Digestion Test Review Essay

Submitted By Danika-Viotto
Words: 798
Pages: 4

Lesson 1: Organs & Organ Systems
Organs: groups of different tissues specialized to carry out particular functions.
Organ Systems: group of organs with similar functions.
CAT Scan: x-ray machine that rotates around an individual taking tons of pics from different angles. Nuclear Imaging: uses radioisotopes.
NMR Technology: Nuclear Magnetic Resonance, subjects nucleus of a specific atom to determine if it behaves normally.

Lesson 2: Importance of Digestion
Digestion: responsible for breakdown of large, complex organic material into smaller components.
Ingestion: taking in nutrients.
Absorption: transports digested nutrients to the tissues of the body.
Egestion: removal of waste.
Digestive Enzymes: function is affected by temp. & ph.
Efficient Temp: 37 degrees Celsius; after 37, the activity increases. pH: depends on area.
Amobea: food engulfed by phagocytosis.
Hydra: food enters single opening in gastrovascular cavity.
Complex Digestion: digestive tracts are called alimentary canals, separate opening for mouth and anus. Gizzard: muscular organ used to physically breakdown food when there are no teeth present.
1. Food is ingested through mouth to pharynx then to esophagus.
2. Held in stomach/crop.
3. No teeth= gizzard.
4. From gizzard to intestine, digestion finishes.
5. Nutrients are absorbed.
6. Circulatory system carries nutrients throughout body.
7. Undigested waste is removed through anus.

Lesson 3: Ingestion
Digestive Tract: 6.5m - 9m long.
Saliva: produced by salivary glands.; Contains amylase enzymes, break down starches (complex carbs) to simpler carbs; lubricates food to be swallowed and makes it possible to taste.
Teeth: Incisors = cutting, Canine = tearing, Premolars = grinding, Molars = crushing, Wisdom = useless. Esophagus: Pathway from mouth to stomach, Bolus stretches walls of esophagus, activating smooth muscles that begin peristalsis, voluntary movement can only occur during chewing, swallowing, and egestion.

Lesson 4: Stomach and Digestion
Stomach: storage of food; can hold up to 1.5L of food.
Sphincters: constrictor muscles that surround a tube-like structure.
Cardiac Sphincter: closest to heart.
Plyoric Sphincter: regulates movement of foods and stomach acids to small intestine.
Gastric Juice: includes mucus, HCl, pepsinogens.
Mucus: alkaline protective coating.
HCl: kills harmful substances ingested with food, converts pepsinogen to pepsin. pH: ranges from 2.0 - 3.0.
Ulcers: mucus lining broken down, cell membrane is exposed, causing peptic ulcer.
Acid: irritates cells= increases blood flow & acid secretion= more tissues are burned= reaction is stronger. Theodor Maiman: built first laser.
Endoscope: a camera, forceps can extract small pieces of tissue.

Lesson 5: Small Intestine & Pancreas
Small Intestine: area after stomach. (7m long, 2.5 cm diameter.); Carnivores= short, Omnivores=
Med, Herbivores=long.
Food that enters small intestine is already soaked in HCl.
Duodenum: majority of digestion occurs here. pH: inactivates pepsin.
Pancreas: pancreatic secretions contain enzymes for breakdown of three major components of food, carbohydrates, lipids, and proteins.
Pancreas: releases amylase; digestion of carbs by salivary amylase.
Lipases: breakdown lipids; pancreatic lipase- fats into fatty acids and glycerol; phospholipasephospholipids.

Lesson 6: The Liver & Gall Bladder
Liver: continually produces bile.
Gall Bladder: storage area and concentrated of bile.
Bile: contains pigments; liver breaks down hemoglobin; breakdown of bile can cause…