intro to cardiovascular system Flashcards
function of cardiovascular system
- Transport of o2 and substrate to cells
- Transport of CO2 and metabolites away from cells
- Distribution of hormones (e.g. adrenaline)
- Defence (WBCs)
- Haemostasis (stopping bleeding and maintaining blood in a fluid) (blood platelets)
Thermoregulation - flow to skin and extremities is regulated (heat from deep organs is dissipated)
blood composition
Cells - 45%
Plasma - 55%
where is the spleen found
located below the diaphragm, and next to the stomach
function of the spleen
Store blood and filter it
what are the 4 pumps in the heart
2 primer pumps and 2 power pumps
what is contraction of the heart controlled by
the pacemaker and autonomic nervous system
difference between arteries and veins
- Arteries
- carries blood away from the heart
- Ends at the capillary beds
- Have muscular elastic walls
- Veins
- Carry blood back to the heart
- Less muscular than arteries but very elastic walls
where are coronary arteries branched off from
aorta
function of coronary arteries
Supply nutrients to heat muscles and waste away from the heart
fish circulatory system
Only have single atrium and a single ventricle
amphibians circulatory system
Double circulatory circuit
- Have two atrium
- Only one ventricle
mammals circulatory system
Mammals:
Double circulatory circuit
- Two atria and two ventricles Septum separates the atria and the ventricles
pressures in the blood vessels
The left side of the heart pumps oxygenated blood to the systematic circulation at high pressure
The right side of the heart pumps deoxygenated blood to the pulmonary circulation at a lower pressure (short distance)
what are the 2 circulations by the heart
Pulmonary circulation - to and from the lungs
Systematic circulation - to and from the body
what is diastolic and systolic pressure
Diastolic pressure - contraction
Systolic pressure - relaxation
the 4 valves in the heart
The four valves in the heart
- Aortic valve
- Tricuspid valve
- Mitral value
- Pulmonary valve
what are the 3 heart walls
endocardium
myocardium
epicardium
What is the function of the cardiac skeleton?
Provides structural integrity to the heart
what makes up the pericardial sac
visceral pericardium = epicardium
parietal pericardium
What is another name for atrium?
Auricle
what are inlet valves
- They separates atria from ventricle
Hence they are called inlet valves
how many cusps does semilunar valves have
They have three cusps
what type of valves are semilunar valves
outlet valves
where are the valves located at
- P (Pulmonary valve): Located near the 3rd intercostal space.
- A (Aortic valve): Located around the 4th intercostal space.
M (Mitral valve, also known as the left atrioventricular valve): Positioned at the 5th intercostal space.
5 functional classes of blood vessels
Elastic vessels
Conduit and feed vessels
Resistance vessels
Exchange vessels
Capacitance vessels
details of elastic vessels
- Larger vessels (aorta and major branches)
- Accommodate stroke volume
- they expand to absorb the surge of blood
- Convert intermittent ejection into continuous flow - elastic recoil to maintain continuous blood flow
details of the conduit and feed vessels
- Medium sized arteries
- Conduct blood flow to organs
Resistance vessels
- Small arteries and arterioles
- Control arterial blood pressure - by adjusting their diameter
- Control local blood flow - respond to local signals to increase or decrease blood flow to specific area
Exchange vessels
- capillaries
- Nutrients delivery to cells
- Lymph formation
- Removal of metabolic waste
Capacitance vessels
- Veins (mainly large veins)
- Control cardiac filling pressure
- Reservoir of blood
3 layers of blood vessel
Tunica intima
Tunica media
Tunica externa
details of tunica intima in artery in vein
- Rippled
- Have internal elastic membrane
- Smooth
- don’t have internal elastic membrane
details of tunica media in artery in vein
- Thick
- have external elastic membrane
- Mostly smooth muscle cells and elastic fibres
- Thin
- Don’t have external elastic membrane
- Mostly smooth muscle cells and collagen fibres
details of tunica externa in artery in vein
Collagen and elastic fibres
Collagen and elastic fibres
what is flow (velocity)
Flow(velocity) - amount of blood flowing through a vessel per given time
what is perfusion
Perfusion - flow per unit mass of tissue
the 2 force acting on a fluid moving across the capillary wall
Oncotic pressure = pressure exerted by the proteins
Hydrostatic pressure = pressure exerted by the blood
what are the name of the forces that affect movement of fluids
starling forces
how is lymph formed
- Blood enters the capillary at the arterial end and leaves it at the venous ends
- This filtration process provides a continuous supply of interstitial fluid to form lymph
function of the lymphatic system
it carries interstitial fluid into the cardiovascular system
what is oedema
Oedema - abnormal accumulation of interstitial fluid
what causes oedema
- Caused by excess filtration
- Defective reabsorption
- Defective lymphatic drainage
