Animal Digestion Flashcards
What are the 4 types of tissue? What are each of their functions?
- Epithelial - protects organs, lines body cavities, covers the surface of the body
- Connective - supports and holds various parts of the body together; e.g., cartilage, bone, fat, blood..
- Muscle - sheets or bundles of cells which contract to produce movement
- Nervous - cells that allow communication between all different parts of the body
What is an organ?
Organs - made up of two or more types of tissue which work together to perform a complex function
What is the function and organs in the digestive system?
- Digestive - the breakdown of food into smaller nutrients which can be absorbed by the body
- Mouth - pharynx - esophagus - stomach - small intestine - large intestine - rectum/anus
- accessory organs: liver, gall bladder, pancreas
What is the function and organs in the respiratory system?
- Respiratory - supplies the body with oxygen and removes carbon dioxide
- mouth - pharynx - trachea - bronchi tubes - bronchioles - alveoli - diaphragm
What is the function and organs in the circulatory system?
- Circulatory - delivers oxygen and nutrients, takes away wastes
- blood - heart - blood vessels
How does cellular respiration relate to the 3 systems?
- digestive - breaks down food into glucose and other nutrients
- respiratory - brings in oxygen and gets rid of carbon dioxide
- circulatory - picks up glucose from the small intestine and oxygen from the lungs and transports them to cells all over the body to be used in cellular respiration
What is the equation for cellular respiration (words + chemical)
Glucose + oxygen → CO2 + water + energy
C6H12O6+6 O2——>6 CO2+ 6 H2O
What is the digestive tract?
- A complex network of organs which work together to maintain homeostasis (balance)
- The hole which runs through your entire body is known as the digestive tract
What is the purpose of digestion? what are the 4 components?
To break down large and complex material into smaller parts which are utilized by the tissues in the body. Four components:
- Ingestion - taking in nutrients
- Digestion - breaking down complex materials into smaller nutrients by way of enzymes
- Absorption - transporting digested nutrients around to different tissues in the body
- Egestion - the removal of food waste from the body
Two types of digestion
- Chemical - large molecules are broken into smaller molecules
- Physical - food is broken into smaller pieces, e.g., in chewing
What are enzymes?
protein molecules which increase the rate at which biochemical reactions take place (catalysts)
What are the three main types of enzymes, and what are their functions?
- Amylase
- breaks starch down into glucose
- Protease/pepsin
- breaks protein into amino acids
- Lipase
- breaks fats into fatty acids and glycerol
different teeth and functions
- Different teeth are used for different functions;
- canines - sharp pointed teeth for cutting and tearing food
- molars - grinding and mashing food
- premolars - crushing and grinding food
- incisors - cutting and chopping food
salivary glands
- produce saliva (water, salt, amylase, mucous)
- the amylase breaks down starch
- mucous lubricates food so it can be tasted and swallowed
Tongue and esophagus
Tongue
- helps drive food into the teeth
- moves food into the back of the throat (pharynx) and the esophagus
Esophagus
- carries food from mouth to stomach
what is peristalsis?
Peristalsis
- the squeezing and relaxing of muscles which allows food to move along the digestive tract
stomach
sac-like organ between the esophagus and small intestine
- stores, dissolves, and partially digests food
- ridges allow it to expand up to 1.5L
- food spends 3-4 hours here
what do gastric juices contain?
- cells which line the stomach contain gastric juices, which consist of:
- hydrochloric acid - to kill bacteria
- pepsin - to digest proteins
- mucous - to protect the stomach lining from acid
the two sphincters are:
- Cardiac/lower esophageal sphincter - a circular muscle which opens and closes the entrance from the esophagus to the stomach
- Pyloric sphincter - opens/closes the opening from the stomach into the small intestine
What is the complete path food takes through the digestive tract?
(write your answer with as much detail as possible, then check notes and make improvements, or just skip this question)
(…)
What are the three major parts of the small intestine and what do they do?
- duodenum - receives chyme (bolus after stomach digestion) from the stomach, and enzymes from the pancreas and gallbladder
- jejunum and ileum - where the majority of absorption of nutrients into the bloodstream takes place
- small subunits, such as monosaccharides and amino acids, are actively transported across the intestinal membrane into the blood
- vitamins and minerals cross the membrane via diffusion and water via osmosis (see below)
What purpose do villi serve?
- to maximize possible absorption, the surface area of the small intestine must be as large as possible. to achieve this, the walls of the small intestine are covered with small finger-like projections called villi.
- greatly increases the surface of the digestive tract; the intestine has a surface area of over 200m^2.
How does absorption happen from the small intestine?
- surrounding the small intestines is a network of blood vessels
- as food enters the small intestines, it’s broken down by enzymes
- the necessary nutrients are then “absorbed” into the bloodstream across the intestinal membrane
- this membrane is very thin so that nutrients can pass through into the blood vessels and blood stream
What are passive and active transport? What are the three types of passive transport, and what do they mean?
- passive transport - the movement of materials across a cell membrane without the use of energy from the cell. There are 3 types;
- diffusion - movement of particles from an area of high concentration to one of low concentration without the input of energy
- osmosis - the diffusion of water
- facilitated diffusion - the diffusion of molecules across a membrane through a transport protein
- active transport - movement of materials across a cell membrane using energy from the cell
- ATP (adenosine triphosphate) is the source of energy for use and storage at the cellular level
Pancreas function
- secretes enzymes that break down/digest polysaccharides, fats, proteins, and nucleic acids
- also secretes bicarbonate, which neutralizes the acid from the stomach as it enters the small intestine
Liver function
- produces a fluid called bile
- bile enables fats to mix with water and processes nutrients once they have been absorbed into the blood
- other functions: detoxification, glycogen storage, hormone production, decomposition of red blood cells
Gall bladder function
- storage vesicle for bile secreted by the liver
- the gall bladder absorbs water from the bile mixture to make sure its concentrated
large intestine/colon function
- approximately 1.5 meters long
- responsible for collecting and concentrating undigested materials
- during concentration, the colon absorbs water and recycles it back into the blood stream
Colon issues
If you are sick, the colon does not do this job as effectively. This results in diarrhea. The main component of fecal matter is cellulose, which we cannot digest. Constipation occurs when individuals do not get enough cellulose or fiber.
What is ATP?
ATP (adenosine triphosphate) is the source of energy for use and storage at the cellular level
