Chapter 5 - Nutrient Utilization & General Metabolism Flashcards
what is the hierarchy of structures that our bodies are made up of?
atoms, molecules, cells, tissues, organs and organ systems
digestive tract
esophagus, small intestine, large intestine, rectum anus
digestion involves ______ system, ________ system, hormones and enzymes
nervous system, musculoskeletal system
what do enzymes do
little chemical machines that can large nutrients in foods and break them down into smaller pieces
true or false: some enzymes break down proteins, others carbs and others fats
true
where does digestion start?
in the mouth
cephalic phase
- starts before the food even hits your mouth
- mouth watering or stomach growling
cephalic
brain/mind
why does our mouth water and our stomach growl before food even hits your mouth?
bodies way of preparing you for food your about to receive
what are 3 roles of saliva
1) moisten food
2) salivary amylase
3) lysozyme
salivary amylase
- the first digestive enzyme that we encounter
- breaks down carbohydrates in your mouth
lysozyme
- powerful antibacterial agent
- try to help bring down bacterial levels to prevent you from getting sick
chewing allows for what?
optimal digestion
why do large nutrients need to be torn apart/ripped open?
to allow digestive enzymes more access to the nutrients
what prevents food from going into the trachea?
epiglottis
the intestinal wall is made up of how many layers?
4
what are the 4 layers of the intestinal wall?
1) external layer of connective tissue
2) layers of smooth muscle
3) connective tissue
4) mucosa
what layer of the intestinal wall contains nerves and blood vessels?
connective tissue
which layer of the intestinal wall contains the cells that absorb nutrients
mucosa
peristalsis
esophagus has the 2 smooth muscle layers that contract to make wave-like muscle contractions to push food
true or false: peristalsis is so strong that it only takes about 5 seconds to get from top of the esophagus to top of the stomach
true
true or false: peristalsis isn’t strong to push food in the right direction when your upside down
FALSE: peristalsis is strong enough to push food in the right direction when your upside down
what does the stomach do to the food
mixes and churns it
what 4 gastric juices are mixed in with the food when it is churned in the stomach?
1) Hydrochloric acid
2) Pepsin
3) Gastric Lipase
4) Mucus
What does Hydrochloric acid do when it is mixed with the food in the stomach?
has antibacterial functions and acts to help body digest proteins by unfolding them
what does pepsin do when it is mixed with the food in the stomach?
breaks down proteins
what does gastric lipase do when it is mixed with the food in the stomach?
breaks down fat
what does mucus do when it is mixed with the food in the stomach?
- has a protective role
- acts as a barrier to protect the cells of the stomach from the extremely low ph (acidity) of HCl
there are __ strong muscle layers in the stomach
3
chyme
mixture of food after it is churned by the stomach
how long can the stomach hold onto chyme?
certain periods of time depending on certain factors
gastric mobility
how long chyme can stay in the stomach
what are 4 factors affecting the rate of stomach emptying?
1) size of meal
2) physical composition of the meal
3) macronutrient composition
4) emotional factors
how does the size of the meal affect gastric mobility?
big meals take more time to churn so held in stomach for longer period of time?
how does the physical composition of the meal affect gastric mobility?
goal of stomach is to churn food into a liquid, so liquid based foods are digested in stomach faster than solids
how does macronutrient composition affect gastric mobility?
- amount or type of macronutrients determine time it stays in your stomach
- foods that are high in carbohydrate don’t stay in stomach long
- foods that are high in fats stay in stomach longer
- protein are intermediate amount of time
how does emotional factors affect gastric mobility?
- mood your in or how your feeling can have an influence
- anger can move food out of stomach fast
- sadness can move food out of stomach slower
______ is the main site for digestion and absorption with help from the liver, gallbladder and pancreas
small intestine
liver and gallbladder produce what
bile
what 4 things does that pancreas produce?
1) pancreatic amylase
2) pancreatic lipase
3) proteases
4) bicarbonate
what are structures of the small intestine designed for?
designed to maximize nutrient absorption
villi
- increase surface area
- capillaries
- lacteals
true or false: products of digestion need to pass through the cells of the intestine to be fully absorbed
true
where are absorbed nutrients taken for processing?
liver
_____ stores food waste until it is ready to be excreted
large intestine
large intestine stores water and nutrients for up to ______
24 hours
material that is not absorbed = _______
feces
peptic ulcers
- erosion of the mucosal layer
- gastric vs. duodenal ulcer
2 disorders of the lower GI
irritable bowel syndrome and inflammatory bowel disease
irritable bowel syndrome
- abdominal cramps
- bloating
- constipation/diarrhea
- stress
- nervous system miscommunication
- certain trigger foods
inflammatory bowel disease
- inflammation of the GI tract
- Crohn’s disease
- ulcerative colitis
carbohydrates, protein and fat are converted to ATP inside ______
the mitochondria
catabolism
taking something large and breaking down into something smaller (breaking down - tend to produce the ATP
anabolism
the opposite (building up - need ATP)
integumentary system
- skin
- gets rid of some wastes, not all (sweat gets rid of ammonia and urea)
