6.1 Transport systems in mammals Flashcards
what is the benefit of a closed circulatory system?
{blood always moves within a vessel}
blood pressure can be maintained
supply to organs can differ depending on function and need
lower volumes of blood volumes
what is the benefit of a double circulatory system?
{pulmonary + systemic}
pressure can be maintained separately
blood does not mix ∴ oxygen/nutrient uptake at exchange site is more efficient
which artery/vein supplies the head and neck?
carotid artery + jugular vein
which artery/vein supplies the upper/forelimbs?
subclavian artery + vein
lymph feeds back in here
which artery/vein supplies the liver?
hepatic artery + vein
which artery/vein supplies the stomach/intestines?
gastric + mesenteric artery + vein
which vein takes blood from the stomach to the liver?
hepatic portal vein
which artery/vein supplies the kidneys?
renal artery + vein
which artery/vein supplies the gonads?
genital artery + vein
which artery/vein supplies the lower limbs?
iliac artery + vein
from lumen to vasa vasorum, list the layers of an artery’s wall
lumen
tunica intima
endothelium
internal elastic lastima
tunica media
external elastic lastima
tunica externa
vasa vasorum
which is the function of elastic fibres in arteries?
allow arteries to expand and contract during ventricular systole
regulate blood pressure
what is the function of smooth muscle in the arteries?
contract –> forces blood through at high pressure
can change the size of the lumen
no friction in blood flow
from lumen to vasa vasorum, list the layers of a vein’s walls
lumen
tunica intima
endothelium
tunica media
tunica externa
vasa vasorum
how is blood moved in veins?
skeletal muscle compresses and decompresses veins
pressure change causes blood to move in from venules and up vein
what are capillaries made of?
squamous endothelium
what is systolic pressure?
the pressure in the arteries as blood is forced out of the left ventricle during systole
what is diastolic pressure?
the pressure during diastole
what is blood pressure measured with?
sphygmomanometer
how is blood pressure measured?
rest 5-10 mins
inflate cuff on left bicep
inflate until pressure on brachial artery cuts off blood supply
stethoscope used to listen for Korotkoff sounds (= systolic pressure)
when heard, pressure released –> when gone = diastolic pressure
what is hypertension?
higher than average blood pressure
what are risk factors that contribute to hypertension?
age + gender
stress/exercise levels
smoking/dietary habits
alcoholism
what are the health risks associated with hypertension?
damage to artery walls –> aneurysm/blood clot
damage to heart valves
kidney disease
what are the health risks associated with hypotension?
weakness/tiredness/fainting
coma
death
what is tissue fluid?
fluid that surrounds the cells of the body
what is the function of tissue fluid?
to supply cells with nutrients and to remove waste products
exchange of materials at capillaries
how is tissue fluid formed?
high hydrostatic pressure at arteriole end of capillaries
water and other soluble materials forced out of the blood plasma
plasma proteins too large to diffuse into tissue fluid ∴ they exert negative oncotic pressure on capillary walls which draws water in by osmosis
what is lymph?
similar to tissue fluid but more leucocytes
what is the function of lymph?
important in immune response - nodes are site for filtration of pathogens/foreign bodies
