Unit 3 Review Questions

Question 1

What are diuretics?

Answer 1

Compounds that cause fluid loss through increased urine volume.
-caffiene due to vasdialation in nephron
-alcohol due to ADH inhibition
high glucose levels
lasix which decrease the medullary osmotic gradient or prevent it’s formation

Question 2

Discuss the anatomy of the oral cavity. What type of digestion occurs here?

Answer 2

NKSSE
contains teeth and tongue
mostly mechanical digestion, small amount of chemical digestion

Question 3

How does gastric filling, mixing, and emptying occur?

Answer 3

Filling: reflexive relaxation coordinated by swallowing center of the brain stem. Stress-relaxation response of smooth muscle
Peristaltic waves: mix food with gastric juice to create chyme. More powerful near pylorus
Emptying: peristaltic waves force 3ml of chime through pyloric sphnicter. Empties in 2-4 hours. Carb rich exits first, lipid rich leaves last

Question 4

What structures make the renal corpuscle?

Answer 4

glomerulus and bowman’s capsule (parietal layer and visceral layer (podocytes)

Question 5

Discuss the structures of the filtration membrane and how they are specialized for their function.

Answer 5

fenestrated simple squamous epithelium of glomeruler capillary
shared basement membrane
slit membrane between pedicels of podocytes
very permeable to allow filtrate out of blood

Question 6

Carbohydrate Digestion

Answer 6

Starch and disaccharides ingested
oral cavity: Salivary amylase digests carbs down to oligosaccharides, dextrin, and disaccharides
small intestine:
-pancreatic amylase breaks them down to smaller oligosaccharides and disaccharides (lactose, sucrose, and maltose)
-Brush border enzymes alpha-dextrinase, lactase, sucrase, and maltase break them down into glucose, fructose, and galactose (monosaccharides)
-Absorbed by enterocytes and brought back to the liver through the hepatic portal vein

Question 7

Describe the structure and function of the pharynx

Answer 7

Pharynx-functions in swallowing(deglutition). Voluntary oral phase, pharyngeal phase and esophageal phase controlled by medulla

Question 8

10. Discuss the 3 stages of gastric regulation.

Answer 8

1. cephalic phase
   -stimulatory events: smell, thought, taste, sigh of food
   -medulla+hypothalamus->vagus nerve->increased secretions
   -inhibited by illness, SNS, or disgust
2. Gastric phase
   -stimulatory events: distension of the stomach from bolus, proteins in food, alkaline environment, or caffeine
   -enteroendocrine cells secrete gastrin to increase gastric juice
   -inhibited by SNS
3. Intestinal phase
   -brief stimulatory event: enteroendocrine cells in the duodenum secrete intestinal gastrin to increase gastric juice
   -inhibitory event: duodenum enteroendocrine cells secrete cholecystokinin and scretin when duodenum is full to decrease gastic juices.

Question 9

Protein digestion

Answer 9

Stomach: pepsin breaks them down into large polypeptides
small intestine:
-Pancreatic enzymes trypsin, chymotrypsin, and carboxypeptidase break them down into small polypeptides and dipeptides
-Brush border enzymes carboxypeptidase, aminopeptidase, and dipeptidase break them down into amino acids
-Absorbed by enterocytes and takes to liver via hepatic portal vein

Question 10

Submucosa

Answer 10

loose areolar connective tissue with blood and lymph vessels, elastic fibers, nerves, glands, and malt. submucosal nerve plexus.

Question 11

Discuss the importance of bacterial flora.

Answer 11

Ferment indigestible carbs and mucus
release gases that create flatus
synthesize vitamin K
keep pathogenic bacteria in check
may influence weight, mood, and susceptibility to some diseases like diabetes

Question 12

What is the countercurrent exchanger and where is it located

Answer 12

The vasa recta, preserves the osmotic gradient in the renal medulla

Question 13

What enzymes are secreted by the pancreas?

Answer 13

Protein:
trypsinogen->trypsin (converted by brush border enzyme enteropeptidase
chymotrypsinogen->chymotrypsin
procarboxypeptidase->carboxypeptidase

Pancreatic amylase (carbs)
pancreatic lipase (fats)
ribonuclease and deoxyribonuclease (RNA and DNA)

Question 14

What is saliva and how is salivation controlled?

