Chapter 5: Digestive System: Vocabulary Flashcards
gastrointestinal tract
Food enters the mouth and solid waste leaves the body.
Four functinos:
- ingestion
- digestion
- absorption
- elimination
ingested
Complex food material is placed in the mouth
digested
Food is broken down chemically and mechanically as it travels through the GI tract
enzymes
Speed up chemical reactions and aid the breakdown of complex nutrients
glucose
sugar
digestion
Occurs in the mouth, stomach, and small intestine
absorption
Nutrients are digested as the food passes through the lining cells or epithelium of the small intestine and into the bloodstream
elimination
Solid waste materials that cannot be absorbed into the bloodstream pass out of the body through the rectum as feces
feces
Solid waste material that could not be broken down and absorbed into the bloodstream
oral cavity
The GI tract begins in the mouth
cheeks
Form the walls of the oval-shaped oral cavity
lips
Surround the opening to the oral cavity
hard palate
Forms the anterior portion of the roof of the mouth
soft palate
Muscular posterior portion of the roof of the mouth
rugae
Irregular ridges in the mucous membrane covering the anterior portion of the hard palate
uvula
Small soft tissue projection that hangs from the soft palate. It aids in production of sounds and speech
rugae
Irregular ridges in the mucous membrane covering the anterior portion of the hard palate and located in the stomach
mastication
chewing
deglutition
swallowing
papillae
Small raised areas on the tongue that contain taste buds
papillae
Small raised areas on the tongue that contain taste buds
tonsils
Masses of lymphatic tissue located in depressions of the mucous membranes on either side of the oropharynx (part of the throat near the mouth).
Filters to protect the body from invasion of microorganisms and produce lymphocytes (disease-fighting white blood cells)
gums
Fleshy tissue surrounding the sockets of the teeth
salivary glands
Exocrine glands that surround and empty saliva into the oral cavity, which lubricates the mouth. Contains digestive enzymes and healing growth factors such as cytokines.
submandibular gland
Secretes saliva
sublingual gland
Secretes saliva
pharynx
throat
About 5” long, lined with a mucous membrane. Serves as a passageway for both air and food
esophagus
9-10” muscular tube extending from the pharynx to the stomach
peristalsis
Involuntary, progressive, rhythmic contraction of muscles in the wall of the esophagus propelling a bolus (mass of food) down toward the stomach
bolus
mass of food
bolus
mass of food
stomach
Three (3) main parts:
- fundus
- body
- antrum
fundus
Upper portion of the stomach
body (of the stomach)
Middle section of the stomach
antrum
Lower portion of the stomach
sphincters
Control the openings into and leading out the stomach
lower esophageal sphincter
Relaxes and contracts to move food from the esophagus into the stomach
pyloric sphincter
Allows food to leave the stomach and enter the small intestine when it is ready
mucosa
mucous membrane
pepsin
Enzyme produced in the rugae of the stomach to begin digestion of proteins
hydrochloric acid
Secreted by the rugae in the stomach to digest protein and kill any bacteria remaining in the food
hydrochloric acid
Secreted by the rugae in the stomach to digest protein and kill any bacteria remaining in the food
small intestine (small bowel)
Extends for 20 feet from the pyloric sphincter to the first part of the large intestine.
Three (3) parts:
- duodenum
- jejunum
- ileum
bile
Produced by the liver and stored in the gallbladder, secreted into the duodenum.
Helps digest food before it passes into the jejunum.
Contains cholesterol, bile acids, and several bile pigments.
Thick, orange-black (sometimes greenish) fluid.
liver
Produces bile continuously
gallbladder
Stores bile
Pear-shaped sac under the liver
pancreas
Secretes pancreatic juice containing enzymes to aid in digestion of food before it passes into the jejunum.
Is both an endocrine gland and an exocrine organ.
jejunum
Second part of the small intestine, approx. 8 feet long. Connects to the ileum
ileum
Third part of the small intestine, about 11 feet long. Connects to the first part of the large intestine
large intestine
Extends from the end of the ileum to the anus.
Three (3) parts:
- cecum
- colon
- rectum
cecum
Pouch on the right side that connects the ileum at the ileocecal valve (sphincter)
appendix
Hangs from the cecum
colon
About 5 feet long and has four (4) segments:
- ascending colon
- transverse colon
- descending colon
- sigmoid colon
ascending colon
Extends from the cecum to the under-surface of the liver where it turns left to become the transverse colon
villus
(singular)
villi
(plural)
Tiny, microscopic projections line the walls of the small intestine. Capillaries in villi absorb the digested nutrients into the bloodstream and lymph vessels
transverse colon
Passes horizontally to the left toward the spleen and then turns downward into the descending colon
descending colon
Section of the colon leading down from the transverse colon to the sigmoid colon
sigmoid colon
Shaped like an S, begins at the distal end of the descending colon and leads into the rectum
rectum
Terminates in the lower opening of the GI tract
anus
Sphincter at the end of the GI tract. Opens for elimination
feces
Stool; bowel movement
defection
Expulsion or passage of feces from the body through the anus
bilirubin
Bile pigment is produced from the breakdown of hemoglobin during normal red blood cell destruction.
Leaves the body in feces
jaundice
hyperbilirubinemia
Yellow discolouration of the skin, whites of the eyes, and mucous membranes.
Caused by bilirubin remaining in the bloodstream
hepatic duct
Transports bile from the liver to the cystic duct
cystic duct
Transports bile from the hepatic duct to the gallbladder
common bile duct
Carries bile from the liver and gallbladder to the duodenum
emulsification
Bile has a detergent-like effect on fats, breaking them apart to create more surface area so pancreatic enzymes can digest the fats
emulsification
Bile has a detergent-like effect on fats, breaking them apart to create more surface area so pancreatic enzymes can digest the fats
glycogen
starch
glycogenolysis
Liver converts stored glycogen back into glucose when blood sugar levels become low
gluconeogenesis
The liver converts proteins and fats into glucose
portal vein
Brings blood to the liver from the intestines.
Nutrients from digested food passes into the portal vein directly after being absorbed into the capillaries of the small intestine.
amylase
Enzyme that digests starch
lipase
Enzyme that digests fat
protease
Enzyme that digests protein
insulin
Hormone secreted by the pancreas. Acts as a carrier to bring glucose into body cells to be used for energy
GI tract path
Oral cavity Pharynx Esophagus Stomach Duodenum Jejunum Ileum Cecum Ascending colon Transverse colon Descending colon Sigmoid colon Rectum Anus
triglycerides
Lipid
Fat molecules composed of three (3) parts fatty acids and one part glycerol.