Flashcards in Human Physiology - Digestion Deck (68)
What is physical digestion?
Digestion through chewing (mastication) and churning in stomach
What is chemical digestion?
Digestion through enzymes, juices,
What controls digestion?
Hormones, phypothalanus, pepsinogen, trypepsinogen
What enzymes are used in digestion?
CCK, Gastrin, Enterogasterone, Secretin, Glucagon, Insulin,
What does CCK do?
Causes gall bladder to contract, and release bile salts
What are the 4 components of the digestive system?
What are the layers of the alimentary canal?
What does Enterogasterone do? Where does it come from?
Excreted from duodenum from high concentration of fats in large intestine, slows peristalsis for more time to digest lipids
Where are bacterial flora? What do they do?
Found in large intestine, ferment indigestible carbohydrates, releasing acids and gases. Also synthesize vitamins B and K
What is egestion?
undigestible cellulose fibres stores until pressure against colon causes bowl movement
What are hormones?
Chemical messenger that travels through the blood stream
What is exocrine?
releases hormones through ducts
What is endocrine?
releases hormones directly into blood stream
What is secretin?
hormone that regulates secretions by pancreas in digestion
What is gastrin?
hormone released from the smell or sight of food, releases gastric juice
What is Insulin?
hormone released by pancreas and causes liver to absorb glucose from blood and convert it into glycogen for storage, can reduce blood sugar levels
What is glucagon?
hormone released in the pancreas for the liver to convert stored glycogen into glucose to increase blood sugar
What is the structure of the small intestine?
Villi and microvilli, used to increase surface area
What is a lacteal?
lymphatic vessels of the small intestine that absorb digested fats
What are some adaptations of the villi?
tight junctions between cells ensure molecules will pass through villi, long structures increase surface area, epithelial cells have more mitochondria to ensure cells have enough ATP to run active transport, lots of pinocytes are present, different kinds of proteins on apical and basal sides to assist in diffusion
How are nutrients moved out of the villus?
simple diffusion, facilitated diffusion, active transport, exocytosis
How are monosaccarides absorbed?
sodium - potassium pump, requires low concentration of sodium in the epithelium
How are lipids absorbed?
monoglycerides and fatty acids through emulsification with bile salts are turned into miscelles, these bile salts carry miscelles into the epithelial cells. They are then converted into triglycerides and combined with cholesterol to become a chylomicron
How are amino acids transported into epithelial cells?
active transport into, facilitated diffusion into capillary
What happens to the things absorbed in the small intestine?
transported to the liver, which filters and protects our bodies from the harmful stuff we eat
What is dietary fibre?
What is a primary structure / polypeptide?
formed in dehydration synthesis, amino group from 1 amino acid bonds to carboxyl group of another amino acid (peptide)
What is a secondary structure?
formed from polypeptide when H bonds cause chain to coil or fold, caused by R group
What is a quaternary structure?
interaction of 2 or more polypeptides