breaking down of nutrients into small, soluble molecules that can be absorbed into the blood.
breaking food into smaller pieces
beaking nutrients into small molecules
What is hydrolysis?
The processes by which chemical digestion occurs. (Splitting molecules by adding water)
What is chemical digestion sped up?
by the action of digestive enzymes (hydrolases)
What is the Alimentary Canal?
Tube that extends between two openings: the mouth and anus w, which has specialized regions that carry out specific phases of digestive processes. (e.g., mechanical digestion, chemical digestion, absorption)
Accessory organs of the digestive system: (3)
Describe mechanical digestion:
What happens to the surface area of food?
Mech. dig. occurs when food enters the mouth and chewed. This increases the food surface area, making it easier to swallow and digest.
What happens to the _____ gland when food enters the mouth?
Salivary gland is stimulated to release saliva, which contains the enzyme amylase, when food enters the mouth.
What is amylase?
Enzyme in saliva (within the mouth, salivary gland) that is stimulated by the presence of food. It breaks down starch into smaller carbohydrate molecules (mono & disaccharides)
What is the job of the pharynx? & what is is aka?
aka--throat. This sections of the alimentary canal pushes food down by the tongue as food is swallowed.
What is the Epiglottis?
Flap at the top of the windpipe to prevent food from entering the respiratory system.
What are muscular contractions of the stomach called?
What is the job of the lining of the stomach?
To produce gastric "juice," which is made up of hydrochloric acid and proteases (protein digestive enzyme).
Describe the environment of the stomach:
& Describe WHY the stomach is in this type of environment.
Acidic environment, having a pH of approx. 2.
BECAUSE gastric acids work best in this envirnt.
How is the stomach protected by its acidic environment?
The lining of the stomach secretes mucus to protects the stomach wall from the actions of the very acidic gastric juice.
What is Chyme?
Released to where && how..?
Liquid created by the smooth muscles of the stomach that mix partially digested food until liquefied.. which is then released in small portions to the small intestine THROUGH the pyloric sphincter
Where does most of the digestion of food take place?
In the Small Intestive.
How long can the small intestine be in humans?
up to 6 meters long.
Why is the small intestine so important to digestion?
Because this is not only a major site for digestion, but also the absorption of nutrients into the bloodstream.
How does the liver contribute to the digestive system?
The livers produces bile, a substance that is stored in the gallbladder, which helps in the breakdown of fats.
What are villi? What do they do, where are they located and what is their purpose?
Villi line the small intestine, their purpose is to increase the intestinal surface area for absorption of the end products of digestion into the blood and lymph.
Where does un-digested food go?
To the large intestine, or colon.
What is the purpose of the large intestine?
To manage un-digested food by reabsorbing water that has entered the alimentary canal. As waste moves along colon it become more solid and stored in the rectum until egestion (bowel movement)
What happens if peristalsis moves feces through the colon too quickly?
Water is not reabsorbed, thus diarrhea results because solid feces was not formed.