FINAL EXAM: Unit 6 Flashcards
describe the three GI tract movements (migrating motor complex, peristalsis, segmental contractions)
migrating motor complex: b/w meals
peristalsis: during a meal, moves food forward
segmental: during a meal, alternate relaxtion & contraction
how does the enteric NS impact the GI tract?
no CNS, uses submucosal & myenteric plexuses (intrinsic)
-release NT, glial support cells
-diffusion barrier
what does gastrin do?
gastric acid secretion
what does CCK do?
gallbladder contraction (bile)
pancreatic secretions
inhibits gastric phase
what does secretin do?
HCO3- secretion
inhibit gastric phase
what does motilin do?
stimulates migrating motor complex
what does GIP do?
insulin release
inhibit gastric phase
what does GLP-1 do?
insulin release
inhibit gastric phase
what is the cephalic phase stimulated by?
anticipatory reflex, food in mouth
what does the cephalic phase do?
vagal reflex: increase gastrin
saliva production
mastication
swallowing reflex
what is the swallowing reflex pathway?
- tongue hits soft palate
- medulla oblongata stimulated
- CN9
- close nasopharynx
- upper esophagus sphincter relaxes
- peristaltic contractions
what stimulates the gastric phase?
vagal reflex, stomach distension (stretch)
what does the gastric phase do?
increase motility & secretions
segmental contractions (stirring)
what does the parietal cells secrete? functions?
HCl: activate pepsin, kill bacteria
Intrinsic factor: vitamin b12, absorption
what does the chief cells secrete? functions?
pepsin: breakdown proteins
gastric lipase: breakdown fats
what does the mucous cells secrete? functions?
mucus: barrier to acid
bicarbonate: increases pH
what does G cells secrete? functions?
gastrin: increases motility & acid secretion
what does D cells secrete? functions?
somatostatin: inhibit gastrin & HCl
what stimulates the intestinal phase?
chyme entering, change in pH
what does the small intestine secrete? functions?
peptidase: breakdown proteins
disaccharide: breakdown carbs
secretin & CCK: inhibit gastric phase, secrete digestive enzymes
what does the liver and gallbladder do?
synthesize and store bile (breakdown fats)
what are the pancreas endocrine secretions? functions?
insulin: glucose high, beta-islet
glucagon: glucose low, alpha-islet
what are the pancreas exocrine secretions? functions?
pancreatic amylase: breakdown carbs
pancreatic lipase: breakdown fats
peptidases: breakdown proteins & fats
what three enzymes help breakdown carbs?
salivary amylase
pancreatic amylase
disaccharides
what is the pathway of carb breakdown?
- polysaccharide (starch, glycogen)
- disaccharide (maltose, sucrose, lactose)
- monosaccharide
- glucose & galactose -> Na+ dependent transport
- fructose -> facilitated diffusion
- hepatic portal system
what enzymes help breakdown proteins?
ENDO: pepsin, trypsin, chymotrypsin (cleave bonds in middle)
EXO: carboxypeptidase, protease (cleave bonds on ends)
what is the pathway of protein breakdown?
- polypeptidase broken by endo/exopeptidases
- free amino acids
- active transport, co-transport, transcytosis
- hepatic portal system
what enzymes help breakdown fats?
salivary lipase
bile
collipase
phospholipase
what is the pathway of fat breakdown?
- fat broken down by bile
- triglycerides broken down by lipase
- monoglycerol & FAs form micelles
- goes to the villi & microvilli
- goes into intestinal cell -> smooth ER
- converted back into triglycerides
- triglyceride + cholesterol + protein = chylomicron
- goes to lacteal
where do fat soluble vitamins go? water soluble?
fat soluble = lacteal
water soluble = hepatic portal system
what three secretions does the hypothalamus release?
NYP: increase food intake
Ghrelin: increase food intake
Orexin: increase food intake
what is the difference b/w the glucostatic theory and the lipostatic theory with relating to hunger?
glucostatic: regulator is glucose metabolism
lipostatic: regulator is fat stores, leptin increases satiety
what is the equation for total body energy?
energy stored + energy intake - energy output
what happens during anabolic rxns?
synthesize large molecules
-storage
-fed state
what happens during catabolic rxns?
breakdown large molecules
-use for energy
-fasted-state
what occurs during the fed state?
storage, insulin dominates (get glucose out of blood)
-glycolysis (use up glucose)
-lipogenesis (store fats)
-glycogenesis (store glycogen)
-protein synthesis (AA -> protein)
what occurs during the fasted state?
need energy, glucagon dominates (need more glucose in blood)
-glycogenolysis (glycogen -> glucose)
-gluconeogenesis (make more glucose)
-lipolysis (make into monoglycerides)
-beta-oxidation (make ketones)
what is the difference b/w Type 1 and Type 2 diabetes?
Type 1: insulin deficient, autoimmune disease, tissue loss
Type 2: insulin resistant, doesn’t respond
what are examples of body temperature inputs and outputs?
inputs: radiation, conduction
outputs: radiation, evaporation, convection
what are ways the body adapts to temperatures BELOW normal?
vasoconstrict
shivering
brown adipose tissue (uses proton gradient)
what are ways the body adapts to temperatures ABOVE normal?
vasodilate
sweat
what is an example of mineralocorticoid, glucocorticoid, androgen, catecholamine? where do they go?
mineralocorticoid: aldosterone -> zona glomerula
glucocorticoid: cortisol -> zona fasciculata
androgen: testosterone -> zona reticularis
catecholamine: E, NE -> adrenal medulla
what is the effect of cortisol on the GI tract?
promotes gluconeogensis (raise glucose)
enhances lipolysis (need energy)
creates low Ca2+ (decrease absorption, increase excretion)
suppresses inflammatory response
what is the synthesis of thyroid hormone?
