Digestive System Flashcards
What is the relationship between the body mass and metabolic rate?
the larger the animal, the slower the metabolic rate
What are nutrients
a chemical that must be obtained by an organism from its environment in order to survive, nutrients provide the raw material for growth and repair and may be a source of energy
How is light energy different from chemical energy?
light energy is used by plants and converted into chemical and cannot be stored in cells
chemical energy is obtained by eating the chemical energy made by plants and can be stored
what is endothermic organisms
mammals and birds- need much energy to keep bodies warm and therefore must consumer lots of energy (warm blooded animals)
What are ectothermic organisms
cold blooded
define metabolism
the set of chemical reactions that occur in living organisms that are necessary to maintain life
define catabolism
the metabolic reactions that break down larger molecules from smaller subunits
define anabolism
the metabolic reactions that use energy to break down larger molecules from smaller subunits
define metabolic rate
the rate at which the body converts stored energy into working energy
wat factors affect a organisms metabolic rate?
body size physical activity sex age hereditary factors
how does body size affect metabolic rate
he karger the body the more energy it requires to stay alive
how does physical activity affect metabolic rate
muscle burns more energy that fat, so physical activity requires more energy
how does sex affect metabolic rate
males are typically bigger and require more energy that females of the same age, size and fitness level
how does age affect metabolic rate
metabolic rate decreases with age
how does hereditary factors affect metabolic rate
some have naturally high metabolic rates
how is energy measured
in joules through the formula of
BMR= [655+(9.6xmass in kg)+(1.8xheight in cm)-(4.7xage in years)] x 4.18
Where do carbohydrate come from
glucose, fructose lactose and starches
What are the different structures that carbohydrates come in
monosaccharides-1 sugar
disaccairdes- 2 sugar
polusacchaides-many sugar
function of carbs in body
energy
where is carbs stored
liver , muscle and tissue
sources of lipids
fats and oils
form/structure of lipids
take form of some hormones
in a cabin-hydrogen chain
function of lipids
chemical energy
helps absorb vitamins
Sources of proteins
animal sources (meat and cheese), plant sources (nuts and seeds)
structure/form of proteins
made of long chains called amino acids
function of proteins
building blocks of cell generates motion generates metabolic rate transports oxygen controls chemical reactions
what are the 6 essential nutrients needed
carbs protein minerals lipids water vitamins
What are the four main steps in digestion
Ingestion, digestion, absorption, excretion
what is ingestion
The taking in of nutrients
What is digestion
The physical and chemical breakdown of complex food molecules to smaller molecules
What is absorption
The transfer of digested nutrients from the digestive system and the bloodstream
Define egestion
The removal of waste food materials from the body
how many digestive openings do more complex animals have
typically two (one for intake and one for outtake)
how long is the digestive track in a human
7m-9m (depending)
how does the muscle and bone system aid digestion
enables animals to catch and ingest food
how does the circulatory system aid digestion
transports oxygen and other materials to the digestive system and caries digesting food to parts of body
what starts the digestion in the mouth
enzymes called amylase
what teeth help digestion
molars are flat for grinding and crushing food, incisors and canines are sharp for grabbing and cutting
what does the teeth organisms have indicate
their diet
what kind of muscles are in the esophagus
smooth
What is peristalsis
Wavelike contractions to move food down
what is sphincter
circular muscles that contract to close an opening in the body
How many sphincters are there in the human body
over 50
where is the gastroesophageal sphincter located
where the esophagus joins the stomach. it prevents food and acid from moving up the esophagus (preventing acid reflux)
where is the pyloric sphincter located
between the exit point of the stomach and the first part of the small intestine
What is the stomach
Parking were food is temporarily stored and chemical digestion continues
What is gastric juice do
Provides the necessary acidic environment for enzymes to function. It also kills most of the bacteria or other microorganisms enter the stomach
What is gastrin
A major hormone that regulates acid secretion in The stomach
What is mucus
It is present in gastric juices and helps protect the stomach from acid damage
What is pepsinogen
It’s secreted in the stomach and is converted to pepsine a protein digesting enzyme, when exposed to the acid present and gastric juices
What does pepsin do
Begins the breakdown of proteins into separate amino acids. Secreting the interactive enzyme pepsin engine prevents damage to the stomach tissue. If gastric glands were to make Pepsin and pepsinogen, the stomach would digest itself
What is the small intestine
Where most digestion and absorption of nutrients take place
How big is the small intestine
It’s a two two only about 2.5 cm in diameter and can we 7 m long
What are the three sections a small intestine is made up of
Duodenum, jejunun, and the lieum
What happens in the duodenim
Most enzymes are added indigestion occurs
