Term
| Name a few examples of organs with endocrine functions |
|
Definition
-ovary
-testes
-Islet of Langerhans
-Kidney
-Enteroendocrine glands |
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|
Term
| Which hormones does the thyroid secrete? What do they do? |
|
Definition
-Thryorxine: regulate metabolic rate
-Triiodothyronine: regulate metabolic rate
Calcitonin: control blood calcium concentration
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Term
| True or False: The thyroid is unilobular. |
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Definition
| FALSE, the thyroid has two lobes |
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Term
| What connects the two lobes of the thyroid? |
|
Definition
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Term
| The thyroid is enclosed in a connective tissue _______ that is continuous with the ______ of the gland: __________ connective tissue surrounding each thyroid _______. |
|
Definition
-capsule
-stroma
-loose areolar
-follicle |
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Term
| Describe the exterior surface and interior "content" of a thyroid follicle. |
|
Definition
-Exterior srface lined with simple epi
-filled with colloid in the lumen of the follicle |
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Term
| Where is the colloid found? What is its function? |
|
Definition
-found in the lumen of thyroid follicles
-storage form of material that is secreted by thyroid epithelial cells that will be converted to thyroxine and triiodothyronine |
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Term
| The height of the epi cells on the surface of a thyroid follicle is inversely/directly proportional to its activity while the diameter of the lumen is inversely/directly proportional to its activity. |
|
Definition
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|
Term
| What two types of cells are found in the thyroid? |
|
Definition
-Principal cells
-Parafollicular cells |
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Term
| Location/Histology/Function of Parafollicular Cells |
|
Definition
-Location: in the epi of the thyroid or in small clusters betweeen thyroid follicles
-Histology: larger than principal cells but less intense (thus aka "clear/C cells)
-Function: secrete calcitonin, which inhibits the action of osteoclasts (lowering the blood [Ca])
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Term
| How is the hormone Calcitonin secreted? What does it do? |
|
Definition
-via parafollicular cells in the thyroid
-it inhibits the action of osteoclasts and therefore lowers the blood calcium concentration |
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Term
| What does the Parathryoid gland secrete? What does that alter? |
|
Definition
-Parathryoid hormone
-stimulates osteoclasts, inh osteoblasts, and stim reabsorption of Ca in kidney, thus raises blood calcium |
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Term
| The body usually has ___ parathryoid gland(s) but it can vary from __-__ |
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Definition
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Term
| True or False: Two parathyroid glands usually adhere to the posterior surface of the thyroid but remain outside the capsule of the thyroid. |
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Definition
| FALSE; two parathyroid glands usually adhere to the posterior side of the surface of the thryoid but are in the capsule of the thyroid |
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Term
| The parenchyma of the parathyroid gland consists of _____ cells and, in the horse and ox, ____ cells. The stroma consists of a small amount of __________ connective tissue. |
|
Definition
-chief
-oxyphilic
-reticular CT |
|
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Term
| Histology/Function of Chief cells and Oxyphilic cells in the Parathyroid |
|
Definition
-Chief cells: undistinguished looking cells; have secretory granules that contain parathyroid hormone
-Oxyphilic cells: eosinophilic, large and have many mit; function unknown
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Term
| What does the adrenal gland secrete? What does this alter? |
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Definition
-Mineralocorticoids: control Na and K levels of the blood
-Glucocorticoids: control rate of glucose metabolism
-Epi and NE |
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Term
| The adrenal glands are flattened organs at the cranial end of ______ (organ). Fresh tissue has a __(color)__ cortex and a thin/thick, __(color)__ medulla |
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Definition
-kidneys
-yellowish
-thin
-gray |
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Term
| The entire adrenal gland is surrounded by a connective tissue _______, which sends ________ projections through the cortex. |
