Anatomy

What structure controls the movement of chyme from the small intestine to the large intestine?

ileocecal valve

where is most of your food digested?

in the small inetstine

what produces bile?

liver

what conditions could lead to jaundice?

gallstones
cirrhosis
hepatitis

Which sphincter, or valve, controls food movement from the stomach into the small intestine?

pyloric

What are the three subdivisions of the small intestine?

duodenum, jejunum, ileum

What are the fingerlike projections of the small intestine that increase the absorptive surface area?

villi

Bile is formed by the ________ and stored in the ________.

liver; gallbladder

Deep folds of both the mucosa and submucosa in the small intestine that increase surface are known as ________.

circular folds (plicae circulares)

Which sphincter operates under voluntary control?

external anal sphincter

Jaundice indicates that bile has backed up into the ________ rather than entering the small intestine.

liver

A stabbing victim sustained a perforation to his large intestine. From the outermost layer to the innermost layer, what is the order in which the knife penetrated his intestine?

serosa, muscularis externa, submucosa, mucosa

Which of the following features is NOT characteristic of the small intestine?

rugae

What organs release secretions into the duodenum of the small intestine?

liver, gallbladder and pancreas

Enzymes and bile are carried by the pancreatic duct and bile duct into the ________.

duodenum

What is one of the main functions of the small intestine?

absorption of nutrients

Which one of the following is NOT a modification (which is designed to increase surface area for absorption within the small intestine?

Peyer's patches

Which one of the following is NOT a subdivision of the large intestine?

duodenum

Which organ is responsible for drying out indigestible food residue through water absorption and the elimination of feces?

large intestine

What organ stores bile when food digestion is not occurring?

gallblader

Which tube brings bile directly back into the gallbladder for storage?

cystic duct

What accessory organ produces bile?

liver

A hiatal hernia is a problem associated with which of the following sphincters?

cardioesophageal

Which of the following enzymes could be a contributor to pancreatitis?

chymotrypsin

The process of eliminating indigestible residues from the GI tract is called ________.

defecation

When feces are forced into the rectum by mass movements and the wall of the rectum becomes stretched, the ________ reflex is initiated.

defecation

What is the end product of protein digestion?

amino acids

Which is a function of saliva?

inhibits bacterial growth in the oral cavity

Which of these is secreted by the pancreas?

trypsin

Which of these is a substrate for amylase?

startch

What hormone secreted by the duodenum inhibits secretion of gastric juices and stimulates the release of insulin?

gastric inhibitory peptide

Which of these are broken down by brush border enzymes?

disaccharides

What organ manufactures and stores most of the body's glycogen as a ready source of glucose?

liver

gastrin

: secreted by cells within the stomach, stimulates stomach activity

secretion

: causes the liver to produce more bile and stimulates pancreatic secretion

cholecystokin

: causes the gall bladder to contract and stimulates pancreatic secretion

Why might it be beneficial to take a digestive enzyme supplement with your meals when you are older?

Fewer digestive enzymes are secreted as the digestive system ages.

What inborn error of metabolism affects pancreatic secretion of digestive fluids?

cystic fibrosis

Which of these is found in saliva?

lysozyme

Which of the following conditions could lead to a pathological electrolyte imbalance?

diarrhea

trypsin digestive enzyme

protien

rennin

milk protiens

amylase

startch

lipase

fat

nuclease

nucleic acids

Which two hormones promote the release of bile and pancreatic juice into the small intestine?

secretin; cholecystokinin (CCK)

The hormone responsible for promoting the release of pepsinogens, mucus, and hydrochloric acid in the stomach is called ________.

gastrin

Hydrochloric acid is necessary in the stomach for the conversion of pepsinogen into its active protein-digesting form called ________.

pepsin

What organs are targeted by the hormones secretin and cholecystokinin (CCK) to release pancreatic juice and bile into the small intestine for digestion?

pancreas, gallbladder, liver

The enzyme responsible for converting milk protein in an infant's stomach to a substance that looks like sour milk is ________.

rennin

enzyme rich pancreatic juices dont conatain

pepsin

We do NOT have the enzymes to digest ________.

cellulose

Which set of salivary glands are situated anterior to the ear?

parotid glands

Maurice was born "tongue-tied." Maurice is unable to speak properly and has difficulty swallowing because his tongue cannot efficiently push food to the back of his mouth. What structure in Maurice's mouth must be surgically corrected to fix these problems?

lingual frenulum

Which of the following teeth are most likely to become impacted and require surgical removal?

third molars

The process of physically and chemically breaking food particles down is referred to as ________.