Answer 14

-secrete slightly acidic saliva that contains water, ions, salivary amylase, proteins, mucin, lysozyme, metabolic wastes, and IgA.
-minor glands keep mouth moist
-stimuli such as taste chemoreceptors, mechanoreceptors, sight/smell/thought of food, or irritated GI tract send impulses to salivary nuclei in pons->parasympathetic impulses to salivary glands to secrete saliva

Question 15

Nucleic acid digestion

Answer 15

Small intestine:
-pancreatic enzymes ribonuclease and deoxyribonuclease digest them down to nucleotides
-brush border enzymes digest them down to phosphate group, pentose sugar, and nitrogenous base
-returned to liver via hepatic portal vein

Question 16

Serosa or adventitia

Answer 16

Serosa in abdominal cavity, peritoneum
adventitia outside of abdominal cavity (collagen fibers)

Question 17

Describe the function of cholecystokinin

Answer 17

CCK: secreted in response to fats and proteins in chyme
-targets:
pancreatic acinar cells to increase enzyme production
gall bladder to contract
hepatopancreatic sphincter to open and release
stomach to decrease gastric juices
tells hypothalamus we are full

Question 18

Urine formation: secretion

Answer 18

-occurs throughout renal tubule and collecting duct
-important for adding substances to urine, disposing of urea/uric acid/ammonia, controlling blood pH, getting rid of excess K+ from Na+/K+ pump

Question 19

What is the function of hepatocytes?

Answer 19

processes and filters nutrient-rich blood, create bile

Question 20

Discuss the structure and function of the peritoneum. What are mesenteries and where are they found?

Answer 20

Protection, anchoring, and reduction of friction.
Double serous membrane
found in the abdominal cavity

Question 21

What are the important structural modifications in the small intestine (think about surface area)?

Answer 21

circular folds, microvilli, and villi

Question 22

Where are nephrons found within the kidney?

Answer 22

In the cortex and the medulla

Question 23

What are the accessory organs in the digestive system?

Answer 23

Tongue, teeth, salivary glands, gall bladder, and pancreas

Question 24

Discuss the different cell types (4) found in the mucosa and the importance of their secretions. How do these secretions work together? What protects the stomach lining from these secretions?

Answer 24

-mucus neck cells: thins acid mucous
-parietal cells- secrete HCl and intrinsic factor (needed for B12 absorption). HCl denatures proteins and activates pepsinogen
-Chief cells: secrete pepsinogen and gastric lipase. Pepsinogen becomes pepsin which is an active protease. Gastric lipase digests milk fats
-Enteroendocrine G cell: secretes gastrin into blood which makes parietal cells secrete more gastric juice
Stomach lining protected by mucus.

Question 25

distal convoluted tubule, substances are reabsorbed or secreted

Answer 25

-aldosterone causes Na+ absorption and K+ secretion (Na+/K+ pumps) -parathyroid hormone causes increased calcium reabsorption -atrial natriuretic peptide causes decreased H2O reabsorption

Question 26

Discuss the flow of blood and bile through a lobule (and through the liver).

Answer 26

Bile: hepatocytes->bile canaliculi->bile duct->R+L hepatic duct-> common hepatic duct->common bile duct-> duodenum Blood-> hepatic arteries and portal veins->sinusoids->central vein-> hepatic vein->inferior vena cava

Question 27

describe salivary glands

Answer 27

minor salivary glands in mouth and tongue but major ones located outside oral cavity -parotid, submandibular, and sublingual -contain serous and mucous cells

Question 28

Urine formation- filtration

Answer 28

Net filtration pressure: pressure responsible for filtration formation. 10mmHg -glomerular blood hydrostatic pressure: 55 mmHg, pressure of blood against capillary walls -capsular hydrostatic pressure: 15 mmHg, pressure of fluid in the capsular space pressing against capillary -blood colloid osmotic pressure: 30mmHg, pressure of blood pulling back in capillary Glomerular filtration rate: volume of filtration formed by both kidneys per minute -controlled by renal blood flow -too high , too low absorption -too low, too high absorption

Question 29

What are the functions of the stomach? What type of digestion occurs here?

