B2 Organisation And The Digestive System Flashcards
What is a cell?
The basic building block of a living organism
What is a tissue?
A group of cells with similar structure and function working together
What is an organ?
A group of different tissues working together to carry out a specific function
What is an organ system?
A group of organs working together to perform specific functions
What is muscle tissue?
Contracts to allow movement
What is glandular tissue?
Produces hormones/ enzymes
What is epithelial tissue?
Lines the surfaces of organs for protection
What are the 9 human organ systems?
Skeletal
Respiratory
Nervous
Digestive
Circulatory
Endocrine
Excretory
Immune
Reproductive
What is the function of the circulatory system?
To transport blood around the body, giving oxygen and glucose to the body’s cells
What is the function of the nervous system?
Control the actions of the body and responses to the environment around it
What is digestion?
The body’s processing and consumption of food, food being broken down
What does the digestive system do?
It breaks down large insoluble molecules into small soluble ones which can be absorbed by the cells
Why do we need to digest food?
So that it can get properly broken down and it’s nutrients used for other bodily functions
What is ingestion?
Food being taken into the mouth
What is egestion?
Undigested food being removed from the body
What is the mouth?
Where the food enters, site of consumption
What is the oesophagus?
Food travels from the mouth down to the stomach in this pipe
What is the stomach?
Food is mixed with acid and broken down here
What is the small intestine?
The rest of the food is broken down and nutrients absorbed
What is the large intestine?
Water is absorbed from the waste matter back into the bloodstream
What is the rectum?
Faeces are stored here, a signal is sent to the brain to let it know that waste needs to be removed
What is the anus?
Undigested food leaves the body here
What is the liver?
Produces bile to help digest fat and filters out toxins
What is the gall bladder?
Stores bile from the liver and releases it into the small intestine
What is the pancreas?
Produces digestive enzymes to help digest fats, carbohydrates and proteins. Regulates blood sugar by producing insulin.
What is a kidney?
An organ designed to act as a filter to remove wastes and extra fluids from the body
What is an adaptation of the epidermal tissue?
Thin and transparent
What is the function of the epidermal tissue?
Allows more sunlight to reach the palisade cells
What is an adaptation of the palisade mesophyll?
Contains lots of chloroplasts, arranged vertically in a single layer near the top of the leaf
What is the function of the palisade mesophyll?
Absorbs more sunlight for photosynthesis
What is an adaptation of spongy mesophyll?
Irregularly hoped and contains many air spaces
What is the function of spongy mesophyll?
Increased surface area so gases can be exchanged
What is an adaptation of lower epidermal tissue?
Contains stomata surrounded by guard cells
What is the function of lower epidermal tissue?
Allows gases to diffuse, guard cells to open and close the stomata
What is an adaptation of vascular bundles?
Contains xylem and phloem
What is the function of vascular bundles?
Transports water and substances around the plant
What are chlorophyll?
They absorb sunlight
Why are leaves thin?
Reduced distance for carbon dioxide to diffuse in the leaf
What are xylem tubes?
Transports water in the plant
What are phloem tubes?
Transport food in the plant
What do stomata do?
Allow the exchange of gases such as oxygen and carbon dioxide
What are guard cells?
Change shape to open and close the stomata
What is the waxy cuticle?
Prevents water loss through evaporation
Describe the movement in xylem cells
Xylem cells transport water and minerals in one direction only from the roots up the stem into the shoots and leaves
Describe the movement in phloem cells
Phloem cells transport sugars produced in the leaves up and down the stem to growing and storage tissues
What is translocation?
The movement of sugars through the phloem
What are enzymes?
Enzymes are biological catalysts which speed up reactions. They are proteins which speed up chemical reactions in the body without being used up in the rpocess
What are proteins?
Molecules made up of long cabins of amino acids . Proteins are the main component of body tissues
What is the lock?
The enzyme
What is the key?
The substrate
What is the lock and key theory?
Each reaction has its own specific enzyme. A key fits a lock so a substrate fits onto an enzyme’s active site
What is the key hole?
The active site
What factors affects how quickly an enzyme works?
Temperature
pH
Enzyme concentration
Substrate concentration
Surface area
Pressur
What is the optimum?
The temperature and pH at which an enzyme works the best
What does denatured mean?
If the temperature or pH changes too far beyond an enzyme’s optimum, the shape of the enzyme irreversibly changes . This affects the shape of the active site meaning the enemy e and substrate and enzyme can’t bind.
How do we measure the rate of an enzyme catalysed reaction?
Measure the rate at which a substrate is used up or the rate at which the product is formed.
What do carbohydrases do?
They break down carbohydrates into simple sugars
What does amylase do?
Breaks down starch into glucose
What does protease do?
Breaks down protein into amino acids.
What does lipase do?
Breaks down lipids into fatty acids and glycerol
Where are digestive enzymes produced?
In the digestive tract and pancreas
Where do enzymes break down food molecules?
In the stomach and small intestine?
What is amylase also produced by?
Pancreas
Where is stretch broken down?
In the salivary glands and small intestine
What is protease also produced by?
