The Digestive System Flashcards
what is ingestion
intake of food via the mouth
what is digestion
mechanically or chemically breaking down food into their subunits
what is absorption within the digestion system
movement of nutrients across the GI tract wall to be delivered to cells/tissues via the blood
what is elimination within the digestion system
removal of indigestible molecules
what is movement within the digestion system
food must be moved along the GI tract in order to fulfill all functions
what are the main steps in the digestive process
ingestion, digestion, movement, absorption, and elimination
what is the overall goal of the digestive process
to breakdown food into usable units and eliminate the rest
what is the function of the mouth
teeth chew food, tongue tastes, and pushed food for chewing and swallowing
what is the purpose of the pharynx
passageway where food is swallowed
what is the purpose of the esophagus
passageway where peristalsis pushes food to stomach
what is the function of the stomach
secretes acid and digestive enzyme for protein; churns, mixing food with secretions and sends chyme to small intestine
what is the function of the small intestine
mixes chyme with digestive enzymes for final breakdown; absorbs nutrient molecules into body; secretes digestive hormones into blood
what is the function of the large intestine
absorbs water and salt to form feces
what is the purpose of the rectum
stores and regulated the elimination of feces
what is the pathway of food entering and exiting the body
mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anus
what are the accessory organs in the digestive process
salivary glands, liver, gallbladder, pancreas
what is the function of the salivary glands
secret saliva
what does saliva contain
digestive enzymes for carbohydrates
what is the purpose of the liver
processes and stores nutrients
what produces bile
the liver
what is bile used for
emulsification of fats
what is the function of the gallbladder
stores bile from liver, and sends it to the small intestine
what is the function of the pancreas
produces pancreatic juice: contains digestive enzymes, and sends it to the small intestine; produces insulin and secretes it into the blood after eating
what hormones regulate hunger and appetite
Gherlin and Leptin
where is Gherlin and Leptin produced
in the GI tract
what are the different ways hormones in the GI tract are released
in the gut through food presence, by the nervous system by seeing or smelling food, some arise from fat cells
what are the layers of the GI tract
mucosa, submucosa, muscular, and serose
what is the mucosa
innermost layer of epithelial cells that produces mucus that protect the lining
what is the submucosa
layer of loose connective tissue that contains blood vessels, lymphatic vessels and nerves
what is the muscularis
layer made of 2 orthogonal layers of smooth muscle that move food along the GI tract
what is the serose
outer lining that is part of the peritoneum that covers abdominal organs
what secretes salivary amylase
3 pairs of salivary glands located in the mouth
what is salivary amylase
an enzyme that begins carbohydrate digestion
what are tonsils
2 lymph organs located in the back of the mouth
what is the purpose of tonsils
serve to fight infection
what is the tongue
skeletal muscle in mouth that is covered in specialized sensory cells
what is the purpose of the tongue
assist in the mechanical breakdown and movement of food
what does the tongue form
a bolus
what is a bolus
mass of chewed food
what are the two ways we swallow food
swallowing and peristalsis
what are the three layers of smooth muscle in the stomach
Longitudinal layer of muscle
Circular layer of muscle
Oblique layer of muscle
what does the mucosa layer of the stomach have
rugae
what is controlled by the stomach
the movement of chyme into the small intestine
what is the purpose of the three layers of the stomach wall
it helps in mechanical digestion and allowing it to stretch
what is rugae
deep folds in the mucosa layer
what is the purpose of rugae
rugae and gastric pits lead into gastric glands that secrete gastric juice
what does gastric juice contain
pepsin, hydrochloric acid, and mucus
what is pepsin
an enzyme that breaks down proteins
what makes up chyme
gastric juice and food
what is the pH of the stomach
2
what causes the acidic pH in the stomach
Hydrochloric acid
what is the purpose of the acidic pH in the stomach
it activates pepsin and helps to kill bacteria in food
what causes peptic or gastric ulcers
a bacterium called helicobacter pylori
what does helicobacter pylori live
in the mucus of the stomach
what is the average length of the small intestine
