Flashcards in Hormones table Deck (75):
What does the Hypothalamus secrete?
- Releasing hormones: TRH, GnRH, CRH, GHRH,
- Inhibiting hormones: Somatostatin, PIH (Prolactin inhibitory hormone...also called dopamine.
What is the chemical nature of all things released by the hypothalamus?
All peptides except for PIH (amine)
Major stimuli for secretion
What is released by the posterior pituitary gland?
Oxytocin and Vasopressin
Function of oxytocin
Let down breast milk by increasing the contractility of the myoepithelial cells, Uterine smooth muscle contraction
Function of vasopressin
Decrease water excretion, (aquaporins)
Increase contractility of smooth muscle which increases blood pressure
Major stimuli for vasopressin release?
Low plasma volume or high plasma osmlarity
What are the major hormones released by the Anterior Pituitary gland
Thyroid Stimulating Hormone
Follicle Stimulating hormone
Growth hormone is responsible for what?
- Growth, organic metabolism; secretion of somatomedin by liver and cartilage
Thyroid Stimulating Hormone does what?
Stimulates synthesis and secretion of thyroid hormones. Increases size of the thyroid gland.
Adrenocorticotrophic hormone does what?
Adrenal cortex (mainly increases in cortisol. Some increase in androgens and aldosterone)
Increases milk synthesis in the breasts, also stimulates breast development and inhibits ovulation
Leutenizing hormone does what
Stimulates testosterone synthesis on Leydig cells of the testes.
Stimulates ovulation, formation of the corpus luteum, estrogen and progesterone synthesis in ovaries
Follicle stimulating Hormone does qhat
Sperm maturation in the testis, follicular development and estrogen in the ovaries.
Which cell types in the anterior pituitary are classified as basophils
Everything except GH and PRL
GH and PRL are
What hormones are released by the adrenal cortex?
Adrenal Androgens (DHEA and adrostenedione)
All of the hormones released by the adrenal cortex are of what chemical nature?
Cortisol does what?
Stimulates gluconeogenesis; inhibits inflammatory response, suppresses immune response, enhances vascular response to catecholamines
Aldosterone does what
increases Na reabsorption in the kidneys, increases K secretion, inc H secretion
Adrenal androgens do what?
stimulate spermatogenesis and male secondary sex characteristics.
Just gonna do some actions for a while
What hormones does the Endocrine Pancreas secrete?
What is the main function of insulin?
insulin decreases blood glucose
glucagon increases blood glucose
What hormones are secreted by the placenta?
- Human Chorionic Gonadotropin (hCG)
- Human Placental Lactogen (HPL) or human chorionic sommatotropin
What does HCG do?
Stimulates Estrogen and Progesteronesynthesis in the corpus luteum of early pregnancy
What does HPL do?
Growth like and Prolactin like actions during pregnancy
What does Estradiol do?
stimulates growth and development of female repro system, follicular phase of menstrual cycle, development of breasts, prolactin; maintians pregnancy
What does Prgesterone do?
Stimulates the Luteal phase of the Menstrual cycle
What hormones are produced by the ovaries?
Estradiol and Progesterone
What hormones are produced by the Testis
Action of testosterone
stimulates secondary sex characteristics in the make, stimulates spermatogenesis
Adrenal cortex hormones?
ALdosterone does what?
increases renal Na absorption, K secretion, H secretion
Cortisol does what
stimulates gluconeogenesis, inhibits inflammation,
suppresses immune response, enhances vascular response to catecholamines
Tits getting bigger (branching of mammary ducts) is accomplished by what three hormones?
Prolactin, Estrogen, Progesterone
Add some PEP to her step.
During pregnancy, what three hormones contribute to enlargement of the mammary alveoli
Prolactin, Estrogen, Progesterone again
Major action of prolactin?
Inducing transcroption of the genes for milk production
Why do breasts not secrete milk during pregnancy?
(Milk production only occurs after the birth of the child)
Because Estrogen and Progesterone levels are very high and they down-regulate the number of Prolactin receptors. At birth though, Estrogen and Progesterone levels fall rapidly and Prolactin is free to bind so milk production begins
How does Prolactin prevent ovulation
inhibits synthesis and release of GnRH. This means that fertility is greatly reduced during breast feeding. Also means that males with a prolactinoma (the most common pituitary adenoma, will have infertility.
Prolactin secretion is inhibited by
What does T3 do to GH levels?
What 2 hormones are needed for spermatogenesis?
Testosterone and FSH....
Really requires 3 because you have to have LH for testosterone
Inhibin does what and is made where
reduces FSH, sertoli cells
Testosterone feeds back and inhibits LH
Testosterone also inhibits GnRH
Estrogen is a type of estradiol
Low Estrogen does what to FSH and LH
High LH and FSH. Leads to mid-cycle LH surge that causes ovulation
Very high E
inhibitory, used to be used as birth control
Very Low E + progesterone
Now used in BC
Does estrogen have an effect on female body configureation
yes....widening of hips, fat content and distribution
Estrogen's effects on the oviducts:
Oviducts: Grwoth of muscle and epithelium, motility, ciliary beating
Uterus: growth of myometrium, increased contractility, growth of endometrium, development of spiral arteries and blood supply
Progesterone's effect on uterine muscle
antagonizes estrogen...decreases contractions partly by downregulating the number of estrogen receptors
Lets talk about the actions of Cortisol
Overall, the metabolic effects of cortisol can be described with two words, they are
Catabolic and diabetogenic....Increases glucose synthesis
- Increases protein catabolism and decreases new muscle synthesis in order to provide new amino acids to the liver.
- lipolysis which provides glycerol to the liver for gluconeogenesis
- decreases glucose utilization bu tissues
- decreases insulin sensitivity in adipose tissue.
SO, in keeping with the adrenal as a stress gland, cortisol makes sense because it keeps blood glucose high during fasting.
Hypercortisolism (Cushing's) leads to what effect onb blood sugar
Low Cortisol (addison's dz) leads to what effect?
Cortisol and inflammation
- No precursors to prastaglandins or leukotrienes
- No IL-2 so no T cell prolif
- Inhibits histamine and serotonin
Immune response and Cortisol
Cortisol and blood pressure
Necessary for normal blood pressure. Upregulates alpha 1 receptors in arterioles. This makes it required for vasoconstriction
Hypocortisolism and blood pressure
Hypercortisolism and bp
Bone formation and Cortisol?
inhibited....no type 1 collagen
Increases awake time
What affect does thyroid have on GH
Increases GH synthesis
PTH encourages the kidneys to do what
Resob calcium and expell phosphate
PTH encourages bones to do what
mobilize calcium....remember our biggest storage area of calcium is the bone
Excessive intake of Vitamin D and ionized calcium
VIT D intoxication can lead to low calcium levels
Structure of ACTH
small single chain peptide hormone with no subunits
The only amine hormones are
dopamine, the two thyroids, and catecholamines
THYROID GOES UP DURING PREGNANCY WHY?
Increased thyroid binding lgobulins
Peptides are broken down by the GI tract and never reach the circulation
Amines and Steroids are succewsfully absorbed
What the fuck does Inhibin do in males?
STOPS FSH SECRETION from teh sertoli cells of the testis which decreases spermatogenesis. Fsh...Fucking...Sperm.