Question | Answer |
Digestive tract from start to finish | mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anus |
alpha-amylase | break down starch |
relationship between pharynx, larynx, and trachea | -pharynx-connect inner nose to throat
-larynx-below pharynx that has vocal cords
-trachea - below larynx that leads to lungs |
epiglottis | separates pharynx and larynx to prevent food from entering respiratory tract |
Describe musculature of esphagus | -starts with striated and ends with smooth
(voluntary and involuntary mvmt) |
cardiac sphincter (lower esophageal) | allows food to pass from esophagus to stomach |
mucus cells | produce epithelial lining made of sticky glycopx and electrolytes |
chief cx | secrete pepsinogen |
function of pepsinogen | digest px |
parietal cx | -secrete HCl
-secrete intrinsic factor |
Function of HCl in digestion? | -lower pH of stomach and raise pH of blood
-kill bacteria
-break down intracx bond of food
-activate pepsinogen --> pepsin |
G-cx | secrete gastrin |
What does gastrin do? | -stimulates parietal cx to secrete HCl
-mix stomach contents to produce chyme |
Function of intrinsic factor in digestion? | helps ileum absorb vitamin B12 |
How does acetylcholine affect secretion of stomach juices? | increases secretion of all cx types |
How does gastrin / histamine affect secretion of stomach juices? | increases HCl secretion |
gastric juice made of? | HCl, pepsinogen, mucus, intrinsic factor, gastrin, BICARBONATE
(think homeostasis!) |
Function of bicarbonate in digestion? | protects mucosa lining |
ulcer | portion of mucosal lining digested and hole forms |
What does sphincter connects stomach to small intestine? | pyloric sphincter |
Where does most digestion occur? most absorption? | -digestion: duodenum
-absorption: jejunum and ileum |
Lining of small intestine is covered with what? | villi |
What is inside each villi? | capillary network and lymph vessel (lacteal)
-some nutrients go into capillary and some into lymph vessel |
What covers villi? | Microvilli (brush border) aka enterocytes |
What does brush border have? | -mem-bound digestive enzymes
-goblet cx that produce mucus for protection |
Cryptes of LIeberkunn-where and what does it do? | -located deep between villi
-secrete intestinal juice with pH 7.6 and lysozyme |
lysozyme | regulates bacteria within intestine |
When food first enters duodenum, what is released? | Cholecystokinin (CCK) |
What does CCK do and what is it released in response to? | -Causes gallbladder, liver, and pancreas to release substances into duodenum
-inhibits gastric emptying and gastric acid secretion
-px or fat rich chyme |
What does pancreas release? | Trypsin, chymotrypsin, amylase, lipase, ribonuclease, deoxyribonuclease |
What is the pH inside duodenum? | pH = 6 because of bicarbonate |
Secretin | causes release of pancreatic juice from pancreas |
What is pancreatic juice? | enzymes in bicarbonate solution |
At what pH are pancreatic enzymes most active? | 8.5 |
enterokinase | activates trypsinogen --> trypsin |
What is importance of trypsin? | activates all other zymogens |
In what form are peptidases released from pancreas? | zymogens |
What are examples of pancreatic peptidases? | trypsinogen, chymotrypsinogen, elastinogen, carboxypeptidase |
What is the exocrine fxn of pancreas? | -secrete pancreatic juice into small intestines
-release enzymes from acinar cx through pancreatic duct |
What is endocrine fxn of pancreas? | releases insulin and glucagon directly into blood |
How is bile released? | bile stored in gallbladder --> joins with common bile duct --> joins pancreatic duct --> duodenum |
Where is bile produced and where is it stored? | produced by liver and stored in gallbladder |
What is bile made of? | bile salts, bile pigments, cholesterol |
How is bile released? | released in response to hx CCK |
What is pH of bile | 7.5-8.8 to neutralize acid chyme |
Why are bile salts important? | hydrolyzes ester bonds to increase SA of fats |
Does bile breakdown fats? | NO |
Where does bile go after it has done its job? | reabsorbed by small intestine and transported back to liver |