18 feet / 6 meters
what is the first section of the small intestine called
duodenum
what connects to the duodenum
liver, gallbladder, and pancreas
what begins the digestion of carbohydrates, proteins, and fats in the small intestine
enzymes secreted by the pancreas
what secretes bile
the gallbladder
how is the digested food absorbed
through the large surface area of the mucosal epithelium
what creates the large surface area in the mucosal epithelium
numerous vili and microvilli
what are vili
finger-like projections
what are microvilli
small membrane projections from each cells
what enters the capillaries during digestion
amino acids and sugars
what enters the lacteals during digestion
fatty acids
what are lacteals
small lymph vessels
what breaks down carbs
pancreatic amylase
what are carbs broken down into
maltose and glucose
where do maltose and glucose flow into
blood capillary
what breaks down protein into peptides
trypsin
what are peptides broken down into
peptidase and amino acids
where do amino acids go after digestion
into blood capillary
what breaks down bile salts and fat globules
emulsification droplets
what are bile salts and fat globules broken down into
lipase
what is lipase broken down into
monoglycerides and fatty acids
what are monoglycerides and fatty acids broken down into
chylomicron
what is chylomicron secreted into after digestion
Lymphatic capillary
how does enzymes affect the break down of food
they catalyze the hydrolysis reactions that break down food
what does the absorption process rely on
facilitated transport
how does blood travel to the liver
via hepatic portal vein
why does blood travel to the liver
for additional metabolism and storage
what are the key organs that aid in digestion
pancreas, liver, and gallbladder
what is the pancreas
fish-shaped, spongy organ behind stomach
what is the exocrine function of the pancreas
secretes bicarbonate into small intestine to neutralize stomach acid, and secretes enzymes to aid in digestion
what enzymes are secreted by the pancreas
trypsin, lipase, pancreatic amylase
what is the endocrine function of the pancreas
secretes insulin into the blood to keep blood sugar levels under control
what causes blood glucose to rise
digested food
what is blood glucose also called
glycemic index
what is secreted when blood sugar is low
glucagon
what does glucagon do
helps to mobilize glucose stored in the body
what is an example of stored glucose is mobilized by glucagon
glycogen in the liver
what makes up the liver
around 100,000 lobules
what is the purpose of the liver
filters blood from the GI tract, acting to detoxify the blood
what does the liver remove from blood to store
Iron, Vitamin A, D, E,K, and B12
what does the liver store glucose as
glycogen
why does the liver store glycogen
for break down, to help maintain steady blood glucose levels
what makes plasma proteins
the liver
what type of plasma proteins are made by the liver
albumin, fibrinogen, and several others
what is used to make bile
high density lipoprotein
what does HDL contain
cholesterol
what is hemoglobin broken down into
bilirubin
what is HDL known as
the good cholesterol
what does the large intestine include
the cecum, colon, rectum, and anal canal
what is the appendix
projection from the cecum
wha is the purpose of the appendix
plays a minor role in fighting infections
what kinda of organ in the appendix
vestigial organ
why is the large intestine considered bigger than the small intestine
it is larger in diameter but smaller in length
what are the functions of the large intestine
absorbs water, absorbs vitamins, forms and rids the body of feces
why is water absorbed in the large intestine
the prevent dehydration
what vitamins are absorbed in the large intestine
B complex, and vitamin K
what produces vitamin B complex and K
intestinal flora
what is intestinal flora
bacteria found in the GI tract
what type of muscles are responsible for defecation
involuntary and voluntary sphincter muscles
what is BMI stand for
body mass index
what is the purpose of BMI
its a measurement of body proportions that help to gauge a person’s overall proportions
what are the five major classes of nutrients needed by our bodies
carbohydrates, proteins, lipids, minerals, and vitamins
what are three types of macronutrients
carbohydrates, proteins and lipids
what are two types of micronutrients
minerals and vitamins
what causes hyperglycemia
excessive carbohydrate intake
why do we need to ingest proteins daily
they are not effectively stored in our bodies
what is the result of excessive protein intake
chronic excretion of nitrogenous wastes and it can overwork the kidneys
what does Hal stand for
high density lipoprotein
