digestion 2 Flashcards
what is digested in the small intestine
carbohydrayes, proteins and lipids
how long is small intestine
2.5 cm in diameter and 7 m in length
what are the 3 parts of the small intestine
duodenum, jejunum, ileum
what happens in the duodenum
first 25-30 cm, enzymes are added and digestion begins
what happens in the jejunum
digestion continues
what happens in the ileum
majority of nutrients are absorbed
what are the finger like projections
villi
to increase surface area ______ is present making it 500x bigger
micorvilli
what are villi filled with
capillaries
digested fats go through small vessels called
lacteals
pyloric sphincter function
controls passage from stomach to small intestine
what does the pyloric sphincter release
when relaxed it releases small amount of chyme into the duodenum. Slow and steady release allows for proper digestion
where are most of the enzymes added
duodenum. this requires help from the liver, pancrease and gallblader
Pancreas role
secrete enzymes and secrete hormones that regulate abosption and storage of glucose
pancrease location
inbetween stomach and duodenum
what is the process in the pancrease
The pancreas releases various enzymes: amylase for starch digestion, trypsinogen (converted to trypsin by enterokinase) for protein digestion, and lipases for fat digestion.
When fat-rich chyme enters the duodenum, the hormone cholecystokinin (CCK) is released, signaling the pancreas to secrete enzymes and bicarbonate ions to neutralize acidity.
Secretin, converted from prosecretin when chyme enters the small intestine, regulates the secretion of pancreatic enzymes and stimulates bile production in the liver.
what do lipases do
break down lipid chains into shorter chains and individual fatty acid molecules.
location of liver and gallblader
under the diaphragm
liver and gallblader role in digestion
produces and secretes bile- which emulsifies fat and breaks it into tiny droplets called micelles.
how do the gallblader and liver work together
Bile is produced in the liver but stored in the gall bladder until food enter the duodenum. When fat enters the duodenum the gall bladder contracts and squeezes out the bile.
what can the liver breakdown/store
toxins and alchohol
stores glycogen and fat soluble vitemins
where are proteins, lipids and carbs absorbed
jejunum and ileum once broken down
what is passive transport
the movement of materials across a cell without the use of energy from the cell
what is diffusion
when particles move from an area of high concentration to an area with low concentration until even
what is osmosis
diffusion of water molecules through a selectivley permiable membrane
whatt is facilitaded diffusion
the diffusion of moleculose across a membrane using transport proteins
what is active transport
materials are moved across a cell membrane from an area with low concetration to an area with concetration using energy provided by the cell
what does the large intestine consist of
cecum, rectum and anus
4 segments of colon
ascending colon, transverse colon, descending colon and the sigmoid colon.
examples of indigestible food
cellulose and fibre
what is endoscopy
a medical procedure that uses an endoscope to look inside the body
what does egestion mean
the elimination of digestive waste
what are the 2 sphincter
The internal anal sphincter is a smooth muscle and is under involuntary control, the external anal sphincter is a skeletal muscle under voluntary control.
