GI Flashcards
Serous membrane which surrounds abdominal organs
Peritoneum
Name the different parts of the peritoneum
- Parietal layer
- Visceral layer
- Peritoneum cavity
Where does the parietal layer attach to?
abdominal wall
Where does the visceral layer attach to?
organs called serosa
Accumulation of fluid to peritoneal cavity
ascites
Bonds organs to each other and to the walls of the abdominal cavity
folds of the peritoneum
Name the layers of the GI tract
- mucosa
- submucosa
- muscularis
- serosa
What contains blood and lymph vessels which are the routes by which nutrients absorbed into the GI tract reach other tissues of the body?
areolar connective tissue
Contains areolar connective tissue, mucosa associated lymphatic tissue, and muscularis mucosae
lamina propria
Thin layer of smooth muscle
muscularis mucosae
Areolar connective tissue that binds mucosa to muscularis
submucosa
Located inferior and anterior to ears; between skin and masseter muscle
parotid glands
Located beneath base of tongue in posterior floor of mouth
submandibular glands
Located superior to submandibular glands
sublingual glands
Collapsible muscular tube that lies posterior to the trachea
esophagus
Controls the passage of food into the esophagus
upper esophageal sphincter
Controls passage of food into stomach
lower esophageal sphincter
Surrounds the superior opening of stomach
cardia
Rounded region superior and to the left of the cardia
fundus
Region that connects to the duodenum
pylorus
Controls passage of chyme into duodenum
pyloric sphincter
Large folds that are present when stomach is empty
rugae of mucosa
Name the regions of the small intestine
- duodenum
- jejunum
- ileum
Controls passage of chyme into large intestine
ileocecal sphincter
About 5 feet longs and attached to posterior abdominal wall by mesocolon
large intestine
The internal sphincter contains _______ muscle and has __________ control
smooth; involuntary
The external sphincter contains _______ muscle and has __________ control
skeletal; voluntary
Opening of common bile duct merges with pancreatic duct and opens into duodenum
hepatopancreatic ampulla
Covered by visceral peritoneum with underlying dense irregular connective tissue
liver
Stimulates enteric nervous system, which increases most GI activity
PNS (vagus nerve)
Inhibits GI activity, mostly by inhibiting enteric nervous system
SNS
- Innervates structures in the submucosa
- Controls secretion of glands
- Controls vasoconstriction of blood vessels
submucosal plexus
Innervates muscularis
myenteric plexus
Digestive enzyme that acts on triglycerides
lingual lipase
Digestive enzyme that acts on starches (carbs)
salivary amylase
Secreted type of antibody that prevents attachment of microbes so they cannot penetrate epithelium
immunoglobulin A
Lyses bacteria
bacterial lysozyme
Salivation controlled by _____
ANS
What stimulates salivation?
PNS
What inhibits salivation?
SNS
Where does food begin to dissovle?
in saliva
In the stomach, the bolus of food is reduced to a liquid substance called _____
chyme
What activates pepsin?
activation of pepsinogen by HCl
Digests proteins
pepsin
Digests fats
- lingual lipase
- gastric lipase
Secretes mucus that forms a protective coating that prevents digestion of stomach wall
mucous cells
Secretes HCl
Parietal cells
Secretes intrinsic factor
parietal cells
Secretes pepsinogen
chief cells
Proteolytic enzyme that breaks peptide bonds
pepsin
Secretes the hormone gastrin into blood stream
G cells
Increases activity of stomach by stimulating parietal, chief, and ECL cells, increasing motility of stomach, and relaxing pyloric sphincter
gastrin
Secretes somatostatin which inhibits H+ secretion by parietal cells
D cells
Secretes histamine which stimulates H+ secretion by parietal cells
ECL cells
What forms the brush border?
absorptive cells lining the villus that have microvilli
Most digestion and absorption occur in ______ intestine (specifically in the __________)
small; duodenum
Contains Brunner’s glands which secrete alkaline mucus with NaHCO3 that helps to neutralize gastric acid in chyme
submucosa of duodenum
Digests maltose into glucose + glucose
maltase
Digests sucrose into glucose + fructose
sucrase
Digests lactose into glucose + galactose
lactase
Breaks down destrins into glucose
alpha-dextrinase
Digests proteins in small intestine
aminopeptidase
Digests dipeptides into amino acids in small intestine
dipeptidase
Digests nucleic acids in small intestine
nucleosidases
Activates trypsinogen into trypsin which digests proteins
enterokinase
Secrete mucus in small intestine
goblet cells
Secrete secretin in small intestine
S cells
Secrete CCK
CCK cells
Secrete GIP which induces insulin secretion from pancrease
K cells
Secrete GLP-1
L cells
- Found in deepest parts of intestinal glands
- Secrete lysozyme and bactericidal enzyme
- Phagocytic properties
Paneth cells
What is second source of bicarbonate next to Brunner’s gland?
pancreatic juice
- Buffers acidic gastric juice in chyme
- Inactivates pepsin
- Creates proper pH for action of digestive enzymes in duodenum
NaHCO3
Carbohydrate digesting enzyme in pacreas
pancreatic amylase
Triglyceride digesting enzyme in pancres
pancreatic lipase
Protein digesting enzymes in pancres
- trypsin
- chymotrypsin
- carboxypeptidase
- elastase
Nucleic acids digesting enzymes in pancreas
- ribonuclease
- deoxyribonuclease
Instead of capillaries, liver contains ______
sinusoids
Delivers oxygenated blood to liver
branch of hepatic artery
Delivers deoxygenated blood rich in newly absorbed nutrients from GI tract to liver
branch of hepatic portal vein
What secretes bile?
hepatocytes
Breakdown of large lipid globules into small droplets
emulsification
What forms micelles?
bile
Ferry lipids to wall of GIT for absorption
micelles
Enhance secretion of bile from liver and gallbladder
CCK and Secretin
Stimulates production of bile by liver
PNS
Most bile salts that enter duodenum are reabsorbed in ______
ileum
Chylomicrons are _______
lipoproteins
Spherical particles with an outer shell of apoproteins, phospholipids, and cholesterol molecules surrounding inner core of triglycerides
chylomicrons
What is the function of chylomicrons?
to transport triglycerides from the small intestine to various tissues
What happens to chylomicron once it enters blood circulation via lymphatic vessels?
taken to adipose tissue and liver
_____ on chylomicron activates endothelial lipoprotein lipase (LPL) located in membrane of endothelial cell
Apo C-2
Removes fatty acids from triglycerides in chylomicron
LPL
Where are triglycerides resynthesized and stored
adipose cells
______ on chylomicron is docking protein recognizing receptor on hepatocyte
Apo E
_____ degrades fatty acids into small compounds that can be used for energy or to synthesize other lipids
liver
Name the fat soluble vitamins
A, D, E, K
Name the water soluble vitamins
B12
