B4 Organising Animals and Plants Flashcards
What does blood do?
Carry substances around the body
Name the 4 components of blood
- Red blood cells
- White blood cells
- Plasma
- Platelets
What does plasma transport?
- Blood cells
- CO2 to the lungs
- Urea to the kidney
- Products of digestion from the small intestine
Function of RBC
- Transport oxygen around the body
Adaptations of RBC
- Biconcave shape -> increase surface area
- No nucleus -> more space for haemoglobin
- Contain haemoglobin -> bind to oxygen
Function of WBC
To fight against infections and foreign pathogens
Adaptations of WBC
- Phagocytes to engulf pathogens
- Lymphocytes to produce antitoxins and antibodies
Function of Platelets
- Blood clotting
Adaptations of Arteries
- Small lumen -> high pressure from heart pumping
- Thick layer of muscle and elastic fibre
- Thick wall
Functions of Arteries
To carry blood from the heart to the rest of the body
Adaptations of Veins
- Large lumen -> low pressure and no pulse
- Often have valves -> so blood flows the correct way
- Relatively thin walls -> low pressure and no pulse
Function of Veins
To carry blood from the organs back to the heart
Adaptations of Capillaries
- Single-cell thick walls
- Tiny vessel with a narrow lumen
- There are lots of them
Function of Capillaries
To join arteries and veins through organs
What is the double circulatory system?
A system where blood passes through the heart twice for every complete circuit of the body
Advantages of the double circulatory system
The pressure of oxygenated blood is increased coming from the lungs before getting sent out to the rest of the body -> Oxygenates the body quicker
What are the four chambers of the heart?
- Right atrium
- Right ventricle
- Left atrium
- Left ventricle
Function of valves
To make sure blood goes the correct way (prevent backflow of blood)
Function of pacemaker cells
Control how fast your heart beats
Where are the pacemaker cells located
In the right atrium
Why are the left muscles of the heart so thick?
It has to pump blood all around the body, unlike the right ventricle which only has to pump blood to the lungs
What is the cause of coronary heart disease?
A build-up of fat in the pulmonary arteries leading to less oxygen getting to the heart
How can coronary heart disease be treated?
- Statins -> drug to reduce cholesterol levels
- Bypass -> add extra capacity to deliver oxygen
- Stent -> open up and hold the artery
What is the cause of arrhythmia?
Pacemaker cells in right atrium don’t work properly
