Circulatory System Flashcards
Why is it known as the double circulatory system
Two circuits joined together
What’s in the first circuit
The Ruth ventricle pumps deoxygenated blood to the the lungs to take in oxygen the blood then returns to the heart
What’s in the second circuit
The left ventricle pumps oxygenated blood around the other organs the blood gives up its oxygen and then returns to the heat to be pumped to the lungs
Why does the heart have valves
To stop back flow
How dies the heart use its four chambers
1) blood flows into two atria from the vena cava and the pulmonary vein
2) atria contracts pushes blood into ventricles
3) ventricles contract forcing blood into pulmonary artery and aorta out if heart
4) the atria fill again and repeat
Where is the pace maker located
The right atrium
What does the pace maker do
Controls the resting heart rate
What are the arteries function
Carry blood away from heart
What are the veins function
Carry blood into heart
What are the capillaries function
Involved in exchange of materials at the tissues
How are arteries developed for function
Strong and elastic walls as carry blood under pressure, thick layers of muscle to make them strong and elastic fibres to allow them to stretch and spring back
How are capillaries developed
Are tiny, permeable walls so substances can diffuse in and out, one cell thick walls to increase rate of diffusion
How are veins developed
Thinner walls as less pressure, bigger lumen to help blood flow, valves to stop back flow
What’s the calculation for rate of blood flow
Volume of blood/ number of minutes
What are the roles of red blood cells
To carry oxygen from lungs to all cells in the body
What shape to red blood cells have
Biconcave disc
How are red blood cells developed
No nucleus to allow space for oxygen, red pigment called haemoglobin,
What do white blood cells do
Defend from infection
How are white blood cells developed
Can change shape to cobble unwelcome microorganisms in phagocytosis, produce antibodies to fight microorganisms, have a nucleus
What to platelets do
Clot blood
What does lack of platelets cause
Bleeding and bruising
What is plasma
Liquid that carries everything in blood
What sure plasma carry
1) blood cells and platelets
2) glucose and amino acids
3) carbon dioxide
4) urea
5) hormones
6) proteins
7) antibodies and antitoxins
