Shared Flashcard Set

Details

Physiology
Endocrine
99
Medical
Graduate
11/08/2009

Additional Medical Flashcards

 


 

Cards

Term
What is normal fasting plasma glucose? For DM?
Definition
<100 mg/dL, 5.6 mmol/L; >126 mg/dL, >7.0 mmol/L
Term
What are symptoms of hyperglycemia?
Definition
polyuria, glycosuria, polydipsia, dehydration
Term
What are symptoms of starvation?
Definition
weight loss, wasting, weakness (breakdown of fats and proteins, particularly in IDDM)
Term
What are symptoms of ketoacidosis?
Definition
lipolysis-->+ FFA-->ketoacidosis (in IDDM)
Term
What are the complications of diabetes?
Definition
+F-->atherosclerosis-->ischemia in brain, heart, kidneys, legs

+F-->microvasucular disease: retina (retinopathy), kidneys (nephropathy), peripheral nerves (peripheral neuropathy), brain
Term
What are the sensorimotor problems associated with diabetic neuropathy?
Definition
muscular: muscle weakness, atrophy, ataxic gait
sensory: pain, paresthesia, numbness, paralysis, cramping, falls
Term
What are the cardiovascular problems assoicated with diabetes?
Definition
exercise intolerance, fatigue, sustained HR, syncope, dizziness, lightheadedness, balance
Term
GI complications of diabetes?
Definition
dysphagia, bloating, nausea and vomiting, diarrhea, constipation
Term
GU complications of diabetes?
Definition
loss of bladder control, UTI, urinary frequency or dribbling, erectile dysfunction, loss of libido, dyspareunia, vaginal dryness, anorgasmia
Term
Sudomotor complications of diabetes?
Definition
pruritis, dry skin, limb hair loss, calluses, reddened areas
Term
Endocrine complications with diabetes?
Definition
hypoglycemic unawareness
Term
some other general complications associated with diabetes?
Definition
difficulty driving at night, depression, anxiety, sleep disorders, cognitive changes
Term
What does glucagon do?
Definition
increase glycogenolysis, increase gluconeogenesis, increase lipolysis, and increas ketoacid formation
Term
How does GH increase blood glucose?
Definition
reduces insulin sensitivity
Term
How does EPI increase blood glucose?
Definition
responds to stress, inhibits insulin secretion
Term
HOw does cortisol increase blood glucose?
Definition
responds to stress, reduces insulin sensitivity
Term
Which hormones stimulate glycogenolysis and gluconeogenesis?
Definition
glucagon, GH, EPI, and cortisol
Term
FSH acts on what cells in the testis?
Definition
Sertoli
Term
LH acts on which cell of the testis?
Definition
Leydig
Term
Explain why testosterone has both endocrine and paracrine effects?
Definition
it effects both target cells and neighboring Sertoli cells
Term
What is the specific action of LH at the level of Leydig cells?
Definition
increases cholesterol desmolase activity (cholesterol to pregnenlone)
Term
What are the 4 androgens secreted by Leydig cells
Definition
 testosterone
DHT
 androstenedione
 dehydropiandrosterone (DHEA)
Term
What enzyme converts testosterone to DHT?
Definition
5 alpha-reductase
Term
What are the effects of testosterone?
Definition
fetal differentiations of epididymis, vas deferens, seminal vescicles; development of muscle, pubertal growth spurt, epiphyseal closure, growth of penis, seminal vesicles, deepening voice, spermatogenesis, libido, negative feedback on pituitary
Term
What are the effects of DHT?
Definition
fetal differentiation of penis, scrotom, and prostate; male hair pattern and baldness; sebaceous gland activity; prostate growth
Term
How are primordial germ cells produced?
Definition
by mitotic division until gestational week 20-24: 7 million oogonia
Term
How are primary oocytes produced?
Definition
from about weeks 8 to 9, some oogonia enter meiosis and become primary oocytes
completed by about 6 months after birth
 oocyte attrition
• birth-2 million oocyte
• puberty-400K oocytes
• menopause-0 oocytes
Term
What is the first stage of follicle development?
Definition
 primary oocyte grows
• granulose cell proliferation-nurtures oocyte, produces hormones
• primordial follicle develops into a primary follicle
• no progression beyond this first stage before puberty
Term
What is the second stage of follicle development?
Definition
 takes place over 70-85 days
 occurs only during reproductive period
 during each menstrual cycle, a few follicles enter this stage, develop a cavity around ovum-antrum formation
• fluid containing steroid hormones and FSH in addition to other proteins and muccopolysaccharides accumulates in the central area
 granulose cells and theca cells continue to grow
Term
What is the third state of follicle development?
Definition
 takes 5-7 days after menses
 one follicle becomes dominant over the other follicles
• non-dominant follicles regress
• dominant follicle grows to 20 mm in diameter
 Day 15 of a 28 day menstrual cycle-ovulation occurs
• dominant follicle ruptures (corpus hemorrhagicum)
• releases oocyte into peritoneal cavity
Term
What happens after ovulation in the peritoneum and fallopian tube?
Definition
 Peritoneum and fallopian tube
• 1st meiotic division is completed
• 2nd oocyte enters fallopian tube and begins 2nd division
o 2nd meiosis completes if fertilized
Term
What happens in the ovary after ovulation?
Definition
• residual elements of ruptured follicle (Graafian follicle) form corpus luteum

