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84 Cards in this Set
- Front
- Back
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how is salivation a reflex?
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it is an unconcious behavior. the result of a genetic brain circuit
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what are some situations that would cause salivation?
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1. thought/sight of food
2. fear (lack of salivation--public speakers drink water) 3. nausea (excess salivation) |
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How did pavlov's dogs change the genetic brain circuit?
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became a modified learning reflex (conditioned reflex--CR). salivated due to sound of bell, not due to food.
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which animals have a "true" pyloric sphincter?
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rodents and horses. humans have one that folds.
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what is pepsinogen?
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inactive pepsin made by the chief cell in the gastric pits. has a blocker, that gets cut off once they reach the stomach. otherwise the pepsin would digest needed proteins.
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where do proteins get cut by pepsin? why?
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they get cut wherever there is a tryosine. because tryosine fits the active site of pepsin.
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what is the gastric mucosa?
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a one cell thick wall of the gastric pit. it is always bleeding a regenerating.
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what are the types of cells in the gastric pit?
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1. chief cells--make pepsinogen
2. parietal cell--makes HCl 3. gastrin cell--makes gastrin hormone (all over body) 4. mucous cell--protects membrane |
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what does the small intestine do?
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has digestive enzymes that do all the absorption to the blood.
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what are the exceptions to sm. intestine absorption?
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anything that goes to the skin (nicotine, alcohol, pollutants)
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how does the sm. intestine increase surface area? why?
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it is 22 ft. long, has intestinal folds, villi on the folds, microvilli on the villi (looks like a brush border).
creates faster absorption, exposes blood to nutrients in chyme |
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what is lacteal?
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part of the lymphatic duct. the lymph goes to shoulders, joind blood
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what does the lymphatic system do?
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drains dirt from body and carries fat
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how do emulsifiers work?
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act like soap.
soap sticks to fat, water sticks to soap, which surrounds the grease and emulsifies it. |
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once fatty acids are broken down, where are the absorbed?
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fatty acids and glycerols are absobred into the intestinal epithelial cells.
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what is emulsifier in sm. intestine?
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in intestine, bile salts are emulsifiers. fat becomes tiny drops.
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what is a cholymicron?
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a bubble of emulsified fats, that are distributed throughout the body's fat cells by lacteal.
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how can LDLs be bad?
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too high=bad.
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how many types of LDLs and HDLs are there?
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20 LDLs
35 HDLs |
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where can bad circulation occur?
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1. cardiac artery--heart attack
2. brain artery--stroke 3. leg artery--caused by smoking--irritates arteries (they get rough and coat quicker with fat) |
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what is special about lactase between the races?
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it was the 1st enzyme difference ever discovered between the races.
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how was it discovered to be different?
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WWII--US sent care packages to japanese that had powdered milk. Japanese got sick, discovered they couldn't digest lactose sugar
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how does lactase work in grain cultures?
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they have lactase enzyme until weaning, then it turns off. most of the world is lactose intolerant (asia, india, w. africa)
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what is a dairy culture?
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the lactase gene never turns off, so adults are lactase tolerant. (Europeans, E. africa)
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were original humans lactose tolerant/intolerant?
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they were lactose intolerant. lactose tolerant people are gene mutants that evolved after cows (3000BC)
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what are some pancreas secretions?
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1. pancreatic amylase--hydrolyzes starch
2. trypsm & chymotrypsm--hydrolyzes proteins into amino acids 3. lipase--hydrolyzes triglycerides 4. NaHCO3--sodium bicarbonate--neutralizes HCl to pH 7 5. insulin & glycogen--go in blood, not sm. intestine |
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how did the liver evolve?
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started out in fish as a digestive gland making bile to emulsify fats.
evolved 10 diff. functions to control blood chemistry |
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what is bilirabin?
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it is in the blood. the liver uses it to make bile. is a yellow-green color. makes feces brown. can see yellow whites of eyes if too high (jaundice)
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what are some causes of jaundice?
