A&P Final Exam Flashcards
Adrenal Medulla
innervated by sympathetic neurons (Chromaffin cells)
Releases norepinephrine or epinephrine (small amounts of dop)
Causes increased:
BP, heart rate, blood flow to skelatal muscle, pulmonary air flow
Inhibits digestion and urination
Chromaffin cells
modified neurons - secretory cells that release into blood stream
adrenal cortex
Produces 25 steroid hormones (corticosteroids)
Categories of Corticosteroids
- mineralocorticoids: regulates electrolytes
- glucocorticoids - regulate metabolism of glucose
- sex steroid - repro. functions (androgens)
Zona glomerulosa (adrenal cortex)
secretes aldosterone in resp to blood Na content and angiotensin 2 from lungs
Increases reabsorption of Na+ and water in kidneys, maintains blood volume
Aldosterone
principle mineralocorticoid produced in zona glomerulosa
Zona Fasciculata and reticularis glucocorticoids
primarily secretes cortisol in resp to ACTH from anterior pituitary
Regulates metabolism by stimulating fat and protein catabolism, as well as as release of fatty acids and glucose into blood (makes nutrients available for ATP production)
Anti-inflammatory effects (steroid creams)
inhibits white blood cells and reduces release of histamine from mast cells, decreases capillary permeability
Androgens from Zona Fasciculata and reticularis
small amounts of androgens produced
Major androgen: dehydroepiandrosterone –> testosterone (large quantities produced in testes, so this is unimportant for males in this location; important for females (sex drive))
Estradiol (adrenal estrogen)
Estradiol
while ovaries produce much more than that derived from zona fasciculata and reticularis, helps to sustain bone mass after menopause
Pancreatic Hormone
1-2 million pancreatic islets producing hormones
clusters of endocrineccells
other 98% of organ produces digestive enzymes (exocrine)
Pancreatic Hormone
1-2 million pancreatic islets producing hormones
clusters of endocrine cells
other 98% of organ produces digestive enzymes (exocrine)
Pancreatic Islets
types of cells: alpha, beta, delta, PP (F), G
alpha cells
glucagon raises blood glucose levels by increasing rates of:
glycogen breakdown in skeletal muscle
glucose release by liver
fat breakdown in adipose
beta cells
insulin secreted after meal with carbohydrates raises glucose blood levels
stimulates glucose and amino acid uptake
nutrient storage effect (stimulates glycogen, fat, and protein synthesis)
stimulation of fatty acid absorption in adipocytes)
Delta Cells
produces somatostatin
inhibits GH (it’s GHIH)
secreted concurrently with insulin
may modulate secretion of alpha and beta cells
G cells
secrete gastrin which stimulates stomach secretions, motility, and emptying
PP (F) cells
produce pancreatic polypeptide (PP)
inhibits gallbladder contractions and regulates production of some pancreatic enzymes
Thrifty genotype
high rates of obesity
rapid production of insulin when food is ingested
permits body to lay down efficiently
may be adapted to environments characterized by feast and famine
Regulation of glucagon and insulin secretion
Low blood glucose stimulates release of glucagon
High blood glucose stimulates secretion of insulin
Corpus luteum
follicle after ovulation
produces estradiol and progesterone for 12 days or 8-12 weeks with pregnancy
Functions of estradiol and progesterone
development of female reproductive system and physique including bone growth
regulates menstrual cycle, sustains pregnancy
Preps mammary glands for lactation
interstitial cells of testes
exists between seminiferous tubules
produces testosterone and estrogen
functions of testes
development of male reproductive system and physique
Sustains sperm production and sex drive
Sustentacular sertoli cells (nurse cells)
secretes inhibin which suppresses FSH secretion and stabilizes sperm production rates
Heart
atrial natriuretic peptide (AMP) released in response to low BP by raising it
Skin
keratinocytes helps produce D3, first step in synthesis of calcitriol
Liver
converts vitamin D3 to calcidiol
source of IGF (insulin-like growth factor) that works with GH
secretes about 15% of erythropoietin
Secretes angiotensinogen
precursor of angiotensin 2 (vasoconstrictor) raises BP
Kidneys
converts calcidiol to calcitriol (active form of vit D)
incr. absorption by intestine and inhibits loss in urine
more Ca2+ available for bone deposition
produces 85% of erythropoietin
converts angiotensinogen to angiotesin 1 with renin
erythropoietin
stimulates bone marrow to produce RBC’s
Lungs
converts angiotensin 1 to angiotensin 2 (vasoconstrictor)
stomach and small intestines (10 enteric hormones)
coordinate digestive motility and secretion
Placenta
secretes estrogen, progesterone, and others
regulates pregnancy, stimulates development of fetus and mammary glands
down regulation of hormone receptors
receptors are degraded, decrease sensitivity of target cell to hormone
Up regulation of hormone receptors
targets tissue more sensitive to the hormone and increase receptor production
Gen mechanism of hormone action
hormone binds to cellular surface or receptor inside target cell
cell may then synthesize new molecules, change permeability of membrane, or alter rates of reaction
Permissive effect
second hormone that strengthens effects of first
ex: estrogen stimulates up regulation of progesterone receptors in uterus
synergistic effect
two hormones acting together for greater effect
Ex: estrogen and LH both needed for oocyte development
FSH and testosterone both needed for sperm production
Antagonistic effect
two hormones with opposite effects
insulin promotes glycogen formation and glucagon stimulates glycogen breakdown
stress response
set of bodily changes called general adaptation syndrome (GAS)
Primary sex organs
organs that produce the gametes (testes or ovaries)
Secondary sex organs (accessory but essential for reproduction)
male = ducts, glands, and penis females = uterine tubes, uterus, vagina that receive sperm and nourish the developing fetus
Secondary sex characteristic
features that develop at puberty to attract a mate
pubic, axillary and facial hair, scent glands, body morphology
Somatic cells (diploid)
23 pairs of chromosomes for total of 46
each pair is homologous - contains similar genes
one member of each pair is from each parent
22 autosomes and 1 pair of sex chromosomes (either X or Y)
Gametes (haploid cells)
single set of chromosomes for total of 23
produced by special type of division: meiosis
Testes
paired oval glands measuring 2 in by two inc
surrounded by dense CT white capsule (tunic albuginea)
Fibrous partitions (septa) form 200-300 lobules
Each is filled with 2 or 3 seminiferous tubles where sperm are formed