Term
|
Definition
1) "Somatotropin"
2) Regulates growth
3) Important in metabolism |
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Term
| Thyroid Stimulating Hormone |
|
Definition
1) TSH
2) stimulates secretion of thyroid hormone
2) growth of thyroid gland |
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Term
| Adrenocorticotropic Hormone |
|
Definition
1) ACTH
2) stimulates cortisol secretion by adrenal cortex
3) promotes growth of adrenal cortex |
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Term
| Follicle-stimulating Hormone |
|
Definition
1) FSH
2) Females: stim. growth & develop. of ovarian follicles; promotes secretion of estrogen by ovaries
3) Males: required for sperm production |
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Term
|
Definition
1) LH
2) Females
- responsible for ovulation
- formation of corpus luteum in ovary
- regulation of ovarian secretion of female sex hormones
3) Males
- stimulates cells in testes to secrete testosterone |
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Term
|
Definition
1) Females
- stimulates breast development
- stimulates milk production
2) Males
- involved in testicular function |
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Term
|
Definition
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Term
|
Definition
1)Posterior lobe of pituitary gland
2) contains axons of neurosecretory cells in hypothalamus |
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|
Term
|
Definition
1) project into posterior lobe
2) axon terminals closely related to BV's
- release secretions directly into blood (neuroendocrine release)
3) axons contain neurosecretory vesicles
- Herring bodies |
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Term
|
Definition
1) Supraoptic
2) paraventricular
3) contain neurons that produce tropic hormones
- oxytocin
- ADH
4) hormones released into capillaries of pars nervosa |
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|
Term
|
Definition
| 1) stimulates uterine contraction & milk ejection |
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Term
|
Definition
1) Antidiuretic hormone
2) decreases urine output by increasing permeability of kidney DCT & collecting ducts
3) regulates blood osmotic pressure
4) tumors interfering with ADH production or release
- can lead to diabetes insipidus
- greatly increased urine output
- extreme thirst |
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|
Term
| Paraventricular and arcuate nuclei |
|
Definition
1) release hypophysiotropic hormones from axon terminals in median eminence
- these hormones stimulate hormone release in anterior lobe |
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|
Term
| Superior hypophyseal arteries |
|
Definition
| 1) break up into primary capillary plexus which drains into portal veins that give rise to secondary capillary plexus which supplies pars distalis of anterior lobe |
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|
Term
| Pars nervose supplied by what: |
|
Definition
| 1) inferior hypophyseal arteries |
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|
Term
| How are anterior lobe hormones regulated? |
|
Definition
| 1) hormones released into prim. cap. plexus in median eminence flow to sec. cap. plexus in pars distalis |
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|
Term
| What are the cell types that release hormones? |
|
Definition
| 1) somatotropes 2) thyrotropes 3) corticotropes 4) gonadotropes 5) mammotropes |
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|
Term
| Where do they release their hormones? |
|
Definition
| 1) sec. cap. plexus and then systemic circulatio to affect peripheral endocrine glands |
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|
Term
|
Definition
1) Before puberty
- gigantism
2) After puberty
- acromegaly |
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|
Term
| Where is the pineal gland located? |
|
Definition
1) above the 3rd ventricle b/w superior colliculus and dorsal thalamus
2) covered by pia mater & attached to brain
3) post-ganglionic sympathetic innervation |
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|
Term
| Is the pineal gland lobular? |
|
Definition
1) yes, irregular lobes
2) rich in elastic fibers |
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|
Term
| What is corpora arenacea? |
|
Definition
1) "brain sand"
2) calcified deposits
- provide convenient landmark on radiographs and CT films |
|
|
Term
| What 2 cell types is the pineal gland made of? |
|
Definition
1) pinealocytes
- more numerous
2) glial (interstitial) |
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|
Term
|
Definition
1) release melatonin into blood stream
- melatonin is "wonder hormone"
- sleep aid |
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|
Term
|
Definition
1) secreted at night
2) possible retina input
3) may have inhibitory affect on gonads |
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|
Term
| Where is the thryoid gland? |
|
Definition
| 1) in the neck above the aortic arch directly adjacent to trachea |
|
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Term
|
Definition
| 1) Yes; right, left, isthmus, narrow tail (pyramidal lobe) |
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|
Term
| Does the thryoid have a CT capsule? |
|
Definition
| 1) yes; helps divide into lobes |
|
|
Term
| How is thryoid organized? |
|
Definition
1) Into cylindrical/spherical follicles
- consist of single layer of epithelial cells surrounding a central mass of colloid |
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|
Term
| What does the colloid contain? |
|
Definition
1) proteolytic enzymes
2) mucoproteins
3) thyroglobulin
- storage form of thyroid hormones thyroxine or T4 & T3 |
|
|
Term
