BIOLOGY - CARDIOVASCULAR SYSTEM Flashcards
What does the cardiovascular system consist of?
Heart
Blood vessels
Blood
What is the function of the cardiovascular system?
To transport important substances around the body for example, oxygen glucose
What is the function of the heart?
Pumping blood around the body
What is a double circulatory system
Blood passes through the heart twice per cycle
What is pulmonary circulation?
The blood passes through the heart and is pumped to the lungs then returns back to the heart
What is mass flow?
Blood moves around the body due to the pressure difference between the pressure in the heart and the pressure in the vessels
What is myogenic?
When the cardiac muscle beats without any nervous stimulation
What is the heart pump made of?
Cardiac muscles
What happens when the heart contracts without any nervous stimulation?
The muscle cells are able to depolarise and generate their own electrical impulses
How much chambers does the heart have?
Four
What is the left and right side of the heart separated by?
Septum
what is the order the heart works
1- deoxygenated blood returns from vena cava, and enters the right atrium
2- then the blood passes into the right ventricle and out into the pulmonary artery
3-the blood now passes through the lungs and returns to the left atrium by the pulmonary vein
4-the blood passes into the left ventricle and then into the aorta, and then onto the body tissues
What does the coronary arteries do?
Supplies the heart muscle with blood
Where does the right ventricle push blood to?
Through the pulmonary arteries only
What do valves do?
Maintain high blood pressure and prevents the backflow of blood
What causes valves to open and close?
Pressure differences on each side of the valve
What are atrioventricular valves?
They are between the atria and ventricle and prevent backflow blood during ventricular systole
What does it mean when the atrio ventricular valves open
Greater pressure in atria, rather than the ventricles
What does it mean when the atrioventricular valves close?
The greater pressure in the ventricles than the atrium
What is diastole?
The heart at reat
Where is the cardiac muscle found?
In the heart
Name the
Structure of the cardiac muscles
It is striated
Contracts without stimulation
The cells are branched to allow faster signal
What does the cytoplasm do?
Allows for rapid movement of ions, and also has a low electrical resistance
What does the shape of the cardiac muscle allow?
A wave of depolarisation to pass through the cells and allows the cells to contract as one
Why are calcium ions needed?
To allow a wave of depolarisation to pass through cells
Why does cardiac muscle have mitochondria?
Because they are reliant on aerobic respiration
Name differences between cardiac muscle and the skeletal muscle
Cardiac- has more mitochondria and a long contraction period and refracts
Unlike skeletal, the heart tissue does not become fatigued, and they are less wide than skeletal muscle fibres