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Anat and Phys 4
Endocrinology
87
Anatomy
Undergraduate 2
05/05/2010

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Cards

Term
Difference between Neural and Hormonal responses?
Definition
  • neural has a rapid and precise response
  • Hormonal is a for a response that requires duration
Term
What defines a hormone?
Definition
  • long distance chemical mediator transported through the blood
  • secreted by endocrine glands
  • bind to target cell receptors
Term
Mechanisms of intracellular communication?
Definition
  1. Direct communication - gap junctions
  2. Paracrine - local hormones within tissue(NO Blood)
  3. Endocrine - Hormonal messengers through blood (one tissue to another)
  4. synaptic - neural communication through release of NT's
Term
A major difference between NT's and hormones is that hormones are secreted.....?
Definition
into the blood
Term
2 types of glands and their differences?
Definition
  1. Exocrine - use ducts to send chemicals like gastric secretions and bile (nonhormonal)
  2. Endocrine - secrete chemicals into the ECF to get picked up by lymphatic ducts or vascular rich surrounding tissue
Term

Major Endocrine Glands?

Partly endocrine?

Definition

Major = pineal, pituitary, thyroid, parathyroid, pancreas, adrenal, ovary, testis

 

Partly = hypothalamus, liver, thymus, heart, kidney, stomach, duodenum

Term
Regulatory effects of Endocrine glands? 6 effects?
Definition
  1. organic metabolism
  2. water/salt balance
  3. stress coping
  4. smooth growith and control of development
  5. Regulate RBC production
  6. control digestion, circulation and absorption of nutrients
Term
If hormones are circulated in the bloodstream how do they only affect a select population of cells in the body?
Definition
It depends which cells have the receptor cells on them.
Term
2 types of hormone classified by type of target?
Definition

Tropic - regulates production of another hormone

Non-tropic - directly stimulate target cells to induce effects.

Term
3 chemical classes of hormones?
Definition
  1. peptides and proteins
  2. Amines
  3. steroids
Term
peptides and Proteins are?
Definition
  • specific chain of AA's (most common)
  • Hydrophilic and lipophobic
  • soluble in water not lipids
Term
Amines are?
Definition
  • Derived from Tyrosine from adrenal medulla (NE and E)
  •  hydrophilic, lipophobic
  • Exception - thyrocrine is lipid soluble and hydrophobic and transported via carrier proteins
Term
Steroids are?
Definition
  • derived from cholesterol
  • some from adrenal cortex (aldosterone, cortisol)
  • others from sex organs (testosterone, estrogen, progesterone)
  • hydrophobic and lipophilic
Term
5 Mechansims/Actions of horomes?
Definition
  1. change membrane permeability of ions
  2. cause protein synthesis
  3. activate/deactivate enzymes
  4. induce secretion
  5. stimulate mitosis
Term
Actions of hydrophilic Hormones?
Definition
  1. bind to target cell receptor
  2. G protein is activated
  3.  activates effector (adenylate cyclase) to produce enzyme
  4. which is 2nd messenger cAMP
  5. cAMP then activates protein kinase
  6. activated kinase can activate enzymes, secrete hormones, stimulate mitosis, etc.
Term
Amplication effect is?
Definition
  • hundreds of final product molecules can be generated from 1 hormone
Term
how do we turn off the effects of hydrophilic action?
Definition
  • phosphodiesterase, an intracellular enzyme, can break down cAMP to deactivate kinase and stop response
Term
lipophilic hormone postreceptor action?
Definition
  1. hormones diffuse through membrane and bind with inracellular receptors
  2. hormone-receptor complex reaches chromatin in nucleus and prompts transcription of mRNA
  3. translation by cytoplasmic ribosomes produce end products
  4. could be enzymes, proteins for export, etc.
Term
interaction with a membrane bound receptor will transduce the hormonal message via....?
Definition
a second messenger
Term
treatment of a hormones target cell with a phosphodiesterase will result in...?
Definition
prolonged cell activity
Term
3 factors that affect probability of hormone interaction
Definition
  1. number of receptors
  2. hormone concentration
  3. binding affinity
Term

increase in hormone will... probability of binding?

increase in # of receptors will...probability of binding?

decrease attraction between hormone and receptor will.... prob. of binding?

