Phys Unit 2 - Endocrine 2

class of steroid hormones with 19 carbons

androgens

class of steroid hormones with 21 carbons

pregnane (progesterone)

class of steroid hormones with 18 carbons

estranes

symptoms of hyperthyroidism

high BMR, agitation, irritability, emotional instability, insomnia, too hot, exophthalmos

actions of thyroid hormone

heat production, metabolism, linear bone growth, nervous system development, epidermal growth & turnover

symptoms of hypothyroidism

low BMR, lethargy, excessive sleep, low energy, slow speech, slow thought, slow reaction time, feeling cold, dry skin, brittle hair and nails

What happens during step 7 of thyroid hormone synthesis?

THs released & carried by binding proteins to tissues

What happens during step 6 of thyroid hormone synthesis?

diffusion from follicle to capillary (enters bloodstream)

What happens during step 5 of thyroid hormone synthesis?

lysosomal digestion

What happens during step 4 of thyroid hormone synthesis?

tyrosine coupling reaction

What happens during step 3 of thyroid hormone synthesis?

iodide converted to iodine via TPO

What happens during step 2 of thyroid hormone synthesis?

diffusion of iodine into small follicular cells

What happens during step 1 of thyroid hormone synthesis?

increased sodium/iodide system activity

Fatigue

Decreased ability of a fiber to produce tension despite continued stimulation

Role of the hypothalamus

"master gland" - secretes releasing and inhibiting hormones

PVN

paraventricular nucleus

SON

supraoptic nucleus

Anterior Pituitary

adenohypophysis

posterior pituitary

neurohypophysis

Pituitary blood supply

superior and inferior hypophyseal arteries

anterior lobe

pars distalis

system that allows hypothalamus to send hormones to pituitary

hypophysial portal system

most portal vessels

unidirectional, long

minority of portal vessels

bidirectional, short

ACTH

corticotropin

LH & FSH

gonadotropins

TSH

thyrotropin

GH

somatotroph

Prolactin (PRL)

lactotroph

anterior pituitary secretes

stimulating hormones

SON produces

vasopressin (ADH)

PVN produces

oxytocin (OT)

carrier protein for oxytocin

Neurophysin I

carrier protein for ADH

Neurophysin II

how viruses get into CNS

axoplasmic transport

clusters of granules of hormones

herring bodies

how hormones are released

stimulus-secretion coupling

stores oxytocin and ADH

posterior pituitary

secretes stimulating hormones or mature hormones

anterior pituitary

endocrine role of hypothalamus

secrete RH and IH

neural role of hypothalamus

send axons with granules of hormones for storage to posterior pituitary

pars nervosa

posterior pituitary

continuous but random

neural firing pattern for oxytocin

two major effects of oxytocin

milk letdown and uterine contractions

the love and bonding hormone

oxytocin

firing pattern for AVP/ADH

rhythmic bursts

major role of AVP/ADH

homeostatic control of ECF volume

NA+ decreases, H2O increases

ECF osmolarity decreases

ECF osmolarity decreases

ADH levels decrease

NA+ increases, H2O decreases

ECF osmolarity increases

ECP osmolarity increases

ADH levels increase

ADH levels increase

urine is hypertonic, low volume

ADH levels decrease

urine is hypotonic, high volume

plasma osmolarity is greater than 280 mOsm/kg

ADH/AVP secretion rises

responsible for 90% of osmotic activity

Na+ (sodium)

baroreceptor locations

aortic arch, carotid sinus, left atrium

CNS depressants (alcohol)

Decrease ADH

CNS stimulants (nicotine, caffeine)

increase ADH

BP increased via arteriole smooth muscle contraction

Pressor Effect

decreased urinary output

antidiuretic effect

hypotonic urine, high urine volume, polydipsia, low ADH level

diabetes insipidus symptoms

continuous ADH release, hyponatremia and water retention

Inappropriate Vasopression Secretion symptoms

direct actions of growth hormone (GH)

increased carbohydrate metabolism, lipolysis, and protein synthesis (diabetogenic)

indirect actions of GH

Operate through IGFs (insulin-like growth factors)

skeletal effects of GH

linear bone growth & cartilage proliferation at growth plates

Excess GH in children

gigantism

Excess GH in adults

Acromegaly

Lack of GH in childhood

short stature (dwarfism)

prolactin inhibitor

dopamine

effect of TRH

increased TSH secretion in anterior pituitary

function of TH binding proteins

prolong half-life of THs

location of thyroid hormone synthesis

small follicular cells of thyroid

location of calcitonin synthesis

large follicular cells (c-cells)

function of colloid space

storage of thyroid hormones

function of calcitonin

decrease serum calcium

fuction of parathyroid hormone

increase serum calcium

vitamin D function

increase calcium absorption in the gut

parathyroid hormone secreting cells

principle cells

parathyroid hormone target tissues

bones, kidney, gut

parathyroid antagonist

calcitonin

stimulus for calcitonin secretion

increased blood calcium levels

calcitonin effect on kidneys

increase calcium excretion in urine

calcitonin effect on bones

reabsorption of calcium for storage

types of osteoporosis

postmenopausal and senile

catecholamines

epinephrine and norepinephrine

location of catecholamine synthesis

adrenal medulla

these cells contain granules, adenine nucleotides, proteins, and lipids

chromaffin cells

epinephrine main role

acts as a hormone

norepinephrine main role

acts as a neurotransmitter

specific catecholamine storage protein

chromogranin

enzyme needed to get from dopamine to norepinephrine

dopamine beta hydroxlase (DBH)

enzymes that catabolize catecholamines

COMT and MAO

localization of COMT

cytosol of target tissues

localization of MAO

mitochondria of nerve terminals

cholinergic receptors

nicotine and muscarinic

cholinergic agent that stimulates skeletal muscle

nicotine

cholinergic agent that stimulates smooth muscle

muscarine

blocks muscarinic receptors

atropine

receptors that bind norepinephrine and epinephrine

adrenergic receptors

adrenergic receptor type that regulates smooth muscle contraction

alpha ARs