digestion

What anchors the tongue to the floor of the mouth and limits its movements?

lingual frenulum

Large wrinkle-like folds in the stomach lining, present when the stomach is empty, that allow for expansion when the stomach is filling are called ________.

rugae

The portion of the tooth embedded in the jawbone is the ________.

root

The area in the mouth contained by the teeth is known as ________.

oral cavity proper

Which one of the following represents the correct order through which food passes in the alimentary canal?

mouth, pharynx, esophagus, stomach, small intestine, large intestine

What sphincter regulates the passage of food from the esophagus into the stomach?

cardioesophageal sphincter

What do the enteroendocrine cells of the stomach produce?

gastrin

Hydrochloric acid is necessary in the stomach for the conversion of pepsinogen to ________.

pepsin

What is the purpose of mastication?

to chew, grind and tear food into smaller pieces while in the mouth

What does salivary amylase digest?

startch

What ceramic-like substance covers the crown of a tooth?

enamel

The anterior chisel-shaped teeth that are adapted for cutting are called ________.

incisors

Which of these is an example of mechanical digestion?

chewing

What term refers to alternating waves of contraction and relaxation of the digestive tract that propel food along the tract?

peristalsis

Which of the following is, essentially, reverse peristalsis?

emesis

The propulsive process that moves food from one organ to the next is called ________.

peristalsis

The sequence of steps by which large food molecules are broken down into their respective building blocks by catalytic enzymes is called ________.

digestion

Where does starch digestion begin?

mouth

Which digestive system organ is the target of gastrin?

stomach

structure of small intestine

goes from plyoric to Large intestine
coiled except for the duodenum
suspended from back abdominal wall by mesentry
3 supdivisions : duodenum, jejunum, and iluleum
ileum meets LI at ileocecal valve

Duodenum

first 10in of digestion
feed into duodenum to do chemical digestion
pancreatic duct bring enzymes from pancreas to SI to break down food
bile ducts from liver to SI

jejunum and ileum

used for absorption
active transport processes except for fat (diffusion)
Increase surface area:
Microvilli-tiny cell membrane projection of mucosa cells.
Brush border - makes enzymes that finish protein/carb
digestion
Villi - mucosa projections
rich capillary beds and lot of lacteal (lymph)
absorb nutrients
Circular folds- deep folds of mucosa and submucosa

peyers patches

lymphatic tissue located in submucosa
increase at end of si
due to large number of bacteria

chemical digestion

brush border enzymes: break disaccharids into monosaccharides and finish protien digestion

Intestinal juice- enzyme poor, mucus rich

pancreatic juice- enzyme rich
pancreatic amylase
tryspin, chymotyspin, carboxidose
lipases
nucleases
Bicarbonate= basic substance to neutraliz acid (not enzyme)

pancreas

retroperitoneal
makes digestive enzymes and basic fluid to neutralize acid from stomach
endocrine function too -insulin & glucagon

liver

largest gland in body
under diaphragm, right side of body
falciform ligament- mesentary cord that liver hangs from
back wall
4 lobes
produces bile
leaves liver through common bile duct
bile salts, bile pigment, (bilerubin), cholesterol, phospholipids,
electrolytes.
bile salts emusify fats

gallbladder

small, thin wall, green, bottom surface of liver
when no food is present, bile backs up into custic duct and goes to gallblader for storage
water removed from bile to concentarte it
when fat gets into duodenum hormone prompts gallbladder to contract and send bile to doudenum

control of pancreas, liver, and gallbladder

pancreatic juice stimulated by vagus nerve and local hormones (secretion and CCK)
secretion causes liver to increase bile
cholecytokin (CCK) gallbladder contraction to release

structure of large inetstine

dries out indigestable food by absorbing water
eleminate waste as feces
no villi
goblet cells - make basic mucus to lubricate feces
haustrea- sections of li

bacteria in li

metabolize remaining nutrients
make methane, hydrogen sulfide, causes flatulence
makes vitamins K and B

Function of LI

big water guy
absorbs water, vitamins, and ion
feces left behind
haustral contraction- slow segmented movements
haustra fills with food, distension stimulates muscle to contract so contents go next to hausta
mass movenemnt long slkow powerful movements moving over li and force contents to rectum

defecation reflex

when feces go to rectum by mass movement
spinal refelx
causes wall of sigmoid colon and rectum to contract so anal sphynxs relax
feces forced through anal canal
brain gets time to decide if open external sphincter
temporary delay possible by brain
reflex ends, rectal walls relax, and defecation occurs.