o primarily granulosa cells, theca cells
o synthesizes and secretes steroid hormones needed for implantation and zygote maintenance
o Fertilization: continues hormone secretion until placenta takes over
o No fertilization: regresses during the next 14 days get corpus albicans
Term
What controls the process leading up to ovulation?
Definition
 hormone control: GnRH (hypothalamus)FSH and LH (anterior pituitary)Theca cells (LH) and Granulosa cells (FSH) Theca cells (progesterone and testosterone) and Granulosa cells (converts testosterone into estradiol)
• steroid hormones
o estrogen
o progesterone
• pituitary hormones
o FSH
o LH
• hypothalamus
o GnRH
Term
What is the division of labor for theca cells?
Definition
 synthesize and secrete progesterone
 expresses 17-beta-hydroxysteroid dehydrogenase
 synthesize and secrete testosterone, an androgen
 under control of LH (stimulates cholesterol desmolase or side chain cleavage enzyme-->stimulates androgen
Term
What is the division of labor for granulosa cells?
Definition
 express aromatase
 converts testosterone to 17-beta-estradiol
 FSH stimulates aromatase
Term
What is the danger of continuous secretion of GnRH from the arcuate nucleus?
Definition
• crucial: continuous GnRH release leads to desensitization and down regulation-leads to inhibition of gonadotropin reelase
• continual stimulation of the pituitary leads to down regulation of the GnRH receptor and inhibition of LH and FSH synthesis and release by the pituitary
Term
What happens during the follicular phase?
Definition
o GnRH pulses are frequent with small amplitude
 estrogen at low levels inhibits GnRH (negative feedback)
 estrogen at higher levels stimulates GnRH (positive)
o **Inhibin from ovary attempts to inhibit FSH but spike in GnRH overrides the effects**
Term
What happens during the luteal phase?
Definition
o GnRH pulses are large but less frequent
o progesterone decreases frequency (negative feedback)
Term
What are the effects of LH in females?
Definition
 effects mediated by a LH receptor located on the theca cellsstimulates synthesis of androstenedione and testosterone
 required for the rupture of the dominant follicle (Graafian)
 induces expression of FSH receptor on the granulosa cells
Term
What are the effects of FSH in females?
Definition
 Effects mediated by a FSH receptor
 stimulates growth of developing follicles
 induces expression of LH receptors on theca and granulose cells
 regulates the activity of aromatase-stimulation of estradiol production
Term
What are the general effects of estrogen?
Definition
Maturation and maintenance of uterus, fallopian tubes, cervix, and vagina
Puberty, secondary sex characteristics
Proliferation of granulosa cells
Term
What are the general effects of progesterone?
Definition
Maintenance of secretory activity of uterus during luteal phase
Reduces estrogen proliferative effects on uterus
Term
What are the feedback effects of estrogen?
Definition
Negative and positive feedback regulation of FSH and LH
Term
What are the feedback effects of progesterone?
Definition
Negative feedback effects on FSH and LH
Term
What are the effects of estrogen and progesterone on pregnancy?
Definition
maintenance
Term
How does estrogen influence uterine contractions?
Definition
Lowers uterine threshold to contractile stimuli
Term
How does progesterone influence uterine contraction?
Definition
Raises uterine threshold to contractile stimuli to pregnancy
Term
How does estrogen effect the breast?
Definition
Blocks action of prolactin on the breast (inhibits milk production)
Term
How does progesterone affect the breast?
Definition
Stimulates transient breast epithelial proliferation-followed rapidly by growth arrest
Term
What are estrogens effects on bones?
Definition
• increase, maintenance of bone mass
