Chapter 4 - Human Digestion & Absorption Flashcards
(110 cards)
Tissue
Collection of cells adapted to perform at specific function
What are the four major types of tissue?
Epithelial, connective, muscle, nervous
Epithelial Tissue
Composed of cells that cover surfaces outside and inside the body (ex: skin)
Epithelial cells absorb nutrients, secret important substances, excrete waste, and protect underlying tissues.
Connective Tissue
Supports and protects the body by holding structures (ex: cells, cell parts) together, stores fat, and produces blood cells (ex: tendons, cartilage, parts of bone, arteries, and veins)
Muscle Tissue
Can contract and relax and permits movement
Nervous Tissue
Transmits nerve impulses from one part of the body to another. Found in the brain and spinal cord.
Organ
A structure consisting of cells and tissues that perform a specific function in an organism
Organ System
Groups of organs classified as a unit because they work together to perform a function or set of functions
Digestion
The process of breaking down foods into a form the body can use.
Absorption
The uptake of nutrients from the GI tract into either the blood or the lymph
What are the nine major parts of the digestive system?
- the mouth/salivary glands
- the esophagus
- the stomach
- the liver
- the gallbladder
- the pancreas
- the small intestine
- the large intestine
- the rectum
What does the mouth/salivary glands do?
Chew food, perceive taste, moisten food with saliva, lubricate food with mucus, release starch-digesting (amylase) enzyme, initiate swallowing reflex.
What does the esophagus do?
Lubricate with mucus, move food to stomach by perialistic waves (swallowing)
What does the stomach do?
Store, mix, dissolved and continue digestion of food, dissolve food particles with secretions, kill micro organisms with acid, release protein-digesting (pepsin) enzyme, lubricate and protect stomach surface with mucus, regulate emptying of dissolved food into small intestine, produce intrinsic factor for vitamin B-12 absorption
What does the liver do?
Produce bile to aid fat digestion and absorption
What does the gallbladder do?
Store, concentrate, and later release bile into the small intestine
What does the pancreas do?
Secrete sodium bicarbonate and enzymes for digesting carbohydrate, fat, and protein
What does the small intestine do?
Mix and propel contents, lubricate with mucus, digest and absorb most substances using enzymes made by the pancreas and small intestine
What does the large intestine do?
Mix and propel contents, absorb sodium, potassium, and waters house bacteria, lubricate with mucus, synthesize some vitamins and short-chain fatty acids, form feces
What does the rectum do?
Hold feces and expel via the anus, the opening to the outside of the body
Alimentary Canal
Tubular portion of the digesting tract that extends from the mouth to the anus. Also known as the GI tract.
What does alimentary mean?
“Relating to nourishment or nutrition”
Nutrients must pass through the walls of what to be absorbed into the body?
the alimentary canal
What are the four layers of alimentary canal wall?
(in order) mucosa, submucosa, muscle, serosa