What happens in the jejunum
The dressing continues and some nutrients are absorbed
Where are the majority of nutrients absorbed
in the ileum
What is villi
The inner layer of the small intestine that is folded into ridges containing fingerlike projections to maximize surface area for nutrient absorption
How is the surface area even more increased in the small intestine
Each of the epithelial cells that make up the villi has even smaller microscopic projections of the cell membrane called microvillous
The combined effect of the villi and microvilli is estimated to increase the surface area by factor of what
500
Within each villus is a network of tiny blood vessels called what
capillaries
all nutrients, except for digestive thoughts, enter the bloodstream through the what
The pillory’s
What are digested fats transported through
Small vessels called lacteals. They are transported into the lymphatic system and from there the bloodstream
What does the pancreas do
Secrete enzymes that are critical to the digestive process, and it also secretes hormones that regulate the absorption and storage of glucose from the blood
Where is the enzyme amylase found
In the saliva is also secrete by the pancreas and continues the digestion of starch
When is a hormone called cholecystokinin (CKK) released
When fat rich chyme enters the duodenim
What does CKK do
To secrete of variety of substances including ones that control the pH of a test signing enzymes that are needed relief this lipid, carbs and protein digestion
Also signals the stomach to slow down the speed of digestion so that fat be properly digested
What is a pH of chyme it enters the small intestine
About 2.5
What is the low pH of chyme trigger
Account cold cold pro secret that is present in the epithelial cells of small intestine is converted into its active form secretin
What is secretions primary function
To simulate the pancreas to release bio carbonate ion to neutralize the acidic chyme and raise the pH 2.5 to pH 9.0
Does secretin to protect the small intestine from stomach acids
Yes
Why is pepsin discontinued in the small intestine
Because it’s only active in acidic conditions
What is trypsinogen
The pancreas releases it and it is an inactive form of protein digesting enzyme called enterokinase
What does trypsinogen do
Travel to the pancreas to the duodenum and once it reaches their an enzyme Called enterokinase converts it into an active trypsin
What is the action of lipases
Thoughts and to enter the duodenum are subject to this which is a group of enzymes secreted by the pancreas that breakdown lipids into fatty acid molecules
What are fats in chyme presented as
Large globules
Can look paces penetrate beyond the surface of fat globules
no, the liver must help
what does the liver produce
bile
what is bile
A substance that emulsifiers fats, breaking them into tiny droplets called micelles
How does this help lipases
Gives them a much greater surface area on which to act in the rate of lipid suggestion increases
Where is bile stored
The gallbladder
When the lipids are present in the small intestine, where is the bile squeezed out of
The bile duct
the breakdown and removal of toxins occurs where
the liver
does the liver also produces in stores glisan gin and fat-soluble vitamins?
yes
Define passive transport
Movement of materials across the cell membrane without the use of energy from the cell. This indicates diffusion, osmosis and facilitated diffusion
Defined diffusion
It will follow the concentrated gradient from an area of higher concentration to an area of lower concentration. For example small amino acid can diffuse directly into the bloodstream
What is osmosis
The diffusion of water molecules across a selectively permeable membrane from an area of higher concentration to lower concentration of water molecules
What is facilitated diffusion
The diffusion of molecules across the cell membrane via transport protein
What is active transport
Materials are moved across the cell membrane from an area of lower concentration to an area of higher concentration using energy provided by the cell
What is active transport used for
To transport molecules that are too large or half stronger on even electrical charge that otherwise will not diffuse across the membrane
About how long is the large intestine
Approximately 1.5 m in length but is 2 to 3 times larger in diameter than the small intestine
What is the large intestine consist of
cecum, colon, rectum and anus
Is most of the digestion and instruction completed by the time the digestive material has reached large intestine
Yes
When is water absorbed through the process of osmosis
At undigested material such as cellulose passes through the Colin
Approximately how many liters of fluids passes large intestine daily
20
What vitamins and I and are also absorbed in the large intestine
Vitamin B and K and sodium and chloride
But how many hours does it take for the undigested material to passive large intestine
4 to 72 hours depending on the types and volume of food eaten
How many species of bacteria are in the large intestine
More than 500
What is most common species of bacteria in human large intestine
E. coli. These bacteria exists in the intestine in a symbiotic relationship
What do the bacteria produce
vitamin K and some vitamin b
What is another byproduct of bacteria action
Gas switches the mixture of carbon dioxide methane and hydrogen sulfide
What is flatulence
Escapes gas made by the bacteria that was not absorbed
