Upgrade to remove ads
ppt 3 and 4
Terms in this set (36)
- enzymes that digest carbohydrates, proteins, fats, and nucleic acids
- bicarbonate to buffers stomach acid
- empties contents into duodenum
What is pancreatic juice made up of?
- mostly H2O
- some salts
pancreatic exocrine cells
2 lobes divided by falciform ligament
major functional cells of the liver, secrete bile
ducts between hepatocytes that collect bile
capillaries that receive O2 rich blood
- stores bile secreted by liver
- a sphincter muscle controls the release of bile from common bile duct
secreted by liver
Where is the bile stored?
What do bile salts play a role in?
emulsification of lipids
pigment released by the liver in bile
What is in the small intestine?
duodenum, jejunum, ileum
True or False: Microvilli increases surface area.
provides a vehicle for absorption of substances from chyme as they come in contact with the villi
Brush Border Enzymes
break down food products
Where are the brush border enzymes located?
surfaces of microvilli on absorptive cells
2 Steps of Mechanical Digestion
Chemical digestion is the digestion of...
- nucleic acids
What are the functions of the colon?
- haustral churning (peristalsis)
- mass peristalsis drives contents of colon into rectum
- bacteria in colon convert proteins into amino acids, break down amino acids, and produce some vitamin B
- absorption of some water, ions, and vitamins
- formation of feces
- distension reaches a certain point
- walls of the haustra contract to squeeze contents onward
a strong peristaltic wave that begins in the transverse colon and quickly drives the contents of the colon into the rectum
How do the last stages of chemical digestion occur?
through bacterial action
- some vitamins
- inorganic salts
- sloughed off epithelial cells
- products of bacterial decomposition
- undigested portions of food
- rectal wall distends
- stretch receptors send sensory nerve impulses to the sacral spinal cord
- motor impulses travel back to the descending colon, sigmoid colon, rectum, and anus
- longitudinal rectal muscles contract and the internal anal sphincter opens
- if the external anal sphincter is voluntarily relaxed, defecation occurs and the feces are expelled
What are the 3 phases of digestion?
What does the cephalic phase prepare?
mouth and stomach for digestion
- smell, sight, thought of initial taste
- activates neural centers
- brain stem stimulates
What are the neural centers?
cerebral cortex, hypothalamus, brain stem
Gastric Phase of Digestion
neural and hormonal mechanisms promote gastric secretion and motility
Intestinal Phase of Digestion
occurs when the duodenum responds to chyme, gastric activity begins through hormones and reflexes
a hormone produced by cells of the intestinal wall. Target organ: the gallbladder. Response: release of bile and slowing of GI motility.
a hormone released into the bloodstream by the duodenum (especially in response to acidity) to stimulate secretion by the liver and pancreas.
THIS SET IS OFTEN IN FOLDERS WITH...
A & P: Chapter 20
A & P: Chapter 27
A & P: Chapter 19
A & P: Chapter 21
OTHER SETS BY THIS CREATOR
Chapter 28 Reproduction
HIST 111 Final
Chapter 24: Digestive System