Chaopter 3 Flashcards
Digestion
Process of breaking food into small pieces to be absorbed
Amount of time it takes food to pass the length of the GI TRACT
24-72 hrs
Layers of gut wall
External connective tissue
Provide strong support and protection
Smooth muscle
Mixes and propels food through gut wall
Connective tissue
Nerve and blood vessels to provide mucosal with nutrients
Help with secretion and muscle contraction
Mucosal Cells provide protection Live 2-5 days Produce mucous Most important cells in GI tract
Liver
Bikes bile
Digestion and absorption of fat
Pancreas
Biocarbonate to neutralize intestinal contents
Produce enzyme that digests protein fats and carbs
Gallbladder
Stores bile
Small intestine
Complete digestion
Absorbs nutrients into blood or lymph
Salivary amylase
Breaks starch into smaller carbs
Rennin
Milk protein to curdle
Pepsin
Protein into polypeptides and AA
Trypsin
Protein and polypeptides into shorter chains
Chymootrypsin
Proteins and polypeptides into shorter chains
Carboxpepidase
Polypeptides into AA
Pancreatic Amylase
Starch into shorter glucose chains
Pancreatic lipase
Breaks down Triglycerides
Lipase
Breaks monoglycerides
Sucrase
Sucrose into glucose and fructose
Lactase
Lactose into glucose and galactose
Maltase
Maltose into glucose
Dexiranse
Breaks short chains of glucose into smaller ones
Gastrin
Secretion of HCI and pepsinogen
Increases motility and emptying
Somatostatin
Stomach secretion Motility Emptying Pancreatic secretion Bile release
Secretin
Gastric secretion
Motility
Increase output of water
Increase bile output from liver
CCK
Contraction of gallbladder
Increase pancreatic juice output
Gastric inhibitory peptide
Inhibits gastric secretion and motility
Explain the barrier function
Lymphocytes
Synthesis of antibodies
Antibodies recognize and bind to antigen
The binding causes the phagocyte to engulf antigen
Destruction of harmful organism
What does saliva contain
Amaylase which helps break down carbs
Lyzosome which helps to inhibit bacterial growth in the mouth
Saliva helps prevent tooth decay
Why is chewing important
Mechanically breaks down food increasing surface area in contact with digestive enzymes
Expose nutrients
Especially with fibre
Pharynx
Shared with digestive and respiratory tract
Epiglottis
Connective tissue which covers larynx and passage way to lungs
Explain peristalsis
Circular muscles contract pushing the bolts down
Longitudinal muscles contract shortening the passageway ahead of the bolus
The rhythmic contractions propel food down the esophagus
Is the stomach wall thick or thin
Thick and have the strongest muscle in the GI tract
Little absorption happens in stomach
What are stomach wall lined with
With mucous and millions of gastric pits-openings that contain gastric glands and secrete gastric juice
What hormone is secreted when food enters the stomach
Gastrin
Secreted by stomach mucosa
Stimulated release of gastric juice from gastric glands
What does HCL do
Help digest food and inhibit bacterial growth
What does intrinsic factor do
Involved in the absorption of b12
What does pepsinogen do
Inactive protein digesting enzyme which is activated to pepsin by acid in the stomach. Most powerful digesting enzyme
Pepsin
Digesting protein into AA
Things that can stimulate gastric secretion and motility
Thought
Smell
Sight
Taste
Food entering stomach