Answer 29

mechanical and chemical digestion very little absorption

Question 30

What organs make up the alimentary canal?

Answer 30

Mouth, oro and laryngopharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus.

Question 31

Describe the functions of the kidneys

Answer 31

filter blood and remove nitrogen compound waste and drugs regulate blood plasma makeup (pH, blood pressure, solute concentrations) hormone production (erythropoietin and renin) activate vitamin D (cholecalciferol to calcitrol) absorb Ca2+ from diet

Question 32

What is digested and what is absorbed in the small intestine?

Answer 32

All macromolecules digested, nutrients absorbed.

Question 33

What is the difference between the two groups of organs?

Answer 33

One is the main digester, on assists in digesting

Question 34

Describe the function of secretin

Answer 34

secreted in response to acidity of chyme in duodenum targets: -pancreas duct cells to release bicarb -hepatocytes to make bile -stomach to decrease gastric juice

Question 35

How is the alimentary canal innervated?

Answer 35

Intrinsic innervation by the enteric nervous system: -Submucosal plexus-regulates digestive secretions and reacts to the presence of food -myenteric plexus- controls motility, peristalsis/segmentation Extrinsic innervation by the autonomic nervous system: -sympathetic nervous system-inhibit digestive processes -parasympathetic nervous system-promotes digestive processes

Question 36

Hormonal control of renal blood flow and GFR (extrinsic)

Answer 36

Renin secreted by JG cells in response to: -reduced stretch of JG cells (low BP) -stimulation of JG cells by activated macula densa cells -direct stimulation of JG cells by SNS Renin-angiotensin-aldosterone system Angiotensin II causes -vasoconstriction which increases TPR and MAP -aldosterone secretion from adrenal gland increases Na+/K+ pump in DCT -thirst center activation in the hypothalamus - vasoconstriction of afferent arteriole nad efferent arterioles to decrease GFR temporarily -ADH secretion from pituatarty increases aquaporins in principal cells in collecting duct

Question 37

How are the mucosa and submucosa specialized in the small intestine?

Answer 37

Mucosa: contains enterocytes (absorptive cells), brush border enzymes, and intestinal glands Submucosa: duodenal glands and peyer's patches

Question 38

How is the secretion of pancreatic juice regulated?

Answer 38

Secretin signals to the duct cells in the pancreas to release bicarb CCK signals to the pancreas acinar cells to secrete digestive enzymes

Question 39

Myogenic mechanism (intrinsic)

Answer 39

Regulated by JG cells in the afferent arteriole If JG cells sense too much stretch the afferent arteriole vasoconstricts to reduce blood flow to glomerulus If JG cells sense too little stretch, vasodialation of afferent arteriole to increase blood flow to glomerulus

Question 40

What is glomerular filtration rate (GFR)? Why is regulation of the GFR important?

Answer 40

Glomerular filtration rate: volume of filtration formed by both kidneys per minute -controlled by renal blood flow -too high , too low absorption -too low, too high absorption

Question 41

Explain the reflexes involved in micturition (urination or voiding).

Answer 41

-distension of bladder activates stretch receptors -initiates sacral spinal reflex that promotes voiding response voiding reflex is controlled by pontine micturition center -increased PSNS causes detrusor muscle to contract and internal urethral sphincter to relax and inhibits somatic motoro activity causing external urethral sphincter to relax storage reflex (controlled by pontine storage center) -increased SNS causes detrusor muscle to relax and internal urethral sphincter to contract -somatic motor activity causing external urethral sphincter to contract

Question 42

Tubuloglomerular feed back (intrinsic)

Answer 42

Macula densa cells monitor NaCl in filtrate If GFR is too high, NaCl will be high, MD cells release vasoconstrictors that affect afferent arteriole If GFR is too low, NaCl will be low, MD cells stop sending vasoconstrictors to afferent arteriole

Question 43

Describe the process of both peristalsis and segmentation. What is their function

Answer 43

Segmentation- smooth muscle contraction to cause mixing of food with GI juices. Contracts nonadjacent segments for mechanical digestion. Peristalsis- for propulsion of bolus, esophagus->large intestine

Question 44

From where are cholecystokinin (CCK) and secretin secreted?

