B4 Blood, Heart, Breathing and Plant Transport Flashcards
What are blood plasma
a pale yellow liquid, which transports dissolved substances around the body
How is oxygen carried around the body
Oxygen binds to haemoglobin (on red blood cells) forming oxyhaemoglobin which is carried to all cells for respiration.
What are the functions of white blood cells
to fight disease. There are two types of white blood cells:
i) Phagocytes – engulf pathogens and digest them
ii) Lymphocytes – produce antibodies which attach
the pathogen and destroy it.
What is meant by humans having a ‘double circulatory system’
The heart is an organ that pumps blood around the body in a double circulatory system. The right ventricle pumps blood to the lungs where gas exchange takes place. The left ventricle pumps blood around the rest of the body.
What are the adaptations of an artery
Thick outer wall
Small Lumen
Thick layer of muscle and elastic fibre
What are the adaptations of a vein
Thin layer of muscle and elastic fibres
Large lumen
Fairly thin outer wall
What are the adaptations of a capillary
Very small lumen
Wall made of a single layer of cell
What is the function of an artery
transport (usually) oxygenated blood under high pressure away from the heart
What is the function of the pulmonary artery
transports deoxygenated blood to the lungs
What is the function of vain
transport (usually) deoxygenated blood to the heart
What is the function of the pulmonary vein
transport oxygenated blood into the left atrium
What are the functions of capillaries
allow fast exchange/diffusion of substances
What’s the acronym to remember which side of the heart is oxygenated or deoxygenated
LORD
L-Left
O-oxygenated
R-right
D-deoxygenated
What are the coronary arteries
these are the arteries that supply the heart muscle with oxygen and glucose for respiration.
What happens when you get coronary heart disease
layers of fatty material build up inside the coronary arteries, narrowing them. This reduces the flow of blood through the coronary arteries, resulting in a lack of oxygen for the heart muscle.
What is a pacemaker
The natural resting heart rate is controlled by a group of cells located in the right atrium that act as a
pacemaker
What is an artificial pacemaker
Artificial pacemakers are electrical devices used to correct irregularities in the heart rate
What drugs are used to treat cardiovascular disease
statins
What mechanical devices are used to treat cardiovascular diseases
stents, artificial valves, artificial pacemakers
What are statins
drugs taken to reduce blood cholesterol levels, which slows down the rate of fatty deposit build up in the coronary arteries.
What are stents
wire mesh (‘balloon’) which is inserted into a (blocked) artery to widen the artery and allow more blood to flow.
What are valves
valves in the heart prevent backflow of blood
What is the pathway of blood flow through the heart
(RHS) Vena cava ➡️ right atrium ➡️ right ventricle ➡️ pulmonary artery (pumps blood to the lungs) ➡️(LHS) Pulmonary vein ➡️ left atrium ➡️ left ventricle ➡️ aorta (pumps blood all around the body).
What happens if the valve becomes faulty
could prevent the valve from opening fully, or the heart valve might develop a leak.
How can a faulty heart valve’s be fixed
replaced using biological or mechanical valves.
What are the advantages of a stent
Minor operation (doesn’t need general anaesthetic)
What are the disadvantages of the stent
Risk of infection
What are the advantages of Statins
Do not require surgery
Reduces the risk of arteries narrowing
What are the disadvantages of
May increase risk of developing type 2
diabetes
What are the advantages of artificial valves
High success rate
What are the disadvantages of artificial valves
Risk of infection
Need to take blood thinners
What are the advantages of getting a transplant
Can treat several heart conditions
Increase life expectancy
What is the disadvantages of getting a transplant
Risk of rejection
3 year waiting list for compatible donor
What are the advantages of getting an artificial pacemaker
Long lasting devices
What are the disadvantages of getting an artificial pacemaker
Doesn’t treat heart disease Patient needs to avoid magnetic and electromagnetic fields of energy.
What are the 3 adaptations of alveoli in the lungs for efficient gas exchange (structure and feature)
Structure: alveoli have a very large surface area
Function: this provides maximum diffusion of gases
Structure: each alveolus is surrounded by a network of capillaries near the surface
Function: to maintain a steep concentration gradient, this means a faster rate of diffusion.
Structure: the alveoli have thin moist walls
Function: this provides a short (& quicker) diffusion pathway for gases
What is transpiration
is the loss of water vapour (by evaporation) from the surface of the leaf.
What is translocation
the movement of dissolved sugars from the leaves (where they are made) to the rest of the plant.
What are stomata
They are tiny pores on the surfaces of leaves, which can open or close
What are guard cells
surround the stomata and control the opening and closing of the stomata
How does the stomata Control gas exchange
Guard cells open and close the stomata and in this way control the levels of carbon dioxide that
enter the leaf and the oxygen & water vapour that leave the leaf by diffusion.
How does the stomata control water loss
In low light the guard cells lose water and become flaccid, causing the stomata to close. They would
normally only close in the dark when no carbon dioxide is needed for photosynthesis.
How do mineral ions enter the plant?
Mineral ions are dissolved in water in low concentrations. Therefore the mineral ions (e.g.
magnesium, potassium etc) enter the plant via the root hair cells by active transport.
What are the factors that affect the rate of transpiration
Light intensity
temperature
Air movement
humidity
What is the description of light intensity affecting the rate of transpiration
Transpiration increases in bright light
What is the description of temperature affecting the rate of transpiration
Transpiration is faster in high temperature because the molecules have more energy
What is the description of air movement affecting the rate of transpiration
Transpiration is faster in windy conditions
What is the description of humidity affecting the rate of transpiration
Transpiration is slower in humid conditions
What is the explanation of light intensity affecting the rate of transpiration
This don’t matter open wider to allow more carbon dioxide into the leaf for photosynthesis. More water is therefore able to evaporate
What is the explanation of temperature affecting the rate of transpiration
Evaporation and diffusion are faster at higher temperatures as enzymes can catalyse more reactions
What is the explanation of air movement affecting the rate of transpiration
Water vapour is removed quickly by air movement, speeding up diffusion of more water vapour out of the leaf
What is the explanation of humidity affecting the rate of transpiration
The less humid air the less water in it. Water molecules move out of the leave from a high concentration to low concentration
