Digestive System and Metabolism Flashcards
Carbohydrates, Lipids, Proteins, and Enzymes, Digestive processes, Organization of GI tract, Digestive organs, Physiology of digestion, Metabolism of nutrients, Minerals and vitamins, Metabolism and body heat
source of chemical energy is
food
energy is needed for?
muscle contraction
conduction of nerve impulses
secretory and absorptive activities of many cells
digestion
the mechanical and chemical break down of food into simple molecules to be absorbed and used by cells
absorption
the passage of small food molecules through plasma membranes of cells lining the stomach and intestines and then into the blood and lymph
Digestive system
ingests food
digest food
breaks it down
absorbs nutrients
eliminates waste
Mechanical digestion
physical breakdown of food by the teeth and mixing/churning of the food with enzymes by the smooth muscles of the stomach and small intestines
chemical digestion
series of catabolic (hydrolysis) reactions that break down large nutrient molecules such as carbohydrates, lipids, and proteins to be absorbed and used by cells
Digestive organs are divided into what 2 main groups?
- Gastrointestinal tract aka alimentary canal = continuous tube running from mouth to anus
- Accessory digestive organs = teeth, tongue, salivary glands, liver, gallbladder, and pancreas
what is the GI or alimentary canal composed of?
mouth
pharynx
esophagus
stomach
small intestine -> duodenum, jejunum, ileum
large intestine -> cecum, colon, rectum, and anal canal
proctology
medical specialty dealing with dx and tx of rectum and anus disorders
gastroenterology
medical specialty dealing with structure, function, dx, and tx of stomach and intestine diseases
list the GI wall layer from deep to superficial
mucosa
submucosa
muscularis
serosa aka peritoneum
important extensions of the peritoneum are
mesentery of small intestine - suspends the jejunum and ileum
transverse mesocolon - suspends the transverse colon
falciform ligament
lesser omentum - mesentery that suspends the stomach by its lesser curvature
greater omentum - apron of peritoneum filled with fat that is by stomach’s greater curvature
parietal peritoneum
lines the interior abdominal wall
visceral peritoneum
covers abdominal organs
deglutition
swallowing food through esophagus to stomach
mesentery
attaches the small intestine to the posterior abdominal wall
right colic (hepatic) flexure
portion of the colon closes to the liver
fauces
the opening between the mouth and the pharynx
ileal orfice aka ileocococal
smooth muscle sphincter that joins the ileum and large intestine
order of food in body from entry to exit
bolus
acid chyme
basic chyme
fecal matter
feces
roof of mouth
hard palate
soft palate
uvula
tonsils
amylase
activated by chloride ions in the saliva
it is an enzyme that breaks down starch into maltose, maltotriose, and alpha-dextrin
found in saliva, small intestine, and pancreas
uvula
prevents swallowed food from entering the nasal cavity
central vein
receives blood from hepatic sinusoids and transfers blood to hepatic veins which drains into inferior vena cava.
(associated with liver)
pepsinogen vs pepsin
chief cells secrete pepsinogen (inactive), and hydrochloric acid secreted by parietal cells or active pepsin molecules converts it into active pepsin
gastric juice is ?
the combined secretions of mucous cells, chief cells, and parietal cells.
what does the enzyme pepsin digest?
pepsin digests protein in the stomach by breaking them down into peptides
peristalsis is?
involuntary smooth muscular contractions that move substances throughout the gastrointestinal tract (GI)
what does Lugol’s solution test for?
it would give a dark blue almost black color for starch.
any other color is negative
what does benedict’s solution test for?
reducing sugars producing precipitate at bottom and solution appearing red or any color except blue.
blue is negative
pancreatic lipase
digests triglycerides into fatty acids and glycerol changing blue litmus paper to red
chief cells secrete what?
pepsinogen and gastric lipase
chemical digestion of carbohydrates (starches) is initiated in the?
mouth by salivary amylase which breaks down starch
circular folds, intestinal villi, and microvilli are?
small intestine structures for absorption by increasing surface area.
