Digestive/Circulatory system Flashcards
Digestive system
group of organs that take in food and change it into a form the body can use
How many ways does the food change as it moves thru the digestive system?
2, physical + chemical change
Physical change
when large pieces of food are broken down into smaller pieces, only size and shape of particles different
Chemical change
turns food into a form that the cells can use by breaking bonds
What speeds up chemical change?
enzymes
What is the digestive pathway made up of?
A one way pathway for ingested food and certain accessory organs that help the digestive system function
What is the one way passageway called?
GI tract (gastrointestinal)
What is the GI tract?
a hollow tube w an opening at either end
How long is the average GI tract?
29ft long
Study Organ Diagram
Do it again
Mouth
Oral cavity
Mechanical digestion in mouth
Teeth break pieces of food into smaller pieces to increase the surface area for enzymes
Chemical digestion in mouth
salivary amylase in saliva breaks down the starch into maltose
What secretes saliva in the mouth?
salivary glands
What is salivary amylase?
Enzyme which begins the digestion of carbohydrates
Tongue
helps mix the chewed food w/ saliva and moves it to the back of the mouth, to the pharynx for swallowing
What does swallowing do?
moves the epiglottis over the trachea to prevent the food from entering the lungs
Esophagus
muscular tube that connects mouth to stomach
Does any digestion take place in the esophagus?
No
Peristalsis
Slow rhythmic muscular contractions of the walls of the esophagus
Function of peristalsis
help move food to stomach
Cardiac sphincter
ring of muscle found btwn the esophagus and stomach.
function of Cardiac sphincter
helps control passage of food from the esophagus to the stomach
stomach
muscular sac w/ glands that both physically and chemically digests.
How does stomach physically digest?
physically mixes food by contracting walls of stomach
How does stomach chemically digest?
releasing gastric juice
What are the two types of glands the stomach contains?
Pyloric glands and gastric glands
Pyloric glands
secrete mucus which covers the stomach lining and protects it
Gastric glands
release gastric juice
What does gastric juice contain?
Hydrochloric acid and pepsin
Why HCl in gastric juice?
providing the right pH for enzymes
Why pepsin in gastric juice?
begins the digestion of proteins by breaking down proteins into polypeptide chain
What stimulates flow of gastric juice?
food touching lining of stomach, thought/smell/sight/taste of food, stretching of stomach wall by large food mass
chyme
new post stomach liquid form of food
What happens to the chyme?
moves into the small intestine
pyloric sphinctor
a sphinctor that controls the passage of food from the stomach to small intestine
small intestine
long coiled 20ft tube w/ a small diameter
Accessory organs function
connect to small intestine, release fluids which help in digestion into the duodenum
duodenum
upper part of small intestine
List of accessory organs
liver, gallbladder, pancreas
Liver
makes bile
Bile
chemical helps liquify fats
What is the process of bile liquifying fats called?
emulsification
What does emulsification do?
Helps increase surface area so that more enzymes can chemically digest it
When the bile leaves the liver, where does it go?
Gallbladder
Gallbladder
small, baglike structure under the liver
Gallbladder function
stores bile until it’s ready to be released into small intestine
Pancreas
Makes enzymes that are released into the small intestine through a duct
What are the three enzymes of the pancreas?
Protease, lipase, and amylase
Protease
digests proteins
Lipase
digests lipids
Amylase
digests carbohydrates
What enzymes does the small intestine produce?
peptidase and maltase
peptidase
breaks down polypeptides to amino acids
maltase
breaks down disaccharides to monosaccharides
villi
fingerlike structures found in lining of small intestines