Where does bile get its color? | bilirubin (end product of hemo degradation) |
2 main functions of large intestine? | 1. water absorption
2. electrolyte abosrption |
3 major sections | cecum, colon, rectum |
cecum | connects small and large intestine
-also has appendix |
colon | absorbs salt and water |
rectum | storage for feces |
anus | -where waste is eliminated
-has voluntary and involuntary sphincters |
What gives rise to anus? | blastopore |
What is function of e.coli in large intestine? | metabolize fiber, produce vitamin K, B12, thiamin, riboflavin |
Why do most fats bypass liver? | -directly enter circulation w/o going to hepatic portal |
Where do carbs and a.a. go before they are released to rest of body? | hepatic portal circulation |
What happens after absorbed fats absorbed through intestinal wall? | -fats reform into triglycerides at smooth ER |
What happens after absorbed fats are reformed to triglycerides? | packaged into insoluble chylomicrons that enter lymphatic circulation through lacterals |
What do chylomicrons do? | chylomicrons enter venous circulation and stick to capillary walls and combine with lipoprotein lipase |
lipoprotein lipase | hydrolyzes triglyercides in the bloodstream
--> products of hydrolysis are taken up by liver and repackaged into HDL, LDL, etc. |
Between meals, 95% of protein is in the form of? | lipoprotein |
VLDL | transport triglycerides from liver to adipose tissue |
LDL | transport cholesterol / phospholipid |
Lacteals converge and dump contents into ___________ that then enters systematic circulation. | thoracic duct |
What happens to proteins and carbs? | absorbed by blood and taken up by cx (esp. by liver) |
What causes allergic rxn? | any protein that is not completely broken down |
What happens inside cx with a.a.? | cx immediately creates px from a.a. so intracell a.a. concentration stays low |
What happens when cx reach upper limit for px storage? | -a.a. are burned for energy
-a.a. are converted to fat for storage |
Calorie rate for proteins, carbs, fats? | -px - 4
-carbs - 4.5
-fats - 9 |
How are proteins transported into cell? | transported down conc. gradient of sodium |
gluconeogenesis | creation of glucose / glycogen in liver from a.a., glycerol, lactic acid |
What is byproduct of gluconeogenesis? | ammonia |
How to get rid of ammonia? | liver converts ammonia to urea and excreted in urine by kidney |
What causes secretin release? | HCl in duodenum
-causes bicarbonate release from pancreas (natural antacid) |
What is main fxn of stomach? | stores food and releases a little at a time to be digested |
How is glucose transported with sodium into cell? | -sodium is pumped out of enterocyte
-resulting low sodium drags sodium and glucose from outside to inside |
All carbs absorbe din blood are carried to? | liver! |
Most carbs are turned into? | glycogen
--> too full? --> fat |
What enzymes does small intestinal mucosa release? | maltase, lactase, sucrase, peptidase, dipeptidase, secretin, CCK |
What enzymes does stomach release? | HCl, pepsinogen, mucus, bicarbonate, water, intrinsic factor, gastrin |
What does pancreatic juice release? | trypsin, chymotrypsin, amylase, lipase, ribonuclease, deoxyribonuclease |
secretin vs. CCK | -secretin released in response to H+ and causes pancreatic juice release -->bicarbonate release
-CCK released in response to fats/px and causes pancreatic juice and bile release |
Where is bile derived from? | cholesterol |
Role of liver and fats | breaks down fats, makes cholesterol, makes lipopx |
Role of liver and vitamins | stores vitamins B12, A, D and iron |
Role of liver and detox | metabolize alcohol, transform ammonia --> urea, remove toxins |
Structure of liver and where does ducts drain to? | -largest gland in the body
-duodenum and gall bladder |
Active transport for glucose. Intestinal lumen has ____ glucose while enterocyte has ______ glucos. | low / high |
Facilitated diffusion for glucose. Enterocyte has ______ glucose while extracx fluid has _____ glucose. Glucose will enter ______ | high / low / bloodsream |
