B4 - organising animals and plants fact test Flashcards
(48 cards)
what is the blood
it’s a tissue
its main components are red and white blood cells, platelets and plasma
how are red blood cells specialised
- no nucleus, making space for haemoglobin
- packed with a red pigment called haemoglobin that binds to oxygen, so it moves from lungs to tissues
- biconcave discs (pushed in on both sides) to increase surface area to volume ratio for diffusion
what are white blood cells
- much larger than red blood cells
- there are fewer of them and they have no nucleus
- they form part of the body’s defence system against harmful microorganisms
- lymphocytes form antibodies against microorganisms
- some form antitoxins against poisons made by microorganisms
- phagocytes engulf and digest bacteria and viruses
what are platelets
- small fragments of cells
- have no nucleus
- help the blood clot and form a scab at the site of a wound
- stops you bleeding to death
- stops bacteria entering the body through the wound
what is plasma
- yellow liquid
- transfers all of your blood cells around the body
- transports waste carbon dioxide, urea, glucose around the body
- DO NOT CARRY OXYGEN
what are arteries and how are they specialised
- thick layer of muscle and elastic fibres
- small lumen
- thick walls
- arteries carry blood away from the heart to other organs
- the blood came from the heart so it’s under pressure
- the elastic allows the vessel to stretch without bursting
- lots of muscle to prevent rupture
- usually oxygenated blood
what are veins and how are they specialised
- have a valve and large lumen
- relatively thin walls
- thin layer of muscle and elastic fibres
- carry blood towards heart (so less pressure)
- valves which open and close to prevent the backflow of blood
thinner walls to prevent the backflow of blood - usually low in oxygen
what are capillaries and how are they specialised
- walls are one cell thick
- tiny vessel with a narrow lumen
- tiny vessels linking veins and arteries
- walls are one cell thick to allow substances to diffuse in and out
where does blood from the aorta go
heart to rest of the body
where does blood from the vena cava go
from body to heart
where does blood from the pulmonary artery go
heart to lungs
where does blood from the pulmonary vein go
lungs to heart
why is the muscle on the left side thicker than the muscle on the right side
the blood needs to be pumped further so it has a higher pressure, the muscle prevents rupture
where are pacemakers
a group of cells in the right atrium and they control the resting heart rate
what are coronary arteries
branch off the aorta and supply the heart muscle with glucose and oxygen which are needed for respiration to release energy
what are cardiovascular diseases
diseases of the heart of blood vessels
how do you treat coronary heart disease (coronary arteries becoming blocked by fatty deposits
- stents can be fitted in narrow arteries to increase bloodflow through them
- statins reduce the risk of fatty plaques breaking off from walls of your arteries
how do you treat heart failure
- heart transplant
- mechanical artificial heart whilst waiting for a donor
how do you treat damaged heart valves as they can break or not open properly
- biological heart valves
- mechanical heart valves
how do you treat an irregular heart rate
get an artificial pacemaker fitted
what does the trachea do
carries oxygen in and carbon dioxide out
what do the intercostal muscles do
move the ribs up and out to provide surface area
what do the alveoli do
where gas exchange happens
what does the diaphragm do
contracts and relaxes allowing a change in surface area / volume
