Intro to Endocrine Flashcards
1
Q
overview
A
- multiple chemical messengers, especially those controlled by autonomic and endocrine systems act in coordinated manner to regulate activities of cells, tissues and organs in the body
- promote growth, reproduction, homeostasis
- classical endocrine hormones are released by ductless glands into the circulating blood to influence the function of distant target cells containing specific receptors
- classical endocrine glands include pit, thyroid, parathyroid, adrenal, pancreas, and gonads, but several other tissues secrete hormones
2
Q
hypothalamus
A
- ADH
- oxytocin
- releasing hormones (TRH, CRH, GHRH, GnRH)
- somatostatin
3
Q
pituitary gland
A
- ant- ATCH, TSH, GH, PRL, FSH, LH, MSH
- posterior pit- release of ADH and oxytocin
4
Q
parathyroid
A
-PTH
5
Q
heart
A
-atrial natriuretic peptide
6
Q
pineal gland
A
-melatonin
7
Q
thyroid gland
A
- thyroxine
- triiodothyronin (T3)
- calcitonin
8
Q
thymus
A
- undergoes atrophy during adulthood
- thymopoietin
9
Q
adrenal glands
A
- epi, norepi
- cortisol, aldosterone, androgens
10
Q
kidney
A
- erythropoietin
- calcitriol
- renin
11
Q
fat
A
leptin
12
Q
testes
A
adrogens
-testosterone
13
Q
GI tract
A
-gastrin secretin CCK GIP motilin
14
Q
ovaries
A
-estrogens, progestins, inhibin, relaxin
15
Q
corpus luteum
A
- estradiol
- progesterone
16
Q
placenta
A
- HCG
- HPL
- estriol
- progesterone
17
Q
fetal placental unit
A
- chorionic gonadotropin
- stimulates corpus luteum to produce estrogen and progesterone during early pregnancy
- human placental lactogen- growth hormone and prolactin like actions
- estrogens and progesterone
18
Q
peptide hormones
A
- ACTH
- ANP
- ADH
- calcitonin
- CCK
- Corticotropin releasing hormine
- FSH
- glucagon
- GnRH
- GH
- GHRH
- inhibin
- insulin
- IGFs
- LH
- oxytocin
- PTH
- prolactin
- secretin
- somatostatin
- TSH
- TRH
- VIP
19
Q
aa hormones
A
- dopamine
- epi
- norepi
- serotonin
- T3, 4
20
Q
steroid hormones
A
- aldosterone
- cortisol
- estradiol
- progesterone
- testosterone
21
Q
hormones
A
- classified by their chemical composition
- typically blood borne polypeptides, amines, steroids that bind with high affinity to specific receptors
- use second messengers to transduce effects
22
Q
classical hormones and other models
A
- peptide hormones have receptors on cell surface
- steroid hormones and thyroid hormones enter the cell and activate nuclear receptors (and sometimes cytoplasmic)
- some hormones are released by cells and act locally in a paracine/autocrine manner
- neuroendocrine hormones are secreted by neurons into the blood to influence the function of target cells
- GH uses tyrosine kinase receptor
23
Q
steroid hormones
A
- no storage pools
- diffusion through cell membrane
- receptor in cytoplasm or nucleus
- regulate gene transcription
- hours to days primarily
- produced on demand
24
Q
peptide amine hormones (important features)
A
- storage pool is secretory vesicles
- bind to receptor on cell membrane
- receptor is on cell membrane
- cause signal transduction cascade that affect a variety of cell processes
- seconds to minutes
25
Q
pseudohypoparathyroidism
A
- defect is in alpha subunit of G coupled receptor
- there is enough PTH, but it can’t cause it’s effect
- low calcium and high P
- primary is problem with gland
26
Q
cyclical fashion
A
- hypothalamic and pituitary hormones released in cyclical fashion
- can be affected by time of day and behavior
- GH at noon and midnight
27
Q
hypothalamus and anterior pit
A
- vascular connections to ant pit
- pit gland highly vascularized and lies at the base of brain in sella tucica
- secretion of pit hormones regulated via vascular connections
- venous blood carrying neuropeptides from the hypothal and pit stalk to different cell types in the gland
- axons from hypothalamic nuclei extend to the median eminance, where they release hormones into the hypophyseal portal circulation, carries them to anterior pit
- the hormones inhibit or stimulate the release of various trophic hormones into the systemic blood
- protein and glycoproteins
- neurons-portal system-anterior pit
28
Q
hypothal and post pit
A
- arterial blood
- neural connections to hypothal
- axons from hypothalamic nuclei extend to the posterior pit (supraoptic and paraventricular)
- hormones oxytocin and ADH stored until they are released into systemic bloodstream
- receives arterial blood
- smaller molecular mass peptides that are associated with neurophysins
*neurons-post pit
29
Q
GHRH
A
- inhibited by somatostatin
- from hypothal to somatotroph cell in ant pit
- ant pit secretes GH
- to multiple somatic tissues
30
Q
TRH
