Chapter 19 Flashcards
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
fat digestion location and enzymes
mouth, stomach, small intestine (mostly here)
bile emulsifies, lipase (pancreatic enzyme) digests into fatty acids and monoglycerides
these then diffuse into intestinal cells and repackaged into triglycerides by smooth ER
packaged with proteins into chylomicrons (blood soluble) and absorbed by lacteals
also absorbed here are fat soluble vitamins
2 fat soluble vitamins
Vitamin D (calciferol)
Vitamin E (tocopherol)
chyle
mixture of fat and lymph that drains from small intestine
hydrolysis
process of digestion where water is added to nutrient molecules as they are split by enzymes
each hydrolysis reaction requires a specific enzyme and 1 molecule of H2O
gastrin
hormone released once food hits the stomach which further increases stomach secretions and motility
cholecystokinin (CCK)
hormone stimulated by fat/protein presence
CCK stimulates secretion of pancreatic enzymes and bile release
secretin
hormone released with increased acidity
secretin stimulates pancreas to release bicarbonate and return pH to normal
gastric inhibitory peptide (GIP)
hormone released upon increased glucose concentrations
GIP stimulates insulin release to decrease blood glucose in anticipation of glucose absorption from chyme
vincent disease
gingivitis caused by spirochete or bacillus bacteria
highly contagious
parotitis
inflammation of parotid glands
contagious form is MUMPS from virus (prevented by MMR vaccine)
gastritis
inflammation of stomach lining
can be caused by direct or indirect damage (like ASA decreasing mucous production)
chronic form can be caused by H. pylori bacterium
diverticula
small pouches in wall of intestine caused by low fiber diet
diverticulosis: formation of high numbers of diverticula
can cause diverticulitis (collection of waste/bacteria)
intussuseption
slipping of part of intestine into adjacent part
volvulus
twisting of intestine
ileus
intestinal obstruction caused by lack of peristalsis
ghrelin
hormone released by empty stomach between meals to stimulate hunger
what hormones decrease hunger?
CCK, GIP
leptin
hormone produced by adipocytes
hypothalamus responds by decreasing food intake and increasing energy expenditure (if disrupted, obesity results)
