Endocrine System Flashcards
What part of the brain links the nervous system to the endocrine system?
Via what gland?
Hypothalamus
Pituitary Gland
What happens in the thryroid follicle when stimulate by Thyroid Stimulating Hormone?
Follicular cells uptake thyroglobulin into cytoplasm to break it down into T3 & T4 to be secreted into blood
Beta cells of the Islets of Langerhans secrete what?
Insulin
What is B?
What does this layer secrete?

Zona glomerulosa secretes mineralocorticoids (aldosterone)
In repsonse to stress, ACTH stimulates Zona fasciculata to secrete its glucocorticoid (cortisol) to do what?
affect the hepatocyte, fat, skeletal muscle to maintain homeostasis by decreasing unnecessary actions
(= negative feedback loop)
What are on either side of the Hypophyseal Cavity?
pars distalis & pars intermedia
What is D?

Hypophyseal cavity
Delta cells of the Islets of Langerhans secrete what?
somatostatin
Alpha cells of the Islets of Langerhans secrete what?
glucagon
What is the retina’s role in regards to Melanin?
Retina detects stimuli, which stimulates secretion of melanin by the pinealocytes when it’s dark, siglans time of day, time of year, is an antioxidant
What does the heart secrete in regards to the endocrine system?
Atrial Natriuretic Peptide (ANP)
What is A and what does it contain?

Colloid & thyroglobulin
What is C?

Pars Distalis
What is the endocrine system?
Ductless system that secretes into blood to affect cells far away
What do the axons pass through when traveling to the andenohypophysis?
Where do the axons release the releasing hormone into?
To what part of the adenohypophysis?
What do the releasing hormones bind to to stimulate it to release its specific hormone?
- pass thru infundubulum
- portal blood supply
- pars distalis
- epithelial cell
What are the three parts of th Adenohypophysis?
Pars distalis
Pars intermedia
Pars tuberalis

What is D?
What does this layer secrete?

Zona reticularis secretes androgens
Once at the target cell, hormones bind to what?
Exception??
Recetor on cell surface
Steroids pass through plasms mem & bind to nucleus
In repsonse to low bp, angiotensin II stimulates Zona glomerulosa to secrete its mineralocorticoid (aldosterone) to do what?
increase activity of Na/K ATPase in kindey to conserve water & increase blood volume
The pyloric region of the GIT secretes what?
gastrin
What percent of the pancreas is exocrine?
98%
What percent of the pancreas is endocrine?
2%
What is B?

Pars intermedia
What are Pituicytes?
support cells for the axons
What is B?

Thyroid follicle cuboidal epithelial cell
In the hypothalamus there are cell bodies; where do the axons go through and where do they terminate?
Axons thravel through the infundibular stalk
Axons terminate on fenestrated capillaries in pars nervosa
What 2 hormones does the kidney secrete affecting the endocrine system?
Renin & Erythropoietin
What does ANP do and what does it target?
promotes Na+ & water loss to decrease bp by targeting distal convoluted tubules of the kindey
Thyroid Gland consists of what?
Follicles
What do endocrine cells produce? (general)
Hormones
What does Calcitonin do?
sense blood Ca2+ levels; when blood Ca2+ concentration is high, calcatonin is secreted to bring blood Ca2+ levels down by increasing excretion of Ca2+ in the kidney AND decreasing osteoclast activity
What are the 3 types of Basophils?
What do they secrete?
What releasing hormone from the hypothalamus is first required?
Thyroidotrophs secrete Thyroid-Stimulating Hormone and requries TRH (thyroid releasing hormone)
Gonadotrophs secrete Follicle Stimulating Hormone & Lutenizing Hormone and require GnRH (gonadotropin releasing hormone)
Corticotrophs secrete Adrenocorticotropin and require CRH (corticotropin-releasing hormone)
What does the Pineal Gland regulate?
daily rhythms of body activity
What is the endocrine part of the Pancreas?
Islets of Langerhan
Other cells of the Islets of Langerhans secrete what?
gastrin
What does the hypothalamus prodcue, via what, to the neurohyophysis?
Produces hormones via axons where the hormone sits in the axons to be secreted into blood
What is E?

Adrenal Medulla
What is a short day breeder?
Sheep, goats, deer, elk cycle when days are shorter in fall
What is A?

Pars tuberalis
What is C?

