-
The continuous muscular tube that winds through the body from the mouth to anus. Consists of the mouth, pharynx, esophagus, stomach, and small & large intestines. Digestion and absorption occur here.
Alimentary canal or gastrointestinal tract (GI) tract:
-
Consist of teeth, tongue, gallbladder, and large digestive glands (salivary glands), liver and pancreas. These organs produce a variety of secretions that help breakdown food or are involved in the physical breakdown of food.
Accessory digestive organs
-
-
The alimentary canal is arranged in ___ layers or tunics surrounding a lumen
Name them.
- 4
- Mucosa, submucosa, Muscularis externa,Serosa
-
holds the blood and lymphatic vessels that supply the tissues surrounding it
Submucosa
-
Functions: secretion (enzymes, mucus, hormones), absorption (nutrients), protection (bacterial infection)
Mucosa
-
Functions:segmentation and peristalsis, intrinsic control of the digestive tract, includes muscle and myenteric nerve plexus, circular muscles form sphincters in some areas
Muscular externa
-
_____: moves the food through the alimentary canal, includes swallowing which is initiated voluntarily, and peristalsis (an involuntary process). Peristalsis, the major means of propulsion, involves alternating waves of contraction and relaxation of muscles in the organ walls. Its main effect is to squeeze food along the tract, but some mixing occurs as well. So powerful that peristalsis still occurs even if one were to stand on their head!
Propulsion
-
_____: simply taking in food into the digestive tract, usually via the mouth.
Ingestion
-
______: increases the surface area of ingested food, physically, preparing it for digestion by enzymes. Mechanical processes include chewing, mixing food with saliva by the tongue, churning food in the stomach and segmentation, the rhythmic local constrictions of the small intestine.
Mechanical breakdown
-
______ mixes food with digestive juices and makes absorption more efficient by repeatedly moving different parts of the food mass over the intestinal wall
Segmentation
-
______: a series of catabolic steps in which enzymes secreted into the lumen (cavity) of the alimentary canal breakdown complex food molecules to their chemical building blocks.
Digestion
-
_____: passageway of digested end products (plus vitamins, minerals, and water) from the lumen of the GI tract through the mucosal cells by active or passive transports into the blood or lymph.
Absorption
-
_____: eliminates indigestible substances from the body via the anus in the form of feces.
Defecation
-
_____- secures the tongue to the floor of the mouth and limits its posterior movements.
Lingual frenulum
-
Some children are born with a very short lingual frenulum often referred to as "tongue-tied" because it restricts tongue movement and distorts speech. Condition is called _____("fused tongue") and it is corrected surgically by snipping the frenulum.
ankyloglossia
-
_____- small projection that hangs in the back of the mouth
Uvula
|
|