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Definition
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Term
| What are the 4 recognized zones of the adrenal cortex in order from capsule inward? |
|
Definition
1. Zona glomerulosa
2. Zona intermedia
3. Zona fasciculata
4. Zona reticularis |
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Term
| What do the cells in the Zona glomerulosa of the adrenal cortex do? |
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Definition
| -secrete minerralocorticoids |
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|
Term
| What do the cells of the Zona intermedia of the adrenal cortex do? |
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Definition
| -this small zone contains indifferentiated cells (I swear that is all it said) |
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Term
| What do the cells of the Zona fasciculata do? What is unique about this layer of the adrenal cortex? |
|
Definition
-synthesize glucocorticoids
widest layer and contians large cells in radial cords that are 1 cell wide
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Term
| Histologically describe the cells of the Zona fasciculata of the adrenal cortex |
|
Definition
-arranged in radial cords 1 cell wide that are flanked by sinusoidal capillaries
-contain many lipid droplets (contain steroid precursors), so look vacuolated |
|
|
Term
| What do the cells of the Zona reticularis of the adrenal cortex do? What is special about their arrangement? (Hint: also seen in the Zona fasciculata) |
|
Definition
-secrete glucocorticoids
-cells are arranged in a network of cords |
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|
Term
| How are cells arranged in the adrenal medulla? |
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Definition
| -in cords clustered around capillaries and venules |
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Term
| What do the cells of the adrenal medulla secrete? How are they innervated? |
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Definition
-contain secretory granules which contain Epi and NE (only one type per cell)
-innervated by preganglionic sympathetic fibers |
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|
Term
| What effect does sympathetic neural stimulation have on the adrenal medulla? |
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Definition
| -causes its cells to release either Epi or NE via exocytosis |
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|
Term
| when fixed in potassium bichromate, the adrenal medullary cells become _______. Thus they are called _____ cells as the color is a result of a rxn b/n chromate, Epi, and NE. |
|
Definition
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Term
| True or False: The capsule of the adrenal gland is severely lacking in vasculature. |
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Definition
| FALSE, the adrenal capsule has a rich arterial supply |
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Term
| Describe the vasculature of the adrenal gland |
|
Definition
-Cortex: arterioles from capsule=>supply sinusoids of Zona Fasciculata=>drain into medullary venules and veins
-Medulla: cortical arteries follow trabeculae to medulla=> branch to form capillary bed around chromaffin cells=> join venule that drains cortex |
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Term
| True or False: There are no veins in the adrenal cortex. Thus all/none of adrenal cortical blood drains through the medulla. |
|
Definition
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Term
| In the secondary blood supply to the adrenal medulla, what specific structure(s) receives the afferent arterial blood? |
|
Definition
|
|
Term
| What is the functional importance of the vasculature architecture of the adrenal gland? |
|
Definition
-Blood that enters the medulla from the cortical sinusoids contains cortical steroids
-Glucocorticoids stimulate chromaffin cells to make Epi=> thus if a chromaffin cell exposed to:
-inc [glucocorticoid]=Epi pdn
-dec [glucocorticoid]= NE pdn |
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Term
| The hypophysis is also known as the _____ gland and is a small endocrine/exocrine gland that sits at the base of the _____. |
|
Definition
-pituitary
-endocrine
-brain |
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Term
| What is the neurohypophysis of the hypophysis? The adenohypophysis? |
|
Definition
-Neurohypophysis= neurosecretory tissue of the hypophysis
-Adenohypophysis= glandular epi tissue of the hypophysis |
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Term
| What are the three main components of the Neurohypophysis of the hypophysis? |
|
Definition
1. median eminence
2. infundibular stalk
3. pars nervosa (=infundibular process) |
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Term
