Digestive and Reproductive Flashcards
(191 cards)
Average digestive tract can be up to ? (Meters)
8 meters long
What is Digestion?
It is the process of breaking down all foods into usable nutrients for absorption into the bloodstream
Mouth
Also known as the “oral cavity;” involved in chemical and mechanical digestion; contains teeth (adults have 32, mechanical digestion) and palate (roof of oral cavity): hard palate is anterior; soft palate is posterior
Digestive System Function
Basically everything from ingestion to defecation
Mechanical digestive #1
Mastication (chewing) involving the teeth, tougher, and palate
Chemical digestion #2
Saliva starts to break down food.
What are the accessory organs? Aid in chemical digestive
Mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus.
Mechanical digestive
Breaks large pieces of food into smaller ones without altering their chemical composition.
Chemical digestive
Breaks down larger nutrient molecules into simper chemicals, allowing them to be absorbed.
What does the digestive system consists of ?
Digestive tract
Accessory Organs also includes
Salivary glands, liver, gallbladder, and pancreas
Propulsion
Tongue aids in swallowing/propelling food down “food tube” or esophagus. Peristalsis is the process that takes place in the esophagus (smooth muscle contractions) to move or propel the food into the stomach.
Mechanical digestion #2
Rugae, or folds, in the stomach work to break up and digest food.
Chemical digestion #2:
Hydrochloric acid (HCl) dissolves food further.
Absorption
The small intestine is the site of the greatest amount of nutrient absorption. The large intestine (colon) absorbs water and packages waste for disposal.
Defecation
Waste and undigested materials passing outside the body in the form of feces.
What are the two basic types for motor functions?
Mixing movements and propelling movements
Mixing occurs when ? (Motor functions)
Occurs when smooth muscle in small segments of the tube contracts rhythmically.
Tongue
Propels food to the back of the throat; all muscle and attached to the floor of the oral cavity via the lingual frenulum
Pharynx
Posterior portion of the oral cavity that allows food to pass aka the ‘throat’ (pharynx means ‘throat’); three parts: nasopharynx (nose-throat), oropharynx (mouth-throat), and laryngopharynx (where larynx-pharynx meet)
Esophagus
Also called the “food tube;” this is the passageway from the mouth to the stomach; lined with smooth muscle; peristalsis occurs here; there is a cardiac or esophageal sphincter at the bottom to control flow into stomach
Stomach
Performs both chemical (HCl) and mechanical (rugae) digestion; Has 4 regions, three to know: fundic—superior, balloon-like portion; body—main width of the organ; pyloric—inferior region where the pyloric sphincter is located (regulates when food can move into the small intestines); the stomach also has three layers: mucosa—first internal layer that protects lining from HCl; submucosa; visceral peritoneum—outermost layer (one that would be pierced in embalming process)
Small intestine
Involved in mineral and nutrient absorption; has three main portions: duodenum is the first portion of the small intestine (it branches off the stomach at the pyloric sphincter); jejunum is the very coiled portion that is held together by mesentery; and the ileum is the portion leading straight out to the large intestine or colon; the ileocecal sphincter controls flow into the large intestine
Large intestine:
Responsible for water absorption; inferior to the small intestine; has several portions: cecum—connects it to the small intestine at the ileocecal sphincter; ascending colon—rises up right side of abdomen; transverse colon—transverses or crosses abdomen; descending colon—runs down left side of abdomen; sigmoid colon—last turn of colon before (finally) the rectum and anus; anal sphincter allows body to pass waste and undigested matter as feces