animal transport Flashcards
how is aorta related to function
elastic tissue stretch and revoil to smooth out blood flow
muscle for contraction
thick wall withstands pressure
smooth endo - reduces friction
SLV prev backflow
why does hydrostatic pressure fall from arteriole ed of capillary to venule end of capillary
loss of fluid
high blood pressure leads to accumulation of tissue fluid. how
high bp - high hydrostatic pressure
increased outward pressure at arterial end ad reduced inward pressure at venule end
so more tissue fluid is formed and less reabsorbed
wp of blood plasma more negative at venule end that arterial end - why
water has left capillary
protiens remain as too large to leave
so higher conc of blood plasma protiens lowering the wp
Some people produce a much higher ventricular blood pressure than normal. This can cause tissue fluid to build up outside the blood capillaries of these people. why
more fluid forced out capillary
less fluid returns due to pressure and lymphatic system cant drain excess fast enough
Suggest how widening of blood vessels can reduce ventricular blood pressure.
larger lumen
reduces blood pressure in blood vessels
less friction and resistance in blood vessels
Explain how their cardiac output could stay the same even when their resting heart rate had decreased.
cardiac output - stroke volume times heart rate
so stroke volume increases
The rise and fall in blood pressure in the aorta is greater than in the small arteries.Suggest why.
aorta is directly linked to heart
so pressure is high
aorta has elastic tissue
aorta has stretch and recoil
Other than causing slow blood flow, explain one advantage of capillaries being narrow.
Short pathway / short distance between blood and outside of capillary
large surface area of blood in contact with capillaries
The oxygen dissociation curve for haemoglobin shifts to the right during vigorous exercise. Explain the advantage of this shift.
lower affinity for oxygen
released to muscles and tissues
for higher rapid respiration
Explain how the heart muscle and the heart valves maintain a one-way flow of blood from the left atrium to the aorta.
atrium - higher pressure than ventricle cause avv open
ventricle higher pressure than atrium causing avv valves to close
ventricle higher pressure than aorta causes slv to open
aorta higher pressure than ventricle slv close
muscle contracts - increased pressure
Explain why a lack of protein in the blood causes a build up of tissue fluid.
wp not as low
less water removed by osmosis
The thickness of the aorta wall changes all the time during each cardiac cycle. Explain why
aorta wall stretch as ventricle pressure increases
aorta wall recoils as ventricle wall relaxed
maintaining smooth flow and pressure
Describe how tissue fluid is formed and how it is returned to the circulatory system.
high hydrostatic pressure
forces fluid out
large protiens remain in capillary
return
low water potential in capillary
due to plasma protiens
water enters capillary by osmosis
rest tissue fluid reabsorbed by lymphatic system - drain it black to blood stream near the heart
