18-Endocrine Flashcards
Endocrine glands 15
Hypothalamus, thymus, pancreas, ovaries, testes, thyroid, parathyroid, kidney, stomach, liver, sm intestines, skin, heart, adipose tissue, placenta
Exocrine glands 4
Sweat, sebaceous, mucous, digestive
up/down regulation
down - abundance of hormone, target becomes less sensitive
up - deficiency of hormone, target more sensitive
hormones act in two ways
circulating - interstitial to blood
local - neighbors (paracrines) or self (autocrines)
lipid soluble hormones 3
steroids
thyroid
nitric oxide - hormone and neurotransmitter, vasodilation
water soluble hormones - 3
amines - epinephrine, NE, dopamine, histamine, serotonin, melatonin - fight or flight
peptide/proteins - peptide 3-49 amino acids, proteins 50-200 - carries lipid soluble in blood
eicosanoids - prostaglandins (vasodilation), leukotriens (vasoconstriction)
hypothalamus and pituitary parts 1+1+2
hypothalamus below thalamus
infundibulum connects two
anterior pituitary - pars distalis and pars tuberalis
posterior pituitary - bulbular pars nervosa and infundibulum
hypothalamus to anterior pituitary
hypophyseal portal system - arteries, capillary sytem, veins, plexus
pituitary secretes 5 classes
act on other glands - tropins
somatotrophs - growth hormone, most plentiful
thyrotrophs - TSH
gonadotrophs - FSH and luteinizing hormone
lactotrophs - prolactin (PRL)
corticotrophs - ACTH
somatotrophs promote
insulin like growth factors, human growth hormone
increase protein synthesis, causing growth
enhance lippolysis
decrease glucose uptake
big in puberty
GHRH and GHIH control
thyrotrophs release
thyroid stimulating hormone TSH
TSH promotes secretion of T3, T4
Hyothalamus produces TRH to promote TSH, feedback by T3, T4
gonadotrophs release
follicle stimulating hormone FSH - ovarian follicle development, estrogen in females, sperm in males
luteinizing hormone - triggers ovulations and progesterone in females, testosterone in males
GnRH from hypotalamus regulates these
lactotrophs secrete
prolactin PRL - initiate and maintain milk production
hypersecretion in males causes ED, females galactorrhea, amenorrhea
Controlled by PIH PRH
corticotrophs secrete 2
ACTH - production and secretion of glucocorticoids, including cortisol by adrenal cortex
melanocyte stimulating hormone MSH
Controlled by CRH, dopamine
Hypothalamus and Posterior Pituitary hormones - 2
oxytocin - smooth muscle contraction (birth contractions), milk ejection, love hormone
Antidiuretic Hormone ADH (vasopressin) - decrease urine volume
Released by neurosecretory bodies, Herring bodies, swelling in axons
Thyroid Anatomy 4
Inferior to larynx
right and left lateral lobe, connected by isthmus
half have a third lobe, pyramidal
only endocrine gland that stores product in large quantities
Thyroid microscopic anatomy 3
follicular cells - secrete T3 and T4, stain darker, squamous inactive, columnar when active
follicle is colloid surrounded by follicular cells
Parafollicular cells - secrete calcitonin
Thyroid T3/T4 cycle 4
Follicular cells get iodine, produce TGB, oxidize iodine to I2 Iodine attaches to TGB to make T1, T2 T1, T2 combine to make T3, T4 T3, T4 diffuse into ISF T3, T4 transported in blood by TBG
Thyroid hormone uses 5
increase BMR Stimulates Na/K pump, calorigenic effect Stimulates protein synthesis increase lipolysis, cholesterol excretion accelerate body growth
Thyroid Calcitonin use 3
decreases level of calcium in body by inhibiting osteoclast
inhibits bone resorbtion
accelerates Ca and P uptake into bone
Miacalcin - calcitonin extract from salmon, 10 times more potent
Parathyroid hormone 4
Chief Cells / Principle cells produce parathormone
Major regulator of calcium and magnesium
Promotes formation of active Vitamin D (D3, calcitrol)
When calcium too low
oxyphil cells no known function
Adrenal gland high level anatomy 3
Superior to kidney
Surrounded by tissue capsule, then adrenal cortex (80-90%)
Small center is adrenal medulla
Adrenal Cortex zones 3
Outside to inside
Zona glomerulosa - secretes mineralocorticoids
Zona fasciculata - secretes glucocorticoids
Zona reticularis - secretes androgens
Adrenal Mineralocorticoids - 1, 2 uses
Aldosterone - Na and K homeostasis, blood volume and pressure, also excretes protons in urine (prevents acidosis)
Renin-angiotensin-aldosterone pathway (RAA) controls aldosterone secretion
Thymus does what?