| What do thyroid hormones do? |
|
Definition
| 1) increase tissue metabolism & regulate tissue growth and development |
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|
Term
| How is the thyroid unique? |
|
Definition
| 1) Stores most of its hormones extracellularly in follicles |
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|
Term
| Where would you find a dense network of fenestrated capillaries in thryoid? |
|
Definition
| 1) surrounding the follicles |
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|
Term
| What 2 cell types make up follicular epithelium? |
|
Definition
1) Follicular/principal cells
2) parafollicular/C cells |
|
|
Term
| What are principal cells? |
|
Definition
1) most numerous
2) make up wall of follicle
3) microvilli extend into colloid |
|
|
Term
| What do principal cells produce? |
|
Definition
1) thryoglobulin
2) release it into follicular lumen by exocytosis |
|
|
Term
| What do follicular/principle cells do? |
|
Definition
1) take up iodide
2) oxidize it to iodine
3) release it into follicular lumen
4) iodine then iodinates tyrosine w/in thryoglobulin |
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|
Term
| How do principle cells react to TSH? |
|
Definition
1) stimulated
2) take up colloid by receptor-mediated endocytosis
3) vesicles fuse w/ lysosomes
4) thryoglobulin is hydrolyzed; T3 & T4 released into fenestrated capillaries |
|
|
Term
|
Definition
| 20:1 when released from thyroid, but T4 is deiodinated in liver to T3 |
|
|
Term
| How are principle cells unique? |
|
Definition
1) Do not store hormones inside cell
2) within colloid in center of follicle as precursor thyroglobulin |
|
|
Term
| Where do C cells come from? |
|
Definition
1) migrate form neural crest
2) less numerous
3) b/w principal cells and basal lamina |
|
|
Term
| What do C cells/parafollicular cells produce? |
|
Definition
1) thyrocalcitonin (calcitonin)
2) stored in C cells in secretory vesicles |
|
|
Term
| How is calcitonin release regulated? |
|
Definition
1) blood calcium levels
- high levels stimulates calcitonin
- low levels inhibit |
|
|
Term
| How is release of T3 & T4 controlled? |
|
Definition
| 1) TSH released by thyrotropes of anterior lobe |
|
|
Term
| What can cause enlarged thyroid? |
|
Definition
1) lack of iodine in diet
2) lack of functioning thyroid hormones causes increased release of TSH (lack of feedback inhibition)
3) thyroid continuously stimulated |
|
|
Term
|
Definition
1) causes enlarged thyroid
2) antibody produced that binds & activates TSH receptors on principal cells |
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|
Term
| Where are parathyroid glands located? |
|
Definition
1) 2 pairs
2) superior & inferior
3) deep to thyroid gland |
|
|
Term
| What are the 2 cell types of parathyroid glands? |
|
Definition
1) Principal/chief cells
- most numerous
- produce & secrete Parathyroid hormone (PTH)
2) Oxyphil cells
- interspersed amongst chief cells |
|
|
Term
|
Definition
1) in response to low blood calcium levels
2) antagonizes calcitonin
3) regulates blood phosphate levels
4) promotes Ca release from bone
5) kidney Ca resorption
6) inhibits kidney phosphate resorption |
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|
Term
| Where are the adrenal glands located? |
|
Definition
|
|
Term
| What are the two parts of suprarenal glands |
|
Definition
1) cortex
- 3 zones
- zona glomerulosa
- zona fasiculata
- zona reticularis
2) medulla |
|
|
Term
| What do adrenal cortical cells release? |
|
Definition
|
|
Term
| What is zona glomerulosa? |
|
Definition
1) under capsule
2) rounded clusters of cells
3) may be absent in some areas |
|
|
Term
| What hormone is released in ZG? |
|
Definition
1) Cells produce mineralcorticosteroids
2) primarily release aldosterone & angiotensin II |
|
|
Term
|
Definition
1) low BP/low blood sodium
2) renin released from kidney JG cells
3) renin --> angiotensin I in blood --> angiotensin II in lung |
|
|
Term
| What does aldosterone do? |
|
Definition
1) stimulates distal tubules & collecting tubules to:
- increase Na resorption & decrease K resorption |
|
|
Term
|
Definition
1) zona fasiculata
2) produces glucocorticoids
- promote carb metabolism & suppress inflammatory response
3) more lipid in this layer (lighter appearance)
- strongly labeled w/ osmium |
|
|
Term
| ZF cells are stimulated by what? |
|
Definition
1) ACTH released from pituitary corticotropes
2) excess of glucocorticoids can lead to Cushings syndrome |
|
|
Term
|
Definition
1) zona reticularis
2) produces gonadocorticoids (sex steroids)
3) stimulated by ACTH |
|
|
Term
| Where does the adrenal medulla originate? |
|
Definition
|
|
Term
| What cells make up of the medulla? |
|
Definition
1) chromaffin cells
- stain brown
- secretory vesicles that store epineprhine |
|
|
Term
| What are chromaffin cells? |
|
Definition
1) can be considered post-G symp neurosecretory cells
2) release hormones from somata and not nerve terminal
3) innervated by pre-G symp nerve fibers |
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|
Term
| Blood supply to adrenal glands: |
|
Definition
1) enter through capsular arteries
2) form cap. plexuses in ZG
3) sinusoids in ZF
4) sinusoids branch to form cap. plexuses in ZR & medulla
5) blood entering medulla contains hormones from cortical cells |
|
|
Term
| What do glucocorticoids do? |
|
Definition
| 1) necessary for conversion of norepinephrine to epinephrine in chromaffin cells |
|
|
Term
| What does norepinephrine do? |
|
Definition
| 1) effects overall BP by constricting arteries throughout the body |
|
|
Term
|
Definition
1) constricts arteries of skin
2) increases heart output
3) increases bronchiole dilation
4) inhibits gastric motility
5) increases anxiety |
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