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1. alcoholism--liver absorbs the alcohol, but too much causes cirhossis. becomes smaller and smaller until no liver left. causes beer belly because liver initally enlarges.
2. hepatitis 3. immature liver (in newborns)--doesnt make bile yet (feces is white). bilirabin causes brain damage (destroyed w/ bright light). |
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can you live without your gallbladder?
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yes, not a drastic change. fat digestion is 1/2 as good.
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how does glucose get into intestinal eipthelial cells?
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by a glucose transporter powered by sodium ion. for fructose, there is a facilitated transporter
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what are the functions of the large intestine?
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1. removes water & NaCl
-if the small intestine is irritated, it wont remove water, causing diarrhea. |
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what is gut bacteria?
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feces are 50% live bacteria and 50% cellulose fiber (undigestible).
-20,000 species of bacteria adapted to gut -antibiotics throw off ecology |
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how do anal sphincter muscles work?
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they are part concious, part unconcious.
1. reflex--open in extreme emergency 2. reflex--tightens during anxiety 3. concious--potty training |
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what are some animals that produce cellulase (can digest cellulose)?
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runminants (cows, goats, deer)
cockroaches termites |
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how is gastrin stimulated? what happens next?
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gastrin is stimulated by food in the stomach. it turns on HCl and pepsinogen to digest food.
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what is a goblet cell?
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produces mucous in the gastric pits to protect.
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how else can you turn on the HCl and pepsinogen?
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the brain knows the time of the day, and turns on those juices
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what is cholycystokinin (CCK)? how does it work?
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from the duodenum. is stimulated by fats in the chyme. it then turns on the gallbladder and pancreas to release bile and lipase enzyme.
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what is DNase?
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hydrolyzes DNA into nucleotides
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what is RNase?
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hydrolyzes RNA into nucleotides. absorb to blood to make our own DNA and RNA
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peptidase?
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hydrolyzes short proteins
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nuclease?
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DNA & RNA to nucleotides
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lactase, maltase, sucrase?
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milk, beer, table sugar
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where are DNA genes found in food?
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any cellular food as DNA.
noncellular foods are sugar, cornstarch, white flour |
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what are some types of circulation?
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1. sponge: no blood circulation
2. hyrda: no blood--diffusion from gut 3. nematoda: same as hydra 4. insect: body cavity fall of hemolymph, plus mixer hearts to stir hemolymph 5. earthworms: like mixer hearts, but closed circulation 6. vertebrates: closed circulation |
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how do valves work?
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cause a one way flow of blood.
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how does a fish heart work?
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has a single heart (1 atrium, 1 ventricle)
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how do bird and mammal hearts work?
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2 atria, 2 ventricles
from RA, through tricuspid valvle, to RV, to semilunar valve, to lungs, to pulmonary veins, to LA, to bicuspid valve, to LV, to aorta, to body |
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what is the heartbeat sequence?
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1. entire heart relaxed--both atria fill up
2. both atria contract together--both ventricles fill up 3. both ventricles contract together--bi and tri valves close and semilunars blow open. blood to lungs and aorta 4. whole heart relaxes--tries to backflow, but semilunars blow closed |
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what is so remarkable about the beat sequence?
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it can go on for 90 years. no human built machine can do that.
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what is a heart murmur?
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any abnomal addition to "lub dub"
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how does an amphibian heart work?
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2 atrium, 1 ventricle
blood to body and lungs flow together side by side without mixing. no low pressure in ventricle, so frogs are sluggish because their blood pressure is relatvely low |
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what are coronary arteries?
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they feed the heart muscles
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what happens when fat and cholestorol coat the coronary arteries?
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they get narrow, can feel it as angina for years (need bypass or stent).
blood clot jams the narrow part of coronary, causing a heart attack which causes part of the muscle to die. by age 16, everyone has some heart attack/black spots on heart |
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how does a manometer work?
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used for low blood pressures (like blood).
measure the distance mmHg changes. |
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how does a bordin tube work?
