Renal and Digestive - Super High Yield! Flashcards
excretory organs
- colon
- liver
- kidney
colon
- eliminates solid waste
- what we eat but do not absorb
- bacteria
liver
- eliminates hydrophobic wastes
- eaten and absorbed but not dissolved in the plasma
- bile salts
- directly detoxifying
kidney
- eliminates hydrophilic wastes
- material that is eaten and absorbed, and dissolved in plasma
other kidney functions
- regulates bp
- water balance
- ion balance
- long term pH
- urea balance
- homeostasis
- activates vitamin D
- secretes erythropoietin to make RBC
internal urinary sphincter
- smooth muscle
- under involuntary control
- dilates
external urinary sphincter
- skeletal muscle
- under conscious voluntary control
bladder
- stores urine
difference between male and female urethra
- males is longer
osmolarity of cortex versus medulla
- osmolarity in cortex is much lower
why is medulla osmolarity higher
- allows us to concentrate urine
processes to produce urine
- filtration
- reabsorption
- secretion
filtration
- moving a substance across a membrane using pressure
- moving blood plasma across a capillary wall using blood pressure
reabsorption
- move a substance from the filtrate to the blood
- glucose, water, ions, AA, water soluble vitamins, HCO3-
secretion
- move a substance from blood to the filtrate
- H+, NH4+, some drugs, creatinine, toxins
- ions can also be secreted (H+, K+)
creatinine
- marker of kidney function
- breakdown of muscle metabolism
- if it’s increased patient needs dialysis
glomerulus
- small hydrophilic molecules are pushed across by pressure
- dilate afferent arteriole (approaches glomerulus)
- constrict efferent arteriole (exits glomerulus)
- to increase blood pressure
proximal convoluted tubule
- 2/3 of reabsorption and secretion occurs
- Na+, K+, Cl-, glucose, AAs, water, vitamins, HCO3
- excretion of H+, NH4+, some drugs
- filtrate roughly isotonic to plasma when it leaves.
- composition and volume has decreased
descending limb of Loop of Henle
- permeable to water
- impermeable to salt
ascending limb of Loop of Henle
- impermeable to water
- Na/K/Cl flows out
- passively in medulla
- actively pump out sodium in cortex and into surrounding tissue
Loop of Henle
- countercurrent multiplier
distal convoluted tubule
- specializes in reabsorption/secretion
- Ca2+ reabsorbed
- where aldosterone has its effects
- PTH increases
- Calcitonin decreases
collecting duct
- regulated water reabsorption
- 10-12 nephrons feed into collecting duct
- ADH (vasopressin) acts here
relationship between ADH and osmolarity
- directly related
- as osmolarity increases, so does ADH.
relationship between urine and blood
- opposite
- as volume of urine increases, volume of blood decreases and vice versa
volume and osmolarity relationship
- opposite
renin-angiotensin system
- angiotensinogen from liver
- > angiotensin I by renin
- > angiotensin II by ACE (in lungs)
- > systemic vasoconstriction (increase BP) and increase aldosterone release
increase aldosterone release causes
- increase # of Na+/K+ ATPases in distal tubule
- Increase in Na+ reabsorption and excretion of K+ into urine
- increase blood osmolarity (also trigger ADH)
- increase water reabsorption
- increase in blood volume
- increase in BP
Juxtaglomerular apparatus
- contact point between afferent artery and distal convoluted tubule
afferent artery
- baroreceptor
- if pressure falls too low, it releases renin
distal tubule
- chemoreceptor - if filtrate osmolarity falls too low
- stimulate afferent artery to release renin
- directly dilate the afferent arteriole to increase pressure in glomerulus
ANP role
- blood pressure regulation to bring down blood pressure
ANP steps
- high blood pressure
- > atria of the heart stretches
- > Right atrium releases ANP - inhibits aldosterone release (increase urine output)
- vasodilator
- inhibits renin release
- decrease BP
alimentary canal
- long muscular tube that makes up the digestive system
- mouth to anus
accessory organs
- digestive role, not part of canal
- liver
- gallbladder
- pancreas
- salivary glands
bile
- amphipathic
- from cholesterol and fat wastes
- produced by liver
amphipathic
- polar and nonpolar
gallbladder
- stores and releases bile
- concentrates bile
emulsification of fats
- forms micelles to break fats into smaller parts
- makes it easier to digest
pancreas endocrine role
- insulin
- glucagon
insulin
- released due to high blood sugar.