• deficiency states lead to osteoporosis
• major effect on bone is to decrease osteoclast activity
• minor effect is to increase osteoblast activity
• estrogen replacement will prevent bone loss
Term
What are the effects of progesterone on temperature?
Definition
Increases body temperature: mid-cycle increase 1 degree, persists through cycle, alteration of CNS temperature regulatory center?
Term
Where are more ER alpha receptors found?
Definition
female reproductive tract, lung, brain, vasculature
Term
Where are more ER beta receptors found?
Definition
prostate, ovaries
Term
What does progesterone receptor A do?
Definition
act as a transcriptional inhibitor of other steroid receptors
 estrogen, glucocorticoids, androgen receptor activation is suppressed
Term
What does progesterone receptor B do?
Definition
mediates the stimulatory activities of progesterone
Term
What hormone output is highest during implantation
Definition
Progesterone from corpus luteum
Term
What is a trophoblast?
Definition
outer rim of cells of blastocyst that invades endometrium and secretes HCG at 8 days after ovulation
Term
What is the function of HCG?
Definition
 HCG rescues corpus luteum
• stimulates corpus luteum to continue to synthesize progesterone and estrogen to maintain the endometrium
 HCG levels are maximal at gestation week 9 and then decline
Term
What happens during the first trimester?
Definition
 Fetal development: most organs develop during the first trimester (sensitive period for chemically induced birth defects)
Term
What occur during the 2nd and 3rd trimester?
Definition
 placenta becomes producer of steroid hormones
 progesterone
• produced from maternally derived cholesterol
 Estrogen-required by mother, placenta, and fetus
Term
What are the roles of physical stimuli, estrogen, progesterone, and prostaglandins during delivery?
Definition
• physical: distension increases contractility
• estrogen/progesterone ratio increases
o increase uterine sensitivity to contractile stimuli
• Prostaglandins of E and F series
o increase uterine contractility
Term
What is the role of oxytocin?
Definition
o can stimulate uterine contraction but levels do not increase near term
o receptors for oxytocin are up regulated
o Stimulated by receptors on the cervix and the mammary gland
 stretching of the cervix stimulates oxytocin secretion
• stimulates frequency and force of contraction
 secreted as a response to suckling
• can also be a conditioned reflex
• stimulates milk ejection from the mammary gland
o acts via G-protein coupled receptors
Term
What are the three stages of labor?
Definition
• 1st: uterine contractions move head toward cervix, progressive widening and thinning of cervix
• 2nd: fetus forced through cervix and delivered through vagina
• 3rd: placenta separates from uterine tissue and is delivered (uterine contractions constrict uterine blood vessels and limit postpartum bleeding)
Term
What is the process of lactation?
Definition
o during pregnancy, estrogen and progestone stimulate growth and development of breast
o estrogen stimulates prolactin (PL) secretion: levels increase over course of pregnancy
 estrogen and progesterone block the action of PL on breast
o after parturition, estrogen and progesterone levels fall and their inhibitory effect o PL activity in breasts are remove
o lactation is maintained by suckling
 stimulates oxytocin and prolactin secretion
Term
What inhibits prolactin?
Definition
 dopamine D2 receptors on lactotropes when stimulated inhibit PL secretion
Term
What stimulates prolactin?
Definition
suckling,  TRH can stimulate release
 hypothyroidism can lead to hyperprolactinemia and galactorrhea
Term
Does PL inhibit GnRH?
Definition
yes, at levels such as that provided by lactation
Term
What does TRH stimulate?
Definition
TSH and Prolactin
