Endocrine Flashcards
What is the endocrine system?
the ductless gland system
What are the functions of the endocrine system?
growth and development
internal environment
energy production, storage and utilization
What are four major characteristics of endocrine organs?
epithelial in origin
ductless
highly vascular
control or mediated by hormones
What can hormones be?
proteins
amino acids
steroids
T or F: most hormones bind to receptors on target cell surface
True
T or F: only steroids pass through plasma membrane of target cells and bind to nucleus
True
T or F: Hormones produce fast, unsustained responses
False, slow and sustained
How does the hypothalamus control distant cells?
via hormones
What are the two pathways the hypothalamus releases hormones by?
- releasing hormones into portal system via adenohypophysis
- hormones transported and stored in nuerohypophysis, then released into blood
What is the posterior pituitary also called?
nuerohypophysis
What is the anterior pituitary also called?
adenohypophysis
What does the posterior pituitary start out as?
nuerohypophyseal bud
What does the anterior pituitary start out as?
hypophyseal pouch
What are the three parts of the nuerohypophysis (posterior)
pars nervosa
infundibular stalk
eminentia mediana
What does the nuerohypohysis produce?
antidiuretic hormone
oxytocin
What are herring bodies?
sites where hormones accumulate in the posterior pituitary in pars nervosa
T or F: in the pars nervosa, axons terminate on vessels
True
What are the three portions of the adenohypophysis (anterior) ?
pars distalis
pars intermedia
pars tuberalis
What is the pars distalis?
part of anterior pit.
bulk of anterior pit. and secretes majority of hormones
What is the source of melanocyte stimulating hormone?
pars intermedia
What is the pars distalis made up of?
chromophils and chromophobes
What are somatotropes?
part of pars distalis acidophils
produce growth hormone
What are mammotropes?
part of pars distalis acidophils
produce prolactin
What are thyrotropes?
part of pars distalis basophils
produce thyrotropin
What are adenrocorticotropes?
part of pars distalis basophils
produce ACTH
What are gondotropes?
part of pars distalis basophils
produce follicle stimulating hormone and luteinizing hormone
What is the process of releasing a hormone from the hypothalamus?
hypo. neurons produce releasing hormones into portal vessels, they travel to anterior pit. where they stimulate acidophils or basophils to produce another hormone, that travels to target endocrine organ where third hormone is produced, that hormone causes an effect on target cell
What is the function of the pineal gland?
regulate daily rhythms of bodily activity
What are pinealocytes?
secretory cells of the pineal gland
What do pinealocytes produce?
melatonin
When is melatonin secreted?
at night
Is melatonin important in seasonally breeding?
yes, long day and short day breeders
What are parafollicular cells?
clear cells that are part of the thyroid gland
secrete calcitonin in response to high blood calcium
T or F: Thyroid gland has follicular cells
True
What does the parathyroid gland secrete?
parathromone into capillaries
T or F: parathromone will stimulate bone resorption?
True
What is the adrenal gland in mammals?
separation between cortex and medulla
in mammals only
Where does the cortex of the adrenal gland arise from? What does it secrete?
mesoderm
corticosteriods
Where does the medulla of the adrenal gland arise from? What does it secrete?
neural crest
catecholamines
What are the three parts of the adrenal cortex?
zona glomerulosa
zona fasciculata
zona reticularis
What does the zona glomerulosa of the adrenal cortex secrete?
aldosterone
What does the zona fasciculata of the adrenal cortex secrete?
cortisol
What does cromoaffin cells of the adrenal medulla secrete?
epinephrine and norepinephrine
stored in secretary granules ( EM only)
What happens if theres low blood pressure?
renin system kicks in
angiotensin II
Water retention
What are the four pancreatic islet cells?
alpha
beta
delta
F cell
What does alpha pancreatic islet cell produce?
glucagon, CCK
What does beta pancreatic islet cell produce?
insulin, IAPP
What does delta pancreatic islet cell produce?
somatostatin
What two hormones does the kidney produce?
renin (juxtaglomerular cells)
Erythopoietin (controls RBC production)
T or F: atrial myocardial cells secrete atrial natriuretic peptide?
True
What does atrial myocardial peptide do?
promote sodium and water loss
decrease blood pressure
