arteries, veins and control of pulmonary vascular resistance Flashcards
name the types of blood vessels in the CVS
large arteries, arterioles, capillaries, venues, veins
which 2 primary cell types are the blood vessels in the CVS composed of?
endothelial cells, and vascular smooth muscle cells
where in the hear are endothelial cells found?
lining all vessels and in the inside of the heart chambers
what are endothelial cells in the heart important for?
local blood pressure control, preventing platelet aggregation and blood clot formation, angiogenesis (formation of new blood vessels), vessel remodelling, permeability barrier for nutrients/fluid between plasma and interstitial fluid
which vessels is vascular smooth muscle found in?
all vessels except the smallest capillaries
what is the function of vascular smooth muscle in the CVS?
determine vessel radius by contraction and relaxation, secrete extracellular matrix giving vessels elastic properties
which disease causes vascular smooth muscle to multiply?
hypertension
why is arterial elasticity important?
allow large arteries to act as pressure reservoir, prevent pressure falling to 0 as blood leaves arteries during diastole
what is systemic circulation?
the portion of the cardiovascular system which transports oxygenated blood away from the heart through the aorta from the left ventricle
what is pulmonary circulation?
the portion of the circulatory system which carries deoxygenated blood away from the right ventricle of the heart, to the lungs,
what is normal BP (systolic/diastolic)
120/80
what does MAP stand for?
Mean Arterial Pressure
what 2 equations can be used to calculate MAP?
. diastolic BP + 1/3 pulse pressure
. CO x TPR (total peripheral resistance)
what does pulse pressure equal?
systolic - diastolic BP
what is BP measured in?
mmHg
describe the structure of the aorta and arteries
very thick walled/ elastic
describe the structure of the capillaries
vast surface area, 1 cell thick
describe the structure of the venules, veins and vena cava
very distensible
which volume and type of blood does the aorta and arteries carry
small volume of blood at high pressure
how does the structure of capillaries aid their function?
vast surface area for interchange of substances with extracellular fluid of tissues
which type of blood vessels can be described as a collecting reservoir?
veins, venules and vena cava
which blood vessels carry blood at low pressure?
veins, venules and vena cava
which blood vessels contain most of the blood?
veins, venules and vena cava
what is an erythrocyte?
red blood cell
what is hydrostatic pressure?
the pressure the blood in capillaries exerts on the capillary wall
what does hydrostatic pressure favour?
movement of fluid out of the capillaries
what is colloid pressure?
intrinsic osmotic pressure due to plasma proteins
what does colloid pressure favour?
movement of fluid into capillary
what are the 2 ends of the capillary?
arterial and venous
what happens to hydrostatic pressure as BP drops arterially to venously?
hydrostatic pressure decreases
what happens to colloid pressure as BP drops arterially to venously?
remains the same as plasma proteins too large to leave capillary
which end does fluid move into the capillary at?
venous
what is the clinal name fro excess fluid in the lungs and what are 2 causes of this condition?
pulmonary oedema - high altitude or left heart failure
which clinical condition causes jugular distension (bulging neck vein)
right heart failure
what are the 2 types of alpha-adrenoreceptor agonists?
selective and non-selective
what is the function of alpha-adrenoreceptor agonists?
decrease vasoconstriction tone
which alpa-adrenoreceptor agonist is used therapeutically and why?
selective as it does not alter HR or CO, non-selective causes hypotension
give an example of when we want to constrict blood vessels
nasal decongestants to vasoconstrictor mucosal blood vessels
define hyperaemia
increased blood flow to organs
define reactive hyperaemia
hyperaemia after blood flow is temporarily blocked
define active hyperaemia
change in O2/CO2/cellular metabolites dilate arterioles