Definition

increase

increase

decrease

Term
if target cell is producing a low level of hormone it could increae the amount of ........ on it or increase?
Definition

receptors

amount of endocrine cells

Term
endemic goiter results from .... deficiency?
Definition
iodine
Term
steroid and thyroid hormones circulate in the blood much longer becuase?
Definition
<1% circulates in the blood freely, and most attach to carrier proteins disallowing them to be degraded.
Term
pituitary gland has two lobes? Name and Function?
Definition
  • Anterior pituitary - NO neural tissue, ENDOCrine Tissue that produces 6 hormones.  release is controlled via hypothalamus which releases hormones to allow or inhibit hormone secretion
  • Posterior pituitary -  NEUral Tissue, stimulated by hypothalamus to secrete 2 hormones; oxycotin, and ADH.
Term
Cortex of adrenal gland has 3 layers? each layer produces what hormones?
Definition
  • zona glomerulosa = mineralocorticoids - mineral, water, and salt balance
  • zona fasciculata = glucocorticoids - metabolism
  • zona reticularis = gonadocorticoids - sex hormones
Term
adrenal medulla has what cells? that produce?
Definition

chromaffin cells that secrete catecholeamines into blood.

80% E and 20% NE

Term

mineralocorticoids?

hyper or hyposecretion caused by?

Definition

water and salt balance

primarily Aldosterone

  • hyper - caused by too much aldosterone production causes hypertension, edema, loss of K+
  • hypo - addison's disease
Term

glucocorticoids?

hyper and hypo?

Definition

regulate metabolism

blood sugar levels and BV

  • primary hormone is cortisol
  •  hyper - inhibits inflammtion and depresses cartilage and bone formation
  • hypo - addison's disease
Term

gametogenesis?

spermatogenesis?

oogenesis?

Definition
  • requires both mitotic and meiotic divisions of germ cells
  • S - spermatogonium (2n) to spermatozoa (1n)
  • O - oogonium (2n) to ovum (n)
Term

what is the sex determining gene? which sex does it create?

which chromosome?

Definition
SRY gene on the Y chromosome creates a male
Term
alternative terminology for wolfian duct and mullerian duct? what duct belongs to which sex?
Definition

W = mesonephric M = paramesonephric

wolfian duct belongs to males and mullerian to females

Term
MAle sex differentiation sequence?
Definition
  • SRY gene encodes for Testis determining Factor(TDF)
  • leydig and sertoli cells act as receptors for human chrionic gonadotropin (HCG)
  • leydig cells produce testosterone
  • sertoli cells produce mullerian inhibiting hormone
  • Therefore the wolfian duct develops into the vas deferens and the mullerian duct degenerates
Term
Female sex differentiation?
Definition
  • No SRY gene so TDF so no testosterone of MIH
  • cortex develops into ovary = estrogen
  • mullerian duct develops into uterine tube (fallopian)
  • wolfian duct degenerates
Term

what induces the formation of the male reproductive tract?

what hormone doesnt induce the formation of the reproductive tract?

Definition

androgens and MIH

estrogen

Term
if estrogen did induce sex differentiation then what would happen to all fetuses when the mother produces lots of E2 in pregnancy?
Definition
they would all be feminized
Term
what causes the testes to not descend in some people?
Definition
reduced production of MIH, fails to degenerate mullerian duct (cryptorchidsm)
Term

formation and differentiation of sex hormones?

what enzyme creates estradiol? dihydrotest?