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used for high pressures. the tube unwinds
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what is direct BP? what are the ways to measure this bp?
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direct bp in the ventricles in labs on dogs
1. needle in large arm artery 2. needle in small finger (low bp) 3. arm vein 4. pulmonary artery |
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how to measure bp indirectly?
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1. listen to arm, hear nothing. pump up cuff to 150 which totally collapses the arm artery. still hear nothing.
2. lower cuff to 118. can hear some blood getting through. this is the diastolic peak 3. lower until you stop hearing blood getting through. this is the systolic pressure. |
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what is a sinoatrial node?
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is a modified muscle on inside of the atrium. acts as the pacemaker for the heart. sends electrical signals (2 nerves--one to slow, one to speed heart rate). these signals fire without brain control.
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what is an atrioventricular node?
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they pick up the sinoatrial node signals and relay them.
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What is an EEG? an EKG?
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EEG--on brain
EKG--on heart |
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how does an EKG work?
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a machine measures the diff. between 2 electrodes.
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what are depolarization signals?
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caused by Na+ in the body. when muscles contract they absorb Na+.
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difference btwn. arteries and veins?
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arteries have muscles, veins don't.
veins have valves, arteries dont. |
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what is an endothelium in vessels?
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is the inner layer that is in contact with blood. controls nutrients that get to cells. damaged by smoking and alcohol
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what are capillaries?
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they are fenestrated for nutrients to get to cells
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how is blood flow controlled?
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brain controls blood flow with 1000s of sphincters
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when is blood flow controlled?
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1. temperature.
a) if cold, increase blood flow b) too cold, shuts off blood to extremeties to save warm blood for vital organs c) extreme heat--more blood to face, head, neck to let air cool 2. sex--erections, female reactions, sex flush 3. posture & movement--brain closes sphincters to avoid blood sloshing. dizziness happens in teens because sphincters don't adjust properly 4. blushing--is a social signal. somehow the truth is necessary for survival. |
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what does hagan-poiseiille law say? what does this mean?
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if you reduce the diameter of a vessel to 1/2, the resistance of flow is 16x great.
shows that sphincters only have to move slightly to get a big change. |
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slow flow in veins and arteries, fast flow in capillaries?
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noooo, it appears that it should be that way.
there are lots of capillaries and so the flow is slowest there. |
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how does the liver "bring you down"?
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has enzymes to remove toxins, from drugs, etc.
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why do we constantly produce testosterone and estrogen?
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because the liver destroys these hormones, and have to replenish.
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which proteins are created by the liver?
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1. serum albumin--makes blood sticky to prevent edema
2. clotting proteins (11) to prevent hemophelia |
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liver cirhossis symptoms?
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1. jaundice
2. edema 3. easily drunk 4. half of any prescription 5. constant gut bleeding |
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what is gluconeogenesis?
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fats and proteins converted through glucose metabolism
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why do we gain weight readily?
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our appetite is suited to stone age, when you had to eat a lot to maintain weight. during medieval times, to be fat was to be rich. only rich people procreated, etc.
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what is leptin?
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a protein that detects fat in the blood, and causes you to stop eating.
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what is insulin?
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goes up when full.
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what is grehlin?
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stimulates hunger. causes hypothalmus to raise hunger.
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what is the difference btwn lymph vessels and blood vessels?
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lymph vessels are one way. there is interstitial fluid in between the cells.
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do lymph vessels have valves?
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yes. all vertebrates except mammals have lymph hearts.
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order of lymph?
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1. plasma out of blood due to pressure
2. water back into blood due to osmosis (proteins in blood absorb water from interstitial fluid) 3. some plasma goes to lymph vessels and becomes lymph |
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what are 3 cardiovascular diseases?
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1. heart attack, angina, stroke (narrow arteries)
2. artherosclerosis--fats, cholesterol in arteries 3. arteriosclerosis--calcium deposits in arteries. |
