intracellular receptor, which activities a specific region of DNA, causing production of mRNA and initiation of protein synthesis |
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Target cell response |
Depends on 3 factors Blood levels of the hormone Relative numbers of the target cell receptors Affinity of receptor for the hormone |
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Water-soluble hormones |
-Act on plasma membrane receptors -Act via G protein second messengers -Cannot enter cell |
3 things |
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Lipid-soluble hormones |
-Act on intracellular receptors that directly activate genes -Can enter cell |
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Negative feedback mechanism |
Regulates release and synthesis of most hormones |
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Endocrine gland stimuli |
May be humoral, neural, or hormonal |
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Humoral stimuli |
Critical ions or nutrients that act as stimuli controlling secretion of hormones |
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Neural |
Nerve fibers stimulates hormone release |
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Hormonal pattern of secretion |
If the secretion of a hormone is in response to hormones produced by other endocrine glands it follows this pattern |
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Nervous system modulation |
Allows hormone secretion to be modified by hormonal, humoral, and neural stimuli in response to changing body needs |
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Concentration of a hormone |
Reflects its rate of release and the rate of inactivation and removal from the body |
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Half life |
Duration of time a hormone remains in the blood and is shortest for water-soluble hormones |
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Permissiveness |
Occurs when one hormone cannot exertits full effect without another hormone being present |
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Synergism |
Occurs when more than one hormone produces the same effects in a target cell and their combined effects are amplified |
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Antagonism |
Occurs when 1 hormone opposes the action of another hormone |
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Pituitary gland |
Located in the Sella Turcica of skull Connected to brain via infundibulum |
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What are the 2 lobes in pituitary |
Posterior pituitary aka. Neurohypophysis *neural in origin Anterior pituitary aka. Adenohypophysis *glandular in origin |
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Hypothalamic-hypophyseal Portal |
Vascular connection between the hypothalamus and the anterior pituitary that extends through the infundibulum |
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NeuroHormones produced by posterior pituitary |
Oxytocin Antidiuretic hormone (ADH) |
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Oxytocin |
Promotes uterine contractions and milk ejection |
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Antidiuretic hormone (ADH) |
Prevents wide swings in water balance |
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Anterior pituitary hormones |
Pro-opiomelanocortin (POMC) Growth hormone (GH) Thyroid-stimulating hormone (TSH) Adrenocorticotropic hormone (ACTH) Gonadotropins FSH & LH Prolactin |
6 |
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(POMC) Pro-opiomelanocortin |
Prohormone that can be split into adrenocorticotropic hormone and melanocyte-stimulating hormone |
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Growth Hormone GH |
Target cells in the liver, skeletal muscle, bone, and other tissues to cause production of insulin like growth factors |
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Thyroid-stimulating hormone (TSH) |
Promotes secretion of the thyroid gland |
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Adrenocorticotropic hormone ACTH |
Promotes release of corticosteroid hormones from adrenal cortex |
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Gonadotropins FSH (follicle-stimulating) & LH (luteinizing hormone) |
Regulate function of gonads |
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Prolactin |
Stimulates the gonads and promotes milk production |
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Thyroid gland |
Consists of hollow follicles with follicular cells that produce thyroglobulin and parafollicular cells that produce calcitonin |
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Synthesis of thyroid hormone |
1. Thyroglobulin is synthesized and secreted to follicle lumen 2. Iodide is trapped & oxidized to iodine, which then attached to the tyrosine portion of thyroglobulin 3. Iodinated tyrosines are linked to form T3 & T4 4. To secrete T3 n T4, thyroglobulin colliod is transported into follicular cells, where thyroglobulin is removed, allowing the hormone to diffuse into bloodstream |
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Calcitonin |
-Secreted by C cells of thyroid -Peptide that lowers blood calcium by inhibiting osteoclast activity, stimulating Ca++ uptake and incorporation of Ca++ into bone matrix |
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Where are Parathyroid located |
Posterior aspects of thyroid |
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Parathyroid hormone |
Causes osteoclasts to break down bone, increases absorption of Ca++ in kidneys, and activates vitamin D, which aids in absorption of calcium from food |
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Adrenal glands consist of 2 regions |
Inner adrenal medulla Outer adrenal cortex |
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Adrenal cortex |
Produces corticosteroids from 3 regions |
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3 regions of adrenal cortex |
1.Zona glomerulosa 2. Zona fasciculate 3. Zona reticularis |
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Zona glomerulosa |
Produces minerocorticosteroids |
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Zona fasciculate |
Produces glucocorticoids |
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Zona reticularis |
Produces sex steroids |
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Mineralocorticoid |
Essential to regulation of electrolyte concentrations of extracellular fluids, raising plasma Na+ n lowering plasma K+ |
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Aldosterone |
Secretion is regulated by the renin-angiotensin-aldosterone mechanism |
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Glucocorticoids |
-Released in response to stress through the action of ACTH - primarily cause gluconeogenesis |
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Gonadocorticoids |
Weak androgens which are converted to testosterone and estrogen in the tissue cells |
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Medullary chromaffin cells |
-in adrenal medulla - synthesizes catecholamines epi n norepi |
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Adrenal catecholamines |
Produce brief stress-mediated responses |
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Pineal gland |
Produces melatonin Input comes from visual pathways in order to determine timing of the day |
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Pancreas |
Mixed gland that contains both exocrine n endocrine gland cells |
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Pancreas exocrine cells |
Have pancreatic islets |
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Pancreas a cells |
Produce glucagon |
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Pancreas b cells |
Produce insulin |
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Glucagon |
Targets liver Promotes glycogenolysis, gluconeogenesis, n release of glucose to the blood |
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Insulin |
-Lowers blood glucose levels by enhancing membrane transport of glucose into body cells -Inhibits glucose production through glycogen breakdown |
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Ovaries |
Produce estrogen n progesterone |
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Testes |
Produce testosterone |
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Adipose tissue |
Produces leptin, which acts on the CNS to produce a feeling of satiety |
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Gastrointestinal tract |
Contains enteroendocrine cells throughout the mucosa that secrete hormones to regulate digestive functions |
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Atria of heart |
Contain specialized cells that secrete atrial natriuretic peptide, resulting in decreased blood vol., blood pressure, and blood sodium concentration |
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Kidneys |
Produce erythropoietin, which signals bone marrow to produce red blood cells |
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Skin |
Produces cholecalcoferol, inactive form of vit D3 |
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Osteoblasts |
In skeletal tissue secrete osteocalcin |
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Osteocalcin |
Hormone that promotes increased insulin secretion by the pancreas and restricts fat storage by adipocytes |
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Second messenger system |
1. Hormone binds to receptor 2. Receptor activates G protein 3. G protein activates adenylate cyclase 4. Adenylate cyclase converts ATP to cAMP 5.cAMP activities protein kinases that phosphorylate proteins 6. Activated kinases phosphorylate various proteins, activating some n inactivating others 7.cAMP is rapidly degraded by enzyme phosphodiesterase 8. Intracellular enzymatic cascades have hugh amplification effect |
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Direct gene actvation |
1. Steroid diffuse through plasma membrane n binds an intracellular receptor 2. Receptor hormone complex enters the nucleus 3. Receptor hormone complex binds a specific DNA region 4. Binding initiates transcription of the gene to mRNA 5. mRNA directs protein synthesis |
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Tropic hormone |
TSH ACTH FSH LH |
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