Chapter 5 Digestive System.txt

begins at the mouth, where food enters, and ends with the anus, where solid wastes leave the body

the four functions of the system

where complex food is taken into the mouth

where food is broken down mechanically and chemically as it travels through the gastrointestinal tract.

Speed up chemical reactions and help the breakdown of complex nutrients

digested food passes through the lining of cells or epithelium of the small intestine and into the bloodstream

form the walls of the oval-shaped oral cavity

surround the opening to the cavity

forms the anterior poertion of the roof of the mouth

lies posterior to the hard palate

irregular ridges in the mucous membrane covering the anterior portion of the hard palate

a small and soft tissue projection; hangs from the soft palate; helps in making sounds and speech

Extends across the floor of the oral cavity & muscles attach it to the lower jawbone; moves food around while chewing and swallowing

chewing

swallowing

small raised areas on the tongue; have taste buds that are sensitive to chemical nature of foods and let discrimination of different tastes when food goes through the tongue

masses of lymphatic tissue located in depressions of the mucous membranes that lie on both sides of the oropharynx; filters to protect the body from invasion of microorganisms and make lymphocytes

fleshy tissue surrounding the sockets of the teeth

for incisor and canine teeth & is located closest to the lips

surface for premolar and molar teeth and lies adjacent to the cheek

dentists refer to both the labial and buccal surfaces of a tooth as this

on the side of the tooth that lies directly opposite the facial surface is this surface

surface that lies closer to the median line

the surface that lies farther from the medial line

is located above the gum line

is located within the bony tooth socket

protects the tooth; dense, hard, white, and the hardest substance in the entire body

the main substance of a tooth, which lies underneath the enamel; extends throughout the crown; yellow, composed of bony tissue that is softer than enamel

covers, protects, and supports the dentin in the root

surrounds the cementum and holds the tooth in place in the tooth socket

lies underneath the dentin; fills the center of the tooth

blood vessels, nerve endings connective tissue, and lymphatic vessels are located within this pulp canal

lubricates the mouth; contains important digestive enzymes as well as healing growth factors such as cytokines

muscular tube that is about five inches long and is lined with a mucous membrane; serves as a passageway for both air traveling form the nose to the trachea and for food traveling from the oral cavity to the esophagus

nine-to-ten inch muscular tube extending from the pharynx to the stomach

involuntary, progressive, rhythmic contraction of muscles in the wall of the esophagus propelling a bolus down toward the stomach

mass of food

upper portion of the stomach

middle section of the stomach

lower portion of the stomach

rings of muscle that control the opening leading into and out of the stomach; prevent food from regurgitating

relaxes and contracts in order to move food from the esophagus into the stomach

lets food leave the stomach when it is ready to do so

folds in the mucous membrane that line the stomach

to begin digestion of proteins