T cell maturation
Pituitary basophilic cells do what?
unknown. melanocyte-stimulating hormone in fetus
sodium potassium pump counts
one ATP pumps 3 Na out and 2 K into cell
Adrenal glucocorticoids 3+7
Cortisol (hydrocortisone), cortisone, corticosterone
regulate metabolism, resistance to stress
protein breakdown, gluconeogenesis, lypolysis
anti-inflammatory, immune system depression
Adrenal Androgens
DHEA - weak, converted to estrogen, females responsible for libido after menopause
Both sexes responsible for prepubertal growth spurt, axillary and pubic hair
Adrenal medulla
modified sympathetic ganglion, chromaffin cells
secretes 80% epi, 20% NE, fight or flight
pancreas
endocrine and exocrine
Isles of Langerhans
Alpha cells secrete glucagon, 17%
Beta cells secrete insulin 70%
ovaries 3
2 Estrogens and progesterone
produce inhibin, inhibits FSH,
In pregnancy increase flexibility of pubic symphysis, dilates uterine cervix
Testes (testis) 2
Secrete testosterone
Secrete inhibin, inhibits FSH
pineal gland
Secretes melatonin
contribute to biological clock
potent antioxident
Eicosanoids
prostaglandins and leukotrienes
inflammatory
NSAID inhibits COX enzymes responsible for prostaglandin synthesis
Pancreas cycle
Hypoglycemia -> alpha cells secrete glucagon ->
glycogen to glucose, stimulates gluconeogenesis -> raises glucose levels in blood
Hyperglycemia -> beta cells secrete insulin ->
slows glucagon, facilitates glucose diffusion into cells, lowers glucose levels in blood
glucagon also stimulated by sympathetic nervous
Posterior pituitary development
neurohypophysis from outgrowth of hypothalamus called
neurohypophyseal bud
Anterior pituitary development
outgrowth of roof of mouth Rathke’s (hypophyseal) pouch
produced in salivary gland
stimulates proliferation of epithelial cells, fibroblasts, neurons, astrocytes
suppresses some cancer cells & secretion of gastric juices by stomach
Epidermal Growth Factors
Produced in blood platelets
stimulates proliferation of neuroglia, smooth muscle fibers, fibroblasts
appears to have a role in wound healing
may contribute to atherosclerosis development
Platelet Derived Growth Factor
Found in pituitary and brain
stimulates proliferation of many cells derived from embryonic mesoderm - fibroblasts, adrenocortical, smooth muscle, endothelial
stimulates formation of new blood vessels - angiogenesis
Fibroblast Growth Factor
Produced in submandibular (salivary) glands and hippocampus
stimulates growth of ganglia in embryo
maintains sympathetic nervous system
stimulates hypertrophy and differentiation of neurons
Nerve Growth Factor
Produced by normal and tumor cells
stimulate growth of new capillaries, organ regeneration, wound healing
Tumor Angiogenesis Factor
Produced by various cells as separate molecules
TGF-alpha has activities similar to EGF
TGF-beta inhibits proliferation of many cell types
Transforming Growth Factor
