B4 Flashcards
What does the human circulatory system do?
Transport substances to and from the body cells
What makes up the human circulatory system?
Blood,blood vessels and the heart
What does plasma do?
Transport proteins and other chemicals around the body
What is suspended in plasma?
Blood cells
What do red blood cells contain that binds oxygen to transport it from the lungs to the tissues?
Haemoglobin
What do white blood cells do?
Protect the body against infection
What are platelets?
Cell fragments that start the clotting process at wound sites
What does plasma carry?
Red blood cells
White blood cells
Platelets
How does blood flow around the body?
Through blood vessels
What are the 3 main types of blood vessel?
Arteries
Veins
Capillaries
Where do substances diffuse in and out of the blood in?
Capillaries
What do valves prevent and ensure?
They prevent back flow ensuring that blood flows in the right direction
What are the 2 parts of a double circulatory system?
1 part carry’s blood from your heart to your lungs and back again
The other part carry’s blood from your heart to all other organs of your body and back again
Do arteries carry blood to or from the heart?
Away from the heart
Do veins carry blood to or from the heart?
To the heart
How many chambers does the heart have?
4
What is the heart?
An organ that pumps blood around the body
What do the valves in the heart do?
Keep blood flowing in the right direction
What can stents be used for?
Keep narrowed or blocked arteries open
What do statins do?
Reduce cholesterol levels in the blood, reducing the risk of coronary heart disease
What is the function of the ventricle in the heart?
To pump blood out of the heart
What can replace damaged heart valves?
Biological or mechanical valves
What is the resting heart rate controlled by?
A pacemaker
Where is the pacemaker for the heart found?
The right atrium
What seperates the lungs and the abdomen?
The diaphragm
What do the alveoli provide?
A large surface area and a rich supply of blood capillaries
What does alveoli allow to happen more efficiently?
Gases can diffuse into and out of the blood
What are plant tissues?
Collections of cells specialised to carry out specific functions
What do epidermal tissues do?
Cover the surfaces and protect them
What does palisade mesophyll tissue do?
Contains lots of chloroplast which carry out photosynthesis
What does spongy mesophyll do?
Has big air spaces and a large surface area to make diffusion of gases easier
What does xylem do?
Carry water and dissolved mineral ions from the roots up to the leaves
What does the phloem do?
Carry dissolved food from the leaves around the plant
What does phloem transport?
The sugars made by photosynthesis
What is translocation?
The movement of dissolved sugars from the leaves to the rest of the plant
What is transpiration?
The loss of water vapour from the surface of plant leaves
What affects the rate of transpiration?
Anything that effects the rate of evaporation
Why does evaporation affect transpiration?
Because when water is evaporated of the surface of leaves transpiration occurs to refill that water on the surface
What do the stomata and guard cells control?
Gas exchange and water loss
What factors increase the rate of transpiration?
Temperature, humidity, air flow and light intensity
When is transpiration faster?
In hot, dry, windy or bright conditions