T + I = MIT (monoiodotyrosine)
MIT + I = DIT (diiodotyrosine)
MIT + DIT = T3
DIT + DIT = T4
*deiodinase = T4 -> T3 *
what does thyroglobulin do?
helps move T3 & T4 from the follicle -> blood
backbone for thyroid hormone
what are some symptoms of hyperthyroidism?
low TRH
hot
weight loss
fidgety
increases HR
autoantibody to increase T3 & T4
what are some symptoms of hypothyroidism?
high TRH
iodine deficient
cold
weight gain
brittle nails, thin hair, dry skin
fatigue
decreases HR
low T3 & T4
what triggers the development of a goiter?
high TSH levels
how does growth hormone impact the body?
promotes gluconeogenesis (need glucose)
stimulates cartilage growth (IGFs)
what does GH deficiency lead to? GH oversecretion?
deficent: dwarfism
oversecretion: acromegaly (bones thicken), overgrowth of bones
how does tissue grow?
hypertrophy: increase in size
hyperplasia: increase in number
GH & IGFs (TH)
insulin (put glucose in the cells)
what is osteoblast and osteoclast?
osteoblast: builds bone
osteoclast: breaks down bone (bone resorption)
how do epiphyseal plates close?
chondrocytes -> cartilage (IGFs)
how does hypocalcemia impact Na+?
increases Na+ permeability
-hyperexcitable
what three hormones control calcium levels?
parathyroid hormone
calcitriol
calcitonin
how does parathyroid hormone work?
active with LOW Ca2+ (put Ca2+ in the blood)
-increase bone resorption
-increase intestinal Ca2+ absorption
-increase kidney Ca2+ reabsorption
how does calcitriol work? (vitamin D3)
active with LOW Ca2+
-enhances parathyroid hormone
-skin -> liver -> kidney
how does calcitonin work?
active with HIGH Ca2+ (put Ca2+ in cells)
-decrease bone resorption
-decrease intestinal Ca2+ absorption
-increase kidney Ca2+ excretion
how does the SRY of Y chromosome work?
- produces TDF
- secretes AMP (destroy mullerian)
- secrete testosterone (wolffian) -> DHT (external genitals)
what is the pathway of spermatogenesis?
- primary spermatocyte (1st meiosis)
- secondary spermatocytes (2nd meiosis)
- spermatids (4)
what is the pathway of oogenesis?
- primary oocyte (1st meiosis, completed during puberty)
- secondary oocyte (2nd meiosis, completed when fertilized)
- ovum + polar body (1)
what does GnRH from the hypothalamus secrete?
LH & FSH
what do sertoli cells secrete? functions?
androgen binding protein: bind testosterone, keeps in testes
inhibin: inhibit FSH
activin: enhance FSH
what do leydig cells secrete?
testosterone
what do LH & FSH cells target?
LH: target leydig
FSH: target sertoli
what are primordial follicles?
6-12 released each month to be matured
what happens during the early follicular phase?
increase FSH: maturation of follicles, activate granulosa
granulosa: secrete AMH, stops further maturation of follicles
thecal cells: secrete estrogen (+ on estrogen, - on FSH & LH)
what happens during the mid-late follicular phase?
increase estrogen: + on GnRH, LH, FSH
LH surge: ovulation, completes meiosis 1
increase inhibin: decrease FSH
what happens during the early-mid luteal phase?
corpus luteum forms (secretes progesterone & estrogen)
progesterone: - on GnRH, FSH, LH
inhibin
what happens during the late luteal phase with NO FERTILIZATION?
corpus luteum destroyed: decrease progesterone & estrogen
tonic levels of GnRH, FSH, LH return
what happens during the late luteal phase with FERTILIZATION?
corpus luteum stays: increase progesterone & estrogen
2nd meiotic division compelte
what happens during the proliferative phase?
overlaps with follicular phase
increase estrogen: growth of endometrium
what happens during the secretory phase with NO FERTILIZATION?
endometrium dies & sheds
vessels contract
what happens during the secretory phase with FERTILIZATION?
increase progesterone
increase nutrients & blood supply
what are the four stages of procreation?
- excitement
- plateau
- orgasm
- resolution
what happens during pregnancy?
blastocyst implants
increase progesterone & estrogen
decrease FSH & LH
what do the sperm do during the beginning of pregnancy?
capacitance: finish maturation
release enzymes to penetrate, zinc spark
what two secretions does the placenta release? functions?
hCG: keeps corpus luteum active, increase testosterone
hCS: lactation, alter mom’s metabolism
what three things happen during parturition?
CRH release: start labor
relaxin & prostaglandin release: soften cervix, loosen ligaments
pressure on cervix: increases oxytocin
what does prolactin and oxytocin do for lactation?
prolactin: milk production
oxytocin: let-down reflex -> milk ejection