- allows sugar into the cells
glucagon
- released due to low blood sugar
exocrine role of pancreas
- main source of digestive enzymes
- proteases
- lipases
- amylases
- nucleases
- release bicarb to soak up H+
circular muscle of alimentary canal wall
- smooth
- segmentation
- mixing
mucosa of alimentary canal wall
- protection
- digest/absorb
- lubrication
- mucus
what produces mucus
- globlet cells
submucosa of alimentary canal wall
- blood vessels - carbs and AAs
- lymph vessels - lipids
- nerves - enteric NS
serosa of alimentary canal wall
- connective tissue membrane
longitudinal muscle of alimentary canal wall
- wave of peristalsis moving bolus of food to mix it up
function of mouth
- grind food (mastication)
- form the bolus
- moisten food
- begin starch digestion
structure of mouth
- teeth
- tongue
- salivary glands - technically accessory organs
exocrine
- through ducts onto cell surfaces
endocrine
- ductless secreted into the blood
exocrine role of mouth
- saliva - mostly water, mucus, and enzymes
- lysozyme - kill bacteria
- amylase - digest starch
endocrine role of stomach
- none
function of esophagus
- tube to carry food to stomach
structure of esophagus
- start skeletal, become smooth to control swallowing
- epiglottis to cover trachea
- cardiac (lower esophageal) sphincter - prevent reflux of stomach contents
exocrine role of esophagus
- none
- mucus found throughout the digestive tract
endocrine role of esophagus
- none
function of stomach
- little digestion and absorption
- storage tank for food
structure of stomach
- gastric glands with
- goblet cells
- parietal cells
- chief cells
- pyloric sphincter
pyloric sphincter
- regulate food entry into the small intestine
parietal cells
- secrete HCl to make stomach acid
chief cells
- secrete pepsinogen -> pepsin (protease) by HCl
- innate immunity
exocrine roles of stomach
- parietal cells
- chief cells
endocrine roles of stomach
- g cells scattered through stomach lumen
G cells
- secrete gastrin
gastrin
- activate gastric glands
- negative feedback from pH - if pH is too low will shut down secretion
function of small intestine
- most of digestion and absorption
structure of small intestine
- three regions: duodenum (5%), jejunum (40%), ileum (55%)
- huge increase in surface area: plicae -> villi -> microvilli (brush border)
exocrine role of small intestine
- enterokinase or enteropeptidase
- brush border enzymes
enterokinase
- activate trypsinogen to trypsin
- sets off a chain of enzyme activation
trypsin
- pancreatic protease
- secreted from pancreas
brush border enzymes
break down (final step in digestion)
- disaccharides
- dipeptides
- creating monomers
endocrine role of small intestine
- enterogastrone
- CCK
- secretin
enterogastrone
- reduce stomach emptying and motility
- triggered by food in intestine
CCK
- cholecystkinin
- increase bile release from liver in gallbladder
- triggered by fats and proteins
secretin
- cause the pancreas to release bicarb due to low pH in duodenum
function of large intestine
- store and form feces
- absorb/secrete H2O and minerals
structure of large intestine
- bacteria
- ileocecal valve
- internal/external sphincters
bacteria
- produce vitamin K and provide natural flora to reduce growth of pathogens
vitamin K
- helping with blood clotting
ileocecal valve
- control release from small to large intestine
- relaxes when food is in stomach
internal sphincter
- smooth muscle control
- involuntary
external sphincter
- skeletal muscle control
- voluntary
exocrine role of large intestine
- none
endocrine role of large intestine
- none
if blood pressure falls
- kidney secretes renin
speed of renal regulation of blood pH
- slow
organization of alimentary canal wall
- mucosa
- submucosa
- muscle layer
- serosa
circular muscle
- squeeze and contract width
longitudinal muscle
- make smaller or longer in length
