Anatomy and Physiology Flashcards
functions of GI system
- Process food substances
- Absorb the products of digestion into the blood
- Excrete unabsorbed materials
- Provide an environment for microorganisms to synthesize nutrients, such as vitamin K.
- For risk factors associated with the GI system,
Mouth
- Contains the lips, cheeks, palate, tongue, teeth,
salivary glands, muscles, and maxillary bones
- Saliva contains the enzyme amylase (ptyalin),
which aids in digestion.
Esophagus
- Collapsible muscular tube about 10 inches
(25 cm) long
- Carries food from the pharynx to the stomach
Risk Factors Associated with the Gastrointestinal System
Allergic reactions to food or medications
Cardiac, respiratory, and endocrine disorders that may lead
to slowed gastrointestinal (Gl) movement or constipation
Chronic alcohol use
Chronic high stress levels
Chronic laxative use
Chronic use of aspirin or nonsteroidal antiinflammatory
drugs (NSAlDs)
Diabetes mellitus, which may predispose to oral candidal
infections or other Gl disorders
Family history of Cl disorders
Long-term GI conditions, such as ulcerative colitis, that
may predispose to colorectal cancer
Neurological disorders that can impair movement,
particularly with chewing and swallowing
Previous abdominal surgery or trauma, which may lead to
adhesions
Tobacco use
Stomach
contains candia, fundus, body, and pylorus
musous glands located in the mucosa prevent autodigestion with alkaline coating
Lower esophageal sphincter (cardiac) sphincter prevents reflux in esophagus
pyloric sphincter regulates rate of stomach emptying into SI
HCl kills bacteria and breaks food down into small particles and gives a chemical environment for enzymatic function
Stomach enzymes and hormones
pepsin = proteins to proteoses and peptones
intrinsic factor from parietal cells = required for B12 absorbtion
gastrin = controls gastric aciditiy
Small intestine
duodenum contains openings of the bile and pancreatic ducts
jejunum is about 8 ft long
ileum is 12 ft long
SI ends at the cecum
Pancreatic juice enzymes (6)
amylase = starch –>maltose
maltase = maltase –> glucose
lactase = lactose –> galactose and glucse
sucrase = sucose –> fructose and glucose
nuclease = nucleic acids –> nucleotides
enterokinase = activates trypsinogen to trypsin
Large Intestine
5 ft long absorbs water and eliminates wastes
intestinal bacteria plays role in synthesis of vit Bs and and vit K
ascending transverse descending sigmoid colons
ileocecal valve prevents reflux into the cecum
internal and external anal sphinters to anal canal
Peritoneum
lines the abdominal cavity and forms the mesentery that supports the intestinas and blood supply
Liver
largest gland
kupfer cells that remove bacteria from portal vein
removes excess glucose and amino acids from portal blood
synth glucose amino acids fats carbs and proteins
stores A, D, B and Fe
secretes bile to emulsify fats
hepatic ducts
delivers bile to gallbladder via cystic duct
and to duodenum via common billiary duct
common bile duct opens into the duodenum with the pancreatic duct at the ampulla of Vater
sphincter precents reflux of intestinal contents into the common bile duct and pancreatic duct
Gall baldder
stores and concentraters bile and contracts to force bile into the duodenum during the digestion of fats
cystic duct joins the hepatic ducts to form the common bile duct
sphinter of Oddi is located at the enteance of the duodenum
presence of fatty material in the duodenum stimulates the liberation of cholecystokinin via contraction of gallbadder and relaxation of sphnicter of Oddi
Pancreas
Exocine function:
secretes NaCO to neutralize stomach acidity
juices contain enzymes for digesting carbs fats and proteins
Endocrine function:
secreates glucagon to raise BG
releases somatostatin to exert an hypogylcemic effect
islets of Langerhans release insulin into blood for carb metabolism