Why is bicarbonate from pancreas important for neutralizing acidic chyme? | enzymes would be denatured |
Does large intestine have folds or villi? | NO |
Anal sphincter | at end of rectum |
Name all sphincters | cardiac, pyloric, anal |
Where does urine go once its made in kidneys? | kidney - calyces - renal pelvis - ureter - bladder - urethra |
What are 5 parts of nephron? | glomerulus, proximal convoluted tubule, descending and ascending LOH, distal convoluted tubule, collecting duct |
What is function of kidneys? | 1. excrete wastes
2. maintain homeostasis
3. control plasma pH |
Glomerulus is surrounded by? | Bowman's capsule |
renal corpuscle? | glomerulus + bowman's capsule |
What forces plasma through fenestrations into Bowman's capsule? | hydrostatic pressure |
How much of blood that passes through glomerulus passes into Bowman's capsule? | 20% |
What does glomerulus retain and what passes through? | -erythrocytes and plasma px
-water, electrolytes, organic solutes (low MW), urea |
Where does blood go that didn't pass into Bowman's capsule? | efferent arterioles and then vasa recta |
Where does major reabsorption and secretion take place? | Proximal convoluted tubule |
What happens in proximal convoluted tubule? | -reabsorb all nutrients,px, and most ions
-secrete wastes |
What does PCT secrete? How does it secrete hydrogen ions? | -ammonia, toxins, hydrogen ions
-secrete through an antiport system with sodium |
What does PCT reabsorb? | glucose, proteins, sodium, calcium through secondary active transport |
transport maxima | concentration of solute that saturates transport px
-when transport max reached, any non-absorbed solute will go into urine |
What is result of teh PCT? | reduce amount of filtrate while changing solute composition without changing osmolarity |
How is water reabsorbed in the PCT? | across tight junctions |
What do diuretics do? | -help body get rid of excess fluids
-inhibit reabsorption of sodium |
What are the 2 types of arterioles in the kidneys? | -afferent - lead to glomeruli
-efferent - lead to vasa recta |
How does LOH differ from PCT in terms of secretion and absorption? | more specific |
ascending LOH and type of transport | permeable to salt not water - reabsorption of salt
-salt passively diffuses out and then actively |
descending LOH and type of transport | permeable to water not salt - reabsorption of water
-water passively diffuses out |
Where is kidney cortex and what does cortex contain? | -outer shell of kidney
-contains convoluted tubules |
Where is kidney medulla and what does it contain? | -inner part of kidney
-LOH |
What is function for distal convoluted tubule? | -aldosterone acts here to reabsorb sodium and secrete potassium
-PTH acts here to reabsorb calcium |
What is function of collecting ducts? | -ADH acts here to reabsorb water
-urea recycling
-reabsorb / secrete various ions |
Regulation of blood pH in kidneys? | -secrete H+ when blood too acidic
-secrete bicarbonate when blood to basic |
Countercurrent multiplier mechanism | -creates osmotic gradient down LOH for collecting duct to concentrate urine |
What drives creation of countercurrent gradient? | -sodium pump on ascending limb |
What's the multiplier in the countercurrent multiplier mechanism? | -longer the LOH, more each individual NaCl pump multiplies down length of LOH, more concentrated urine can be produced |
In the ascending limb, sodium is actively diffused out but chloride ______ diffuses out. | passively |
The collecting duct goes from the ______ to the ________ | cortex to medulla |
Urea recycling | urea diffuse out of collecting duct back into LOH to help maintain osmotic gradient |
What releases Aldosterone? | adrenal cortex in response to decrease in blood pressure |
What does aldosterone do? | -increases ability of distal tubule to reabsorb sodium
-increases blood pressure
-increases potassium secretion |
What does ADH do? | collecting duct becomes permeable to water |
afferent arterioles constrict, GFR increases / decreases.
efferent arterioles constrict, GFR increases / decreases. | - decreases
-increases |
High hydrostatic pressure forces water out / in.