Pars intermedia
What does the hypothalamus produce, via what, to the adenophypophysis?
Production of Releasing Hormones via blood
What are the 2 types of acidophils?
What do they secrete?
What releasing hormone from the hypothalamus is first required?
Somatotrophs secrete Growth Hormone and require GHRH (growth hormone releasing hormone)
Lactotrophs secrete Prolactin and require PRF (prolactin releasing factor)
What is “H” ?

Herring Bodies
What is A?

Capsule
What are the 3 parts of the neurohypophysis?
Pars nervosa
Infundibular stalk
Eminentia Mediana

What is B?

Capillary
What cells of the kidney secrete erythropoietin in?
In repsonse to what?
Where does it go?
What does it result in?
Interstitial cells secrete erythropoietin in repsonse to hypoxia which goes through blood to bone marrow to increase production of rbc’s
What is the adrenal medulla stimulated by?
autonomic nervous system (to Chromaffin cells to release ep & norep)
What is A?

Pars distalis
Along the axons of the neurons from the hypothalamus, what stores the hormones?
What hormones do they store?
Herring Bodies
ADH & Oxytocin
What are the 5 layers of the adrenal gland?
- Capsule - outer layer
- Zona glomerulosa - cortex
- Zona fasciculata - cortex
- Zona reticularis - cortex
- Adrenal Medulla
What are the cells adjacent to the follciles called?
What do they secrete?

Parafollicular Cells (C-cells) secrete Calcitonin
What are the secretory cells of the Pineal Gland called?
What do they produce?
Pinealocytes produce Melanin
What are the 2 parts of the pituitary gland?
Adenohypophysis - anterior part, glandular lobe
Neurohypophysis - posterior part
What is a long day breeder?
Horses; cycle when days are longers in leat spring, summer, & early fall
What determines if the thyroid follicle is active or inactive?
A more active follicle has colloid that is squished, looks depleted, follicle cells look more columnar than cuboidal
What do Cheif cells secrete?
When do they secrete this?
Parathormone (PTH) into capillaries when blood Ca2+ concentration is low to increase reabsorption of Ca2+ AND increase osteoclast bone reabsorption
What cells of the kindey secrete renin?
In repsonse to what?
Juxtaglomerular Cells
(part of the renin-angiotensin II-aldosterone system) in repsonse to low bp
What surrounds the parathyroid gland and what type of cell is it composed of?
adipose tissue
Cheif cells
Where does the neurohypophysis originate from?
nervous tissue from the brain
What os the adrenal cortex derived from and what does it secrete in general?
mesoderm
secretes corticoids
What is in the lumen of the thyroid follicle called?
Basophilic or Eosinophilic?
What is stored here?
Colloid (glassy substance) is eosinophilic and stores thyroglobulin
What type of cells line thyroid follicles? (general)
What do the follicles secrete and into what?
cuboidal epithelial cells
Thyroglobulin into vesciles
What is A?

Pinealocytes
The enteroendocrine cells of the GIT secrete what to do what?
cholecystokinin (CCK) for gall bladder contraction
What does the Pars distalis secrete? (general)
Acidophils
Basophils
Chromophobes
What is E?

Neurohypophysis: pars nervosa
What is the adrenal medulla derived from?
What does it secrete?
What are they stored in?
neurocrest cells
Catecholamines (epinephrine & norepinephrine)
granules of Chromaffin cells
Hormones travel via what to the target cell?
blood
Where does the adenohypophysis originate from?
epithelial cells from mouth
What structure is this and what tissue does it belong to?

Islet of Langerhan in the Pancreas

What is G?

Adrenal Cortex
What is F?

Infundibulum
What is C?

Thyroid follicle
What is B?

Pars nervosa
What is the Hypophyseal Cavity?
forms the left cleft, which is left of from Rathke’s pounch w epithelium on both sides
What hormone stimulates the adrenal cortex (3 zones)?
ACTH
What is secreted by the Pars intermedia?
Melanocyte Stimulating Hormone
What is C?

Corpora Arenacea
What are the cells surrounding the “H’s”?

Pituocytes
What is C?
What does this layer secrete?

Zona fasciculata secretes glucocortidoids (cortisol)
Endocrine functions:
maintain homeostasis to minimize variability internally
What are the primary endocrine organs?
Hypothalamus
Pituitary Gland
Pineal Gland
Thyroid Gland
Parathyroid Gland
Adrenal Gland