| What are the 3 main components of the Adenohypophysis of the hypophysis? |
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Definition
1. Pars distalis
2. Pars intermedia
3. Pars tuberalis |
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Term
| Which of the 3 divisions of the adenohypophysis is the largest? |
|
Definition
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Term
| Describe the arrangement of the cells in the Pars Distalis of the adenohypophysis. |
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Definition
| -cells are in cords/clusters and associated with sinusoidal capillaries |
|
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Term
| True or False: the parenchyma Pars distalis of the adenohypophysis is surrounded by an obvious, continuous layer of reticular CT. |
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Definition
| FALSE; contains scant reticular CT surroinding the parenchyma |
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Term
| What are a few example of organs affected by the 6 hormones secreted by the Pars distalis of the adenohypophysis. |
|
Definition
-thyroid
-adrenal cortex
-ovaries
-testes
-mammary glands |
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|
Term
Name the function of the following cells contained in the hypophysis:
a) Somatotrophes
b) Mammotrophs
c) Thyrotrophs
d) Corticotrophs
e) Gonadotrophs
f) Chromophobes |
|
Definition
a) acidophil cells that secrete growth hormones
b) acidophils that secrete prolactin
c) basophils that secrete thyroid stimulating hormone (TSH)
d) basophils that secrete adrenocorticotrophic hormone (ACTH)
e) basophils that secrete follicle stimulating hormone (FSH) and luteinizing hormone (LH)
f) hormone-poor cells of many different types
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|
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Term
| Secretion of Pars Distalis hormones is controlled by polypeptide _________ hormones that are discharged into the ________ by hypothalmic neurons. |
|
Definition
-releasing
-median eminence |
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|
Term
| Outline the pathway of polypeptide releasing hormones that control the secretion of pars distalis hormones in the hypophysis. |
|
Definition
| hypothalamic neurons=>median eminence=> capillaries in median eminence (primary plexus)=> portalveins=> sinusoidal capillaries of pars distalis=> diffuses to endocrine cells where they act to modicy their rate of secretion |
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|
Term
| Which two portions of the hypophysis are examples of circumventricular organ portions f the CNS? What does this mean? |
|
Definition
-median eminence and infundibular stalk
-do not exhibit a blood-brain barrier |
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|
Term
| In most species, the cells of the Pars intermediai of the adenohypophysis of the hypophysis are posterior to the _________ and contains basophilic/eosinophilic cells. These cells are called ______ and secrete ______-stimulating hormone. |
|
Definition
-remant cleft
-basophilic
-melanotrophs
-melanocyte |
|
|
Term
| Describe the arrangement/function of the cells in the Pars tuberalis of the adenohypophysis of the hypophysis |
|
Definition
-arranged in longitudinal cords between hypophyseal veins
-function unknown (I swear this is what it said) |
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|
Term
| True or False: Much of the neurohypophysis consist of myelinated fibers. |
|
Definition
| FALSE, much of it consists of unmyelinated fibers |
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|
Term
| Where are the nerve cell bodies of the neurohypophysis located? What do they run down and what do thay make up? |
|
Definition
-in the hypothalamus
-run down the ifundibular stalk to the pars nervosa
-make up the hypothalamohypophyseal tract |
|
|
Term
| What type of cells are in the neurohypophysis? What do they do/look like? |
|
Definition
-Pituicytes
-have cytoplasmic projections that surround nerve axons
-function similarly to glial cells |
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|
Term
| What do the neurons in the neurohypophysis secrete? How do they travel from the nerve cell bodies to the pars nervosa? |
|
Definition
-antidiuretic hormone and oxytocin
synth in nerve cell bodies of hypothalamus=>transported in vesicles down axon=> released by exocytosis in parse nervosa when cell bodies stim |
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|
Term
Out of the following, which are exocrine? Endocrine?
a) merocrine
b) apocrine
c) holocrine
d) endocrine |
|
Definition
-Exocrine= merocrine, apocrine, holocrine
-Endocrine= endocrine (go figure) |
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|
Term
Out of the following organs, which are endocrine only? Which is exocrine and endocrine?
