Digestive System Exam
What organs are included in the digestive system? - correct answer oral cavity
(mouth), pharynx (throat), esophagus, stomach, small intestine, and large intestine
What accessory organs are included in the digestive system? - correct answer teeth,
gall bladder, tongue, salivary glands, liver, and pancreas
Name the functions of the digestive system? - correct answer ingestion: material
entering the digestion tract via the mouth; conscious choice
mechanical digestion: physical manipulation of food such as chewing churning, mixing
propulsion/peristalsis: movement of materials through the digestive system
chemical digestion: chemical breakdown of food into small molecules for absorption by the interstitial
epithelium
secretion: water, enzymes, buffers, acids, salts by the interstitial epithelium and accessory glands
absorption: small food molecules, electrolytes, water and vitamins across the digestive epithelium into
the bloodstream
excretion: elimination of waste products from the body--a process called defecation
What layers make up the wall of the digestive system? What is the organization of each layer? - correct
answer mucosa: inner-most lining the lumen of the digestive tract. it is a mucous
membrane.
,submucosa: layer of dense irregular CT that surrounds the mucularis mucosae. contains larger blood
vessels and lymphatic vessels, lymph nodules, and nerve fibers
muscular layer: smooth muscle layer arranged in an inner circular layer and outer longitudinal layer.
responsible for muscle contractions
What is segmentation? What is peristalsis? - correct answer segmentation-churning
or mxing movement within a portion of the digestive tract. movement is accomplished by the smooth
muscle of the muscular layer. muscle contracts and relax without a certain pattern. does not push
materials along the digestive tract in one direction
peristalsis-propels materials from one portion of the digestive tract to another. primarily accomplished
by the smooth muscle of the muscular layer. circular muscles contract behind digestive contents.
longitudinal muscles contract next, shortening adjacent segments. a wave of contraction then forces the
materials in the desired direction
What organs are retroperitoneal? - correct answer duodenum, pancreas, ascending
colon, descending colon, rectum, and anal canal
What organs are intraperitoneal? - correct answer stomach, jejunum, ileum,
transverse colon, sigmoid colon, liver, and gallbladder
If an organ is intraperitoneal, what mesentery connects it to the body wall? - correct answer
organs located within the peritoneal cavity supported transverse mesentery/sigmoid mesenteries.
What is the function of peritoneal fluid? - correct answer made in the abdominal
cavity, which lubricates the surface tissue that lines the abdominal wall and pelvic cavity.
What are the three mechanisms of control of digestive function? - correct answer
local factors: local factors are the primary stimulus for digestive activities. include pH changes, physical
distortion of the wall of digestive tract, or the presence of chemicals.
neural controls mechanisms: primary mechanism for movement and gland secretions along digestive
tract.
, short reflexes:
-sensory receptors
-integration
-response by myenteric plexis
-causes glands to secrete and muscles to contract
long reflexes:
-higher level of control that coordinates activity along the entire digestive tract
-cause large peristaltic movement; moves material from one region to the next
-parasympathetic response
hormonal mechanisms: digestive tract produces many hormones by cells scattered along the digestive
tract. hormone-producing cells of the digestive tract are called enteroendocrine cells; they affect most
digestive function. hormones must first enter the circulatory system for distribution to target organs
What is the enteric nervous system? - correct answer ENS--main division of the
autonomic nervous system consisting of mesh-like neurons that governs the function of the
gastrointestinal tract, coordinates reflexes.
What is the function of the oral cavity? - correct answer analysis of material before
swallowing, mechanical digestion through the actions of the teeth, tongue, and palatal surfaces,
lubrication by mixing with mucus and salivary gland secretions, limited chemical digestion of
carbohydrates and lipids
What are anatomical boundaries of the oral cavity? - correct answer lipds, lateral
boundary: cheeks; superior boundary: hard and soft palate; inferior boundary: body of the tongue and
floor of the mouth supported by the skeletal muscle; posterior boundary: posterior margin of the soft
palate, uvula, root of the tongue
Describe the oral epithelium. - correct answer oral mucosa is composed of stratified
squamos epithelium that helps protect the oral cavity against surface abrasion--protective
