Digestive Lab quiz

carbohydrate role

used as fuel to drive processes throughout the body by converting glucose into ATP

protein role

form cellular and tissue-level structures. components of many chemicals in the body

lipid role

key part of cell membrane, act as signaling molecules, major fuel source

nutrient breakdown in GI tract (mechanical)

chewing of food into a bolus, swallowing and entering stomach, peristalsis mixes and softens food to create chyme, pylorus acts as a filter for pyloric sphincter, intestines work to mix and absorb food

what impacts enzyme function?

temperature and pH

monosaccharides

glucose, fructose, galactose, ribose, deoxyribose

disaccharides

sucrose, lactose, maltose

sucrose

glucose and fructose

lactose

glucose and galactose

maltose

two of glucose

polysaccharides

starches, glycogen, cellulose

building blocks of proteins

amino acids

nutrient breakdown in GI tract (chemical)

salivary amylase starts breaking down carbohydrates, fundus stores undigested food and gases, food mixes with acidic chyme and starts breaking down, protein breaks down due to HCl and pepsin, stomach contents enter duodenum, intestinal and stomach juices facilitate absorption in small intestine, large intestine secretes mucus

salivary amylase

site of origin: salivary glands

action: break down polysaccharides into smaller polysaccharides

pancreatic amylase

site of origin: pancreas

action: break down smaller polysaccharides into disaccharides and monosaccharides

alpha-dextrinase

site of origin: brush border (SI)

action: breaks down alpha-dextrins into monosaccharides

sucrase

site of origin: brush border (SI)

action: breaks down sucrose into glucose and fructose

lactase

site of origin: brush border (SI)

action: breaks down lactose into glucose and galactose

maltase

site of origin: brush border (SI)

action: breaks down lactose into glucose and galactose

pepsin

site of origin: chief cells

action: break down polypeptides into smaller polypeptides

trypsin

site of origin: pancreas

action: break down smaller polypeptides into dipeptides and amino acids

aminopeptidase

site of origin: brush border (SI)

action: break down smaller polypeptides into amino acids and smaller polypeptides

dipeptidase

site of origin: brush border (SI)

action: break down dipeptides into amino acids

lingual lipase

site of origin: salivary glands

action: breaks down lipids into glycerol and fatty acids

gastric lipase

site of origin: chief cells

action: breaks down lipids into glycerol and fatty acids

pancreatic lipase

site of origin: pancreas

action: breaks down lipids into glycerol and fatty acids

enzyme function

catalysts on biological processes

GI tract organs

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

accessory organs

teeth, tongue, salivary glands, liver, gallbladder, pancreas

absorption

uptake of a substance

desiccation

removing water

secretion

release of a substance

mechanical digestion

breakdown of chunks of food into smaller bits of the same food

chemical digestion

breakdown of macronutrients (by enzymes/acid) into smaller molecules

ingestion

consumption via mouth

mastication

chewing

deglutition

swallowing

propulsion

pushing/moving forward

peristalsis

waves of smooth muscle contraction that causes propulsion

defecation

expelling feces from GI tract

churning

method of mechanical breakdown

segmentation

mechanical breakdown in intestines, breaking food into “segments” as well as mixing

bolus

rounded mushy lump of food

chyme

liquified food

feces

found in colon

layers of digestive tract

mucosa (superficial), submucosa, muscularis extrema, serosa (deep)

mucosa layers

epithelium (stratified squamous), lamina propria, muscularis mucosae

muscularis externa layers

inner circular, outer longitudinal

myenteric plexus function

controls peristalsis and other contractions of muscularis externa

submucosal plexus function

controls muscularis mucosae and glandular secretions of mucosa

parietal peritoneum

covers abdomen

visceral peritoneum

covers organs

mesentery

holds small intestine to posterior abdominal wall

mesocolon

holds large intestine to posterior abdominal wall

falciform ligament

binds liver to anterior abdominal wall

greater omentum

layer of fat that loosely covers transverse colon and small intestine

lesser omentum

connects medial curve of stomach and liver

upper esophageal sphincter

regulates swallowing reflex and keeps excess air out of esophagus when not in use

lower esophageal sphincter

prevents reflux of contents from stomach

stomach layers

inner oblique (innermost), middle circular, outer longitudinal

cardia

interface between esophagus and stomach

fundus

holds both undigested food and gases released during digestion

body

main portion of stomach where most churning and digestion takes place

pyloric antrum and canal

holds the broken down food until it is ready to be released into small intestine

pyloric sphincter

keeps contents in stomach until liquified and regulates slow release of chyme

parietal cells

secrete HCl and intrinsic factor

chief cells

secrete pepsinogen and gastric lipase

G cells

secrete gastrin into the blood stream

regions of small intestine

duodenum, jejunum, ileum

small intestine ways to absorb

plicae circularis, villi, microvilli

regions of large intestine

cecum, ascending/transverse/sigmoid colon, rectum, anal canal, anus

internal anal sphincter

smooth muscle, involuntary

external anal sphincter

skeletal muscle, voluntary

hard palate

bony, forms most of roof of mouth

soft palate

muscular, forms rest of mouth’s roof

uvula

prevents swallowed food from entering nasal cavity

cheek

forms lateral wall of oral cavity

molars

grind food

premolars

crush and grind food

canines

tear food

incisors

cut food

superior labial frenulum

attaches superior lip to gum

tongue

forms floor of mouth, manipulates food for chewing and swallowing, shaoes food, senses taste

lingual frenulum

limits movement of tongue posteriorly

gingiva

cover tooth sockets and help anchors teeth

inferior labial frenulum

attaches inferior lip to gum

enamel

protects tooth from wear and tear, made of calcium salts

dentin

makes up majority of tooth, calcified connective tissue

pulp cavity

contains pulp (connective tissue containing nerves and blood vessels)

cementum

bone-like substanxe that attaches the rooth to the periodontal ligament

periodontal ligament

helps anchor tooth to underlying bone

apical foramen

opening at base of root canal through which blood vessels, lymphatic vessels, and nerves enter a tooth

salivary glands

parotid gland (cheek), submandibular gland (jaw), sublingual gland (tongue/under mouth)

intrinsic salivary glands

scattered throughout mouth, always producing saliva. minor

extrinsic salivary glands

3 pairs of glands, major

salivary gland histology

serous cells (watery fluid, enzyme), mucous cells (mucous), duct cells (form ducts leading to oral cavity)

hepatic triad

branch of hepatic portal vein, branch of hepatic artery proper, bile ductule

liver

produces bile

gallbladder

stores and concentrates bile

pancreas histology

islets of langerhans (endocrine), acini (exocrine)