Pancreas
Where are proteins broken down?
In the stomach and small intestine
Where is lipase also produced?
Pancreas
Where are lips broken down?
In the small intestine
What happens when food enters the stomach?
Stimulates the secretion of hydrochloric acid from the stomach wall. Acidity of stomach is now pH2. This is the optimum pH for stomach enzymes
Where is bile produced?
Liver
What is bile?
It neutralises the stomach to create optimum pH for for enzymes in the small intestine
Emulsifies fats to in increase the surface area for efficiency
What is important about double circulation?
Allows oxygen rich and oxygen poor blood to be kept separate
Ensure blood pressure is high enough to reach all parts of the body
What is an example of single circulation?
Earthworms, fish
What type of muscle is the heart made from?
Cardiac muscle
How is oxygen supplied to the heart?
Coronary arteries
What is the pacemaker?
Sends an electrical impulse to the heart muscle cells telling them to contract at the same time
What is the flow of blood around the body?
Deoxygenated
Enters the right atrium via the Vena Cava
Drops into right ventricle
Heart to lungs via the pulmonary artery
Oxygenated
Lungs to heart via pulmonary vein
Left atrium
Left ventricle
Body
What are the arteries?
Carry oxygenated blood away from the heart at high pressure. Have strong, thick walls and no valves
What are veins?
Carry deoxygenated blood back to the heart at low pressure. Has valves to prevent back flow and thin walls.
What are capillaries?
Connect arteries to veins, very thin walls, low pressure, no valves.
What are stents?
Widen narrow arteries to allow blood to flow around the body. Stents are metal grids that are placed in an artery. A catheter with a balloon is inserted into a blood vessel. The balloon is inflated at the narrow section of the artery.
What are positives of stents?
Lowers risk of heart attack
Works for a long period of time
Recovery time is quite short
What are the negatives of stents?
Risk of blood clot near the stent
Complications during surgery
Risk of infection
What is a heart transplant?
If the heart is severely damaged, a heart transplant can save lives but needs an exact match, drugs and there is a risk of infection
What are statins?
Lower amount of cholesterol in the blood, helps prevent blood clots and heart attacks. Can cause sickness, liver failure or skeletal damage.
What is Coronary Heart Disease?
A condition where fatty deposits build up in the coronary arteries causing the vessels to narrow and a subsequent reduction in blood flow. Affects supply of oxygen and glucose.
What are risk factors of CHD?
Older, smoking, overweight, stress, inactive
What are risk factors for high blood pressure?
Genetics, stress, smoking, alcohol, overweight
What are the 3 valves?
Tricuspid, bicuspid, semi-lunar
What splits the heart chambers?
The septum
What are the 2 circulatory transport systems?
Pulmonary and systemic
How many litres of blood does the average adult have?
4-6 litres
What are some functions of blood?
Thermoregulation, defence, transport, maintaining pH of body fluids
What is blood plasma?
Yellow fluid, 55% of blood, transports substances
What are red blood cell features?
Larges surface area to volume ratio, biconcave shape, haemoglobin, no nucleus, wider than capillary
What is Hb?
A large protein molecule folded around 4 iron atoms. Haemoglobin combine with oxygen to form oxyhemoglobin
What are white blood cells?
Help fight disease and infection
What are platelets?
Help form blood clots
What are phagocytes?
Engulf bacteria
What are lymphocytes?
Make antibodies to target pathogens
How much of inhaled hair is oxygen?
21%
How much of exhaled air is oxygen?
16%
How much of inhaled air is carbon dioxide?
0.04%
How much of exhaled air is carbon dioxide?
4%
How much of inhaled air is nitrogen?
78%
How much of exhaled air is nitrogen?
78%
What other component makes up inhaled and exhaled air?
Water vapour
What are alveoli adaptations?
Well ventilated, efficient blood supply, thin wall, moist lining
What is the process of inhalation?
Intercostal muscles contract
Ribs move upwards and outwards
Diaphragm contracts and flattens
Volume of thorax increases
Pressure of thorax decreases
Pressure outside the lungs is greater than inside
Air moves into the lungs
What is the process of exhalation?
Intercostal muscles relax
Ribs move down and inwards
Diaphragm relaxes and moves up
Volume of the thorax decreases
Pressure of thorax increases
Pressure inside the lungs is greater than outside
Air moves out of the lungs
What is atherosclerosis?
The build up of fatty material/ atheroma in the arteries
What is angina?
Pain or discomfort in the chest
What are artificial valves?
Device implanted into the heart to replace a faulty valve
Lasts 20-30 years with no rejection
Medicine needed to prevent blood from clotting
What are biological valves?
Based on animal valves form animal or human donors
Can harden and need replacing after 12-15 years
No need for blood thinning drugs
What is bypass surgery?
Transplants a vein from the leg to divert blood
Very effective
Major surgery
What is transpiration?
The evaporation and diffusion of water from inside the leaves
What are communicable diseases?
Caused by pathogens and can be spread from one person to another
What are non-communicable diseases?
Not passed from one to another