a) pancreas
b) kidney (JGA cells- renin, erythropoietin)
c) stomach (neuroendocrine cells)
d) uterus (placenta)
e) ovary (theca folliculi cells, corpus luteum, granulosa cells) |
|
Definition
b,c,d,e= endocrine
a= endocrine + exocrine |
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|
Term
| Describe the macroscopic structure of the thyroid |
|
Definition
-two lobes on trachea close to larynx
-has a CT capsule |
|
|
Term
| What is the function of the thyroid? |
|
Definition
-secretes thyroxine (T4): reg met rate
-secreted triiodothyroxine (T3): reg met rate
-secrete calcitonin: inh osteocloasts, stim osteoblasts (inc osteoid calcification) thus lower plasma Ca |
|
|
Term
| What is the functional unit of the thyroid? |
|
Definition
|
|
Term
| Structurally describe thyroid follicles |
|
Definition
-lined with simple epithelium cuboidal to low columnar
-follicular/principal cells
-well-develoed ER
-inc apical vesicles
-inc microvilli
-inc lysosomes
-central area contains protein-righ colloid |
|
|
Term
| What is the function of follicular cells? |
|
Definition
-secrete thyroglobulin into lumen of thyroid follicles
-thyroglobulin acquires iodine in lumen, taken up by follicular cells and is degraded to AAs, some still have iodine (T4 and T3) |
|
|
Term
| What indicates activity level in thyroid follicles? |
|
Definition
| -inc activity= taller epi + paler nuc + dec follicle size + vacuolated colloid |
|
|
Term
| _______ cells are located b/n thyroid follicles and they secrete ______ |
|
Definition
-Parafollicular cells/ C-cells
-secrete calcitonin |
|
|
Term
| Most species have ____ parathyroid glands |
|
Definition
|
|
Term
| Describe the parenchyma of the parathyroid. Functions? |
|
Definition
-Chief cells: contain granules of parathyroid hormone
-Oxyphilic cells in horse, ox: function unknown |
|
|
Term
| What is the function of Parathryoid Hormone (PH)? What type of cells secretes it? |
|
Definition
-secreted by chief cells
-increases plasma [Ca]: inc osteoclastic activity, dec osteoblastic activity, inc Ca reabsorption by kidneys, inc formation of active vit D by kidney |
|
|
Term
| Definition/Structure/Function: Adrenal gland |
|
Definition
-flattened oval organs at or near cranial aspect of kidney
-Cortex secretes:
-mineralcorticoid: aldosterone inc Na reabsorption and dec K reabsorption by DCT of Kidney
-glucocorticoids: cortisol has broad effects on glucose control, AA, and lipid met
-Medulla secretes:
-catecholaimes: Epi and NE |
|
|
Term
| What are the 4 zones of the adrenal cortex? What are there functions? |
|
Definition
Zona glomerulosa (ZG): cells in clusters or arches
-secrete mineralcorticoids
Zona intermedia: in some species
Zona fasciculata: cells in columns (continuous w/ ZG cells) separated by sinusoidal capillaries (fenestrated)
-secrete glucocorticoids
Zona reticularis (ZR): cells in branched network
-secreete glucocorticoids
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|
|
Term
| How are cells arranged in the adrenal medulla? |
|
Definition
| -cells in groups or clusters close to capillaries and venules |
|
|
Term
| What kind of cells is found in the adrenal medulla? What is their function? Why are they named this? |
|
Definition
-Chromaffin cells
-secrete Epi and NE (only one type per cell)
-called chromaffin b/c stain brown due to to rxn b/n Epi/NE and chromate in potassium dichromate |
|
|
Term
| How do chromaffin cells relate to the nervous system? |
|
Definition
| -are innervated by sympathetic neurons that when stimulated cause release of Epi and NE (similar to an autonomic ganglion since these neurons are presynaptic) |
|
|
Term
| Outline Adrenal Gland Blood Flow |
|
Definition
arteries enter capsule=> cortical sinusoids=> go through medulla=> collect in veins=> exit medulla (contain glucocorticoids to stim Epi synth)
Second set: arteries go directly to medulla to provide arterial O2 blood without glucocorticoids=> join up with veins=> exit |
|
|
Term
| What is the pituitary/hypophysis? Where is it located? |
|
Definition
-a small gland at base of the brain connected by a small stalk
-resides in a depression of the cranium floor called hypophyseal fossa |
|
|
Term
| True or False: Pituitary/hypophysis has vascular and neural connections to brain that integrates neural and endocrine control systems |
|
Definition
|
|
Term
| Outline the development of the pituitary |
|
Definition