Definition

cholesterol to progesterone to testosterone

then

dihydrotestosterone or estradiol

 

aromatase and reductase

Term
what is probably the primary sex organ?
Definition
the brain
Term
whats the difference between the pre-optic area in males and females
Definition
  • MAles - T can enter and be transformed into Estrogen which then goes to the hypothalamus and releases other hormones producing a Tonic pattern of neural signaling
  • Females - E2 can't enter the POA and therefore no estrogen can affect the hypothalamus so it produces a pulsatory pattern of neural signaling
Term
what establishes the male brain and waht does it affect?
Definition
estrogen  and it affects behavior and release of hormones
Term
what initiates puberty?
Definition
adrenal cortex (gonadocorticoids)
Term
what muscle controls testicle depth?
Definition
cremaster muscle
Term
each germ cell = # of gametes?
Definition
4
Term
function of sertoli cells?
Definition
  1. nourish sperm cells
  2. phagocytize dead cells
  3. secrete inhibin
  4. use ABP (androgen binding protein)
  5. secrete luminal fluid
Term

negative feedback mechanism

Role of T?

role of sertoli cells?

Inhibin?

ABP?

Definition
  1. T produced by leydig cells - stimulates sertoli cells to increase spermatogenesis.  inhibits release of LH from pituitary and gonadotropin releasing hormone from hypothal.
  2. SC - produces inhibin and stimulates spermatogenesis
  3. I - inhibits FSH secretion by pituitary
  4. ABP - concentrates T for sertoli cells
Term
effects of T?
Definition
  • enhances synthesis of proteins in target cells
  • development and maintenance of male reproductive organs
  • skin, hair, libido
Term
effects of anabolic steroids?
Definition
negative feedback to produce inhibin and excess testosterone to stop LH FSH and GRH horomes to reduce sperm count
Term
composition of semen?
Definition

5% sperm

95% fluids

Term
physiology of an erection, which system causes it?
Definition
parasympathetic activity dilating arterioles allowing erectile tissue to fill with blood
Term

what triggers erection?

summary of chemical events?

Definition

spinally mediated through thoughts and mechanoreceptors in tip of penis

  • increase in NO triggers cGMP which maintains vasodilation
  • phosphodiesterase breaks down cGMP which stops erection
Term
what is the main component of viagra?
Definition
phosphodiesterase inhibitors
Term
life span of sperm? how do they die?
Definition

4-6 days

low pH of vagina, phagocytosis by uterus

Term
fate of ovum life span? where does fert occur?
Definition

24 hours

in the distal 1/3 of the oviduct

Term
regions of uterine tube?
Definition
  • infundibulum - closest to ovary, have fimbriae
  • ampulla - site of fertilization
  • isthmus - connects to uterus, moves egg down by peristalsis
Term
why is it easier for sexually active teens to get an STD?
Definition
becuase their vaginal wall isn't producing acidic secretions yet.  doesnt kill bacteria
Term
how many ova are released on average in a reproductive life
Definition
400-500
Term
cell types of follicle and what do they secrete?
Definition
  • granulosa - secrete inhibin and estrogen
  • Theca - secrete androgens
Term
2 cell 2 gonadotropin mechanism (for women)?
Definition
  • FSH initiates Cholesterol conversion to testosterone in theca cells
  • T transferred to to granulosa cells where it is converted into Estradiol by aromatase (supplied by LH).
  • LH also produces inhibin which stops production of FSH and increases LH
  • follicle continues growth
Term
What causes puberty in female?
Definition
hypothalamus becomes less sensitive to estrogen therefore it is no longer inhibited and starts to release GnRH.  This starts secretion of LH and FSH by pituitary and starts follicle growth
Term

early follicular phase?

mid follicular phase?

late follicular phase?