Answer 44

Secreted by enteroendocrine cells in the duodenum.

Question 45

Discuss the location, structure (and divisions), and function of the large intestine

Answer 45

Surrounds the small intestine in the abdominal cavity cecum, ascending, transverse, descending, sigmoid, rectum, and anal canal. Function: -finish H2O absorption -synthesize vitamins via bacteria -form and eliminate feces

Question 46

What structures make up the juxtaglomerular apparatus (JGA)? What is their function?

Answer 46

Juxtaglomerular cells: mechanoreceptors that sense the stretch of the afferent capillary. secretes renin in response to low BP Macula densa: chemoreceptors that respond to rate of filtrate flow and concentration of NaCl in filtrate

Question 47

describe the teeth

Answer 47

-Contains a pulp cavity with blood vessels and nerves, dentin (bonelike tissue, avascular), and enamel which contains calcium-phosphate crystals -function is mastication -located in the maxilla and mandible

Question 48

Discuss the external and internal anatomy of the kidney

Answer 48

external: renal fascia->renal fat pad->fibrous capsule internal: -renal cortex: blood filtration -renal medulla: renal columns, renal pyramids, renal papilla -renal lobes -calyces and renal pelvis -renal hilum

Question 49

Discuss the gallbladder. What is its main function? Is it involved in bile storage or secretion? How is gallbladder activity regulated?

Answer 49

muscular sac that stores, concentrates, and propels bile into the duodenum. Regulated by secretin and CCK

Question 50

describe the tongue

Answer 50

-tongue is used to move food in mouth and is a sensory organ. Covered in filiform, circumvallate, and fungiform papillae. Contains taste buds. -has mucus and serous glands (secrete lingual lipase) -large amount of skeletal muscle running in lots of directions

Question 51

loop of henle, substances are reabsorbed or secreted

Answer 51

descending: water reabsorption ascending: reabsorb NaCl

Question 52

What is the structure and function of a portal triad

Answer 52

Contains bile duct, branch of the hepatic artery (portal arteriole), and branch of the hepatic portal vein (portal venule) bile duct: moves bile from hepatocytes to duodenum artery: brings oxygenated blood vein: brings deoxygenated nutrient rich blood

Question 53

Urine formation: reabsorption

Answer 53

-occurs throughout renal tubule and collecting duct, mostly proximal convoluted tubule -Nat+ active transport, transcellular -nutrients co transported with Na+, transcellular -H2O flows by osmosis following solutes, transcellular -K+, Ca2+, and Mg2+ and urea: diffuse through H2O filled spaces between cells. -100% of glucose reabsorbed in PCT -not reabsorbed: creatinin

Question 54

Discuss the location, structure, and function of the liver.

Answer 54

Largest gland in the body, 4 lobes 500 functions including production of bile, production of cholesterol and lipoproteins, processing blood, makes albumin and clotting proteins, stores glucose as glycogen, releases glucose, stores fat soluble vitamins and iron, detoxification. connected to the diaphragm and stomach

Question 55

Describe the structure and function of the esophagus.

Answer 55

All 4 alimentary canal layers Contains esophageal glands in the submucosa muscularis external transitions from skeletal to smooth muscle functions in deglutition- upper esophageal sphincter opens to let in food, moved my peristalsis, passes through the diaphragm and lower esophageal sphincter

Question 56

What is the structure and function of a lobule?

Answer 56

Filtering blood and producing bile. -bile canuliculi move bile away from hepatic lobule -hepatic sinusoids bring blood from artery and portal bring through the lobule to the central vein -kupffer cells: fixed macrophages in the walls of hepatocytes, phagocytize antigens and old RBC/WBC

Question 57

Discuss the effects of ADH on the production of concentrated urine.

