Posterior Pituitary, Thyroid, Repro, GI Flashcards
What are the two hormones stored in the posterior pituitary
ADH (antidiuretic hormone) and Oxytocin
what is the part of the hypothalamus that produces ADH
supraoptic nucleus
what is the part of the hypothalamus that produces Oxytocin
Paraventricular nucleus
what is vasopressin
ADH
what is the function of ADH
initiates water reabsorption in the kidneys, increases blood pressure
what causes increased ADH secretion
sweating, nicotine, sleeping
what causes decreased ADH secretion
alcohol, caffeine, drinking lots of water
what is caused by low ADH levels
diabetes insipidus
What is the function of Oxytocin
causes uterine contraction, contraction during orgasm, milk let down
what is unique about the oxytocin regulation system
it is a positive feedback system
where is the pineal gland, and what does it do
it is part of the epithalamus, and it produces melatonin from seratonin.
what is the function of melatonin
it helps regulate circadian rhythm, anti-oxidant, inhibits reproductive function (via inhibiting GnRH)
what is the problem caused by pineal tumors which cause low melatonin
precocious puberty (early puberty)
What is the anatomy of thyroid follicles
a wall of simple cuboidal epithelium, a cavity of viscous colloid. surrounded by capillaries
what is the synthesized by thyroid follicles and stored in the colloid of them
thyroglobulin (globular protein)
what is thyroglobulin
a globular protein synthesized and stored in thyroid follicles that contains tyrosine, which is the main building block of thyroid hormones
What are the thyroid hormones
thyroxine (T4) (tetraiodothyronine)
triiodothyronine (T3)
what is caused by a lack of dietary iodine
endemic goiter
what are the target cells of thyroid hormones
most cells in the body
what does it mean that thyroid hormones have a calorigenic effect
they produce heat
what are the functions of thyroid hormones
- increases oxygen use and energy use
- increases heart rate and contraction force (high bp)
- increased sensitivity to sympathetic stimulation
- helps sensitivity of respiratory centers to concentration
- stimulate erythropoeisis
- stimulates endocrine activity
- accelerates mineral turnover in bone
What does hyperthyroidism (thyrotoxicosis) cause
high metabolic rate, weight loss, hyperactivity, always hot, tachycardia, (graves disease - exopthalmos)
what is hashimoto thyroiditis
hypothyroidism leading to low metabloic rate, weight gain, fatigue, feeling cold
what is myxedemia
sever hypothyroidism in adults - apathy, slugishness, cold, obese
what is cretinism
extreme hypothyroidism in children - retardation, short stature, protruding tongue
what is calcitonin
hormone produced by C (parafollicular) cells, that decreases blood calcium and causes calcium uptake in the bones, and stimulates Ca excretion from the kidneys
what are the parathyroid glands
four small glands on the posterior of the thyroid gland that produce the parathyroid hormone
what is parathyroid hormone
a hormone produced in the parathyroid (chief) cells that increases osetoclast activity, increases blood calcium, reabsorption of Ca in the kidneys, stimulates calcitrol from the kidneys (antagonist to calcitonin)
What is caused by hyperfunction of the parathyroid
osteoporosis, kidney stones, depression
what is caused by hypofunction of the parathyroid
low blood calcium - muscle cramps, numbness, tetanus, mood swigns
which organs have secondary endocrine functions
gonads, intestines, kidneys, heart, thymus, and adipose
what are the hormones produced by the ovaries
estrogens, inhibin, and progestins
what are estrogens
hormones produces by ovarian follicular cells that stimulate follicle maturation, secondary sex characteristics, and behaviors
What is ovarian inhibin
a hormone produced by the follicular cells that targets the pituitary gland and inhibits FSH secretion
what are progestins
hormones produced by the corpus luteum that target the uterus and mammary glands. they prepare the uterus for implantation, and mammary glands for secretion
What are the hormones produced by the testis
androgens and inhibin
what are androgens
hormones produced by the interstitial cells of the testis that target most cells and cause the maturation of sperm, secondary sex characteristics, and synthesis of skeletal muscle
what is testicular inhibin
a hormone produced by the nurse cells of the testis that targets the pituitary gland and inhibits FSH secretion
what can excess androgens cause
hirsutism or hypretrichosis (excessive hair growth)
what are problems with anabolic steroid use
liver damage, jaundice, fluid retention, high blood pressure, increased cholesterol, shrinking of testis, baldness, boobs, infertility, stunted height, severe acne
what are the hormones of the intestines and what do they do
secretin, gastrin, cholecystokinin. they coordinate digestive activities
what are the hormones produced by the kidneys
Erythropoetin, calcitrol, and renin
what is the action of erthyropoetin (EPO)
causes blood vessel constriction and increased RBC production in red bone marrow
what is the action of calcitrol
calcium release from bone, inhibition of parathyroid hormone
what is the action of Renin
stimulates the renin-angiotensin system
(renin - angiotensin 1 - angiotensin 2 = aldosterone and ADH) decreases water loss, stimulates thirst, increases blood pressure
what are the hormones of the heart
natriuretic peptides (ANP - atrial) BNP - brain
what stimulates the heart to release natriuretic peptides
increased blood volume/stretching of the heart
what do natriuretic peptides of the heart do
increase water and salt loss at kidneys
decrease thirst
supress ADH and aldosterone secretion
What is the thymus
an organ that atrophies at puberty, but produces thymopoeitin and thymosins in youth
what do thymopoietin, and thymosins do
coordinates and regulates immune responses
what hormone does adipose secrete and what does it do
leptin, it targets the hypothalamus and causes suppression of appetite and increased gonadotropin synthesis
