chapter 14 digestive system Flashcards
what are the functions of the digestive system?
1) secretion
2) digestion
3) absorption
4) elimination
the digestive systems function of secretion :
digestive system secretes mucin, acid, bile, and other digestive enzymes
the digestive systems function of digestion :
the digestive system breaks food down into smaller substances mechanically and chemically (with enzymes)
the digestive systems function of absorption :
the digestive system obsorbs molecules into the blood and lymph through GI tract epithelium
the digestive system of elimination is :
defication of indigestible materials
what does the digestive system break carbohydrates into?
monosaccharides (simple sugars)
what does the digestive system break proteins down into?
amino acids
what does the digestive system break fats down into?
fatty acids and glycerol
what is bolus?
food mixed with saliva
what does the stomach convert bolus into?
chyme
ingestion =
the introduction of materials into the mouth
motility =
voluntary/involuntary contractions that mix and move materials through the gastrointestinal tract
mixing =
the churning movements in the small intestine that disperses ingested materials and combines them with digestive secretions
peristalsis =
ripple-like wave of muscular contraction that forces material to move further along the GI tract
what are the functions of the salivary glands?
to lubricate, cleanse, and moisten structures of the oral cavity
what 2 types of secretory cells are found in the salivary glands and what do they secrete?
mucous cells- secrete mucin.
serous cells- secrete fluid with ions, lysozyme, and salivary amylase
what does mucin form when hydrated?
mucous
what are the 4 tunics of the GI tract?
(basic pattern)
(deep to superficial)
1) mucosa
2) submucosa
3) muscularis
4) serosa or adventitia
what is the connective tissue membrane that wraps around the serosa in the GI tract?
mesentary
what are the layers in the mucosa tunic in the GI tract?
(deep to super)
1) endothelium
2) lamina propria
3) muscularis mucosae
what are the 2 layers in the muscularis tunic of the GI tract?
1) inner circular layer
2) outter longitudinal layer
what is the submucosa of the GI tract composed of?
1) connective tissue
2) lymphatic ducts
3) mucin
4) blood vessels
5) nerves
where is the submucosal nerve plexus located?
in the submucosa of the GI tract
what does each layer of the muscularis do?
inner circular layer - constricts the lumen and forms sphincters
outter longitudinal layer - shortens the tube
what is located between the 2 layers of muscle in the muscularis?
myenteric nerve plexus
how is adventitia and serosa similar and how are they different?
theyre both areolar CT w/ collagen and elastic fibers
serosa is covered with visceral peritoneum and adventitia is not
what are the sphincters in the esophagus?
what type of muscle is each one made of?
where are they located?
1) superior esophageal sphincter - is made of skeletal muscle - top of esophagus
2) inferior esophageal sphincter - made of smooth muscle - located at the bottom of esophagus
what does the superior esophageal sphincter do during inhalation?
closes to prevent air entry into esophagus
which quadrant is the stomach located in?
upper left quadrant
what does the stomach turn bolus into?
chyme
what does the rate of passage through the stomach depend on?
depends on food contents
lipids pass slower and liquids pass through more quickly
specialized cells in the stomach secrete what?
1) mucous
2) HCI
3) enzymes
4) hormones
what are the names of the 3 layers of smooth muscle located in the wall of the stomach?
(deep to super)
1) oblique layer
2) circular layer
3) longitudinal layer
what are gastric folds AKA?
rugae
what are the names of the cells in the stomach?
1) surface mucous cells
2) mucous neck cells
3) parietal cells
4) cheif cells
5) enteroendocrine cells
what are the 3 sections of the small intestine?
(upstream to downstream)
1) duodenum
2) jejunum
3) ileum
what are intestinal villi?
projections on the circular folds of the small intestine.
they absorb nutrients
what are the 4 layers of tunic in the small intestine?
(deep to super)
1) mucosa
2) submucosa
3) muscularis
4) serosa
what does the epithelium with microvilli in the small intestine do?
absorb nutriunts
what do goblet cells produce?
mucous
what are the sections of the colon?
(upstream to downstream)
1) ascending colon
2) transverse colon
3) descending colon
4) sigmoid colon
what is the name of the first section of the large intestine after the small intestine?
the cecum
what are the names of the final 2 sections of large intestine following the colon?
1) rectum
2) anal canal
what is the energy value of food measured in?
kilocalories(Kcal)
or
calories (C)
foods are oxidized and turned into fuel called what?
adenosine triphosphate (ATP)
ATP =
the chemical energy that drives cellular activities
nutrient =
a substance used by the body for growth, maintenance, and repair
major nutrients =
1) carbohydrates
2) lipids
3) proteins
4) water
minor nutrients =
1) vitamins
2) minerals
what are the mechanisms that may regulate food intake?
1) nutrient levels in blood
2) hormones
3) body temp
4) psychological factors
how many kcal per gram does cabs have?
4 kcal / gram
how many kcal per gram do fats yield?
9 kcal/gram
how many kcal per gram does alcohol have?
7 kcal/gram
BMR =
basic metabolic rate.
the number of calories needed to keep your body functioning at rest
what is the average bmr for an average adult?
the average 154 lb adult needs 60-72 kcal/hour
TMR =
total metabolic rate
the total amount of kilocalories the body must consume to fuel ongoing activities
gastroenteritis =
inflammation of the GI tract
(this can happen anytime)
appendicitis =
inflammation of the appendix
(tends to happen in adolescents)
ulcers and gall bladder problems are more common in people of which age group?
middle aged individuals
which age group is more commonly affected by obesity and type 2 diabetes?
later middle aged individuals
activity of the digestive tract in old age :
1) fewer digestive juices
2) peristalsis slows
3) diverticulosis and GI cancers are more common
