4.2.2.2 The heart and blood vessels Flashcards
(22 cards)
What is ths heart
An organ that pumps blood around the body
What is the purpose of the circulatory system
Carries oxygen and other useful substances to bodily tissues and remove waste substances
How does the double circulatory system work
One path carriage blood from the heart to the lungs where gas is exchange of oxygen carbon dioxide takes place
One pathway cabbage blood from the
heart to the tissues
Where does the blood pump by the right ventricle go
The lungs
Where does the blood pumped by the left ventricle go
Body tissues
Why is the double circulatory system important
It makes a circulatory system of fishing for example oxygenated blood can be pumped around the body or high pressure by the ventricle
How many chambers does the heart have and what are they called
4-left atrium right ventricle left atrium left ventricle
Why is the wall of the left ventricle thicker
As the left ventricle has to pump blood at a high pressure around the whole body
What are the four main blood vessels associated the heart
Aorta -Carrie’s alternative blood from the heart to the body
Pulmonary vein-carries oxygenated blood from the lungs to the heart
Vena cava-carries the deoxygenated blood from the body to the heart
Pulmonary artery- it carries deoxyrated blood from the heart to the lungs
What is the purpose of the valves in the heart
Prevents the backflow of blood
Describe the process of blood flow through the heart
-Blood entrance to write atrium via the vena cava and the left atrium by the pulmonary vein
-The atria contracts forcing blood into the ventricles and causing the valves to shut
-After the ventricles contract blood in the right ventricles enters the pulmonary artery and the blood in the left ventricle enters the aorta
What is the approximate value for the natural resting heart rate
70 beats per minute
How is the heart rate controlled
Heart rate is controlled by a group of cells in the right atrium which acts as a pacemaker
How can you abnormal heart rhythms be treated
An artificial pacemaker which sends out electrical signals to correct the heart rhythm
What are the three types of blood vessels in the body
Arteries
Capillaries
Veins
How are veins adapted for its function
Wide lumen-enables low pressures
Valves-prevent backflow of blood
Function of the veins
To carry blood to the heart
Function of the capillaries
Enable transfer of substances between blood and tissues
How are the capillaries adapted for their function
Walls are one cell thick so short diffusion path
Permeable wall so substances can diffuse across
Narrow lumen so blood moves slowly for more diffusion time
Function of the arteries
Carry blood away from the heart
How are the arteries adapted for their function
Thick muscle layer with add strength to resist high pressure
Set elastic layer which allows arteries to stretch and recoil in order to withstand high pressure
How would you calculate the rate of blood flow
Volume of blood / number of minutes