High osmotic pressure forces water out / in. | - out
- in |
What happens when you have diarrhea in terms of acid/base homeostasis? | metabolic acidosis |
How can kidney help metabolic acidosis? | -decrease in pH stimulates DCT to secrete hydrogen and reabsorb as much bicarbonate as possible |
Juxtoglomerular apparatus | juxtoglomerular cells and macula densa cells |
What do j.g. cells sense and macula densa cells sense? | -j.g. - sense change in BP
-macula dense - sense changes in sodium concentration |
When sodium concentration goes down in distal tubule, macula densa cells stimulate _____ secretion by j.g. cells | renin |
What does renin do? | converts angiotensinogen --> angiotensin 1 |
What does angiotensin 2 do? | increases aldosterone secretion |
What should ultimately be foudn in urine fluid? | urea, uric acid, sodium, potassium, magnesium, calcium |
What SHOULD NEVER be in urine? | blood, protein, glucose |
All blood received by liver will move to? | vena cava |
What oxygenates the liver? | hepatic artery |
Where do all nutrients absorbed as well as blood from all other organs travel through? | hepatic portal vein |
Where are most erythrocytes destroyed? | spleen |
Where is albumin, prothrombin, and fibrinogen produced? | liver |
When liver metabolizes fat/proteins for energy, blood acidity ______ | increases |
What are 2 principal parts of skin | epidermis and dermis |
epidermis and what is it made of? | -avascular epithelial tissue
-stratified squamous epithelial tissue |
dermis | vascular connective tissue derived from mesodermal cells |
ADH is also called? | -vasopressin
-causes vasoconstriction |
What is atrial natriuretic peptide and where is it released? | -released from heart
-antagonizes aldosterone and causes kidney to release more sodium and water |
ANP vs. ADH | -vasodilation
-vasoconstriction |
blood osmolarity is determined by _______ | Na Cl |
what does PTH regulate in kidneys? | calcium absorption and phosphate excretion |
How are amino acids excreted in kidneys? | amino acids --> ammonia --> urea --> peed out |
What does the renin-angiotensin pathway respond to? | low blood pressure |
What does ANP respond to? | high blood pressure |
Vasoconstriction / dilation when too cold? Too hot? | -vasoconstriction of arterioles decrease blood supply
-vasodilation of arterioles increase blood supply |
What does salt excrete? | -salts
-nitrogenous wastes |
How does hair help insulate the body? | traps air in them |
Where is fat layer located in skin? | hypodermis |
Where are sweat glands, blood vessels, and hair follicles located? | dermis |
What is function of keratin? | -protect against abrasion
-waterproof seal
-block out pathogens |
Where is keratin found? | nail, skin, hair |
How does sweat provide chemical protection? | sweat is acidic and contains antibodies and antimicrobial agents |
What are benefits of natural flora? | fight of bad bacteria |
keratinocytes and how are they produced? | -cells that produce keratin
-start off like normal cells at bottom of epidermis, get flatter as you go up, and become dead keratin plates at surface |
melanocytes | cells that make melain |
Langerhans cells | phagocytes that eat pathogens |
What is found in epidermis? | keratinocytes, melanocytes, Langerhans cells |
What is found in dermis? | fibroblasts, hair follicles, sweat glands, oil glands, blood vessels |
fibroblasts | make fiber and "glue" for extracx matrix that makes up connective tissue |
Why is skin relatively impermeable to water? | layer of dead, keratin-packed cells sealed with glycolipids
-skin oil contributes to some (glands not present in palms and soles) |
What is the source of energy that forces fluid into capsular space? | blood pressure from heart |
What would happen if heart stopped with GFR? | fluid in space around glomerulus would flow back into capillary blood |
Low BP allows for ______ time for GFR | decreased |
In proximal convoluted tubule, filtrate is _______ to surrounding interstitium | isotonic |
Tm = | tubular transport maximum |
What is the major osmoregulatory px in blood? | albumin |
What is part of the excretory system? | skin, lungs, kidney |
What is part of the digestive system? | mouth to anus |
Why are micelles circular? | to minimize exposure to hydrophilic surfacs |
What makes up the kidney filter system? | glomerulus and Bowman's capsule |
What is the normal volume of urine? | 1-2L |
What is the shortest part of the small intestine? | duodenum |
Where does most absorption occur? | jejunum and ileum |
What is the beginning of the large intestine? | cecum |
Describe path of glucose and a.a. during filtration. | Glucose and a.a. are freely filtered and then reabsorbed by PCT and returned to circulation |
What stimulates aldosterone? (particle) | angiotensin II |
What does dehydration cause in kidneys and hypo? | release of renin from kidneys and stimulation of osmorx in hypo |
Where is appendix located? | near cecum (jxn of small intestine and large intestine) |
What are fat-soluble vs. water-soluble vitamins? | -fat soluble: Vitamins D, A, K, E
-water-soluble: Vitamins B, C |