Definition
  • LH and FSH start to increase, group of follicles begin growth
  • dominant follicle selected, increase of estrogen and inhbin causes decrease of FSH(less T made)
  • high E2 levels induce pituitary to produce a LH surge.  increase GnRH and LH while FSH is still inhibited by inhibin
Term
effects of LH surge?
Definition
  • rupture of graafian follicle
  • ovulation
  • theca and granulosa cells transformed into corpus luteum
Term
what does corpus luteum secrete? what does it cause?
Definition
  • progesterone and small amounts of estrogen
  • causes no new follicles to develop
Term
what kills corpus luteum?
Definition
eventually LH reaches levels that can't support CL
Term
estrogen and progesterone effects on cervix?
Definition
  • estrogen alone makes mucus plug thin and watery to allow sperm entrance
  • progesterone makes mucus plug thick so no bacteria can get into the uterus to affect reproduction
Term
what if pregnancy occurrs? why do periods not continue?
Definition
  • the corpus luteum will remain active for around 3 months continuing to produce estrogen and progesterone until placenta can take over to produce lots of hormones
  • continued by HnCG
Term
wht hormone is used to detect pregnancy?
Definition
  • hCG - becuase it begins secretion about 1-10 days after fertilization and continues for about 3 months.
Term
Thyroid gland has two cell types? what hormones do they produce?
Definition
  • follicular - produce thyroglobulin that combines with iodine to produce 4 different throid hormones (T1, T2, T3, T4)
  • parafollicular - produces calcitonin
Term
difference between T3 and T4?
Definition
amount of iodine molecules attached
Term
  • what does TH do?
Definition

concerned with:

-glucose oxidation

-increasing metabolic rate

-heat production

for:

- developing skeletal and nervous systems, BP, Reproduction, tissue growth

Term
synthesis of thyroid hormone?
Definition
  1. thyroglobulin enters lumen of follicle
  2. iodide is converted into iodine in the follicle cells and secreted into lumen
  3. iodine attaches to thyroglobulin to form T1 or T2.
  4. then tyrosines are linked together to form T3 and T4.
  5. enter lysozomes and are cleaved from thyroglobulin colloid and hormones diffuse into bloodstream.
Term
transport and regulation of TH?
Definition
  • bind to TBG (thyroglobulin binding protein) produced by liver
  • T3 is 10 ten times more active than T4
  • peripheral tissue cells regulate conversion from T4 to T3
Term
why doesn't T3 just only get produced?
Definition
becuase the peripheral cells can self regulate and do a much better job maintaining homeostasis than the production of  a lot of one very active hormone
Term
where is calcitonin produced? what does it do?
Definition
  • parafollicular cells
  • lowers blood Ca levels - important in bone growth
  • antagonist to Parathyroid hormone
Term
how does it work? regulated?
Definition
  • reduces osteoclast activity (which degrades bone to increase Ca)
  • increases reabsorption of Ca into bone matrix
  • regulated by Ca ion concentration in blood, neg. feedback mech.
Term
what cells secrete PTH? PTH does what? what inhibits it?
Definition
  • chief cells in parathyroid gland
  • regulates [Ca] in blood
  • stimulates osteoclast activity
  • increase Ca reabsorption by kidneys and intestinal mucosa
  • PTH inhibited by high levels of Ca in blood
Term

calcitonin ... importance in adults?

PTH ... importance in adults

Definition

loses

gains

Term

Pancreas acinar cells secrete?

2 islet cells? secrete what?

which are endo or exorine

Definition
  • digestive enzymes (exocrine)
  • endocrine below>>
  • alpha - secrete glucagon
  • beta - secrete insulin
Term

purpose of glucagon: it promotes?

glycogenolysis?

glycogenesis?

Definition
  • production of glucose in liver
  • - conversion of glycogen to glucose
  • - formation of glucose from noncarbohydrates and lactic acid
Term
purpose of insulin?
Definition
  • lowers blood glucose levels by enhancing transport of glucose into cells
Term
after glucose enters a cell insulin binding triggers?
Definition
  • oxidation of glucose for ATP production
  • transforms glucose to glycogen
  • converts glucose to fat

 

Term
what happens if hyper or hypoglycemic?
Definition
  • hyper - pancreas releases insulin which stimulates the polymerization of glucose to glycogen which lowers the blood glucose level
  • hypo - pancreas releases glucagon which causes the break down of glycogen to glucose increasing the blood glucose levels
Term
results of short term and long term stress on adrenal gland?
Definition
  • short - increased BP/HR, dilation of bronchioles, glycogen to glucose, ^ metabolic rate ( release NE and E)
  • long term - retention of water and salt, increased glucose, increased BV/BP, suppression of immune system (release Glucocorticoids, mineralocorticoids
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