A
- to thyrotroph cell in anterior pit
- secretes TSH
- to thyroid to make thyroid hormone
31
Q
CRH
A
- to corticotroph cell in ant pit
- ant pit secretes ATCH
- fasciculata and reticularis cells of adrenal cortex, to make corticosteroids
32
Q
GnRH
A
- to gonadotroph cell in pit
- ant pit secretes FSH and LH
- FSH to ovarian follicular cells, to make estrogens and progestins, sertoli cells to make sperm
- LH to ovarian to make estrogen and progestins, to leydig cells to make testosterone
33
Q
dopamine from hypothal
A
- to ant pit
- inhibits lactotroph cell
- inhibits secretion of prolactin
34
Q
post pit
A
ADH, oxytocin to post pit and stored until release
35
Q
distinguishing cell types
A
- use size and cellular stains
- large acidophilic cells are somatotropes are 30% of secreting cells and release GH
- basophilic cells are corticotropes represent 20% of secreting cells and release ACTH
- territories occupied by different cell types can be dynamic
- increase in lactotrophic cells during pregnancy
36
Q
negative/positive feedback
A
- females negative until right before ovulation
- pos and neg feedback control amounts of circulating hormones
- closed loop systems that can be simple or involve hierarchical control
- system senses when it should increase or decrease activity
- peptides that feedback on HPA can pass BBB
- feedback of hormones released from peripheral glands onto HPA is long loop
- short loop is anterior pit feeding back on hypothal
37
Q
prolactin
A
- under tonic inhibitory control
- TRH small stimulus
- dopamine inhibits, so do dopa agonists (bromocriptine)
- antagonists can cause decrease in inhibition and change breast tissue
- prolactin has neg feedback on own release by enhancing dopamine via short loop pathway
- circulating prolactin increases if the pit stalk is severed or an individual is taking dopamine antagonist
38
Q
post pit hormones
A
- pre pro to pro in hypothal
- pro to actual hormone and neurophysins in axon
- hormone and neurphysins released together
39
Q
oxytocin
A
- promotes milk let down and uterine contractions
- responds to suckling
- responds with contractions in response to cervix
- can also be secreted in response to sight, smell, sound of an infant and orgasm
- the hypothalamic cell bodies that synthesize oxytocin are primarily in the paraventricular nuclei
40
Q
ADH
A
- supraoptic nuclei
- stored and released in post pit
- main function is water balance
- it is released in response to increased osmolarity of extracellular fluid and decreased blood pressure
- major effect of promoting water reabsorption from the kidney
- when ADH is high, low volume of concentrated urine is produced
41
Q
ADH and volume contraction
A
- increases in response to volume contraction- losing blood need to keep fluid
- also decreases with volume expansion- drinking too much water
- ADH major regulator of fluid osmolarity
- secretion increases in response to increase serum osmolarity (dehydration)
- promotes water reabsorption- decreases osmolarity- V2 receptor
- V1 causes contraction of smooth muscle which increases TPR
42
Q
central diabetes insipidus
A
- failure of post pit to secrete ADH
- produce large volumes of dilute uring
- body fluids become concentrated
43
Q
hypopituitarism
A
- insufficiency of pit to release hormones
- insufficiency of hypothalamic releasing hormones
- multiple causes- pit tumor/brain damage
- clinical symptoms are unspecific, can be life threatening and lead to increased mortality
- TBI or subarachnoid hemorrhage
- brain tumor causes might be more common than adenomas
44
Q
corticotropin deficiency
A
- chronic: fatigue, pallor, anorexia, weight loss
- hypocalcaemia, hypotension, anaemia, lymphocytosis, eosinophilia, hyponatraemia
- acute:weakness, dizziness, nausea, vomiting, circulatory collapse, fever, shock
- children: delayed puberty, FTT
45
Q
thyrotropin deficiency
A
- tiredness, cold intolerance, constipation, hair loss, dry skin, hoarseness, cognitive slowing
- weight gain, bradycardia, hypotension
- children-retarded development, growth retardation
46
Q
gonadotropin deficiency
A
women: oligoamenorrhea, loss of libido, dyspareunia, infertility
- osteoporosis
men: loss of libido, impaired sexual function, mood impairment, loss of facial, scrotal, and trunk hair
- decreased muscle mass, osteoporosis, anaemia
- children: delayed puberty
47
Q
growth hormone deficiency
A
- decreased muscle mass strength, visceral obesity, fatigue, decreased QOL, impairment of attention and memory
- children:growth retardation
48
Q
ADH deficiency
A
- polyuria, polydipsia
- decreased urine osmolarity, hypernatraemia, polyuria
