Unit 3, structure of the heart,circulatory system and cardiac cycle Flashcards
What does myogenic mean?
It can contract without nervous or hormonal stimulation
What are the properties of the cardiac muscle?
it has a thick muscular layer in the walls of the heart, it is myogenic, it never fatigues as long as there is a supply of oxygen.
What are the properties of the coronary arteries?
supplies the cardiac muscle with oxygenated blood
What will happen if the coronary artery is blocked?
The cardiac muscle will not receive oxygen, so cells will not be able to respire, resulting in myocardial infarction
Where is the coronary artery?
They branch off the aorta
What is myocardial infarction?
Heart attack
What are the 4 chambers?
Right atrium, left atrium, right ventricle, left ventricle
What are the properties of the atria?
- thinner muscular walls compared to the ventricle
- elastic walls to stretch when blood enters
- do not need to contract as hard as they pump blood to the ventricles
What are the properties of the right ventricle?
- pumps blood to lungs at low pressure to prevent damage to capillaries and so blood flows slowly to allow time for gas exchange.
- thinner walls compared to left ventricle
What are the properties of the left ventricle ?
- pumps blood at high pressure to ensure it gets to all cells in the body
- thicker walls compared to right ventricle for larger contractions of the muscle to create higher pressure
What are the two veins?
-vena cava
-pulmanory vein
What is the property of the vena cava? ( body vein)
Carries deoxygenated blood from the body into the right atrium of the heart
What is the property of the pulmanory vein?
Carries oxygenated blood from lungs intro left atrium
What are the two arteries?
- pulmanory artery
- aorta
What is the properties of the pulmanory artery?
Carries deoxygenated blood from the right ventricle to lungs to become oxygenated
What is the properties of the aorta?
Carries oxygenated blood from left ventricle to the rest of the body
Explain four ways in which the aorta is adapted for its function.
- elastic tissue to allow stretch and recoil to maintain blood pressure
- muscle for contraction and vasoconstriction
- semi lunar valve to prevent back flow
- thick walls to withstand pressure
- smooth endothelium to reduce pressure
What are the two valves?
- semi lunar
- atrioventricular valve
Where is the semi lunar valve?
In the aorta and pulmanory artery
Where is the atrioventricular valve and what is the right and left one called?
Between atria and ventricles
Left= bicuspid
Right= tricuspid
When does the valve open and close
It opens when the pressure is high behind the valve
It closed when the pressure is high infornt of the valve
What is the main property of valves?
Prevent back flow
What is the properties of the septum?
- cardiac muscle that separates the right and left side
- separates oxygenated and deoxygenated blood
- maintains high concentration of oxygen , in oxygenated blood to maintain concentration gradient to enable diffusion at respiring cells
- high oxygen in oxygenated blood
What circulatory system do mammals have?
Closed, double circulatory system