lingual lipase
produced by tongue and digests triglycerides (fats) into fatty acids and diglycerides
parietal cells in stomach secrete
intrinsic factor for absorption of vitamin B12 (B12 needed for blood cell formation aka erythropoiesis)
hydrochloric acid - to kill microbes, convert pepsinogen to pepsin, and denature proteins
hepatopancreatic ampulla aka ampulla of Vater is
a major duct of the pancreas that transfer pancreatic juices from exocrine cells into the small intestine. it also transports bile.
pancreatic juice
mixture of fluids and enzymes
the lamina propria is found in which coat?
mucosa (inner lining of digestive canal)
most sugars from nature are ?
dissacharides
basal metabolic index
how much energy you use at rest
basal metabolic rate
how much energy your body requires to work on a daily basis
sugars get converted into what for long term storage?
lipids
energy in usage from low to high requiring enzyme
glucose
lipid
protein
electron transportation does
oxidation and reduction
how many ATP molecules does the electron transport chain produce?
26 or 28 ATP
nutrient molecule: carbohydrate
a sugar
polar (polar food requires active transport)
short energy
nutrient molecule: lipid
non polar
long energy
oils, fats, waxes
nutrient molecule: polypeptides
protein
enzymes are proteins
macrounits vs microunits
macrounits are polymers (polysaccharides and disaccharides)
and monomers (monosaccharides)
microunits are vitamins(organic and can be polar or nonpolar based on how they interact with water) and minerals(inorganic, examples are cobalt and iron)
cellulose
fiber from plant cell wall
good for bowel movement to prevent cancer cells from trapped toxins
glucagon
available in liver for energy
if not used in a couple of days it gets stored as fat (lipid)
chitin
found in exoskeleton of animals such as shrimp, crab, and lobster
chitin is absorbed fast and curves apetite
enzyme break downs
lactase
sucrase
lactose breaks down to galactose
sucrose breaks down to fructose
saccarine
artificial sweetner
made for diabetics
caused cancer in lab rats
sodium saccarine
retains water
unsaturated lipid vs saturated lipid
saturated lipid - unhealthy, straight, fats
unstaturated lipid - healthy, kink, oils, can be broken down easier
pancreas enzyme
lipase
breaks down fat droplets into glycerol and fatty acids to get absorbed by lacteals in the small intestine
lacteals
the lymphatic vessels of the small intestine which absorb digested fats into the lymphatic system
what mechanism does fats get absorbed into body?
no mechanism
they just get absorbed by simple diffusion
PKU phenylkeonuria
build up of phenylalanine because enzyme is not produced due to lack of gene that produces it. phenylalanine found in meat, dairy, eggs, nuts.
polar vitamins
B
C
non polar vitamins
A
D
E
K
where do nutrients like iron and fats get stored?
liver
what is the ph in the stomach
1-3
gastric ulcer
wear down of epithelial wall in stomach
can be treated by antibiotic
duodenal ulcer
is directly related to acidic foods
acid chyme
when bolus enters stomach
what increases bile to be released from liver?
fatty food diet
pancreatitis
caused by blockage in pancreas
gallbladder
stores and concentrates bile
mesentary
holds intestines together
is membranes creating the cavity
the membrane goes around each organ
greater omentum
contains lots of adipose tissue
largest peritoneal fold draping over transverse colon
jejunum
contains vili and microvili for absorption
ileum
more involved in mineral absorption
where does maximum amount of energy come from?
glucose
glycolysis
process where sugars turn into fats
diabetics have to break down
fats because they cannot break down sugars
essential amino acids and lipids are
sourced outside of the body because we cannot produce them ourselves
when you denature a protein it changes from liquid to ?
solid
uvula has nerve endings that trigger?
response for swallowing
chrohns disease affects
ileum
appendix
has collection of bacteria
3 major salivary glands
parotid gland
submandibular gland
sublingual gland
what is the largest gland in the body
liver
what is the gallbladder
stores and concentrates bile needed for fat digestion
what is pancreas
an exocrine and endocrine organ
where is water absorbed
in large intestine
what is saliva
largely water
slightly acidic (ph of 6.75-7
secretes lysozome, calcium, phosphate for tooth formation and maintenance
protects against microorganisms by secreting IgA antibodies, lysozyme, cyanide compound, and defensins
mumps
childhood disease where parotid salivary glands become inflamed by myxovirus
what is the hardest substance in the body?
enamel
enteroendocrine cells
secretes hormones that help regulate digestion
