Ch. 46 - Bowel Elimination

Teeth masticate food, breaking it down to swallow, and saliva is produced to dilute and soften the food for easier swallowing

The bolus of food travels down and is pushed along by peristalsis, which propels the food through the length of the GI tract.

stores swallowed food and liquid, mixing of food, liquid and digestive juices, and empties its contents into the small intestine; produces HCL, mucus, and pepsin and intrinsic factor, which is essential for the absorption of Vitamin B12

segmentation and peristaltic movement facilitate both digestion and absorption; chime mixes with digestive juices

lower GI tract (colon) divided into the cecum, colon, and rectum. It is the primary organ of elimination.

contraction and relaxation of the internal and external sphincters, innervated by sympathetic and parasympathetic stimuli, aid in control of defecation

at the time of defecation, the external sphincter relaxes and the abdominal muscles contract, increasing intrarectal pressure and forcing the stool out. Pressure can be exerted to expel forces through a voluntary contraction of the abdominal muscles while maintaining forced expiration against a closed airway.