Answer 57

mild dehydration causes increased blood osmolarity which is detected by osmoreceptors in hypothalamus which secretes antidiuretic hormone from posterior pituitary. ADH causes increased aquaporins in the collecting duct which increases the reabsorption of water via the osmotic gradient, and a small amount of concentrated urine is produced.

Question 58

What is bile and where is it made? Where in the digestive tract does it function?

Answer 58

yellow-brown-green solution that contains water, electrolytes (bicarb), and has an alkaline pH functions in the duodenum

Question 59

What type of epithelium do you find in each organ?

Answer 59

oral cavity- NKSSE Esophagus- NKSSE Stomach- simple columnar w/ goblet cells Small intestine- simple columnar w/ goblet cells and microvilli Large intestine- simple columnar w/ a lot of goblet cells

Question 60

How is bile involved in the breakdown of lipids?

Answer 60

Bile salts made of cholesterol coat fats to increase emulsification (makes smaller particles to increase surface area), and micelle formation around fat molecules increases absorption.

Question 61

Discuss the location, structure (and divisions), and function of the small intestine

Answer 61

Long tube that runs from pyloric sphincter to ileocecal valve duodenum-10 inches jejunum- 3ft ileum- 6 ft Function: mechanical and chemical digestion absorption of nutrients

Question 62

Lipid Digestion

Answer 62

ingestion of triglycerides oral cavity: lingual lipase (inactive) stomach: lingual lipase (active) and gastric lipase (milk fat) small intestine: -bile salts from liver emulsify fats -pancreatic lipase breaks the triglycerides down into Short fatty acids and glycerol, and long fatty acids, monoglycerides, and diglycerides. -short fatty acides and glycerol returned to liver via hepatic portal vein -long fatty acids, monoglycerides, and diglycerides are coated with bile to form micelles, absorbed by enterocytes, rebuilt into triglycerides, coated with proteins to form chylomicrons, released from cell, enter lacteals in villi, and are transported to venous blood.

Question 63

proximal convoluted tubule, substances are reabsorbed or secreted

Answer 63

Reabsorb: Na+ active transport nutrient co-transport (glucose, amino acids, vitamins) H2O passive transport Bicarb and other ions passive transport urea/uric acid passive transport

Question 64

Describe the structure and function of the nephron.

Answer 64

-series of tubes, renal corpuscle and renal tubules -filtration, reabsorption, and secretion

Question 65

Describe the difference between short and long neural reflexes.

Answer 65

Short reflexes- involve intrinsic nerve plexuses -chemoreceptors+osmoreceptor+mechanoreceptor signals sent to local nerve plexus->smooth muscle or glands are affected Long reflexes- involve CNS and ANS. external stimuli such as smell or sight->nerve plexuses->effectors

Question 66

What is net filtration pressure (NFP) and how is it determined?

Answer 66

Net filtration pressure: pressure responsible for filtration formation. 10mmHg -glomerular blood hydrostatic pressure: 55 mmHg, pressure of blood against capillary walls -capsular hydrostatic pressure: 15 mmHg, pressure of fluid in the capsular space pressing against capillary -blood colloid osmotic pressure: 30mmHg, pressure of blood pulling back in capillary NFP= GBHP-(CHP+BCOP)

Question 67

What is the countercurrent multiplier and where is it located?

Answer 67

the ascending limb of the loop of henle, which establishes an osmotic gradient in the renal medulla

Question 68

How is urine drained from a kidney?

Answer 68

renal papillae-> minor calyx-> major calyx-> renal pelvis->ureter via peristalsis

Question 69

What is the purpose of enterohepatic circulation?

Answer 69

bile salts are reclaimed by the enterohepatic circulation. Reabsorbed in the ileum and brought back to the liver by the portal vein.

Question 70

Mucosa

Answer 70

Epithelium- nonkeratinized stratified squamous epithelium for protection from abrasion or simple columnar epithelium for absorption Lamina Propria- loose areolar connective tissue with blood and lymph vessels, elastic fibers, nerves, glands, and malt muscularis mucosae- thin layer of smooth muscle, creates folds in GI tract, not a major mover.

