Chapter 19 Flashcards
(42 cards)
Mesentary peritoneum
“fan-shaped” attached to posterior abdominal wall and expanding along edge of small intestine
has nerves and vessels between 2 layers
Deglutition
moves controlled amounts of food toward throat to be swallowed
Deciduous teeth
“baby teeth” about 20
Dentin
main substance of tooth; calcified substance harder than bone
cementum
rigid connective tissue helping to hold root of tooth in place
periodontal ligament
connective tissue sheet that joins cementum to tooth socket
esophageal hiatus
opening in diaphragm for passage of esophagus; causes weak point
segmentation
rhythmic contractions causing food to mix with gastric juices
4 layers of the digestive tract
- mucous membrane (mucosa)
- submucosa
- muscularis externa
- serous membrane (serosa)
what is special about the stomach lining
has 3 muscular layers (circular, longitudinal, and inner oblique)
the inner oblique fibers help to grind food and mix with digestive juices
2 sphincters of the stomach
lower esophageal (cardiac)
pyloric
2 active portions of gastric juices, functions, and when they are activated/secreted
- hydrochloric acid (HCl); denature proteins and destroy foreign organisms; produced in anticipation of eating and when food enters stomach
- pepsin; protein-digesting enzyme; produced in inactive pepsinogen form and activated upon HCl or pepsin contact
chyme
mixture of food, gastric joices, and muicous released into the small intestine
name 2 things the small intestine secretes
- mucous to protect from acidic chyme
- enzymes for final stages of carb/protein digestion
name 3 modifications of small intestine lining for absorption
- mucosa and submucosa formed into large circular folds
- mucosa of each fold are formed into villi (each with their own capillary and lacteal)
- each cell of the villi have microvilli (projecting folds of plasma membrane)
teniae
surface bands giving puckered appearance to large intestine
name 3 functions of large intestine
- secretes mucous (no enzymes)
- water absorption
- bacteria present produce vitamin k and some complex b vitamins which are then absorbed by mucosa
function of salivary amylase
enzyme in saliva that initiates carbohydrate digestion
7 functions of the liver
- manufacture bile
- control blood glucose (insulin and glucagon)
- storage (fat, iron, vitamins)
- formation of blood plasma proteins (albumin, globulins, clotting factors)
- destruction of old RBCs and recycling/elimination of products (bile)
- synthesis of urea
- detoxification
urea synthesis and elimination
urea is synthesized in the liver as a waste product of protein metabolism
it is released into the blood and promptly eliminated by the kidneys
functions of bile and pathway to duodenum
needed for processing of fats
contains bile salts that emulsify fat droplets to be acted on by digestive enzymes
leaves liver through common hepatic duct, joins cystic duct (gallbladder) to form common bile duct, joins pancreatic duct to form hepatopancreatic ampulla (empties into duodenum through hepatopancreatic sphincter)
since this is closed a majority of the time, back up sends excess bile into gallbladder
secretions of pancreas
- insulin/glucagon
- enzymes for digestion of fats, proteins, carbs, and nucleic acids (the protein enzymes are inactive and activated by other enzymes in small intestine)
- high amounts of sodium bicarbonate to neutralize chyme
carbohydrate digestion locations and enzymes
mouth and small intestine
pancreatic amylase (small intestine) and maltase, sucrase, and lactase from the small intestine
also salivary amylase
protein digestion location and enzymes
stomach and small intestine
HCl denatures, pepsin cleaves, trypsin (pancreatic) splits into peptides
