B2 Flashcards
Name the 4 components of blood and their function
Red blood cell - transport oxygen
White blood cell - defend against pathogens
Platelets - clot the blood
Plasma - carries many substances (glucose, hormones)
Define carcinogen
A substance/chemical that causes cancer
E.g. chemicals in cigarette smoke
Pacemaker
A group of cells that control the resting heart rate
What’s the difference of the left ventricle and right ventricle?
Left ventricle has to pump blood at a high pressure to it can reach all body cells (due to thick, muscular walls)
Right ventricle only has to pump blood to the lungs
What’s the structure of an artery and why?
Thick layers of muscle - maintain high pressure
Elastic fibers - spring back (withstand pressure)
Narrow lumen - strong thick walls
What are the functions of statins and the advantages/disadvantages?
Definition - drugs to lower cholesterol levels in the blood, by reducing the amount produced in the liver
Advantage - prevent development of heart disease
Disadvantage - side-effects, long term treatment
What are the functions of stents and the advantages/disadvantages?
Definition - mechanical device to stretch narrow arteries, restoring blood flow
Advantage - long term benefit, drugs (statins) are less effective
Disadvantage - risk of infection in surgery
What are the functions of heart transplants and the advantages/disadvantages?
Definition - entire organ is replaced with another from a donor
Advantage - can treat complete heart failure
Disadvantage - requires major surgery which involves lots of recovery
What’s the equation for cardiac output
heart rate X stroke volume
Define stroke volume
A measure of the volume of blood pumped from the heart each contraction
Oxyhaemoglobin
haemoglobin + oxygen
What is coronary heart disease and the symptoms?
Blockage in the coronary arteries
Symptoms:
Chest pain, heart attack, heart failure
Name 3 factors that increase the risk of CHD
Diet - high fat = high cholesterol
Smoking - reduces oxygen
Stress - high blood pressure
Describe the difference between a benign and malignant tumour
Benign:
Remains in one place
Doesn’t invade other tissues in the body
Not cancerous
Malignant:
Spreads to other parts of the body when cells break off and travel in the bloodstream to form secondary tumours
Cancerous
Can’t be removed
How does smoking tobacco affect adults and unborn babies?
Adult - can cause lung disease, cardiovascular disease, cancer
Unborn babies - can cause low birth weight and premature birth
What’s the function of valves?
Prevent backflow of blood between chambers and vessels
Which blood vessel transports blood AWAY from the heart?
Artery
Which blood vessel transports blood TO the heart?
Vein
What’s the function of blood in the circulatory system?
Transport oxygen and nutrients to tissues
What’s the function of blood vessels in the circulatory system?
Holds/ transports blood
What’s the function of pacemakers?
Produce small electrical impulse in the right atrium to keep a regular heartbeat
What’s the function of the heart in the circulatory system?
Pumps blood to move it through vessels
Name adaptations of a leaf and it’s function
Flat and thin - reduces distance for diffusion
Large surface area - maximum area to absorb sunlight and carbon dioxide for photosynthesis
Name the function of a xylem
Transport water and minerals to leaves
Name the function of a phloem
Transport glucose and other nutrients around the plant
Describe the structure of a xylem
Thick walls strengthened with lignin
MOVEMENT: ROOTS - LEAF
Describe the structure of a phloem
Thin cell walls with live cells and cellulose
MOVEMENT ALL AROUND PLANT
What’s the function of guard cells?
To open and close the stomata, controlling the rate of gas exchange in the leaf
(positioned in pairs, underside of the leaf)
Define transpiration
The loss of water by evaporation and diffusion from leaves
Define translocation
Food produced in photosynthesis is transported from the leaves to the growing regions of the plant
(OCCURS IN PHLOEM)
Name 4 factors affecting rate of transpiration
Light intensity
Temperature
Humidity
Wind speed
What does BENEDICT’S TEST test for?
Sugar
(blue - brick red ; needs heating up)
What does IODINE test for?
Starch
(black when present)
What does BIURET’S TEST test for?
Protein
(blue - purple)
