Anatomy & Physiology of The Cardiovascular Flashcards
What is the Cardiovascular system a bulk flow system of
O2 and CO2 Nutrients Metabolites Hormones Heat
What is two characteristics of the cardiovascular system
Reliable
Flexible
What two pumps make up the cardiovascular system
Pulmonary circulation
systemic circulation
What features allow the cardiovascular system to be flexible
pump can vary output
vessels can redirect blood
vessels can store blood
What is the benefits of the parallel arrangement of the vascular bed
All tissues get oxygenated
allows the regional redirection of blood
What is the benefit of the serial arrangement of the vascular bed
allows hormones to directly reach target rather than being diluted in the blood
Portion of cardiac output going to each region corresponds with oxygen consumption in each of these with the exceptions of cardiac output is bigger than its O2 consumption in:
the skin
The kidney
Why is the oxygen consumption of the cardiac output to the kidney alot smaller in comparison to how much is being delivered
as the blood goes to the kidneys through the process of filtration
What organ groups uses 20% cardiac out put and 20% oxygen consumption
skeletal muscle - uses on demand
Why does the skin have a higher cardiac out put than oxygen consumption
as uses the cardiac output for thermoregulation
Why is the heart percentage oxygen consumption higher than its percentage cardiac output
The heart is continuously working hard therefore has a high demand ??
How is the flow of blood determined?
flow is proportional to pressure difference and inversely proportional to resistance
What is the pressure difference between
mean arterial pressure - central venous pressure
What controls the resistance of the flow
the radi of the blood vessels
How do arterioles control resistance
They act as taps
What is an example of an elastic artery
the aorta
What is the capability of elastic arteries
store energy allowing for pressure variations
What is the structure of elastic arteries
wide lumen
with lots of elastic fibres in the tunica media
What is the structure of muscular arteries
wide lumen,
No elastic fibres in the tunica media but surrounded by internal and external elastic lamina
What is the property of muscular arteries
low resistance conduit
What is another name for arterioles
resistance vessels
What is resistance vessels made up of
Thick smooth muscle - (contractile wall)
Narrow lumen
What does the thick contractile wall of the arterioles allow control of
regional redirection of blood as can control resistance due to contractions
What kind of vessels are capillaries
exchange vessels
What is the structure of capillaries
Very thin wall
Narrow lumen
(leads to greater surface area)
What is the capacitance vessels made up of?
Venules and veins
What is the structure of capacitance vessels
wide lumen, distensible wall (swollen) smooth muscle (however less than arteries)
What factor of capacitance venuels allows fractional distribution of blood
low resistance conduit/ reservoir
allows the storage of blood
Where is most of the blood volume contained
2/3 kept in the veins
why must blood be stored
as excess needs to be available be expelled form th heart due to exercise or heat
What separates the heart
the septum
What is the wall of the heart called
Myocardium
What does the superoir and inferior vena cave flow blood into
Right atrium
What is the name of the right ventral AV valve
Tricuspid valve
What blood vessels is deoxygenated blood pushed though leaving the right ventricle
Pulmonary artery
What blood vessels does oxygenated blood return to the heart from the lungs through
Pulmonary vein
What is the name of the left ventral AV valve
Mitral valve
bicuspid valve
What is the function of thechordae tendinae
cord-like tendons that connect the papillary muscles to the tricuspid valve and the mitral valve in the heary and prevents them inverting
What controls the opening and closing of the heart valves
The valves are passive, open and close due tot he pressure differences
Where is papillary muscle located and what do they attach to
located in the ventricles of the heart - attach to the cusps of the atrioventricular valves (also known as the mitral and tricuspid valves)
How does papillary muscles prevent valve inversion
contracts
What allows output from right and left side of
heart to be equal
the series arrangements of the pumps
what creates passive valves
papillary muscle
chordea tendon
What valves are present in the aorta and pulmonary
semi lunar valves