Term
Does prolactin inhibit GnRH?
Definition
Yes
Term
What is the axis beginning at CRH?
Definition
CRH-->ACTH-->aldosterone (zona glommerulosa), cortisol (glucocorticoids), androgens (zona reticularis)
Term
What is the axis beginning at TRH and continuing with TSH?
Definition
TRH-->TSH-->T3 and T4
Term
What is the axis for GnRH and LH in females?
Definition
GnRH-->LH-->theca cells of follicle, rupture of follicle, estogen and progesterone
Term
What does dopamine do to prolactin?
Definition
It inhibits
Term
What is the GnRH and FSH axis in women?
Definition
GnRH-->FSH-->granulosa cells (aromatase-->estrogen), developing follicles
Term
What is the GnRH and LH axis in males?
Definition
GnRH->LH->Leydig (testosterone)->sertoli and target cells
Term
What is the GnRH and FSH axis in males?
Definition
GnRH->FSH->Sertoli cells (sperm maturation)
Term
What is the GHRH axis?
Definition
GHRH->GH->protein synthesis, organ growth, amino acid uptake, DNA and RNA synthesis, linear growth, insulin resistance: increased plasma glucose, lipolysis, and use of fat stores
Term
What is the connection between ACTH and MSH?
Definition
the more ACTH, the more MSH (increased pigmentation)
Term
What is the function of cortisol?
Definition
increases gluconeogenesis, vascular response to EPI and NE (alpha 1, beta 2); decreases inflammatory and immune response
Term
What are the effects of T3 and T4?
Definition
skeletal growth, oxygen consumption, heat, protein/carb/fat usage; CNS maturation
Term
What is the function of estradiol?
Definition
growth and development of sex organs, spikes LH for ovulation, inhibits prolactin secretion, maintains pregnancy
Term
Which hormones are secreted by the corpus luteum?
Definition
estradiol and progesterone
Term
How role does the suprachiasmatic nucleus play in sleep cycles?
Definition
light->retinohypothalamic tract->SCN->pineal gland and melatonin secretion decreases
Term
What does the arcuate nucleus do?
Definition
releases GHRH and GnRH
Term
What are the roles of the supraoptic and paraventricular nuclei?
Definition
release of ADH and oxytocin
Term
What receptor senses increased plasma osmolarity?
Definition
V2
Term
ADH in circulations acts via which receptor?
Definition
V1
Term
Cortisol has negative feedback on ___________.
Definition
ACTH and CRH
Term
What is IGF-1?
Definition
insulin-like growth factor, secreted in liver, acts like insulin, negative feedback on GH and GHRH
Term
What does somatostatin do?
Definition
inhibits cAMP, opposite of GH
Term
What does prolactin inhibit?
Definition
ovulation
Term
Panhyperpituitarism leads to _________.
Definition
amenorrhea (prolactin), gigantism or acromegaly (GH), infertility (LH,FSH), high cortisol (ACTH), hyperthyroidism (TSH)
Term
What does hypopituitarism do?
Definition
failure to lactate (PL), dwarfish (GH), gonadal insufficiency (LH,FSH), adrenal insufficiency (ACTH), hypothyroidism (TSH)
Term
What are the signs and symptoms of hyperthyroidism?
Definition
weight loss, excess heat, increased heart rate and contractility, afib, tremor, increased BMR, exophthalmos, goiter
Term
Signs and symptoms of hypothyroidism?
Definition
increased weight, lower heat, lower HR and CO, lower BMR, drooping eyelids, goiter
Term
What inhibits peroxidase activity?
Definition
PTU
Term
What are the signs and symptoms of Cushing disease?
Definition
high blood glucose, muscle weakness, atrophy, fatigue, bruising, fat distribution, poor healing, HTN
Term
Signs and symptoms or Addison's disease?
Definition
hypoglycemia, high ACTH (low ACTH if secondary adrenal insufficiency), skin darker (MSH), hypotension (low mineralocorticoid)
Term
What will pheochromocytoma do?
Definition
increase EPI and NE, HTN, tachycardia, glucose intolerance, HA, sweating, anxiety, tremor
Supporting users have an ad free experience!