Notes: Digestive System Anatomy Item # _____
A. ___________________ is the process by which food substances are changed into forms that
can be absorbed through cell membranes.
B. The digestive system consists of the _________________________ canal, which extends
from the mouth to the anus, and several __________________ organs, which release
secretions into the canal.
1. Alimentary canal includes:
2. Accessory organs include:
II. The Alimentary Canal
A. ___________________ tube about _____ m long passing through the ventral cavity
B. Movements can be _______________ (rhythmic contractions) or propelling (wavelike). The
wavelike movements are known as ___________________.
III. Oral Cavity
A. The _____________ receives food and prepares it for digestion by mechanically decreasing
B. The cheeks contain muscles associated with ________________ and chewing.
C. The lips contain skeletal muscle for movement and _____________ receptors. Their reddish
color is associated with an abundance of ____________ vessels near the surface.
D. The ___________ is composed primarily of skeletal muscle and functions to aid in mixing
food with ___________________.
1. connected to the floor of the mouth via the __________________
2. rough projections called ______________ contain taste buds
E. The _____________ forms the roof of the mouth.
1. The anterior portion is the __________ palate and the posterior portion is the
__________ palate which forms a projection called the uvula.
2. The _______________ tonsils lie laterally to the tongue in the back of the mouth and
have some immune function.
3. The _______________ tonsils, or adenoids, are located on the posterior wall of the
pharynx and also have some immune function.
1. _______ primary (deciduous:ages 6 months – 3) and _______ secondary (permanent:
2. function: break food into smaller pieces to increase _____________ area
a. ____________ (front): biting
b. ____________ (canines): tearing
c. ____________ (premolars): grinding
d. ____________ (molars): grinding
4. Each tooth consists of a crown and root is composed of ____________ (glossy
white), _____________ (bone-like), __________ (connective tissue), nerves, and
5. Attached by the _____________________ ligament.
A. cavity behind the ____________ that connects the nasal and oral cavities with the larynx and
1. ______________________: passageway for air during breathing
2. ______________________: behind soft palate; passageway for food and air
3. ______________________: opens into larynx and esophagus; passage for food and air
A. Occurs in _____ stages
1. Food mixed with ____________, called a ________________, is forced into the
______________ by the tongue. This action is initiated voluntarily.
2. Involuntary reflex actions move food into the esophagus. The ___________________
helps to prevent food from entering the trachea.
3. Food is transported to the _________________ via peristalsis
A. straight, collapsible tube ~ _______ cm long providing a passage for food between the
pharynx and stomach
1. runs behind trachea, through mediastinum, and penetrates the ______________
B. contains circular _____________ muscle fibers at the distal end to help prevent regurgitation
of food from the stomach
A. General Info
1. J-shaped, _____________ organ in the upper __________ abdomen
2. hold ~ ____L
3. Inner mucosa lining of thick folds called ____________
4. Mixes bolus with hydrochloric acid and gastric juices to become _________________
1. ___________ Sphincter: small valve at the esophageal opening prevents regurgitation
2. _____________: balloon area above cardiac serves as temporary storage
3. _____________: main portion
4. _____________: lower portion
5. _____________: narrowed distal portion which becomes a canal to the small intestine
a. ________________ Sphincter: powerful circular muscle at the end of the
pyloric canal serving as a valve that prevents the __________________
of food from the intestine back into the stomach
VIII. Small Intestine
A. Tubular organ extending from the ______________ sphincter to the large intestine (~20 feet)
1. receive ______________ from the pancreas and liver
2. completes the digestion of nutrients in _____________
3. ______________ the various products of digestions
4. ______________ remaining residues to large intestine
C. Anatomy: ___ portions
1. _______________: proximal C-shaped portion; ~1 ft long
2. _______________: middle portion; ~ 8 ft long
3. _______________: distal portion; ~ 12 ft long
a. suspended from the abdominal wall via the ________________
IX. Large Intestine
A. diameter greater than the SI and ~ ______ ft long
a. __________________: beginning of LI; dilated, pouch-like structure
(i) ____________________: worm-like outgrowth; immune function?
b. ___________________: main portion of the LI
(i) ______________________ colon: travels upward just below liver
(ii) ______________________ colon: longest; below stomach
(iii) ______________________ colon: downward from spleen
(iv) ______________________ colon: S-shaped curve at pelvis
c. __________________: next to the sacrum; ~ ___ cm long
d. __________________ canal: last ________ cm of LI
(i) _________: distal opening
(a) ____________ anal sphincter: involuntary smooth muscle
(b) ____________ anal sphincter: voluntary skeletal muscle
(ii) _________________: enlargement and inflammation of the rectal veins
within anal columns; aggravated by bowel movements and cause
discomfort and bleeding
1. Little to no ________________________ function
2. contributes ________________________ secretions
2. absorbs _________________ and electrolytes
3. ______________, stores, and expels feces
1. mixing and ______________
2. Mass movements _________ times per day, usually following a meal.
2. __________________ involves a defecation reflex.
a. Aided by the _______________ maneuver
1. consists of water (_____%), ____________ material, mucus, and _______________.
2. color due to ________________ altered by bacterial actions
Notes: Digestive System Anatomy – Accessory Organs
X. Salivary Glands
1. secrete fluids to moisten food and begin ______________________
3. Major Glands
a. _____________ (largest): in front of the ear
b. __________________: in floor of mouth by jaw
c. _______________ (smallest): under tongue
A. located in the upper right and central portion of the abdomen, just below the ______________
1. ___________________ of carbohydrates, lipids, and proteins
2. _________________ of substances including vitamins ___, ___, and ______.
3. _________________ of blood
4. _________________ of toxic chemicals
5. _________________ of bile
a. Bile is the only liver secretion that directly affects digestion.
1. color: ___________________
2. enclosed in a fibrous capsule and divided into _____________
a. Lobes are separated into ____________ lobules, which are the functional unit.
3. Bile from the lobules is carried by the bile canals to the _______________ ducts.
a. Merging of hepatic ducts forms the ________________ bile duct.
1. yellowish-green liquid secreted by _______________ cells
2. contains bile __________, bile _______________, cholesterol, and electrolytes
a. Only _____________________ have a digestive function.
A. pear-shaped sac attached to the __________ by the ___________ duct (joins the hepatic duct)
1. ___________ bile between meals
2. _____________ bile by reabsorbing water
3. _____________ bile into the small intestine
4. Bile salts aid the actions of digestive enzymes and enhance the absorption of
_________________ and some fat-soluble vitamins.
a. The breakdown of fat globules is known as _______________________.
C. The common bile duct is formed by the union of the _______________ and ____________
ducts and leads to the duodenum.
D. _________________ are crystallized forms of cholesterol in bile that block the bile duct.
A. While pancreas has _______________ functions, it also has ________________ functions by
secreting digestive juices.
1. extends ____________________ across post. abdomen in the C-shaped curve of
duodenum of SI
2. The pancreatic duct connects with the duodenum of SI where the _______ duct from
the liver and gallbladder joins the duodenum.