Question 71

What enzymes do you find at the brush border, and what do they digest? 5 carb, 3 protein, 2 RNA/DNA

Answer 71

Carbs: -alpha-dextrinase: breaks down dextrin to glucose -lactase breaks down lactose to galactose and glucose -sucrase breaks down sucrose to fructose and galactose -maltase breaks down maltose into two glucose Proteins: -aminopeptidase breaks down amino chain on the amine side -carboxypeptidase breaks down amino chain from carboxyl side -dipeptidase breaks down bond between two amino acids RNA/DNA: nucleosidase breaks off nitrogenous bases from nucleotides phosphatase breaks off phosphate group from nucleotide (sugar pentose left over)

Question 72

muscularis externa

Answer 72

smooth muscle, inner circular layer, outer longitudinal layer. Used for segmentation and peristalsis. Contains the myenteric nerve plexus. The stomach contains an additional oblique layer.

Question 73

Neural control of renal blood flow and GFR (extrinsic)

Answer 73

-PSNS stimulation-> vasodilation of renal blood flow -SNS stimulation -> vasoconstriction of renal blood flow, renin secretion-> increase MAP

Question 74

Discuss the motility of the small intestine.

Answer 74

-segmentation takes place when chyme is present -peristalsis takes place once chyme is absorbed. Initiated when duodenal glands secrete motilin. each eave starts distal to previous wave

Question 75

Discuss the location, structure, and function of the pancreas.

Answer 75

-deep to the stomach and retroperitoneal, against the duodenum -both an endocrine and exocrine gland -sends pancreatic juice to the duodenum -has a main and accessory pancreatic duct

Question 76

Describe the structure and function of the rectum and anal canal. What sphincters are located here and how are they controlled?

Answer 76

Rectum has three rectal valves that help prevent simultaneous passage of feces and gas Anal canal has 2 sphincters -internal smooth muscle -external skeletal muscle

Question 77

What is the function of pancreatic juice?

Answer 77

produced by the acinar cells, enzyme-rich juice is secreted into the duodenum to digest macromolecules.

Question 78

How is bile release regulated?

Answer 78

Entry of chyme into duodenum stimulates the release of CCK and secretin. Secretin increases bile production in the liver and CCK causes the gallbladder to contract and the hepatopancreatic sphinter to open

Question 79

Discuss the digestive processes (6) that occur in the alimentary canal. Where does each specifically occur?

Answer 79

-Ingestion- bringing food in, oral cavity -Propulsion- move substances through digestive tract (esophagus, stomach, small/large intestine) -Mechanical digestion-physical forces to break apart food. Oral cavity, stomach, and small intestine -Chemical Digestion- breaking chemical bonds of food we eat w/enzymes, oral cavity, stomach, small intestine -Absorption- of nutrients and H20 into blood and lymph, small intestine -Defecation- removal of things not used or digested, anus

Question 80

Discuss the process of defecation.

Answer 80

-Distenstion of rectal walls by feces causes parasympathetic reflex mediated by spinal cord. -Mass movement in sigmoid colon and rectum. -Internal anal sphincter send message to brain -External anal sphincter initially contracts, relaxes under conscious decision -Defecation assisted by rectal muscle.

Question 81

What is the sequence of blood flow through the arteries, capillaries, and veins of the kidneys?

Answer 81

renal artery-> segmental artery->interlobar artery->arcute arteries-> cortical radiate artery-> afferent arteriole-> glomerulus-> efferent arteriole-> vasa recta or peritubular capillaries-> cortical radiate vein, arcute vein-> interlobar vein-> renal vein

Question 82

How are these involved in the maintenance of concentration gradients in the interstitial fluid of the medulla and in the formation of dilute urine?

Answer 82

countercurrent multiplier-ascending loop of Henle -solute pumps increase the concentration of interstitial Na2+ deep in the medulla -allows filtrate to be dilute by the end of the limb countercurrent exchanger -by matching the osmolarity in the blood of the IF, solutes are not drawn into the blood and conserve the gradient

Question 83

What structural modifications are found in the mucosa of the large intestine?

Answer 83

Large amount of goblet cells and enterocytes