| -Oral ectoderm invaginates into Rathke’s pouch=> infundibular process forms at base of diencephalon=> Rathke’s pouch pinches off and adheres to infundibular stalk (some lumen remains and contains colloid) |
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|
Term
| What are the two divisions of the pituitary? What are the components of each? |
|
Definition
-Neurohypophysis: neural tissue
-median eminence
-infundibular stalk
-pars nervosa
-Adenohypophysis: epithelial tissue
-Pars tuberalis
-Pars intermedia
-Pars distalis |
|
|
Term
| What is the neurohypophysis mainly composed of? Where are the cell bodies? What do their axons comprise? |
|
Definition
-mainly unmyelinated nerve axons
-neuron cell bodies are in hypothalamus
-their axons comprise the hypothalamohypophyseal tract |
|
|
Term
| What kind of cells does the neurohypophysis contain? What do they secrete? |
|
Definition
-neurosecretory cells
-make antidiuretic hormone (ADH) and oxytocin in hypothalamus |
|
|
Term
| Outline how neurosecretory cells of the hypophysis secrete ADH and oxytocin. |
|
Definition
-ADH and oxytocin are packaged into granules that move down axon to neuron termini
-with stim the neurons release hormones into capillaries arising from inferior hypophyseal artery |
|
|
Term
| Where are pituicytes found (specifically)? What is their function? |
|
Definition
-found in the infundibular stalk and pars nervosa in the neurohypophysis of the pituitary
-functionally similar to glial cells
|
|
|
Term
| What type of tisssue composes the adenohypopysis of the pituiatry? What are its divisions? |
|
Definition
-epithelial tisssue
-pars tuberalis, pars intermedia, pars distalis |
|
|
Term
| In most species, where are most cells in the pars intermedia of the pituitary gland? What cells are these? |
|
Definition
-cells are posterior to the remnant cleft of Rathke's Pouch
-melanotrophs |
|
|
Term
| What cells are in the Pars intermedia of the pituitary? What do they do? |
|
Definition
| -Melanotrophs: secrete melanocyte stimulating hormone that stimulates melanin production in melanocytes |
|
|
Term
| Describe the arrangement of cells in the Pars distalis of the Pituitary gland. What organs do the hormones it secretes effect? |
|
Definition
-cells arranged in clusters associated with sinusoidal capillaries
-secrete at least 6 different hormones that impact: thyroid, adrenal cortex, ovary, testis, mammary gland |
|
|
Term
|
Definition
| -cells whose granules can be successfully stained by acid dye |
|
|
Term
|
Definition
| -cells whose granules can be stained by basic dye |
|
|
Term
| How can you differentiate between cells in the pars distalis of the pituitary? |
|
Definition
| -can detect hormone in hormone in cells by immunocytochemistry using Ab to specific peptide hormone (eg Luteinizing hormone) |
|
|
Term
| Compare/contrast: Chromophils vs Chromophobes |
|
Definition
-Chromophils: stain well
-Chromophobes: stain poorly |
|
|
Term
| What are the divisions of acidophils and basophils? What do they secrete? |
|
Definition
Acidophils:
-Somatototrophs: secrete growth hormone (GH)
-Mammotrophs: secrete prolacting (stim mammary gland in female)
Basophils:
-Thyrotroophs: secrete thyroid stim hormone (THS)
-Corticotrophs: secrete adrenocorticotropic hormone (ACTH), controls glucocorticoid secretion
-Gonadotrophs: secrete follicle stim hormone (FSH) and luteinizing hormone (LH) |
|
|
Term
| How is the secretion in Pars distalis of the Pituitary contolled? |
|
Definition
-releasing hormones secreted by the hypothalamic neurons which terminate in median eminence (ME)
-these releasing hormones eneter a capillary network in ME called primary plexus/network receiving blood from superior hypophyseal artery |
|
|
Term
| Outline the Blood Flow through the Pars Distalis of the Pituitary |
|
Definition
| superior hypophyseal artery=> primary capillary plexus=> hypophyseal portal veins=> secondary capillary plexus=> hypophyseal veins |
|
|
Term
| What cells do releasing hormones act on? Give examples. |
|
Definition
-act on chromophils to either inc or dec rate of secretion
-Ex: growth hormone releasing hormone: act of somatotrophs to inc GH secretion
-Ex: somatostatin: act on somatotrophs to dec GH secretion |
|
|
Term
| Describe the cellular arrangement of the Pars tuberalis of the pituitary. |
|
Definition
--cells arranged in cords b/n hypophyseal portal veins
FUNCTION UNKNOWN |
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