Hypocalcemia | low blood calcium
--> spastic twitches |
What makes up glomerular capillary BP? | plasma osmotic P + Bowman's capsule hydrostatic pressure |
What are the proteolytic enzymes from pancreas? | trypsin, chymotrypsin, carboxypeptidase |
Perineum vs. Peritoneum | -perineum - area between legs that rips during birth
-peritoneum - cavity that contains pelvis, stomach, spleen, gall bladder, liver, intestines |
An ulcer in wall of intestine would allow contents to enter perineum or peritoneum? | peritoneum |
Digestion of carbs starts in? Proteins? Fats? | mouth / stomach / small intestine |
liver and pancreas are associated with which system? | digestive |
What is bile made of? | breakdown of hemoglobin, bilirubin, and bile salts |
TO have a hydrophilic and a hydrophobic portion? | amphipathic |
What vitamins do E.Coli produce? | Vit B12 and Vit K |
Where is appendix located? | continuous with colon |
What is the shortest and longest part of the small intestine? | duodenum / ileum |
What stimulates parietal cells? | gastrin, AcH, and histamine |
What is the best way to inhibit stomach acid synthesis? | inhibit proton pump |
Is the digestive system a blind tube? | NO |
What is the most important extracx ion? intracx ion? | Sodium / Potassium |
What is one of the main nerves of the PNS in digestion? | vagus nerve |
Where is oxytocin made? | Hypothalamus and stored in posterior pituitary |
What areh most numerous gastric cell types? | chief cells |
Main function of hypothalamus? | maintain homeostasis --> BP, body temp |
Main function of medulla oblongata? | -controls rate of breathing |
What would long-term lipase inhibition create? | depletion of fat-soluble vitamins (DAKE) |
What are the digestive accessory organs? | liver, gall bladder, pancreas, salivary glands |
Cortisol vs. insulin on glycolysis | -cortisol inhibits glycolysis
-insulin increases glycolysis |
sodium / hydrogen antiport system used in kidneys | sodium in, hydrogen out |
Is urine acidic or basic? | acidic |
Is the renal filtration membrane negative or positive? | negative |
somatostatin | inhibits release of insulin and glucagon |
What test can check for Type 1 diabetes mellitus? Type 2? | -self-antibodies
-insulin receptor count |
What are the main functions of colon? | -secretion of K+
-absorption of Na and water |
Where are the main targets for aldosterone? | -distal convoluted tubule
-large intestine |
What does ACTH cause the release of? | cortisol and aldosterone and other hx of adrenal cortex |
The conversion of Vit D to is active form, synthesis of renin, and release of erythropoietin all occur where? | kidney |
What does erythropoietin do? | activates bone marrow to produce red blood cells |
primary active transport | moves cpds against concentration gradient with Na/K pump and ATP |
secondary active transport | symport and antiport |
Where is bicarbonate most important? | blood an GI tract |
acinar cells | secrete pancreatic digestive enzymes |
Does insulin cause hyper or hypoglycemia? | hypoglycemia |
Where does final disaccharide digestion/absorption occur? | brush border of small intestine |
Difference btwn cilia and microvilli | microvilli are not motile |
Is glucose ever secreted under normal circumstances? | NO |
What does alcohol and caffeine inhibit? | ADH |
Why do diabetics have glucose in urine? | so much glucose isn't taken up by body that filtrate entering kidneys has a lot of glucose
-too much to filter
-gets into urine |
Is the esophagus purely involuntary muscle? | NO --> some voluntary for swallowing |
What is sucrose made of? | frucotse and glucose |
In the PCT, the reabsorbed fluid is _____ with the nephron lumenal contents? | isosmotic |
hyperosmotic? | greater solute concentration in comparison |
What does angeiotensin-converting enzyme do? | increases BP |
Where are macula densa cx located? | distal convoluted tubule |
What releases renin and when does it release it? | macula densa cx in response to low NaCl |
Diuretics that affect what part of nephron will be most effective? | loop of henle |
What reaction does dehydration create? | -release of renin from kidneys --> aldosterone
-stimulation of osmorx in hypo --> ADH release |
What does thyroid hx cause? | increase basal metabolic rate and increase metabolism of all nutrients
-increase px synthesis |
Where does most digestion and absorption occur? | jejunum |
What are the 2 important tasks for large intestine? | water reabsorption and K secretion |
What is hippocampus for? | emotion and sexuality |
How are glucose, a.a., and phosphate reabsorbed in PCT? | secondary active transport |
Is urea ever actively transported? | NO |
Where does aldosterone act? | distal convoluted tubule, collecting duct, large intestine |
What does aldosterone do with K and H? | -increases urine K with Na/K pump
-increases H in urine |
Where is bicarbonate reabsorbed in nephron? | PCT |
What are 2 important properties of hx action? | -receptor specificity
-signal amplification |
When is aldosterone produced in response to? | low sodium / elevated potassium in blood |