Unit 2 Cardiovascular System, Blood pressure, vessels, glucose levels. Structure of the heart, cardiac cycle, obesity and CVD. Flashcards
In what order does the blood flow through the vessels.
Arteries, arterioles, capillaries, venules, veins
What happens to the blood pressure as blood moves away from the heart.
Blood pressure decreases.
What type of lining is found within the inner lining of vessels?
Endothelium Lining
Describe the structure of arteries.
Outer layer of connective tissue containing elastic fibres, thick muscular layer containing smooth muscel and more elastic fibres. Narrow lumen
(Blood travels under high pressure)
What is the function of elastin in the elastic walls?
Allows the walls of the arteries to stretch and recoil to accommodate the surge of blood after each contraction of the heart.
What is the structure and function of the capillary?
Capillaries have walls which are one cell thick and allow for rapid exchange of substances within tissues.
Describe the structure of a vein.
Outer layer of connective tissue with elastic fibres, Wide lumen, thin muscular smooth wall (blood travels under low pressure)
Contain valves to prevent the backflow of blood.
Describe the process of pressure filtration that occurs at the capillary bed
The blood arriving at the arteriole side of the capillary bed is at a higher pressure than blood in the capillaries. As blood is forced into these narrow exchange vessels, it undergoes a form of pressure filtration and much of the plasma is squeezed through the thin walls
What is the liquid formed when blood is forced into narrow exchange vessels of the capillary called? (After pressure filtration and plasma is squeezed out.)
Tissue fluid
What is the function of tissue fluid?
To supply the cells with oxygen, glucose, amino acids and other substances
Name a gas which diffuses from the capillary bed back into the blood
Carbon Dioxide
What happens to the tissue fluid after the substances have diffused?
It returns to the blood
Name the vessels which absorb excess tissue fluid and return the lymph fluid to the circulatory system.
The Lymph vessels (Lymphatic system)
What is the cardiac output?
The volume of blood pumped through each ventricle per minute.
How is the cardiac output calculated?
Heart beat X stroke volume (the volume of blood expelled by each ventricle on contraction. The stronger the contraction , the greater the stroke volume)
Does the right hand side of the heart and the left hand side pump the same volume of blood through the pulmonary artery and aorta?
Yes
Why does the left hand side of the heart contain a bigger muscle than the right hand side?
The left hand side pumps blood to the whole body where as the right hand side just pumps blood to the lungs
What is the function of the valves in the heart?
To prevent backflow of blood into (depending on what valve your talking about)!
Define diastole
The heart relaxing
Define systole
The heart contracting
Define atrial systole
The atria contracting
Define ventricular sytole
The ventricles contracting
Define atrial diastole
The atria relaxing
Define ventricular diastole
The ventricles relaxing
How long approximately is 1 cardiac cycle?
0.8 seconds
Describe the cardiac cycle in terms of systole and diastole.
Atrial systole (ventricular diastole), Ventricular systole (atrial diastole), Atrial diastole and ventricular diastole
Describe what is happening to the blood during this period of dual atrial and ventricular diastole.
Blood returning to the atria is flowing into the ventricles.
Describe what is happening to the blood during atrial systole.
The remainder of the blood is transferred through the tricuspid/biscupid valves
Which valves are open during arterial systole and which ones are closed?
Tricuspid and bicuspid are open and semi-lunar are closed.
Which valves are open during ventricular systole?
Semilunar valves
Which valves are closed during ventricular systole?
Biscuspid and tricuspid valve
What is responsible for the sounds of the heart?
Lubb is the bicuspid closing and dupp is the semi lunar closing (in the aorta)
Where does the heart beat originate?
Within the heart itself but it is under both hormonal and nervous control.
What is the vein which enters the right atrium called?
The vena cava (deoxgenated blood)
What is the artery leaving the right hand side of the heart called?
The pulmonary artery (deoxygenated blood)
What is the vein called which enters the left hand side of the heart?
Pulmonary vein (oxygenated blood)
What is the artery called which leaves the left hand side of the heart?
Aorta
What is the artery entering the kidney called?
Renal artery
What is the vein called which leaves the kidney?
Renal vein
What is the artery called which enters the liver?
Hepatic artery
What is the vessel connecting the liver to the small intestine?
Hepatic portal vein
What is the vessel called which leaves the left hand side of the heart and goes up to the head?
The carotid arteries
What is the vein called which leaves the brain and goes back to the heart?
Jugular Vein
What are the vessels called which supply the heart with its own supply of glucose and oxygen?
Coronary arteries
Does the right hand side of the heart and the left hand side pump the same volume of blood through the pulmonary artery and aorta?
Yes
What is responsible for closing the AV valves?
The higher pressure in the ventricles slams shut the AV valves
What is the SAN?
The sino atrial node which sets the rate of the heart beat