The Circulatory System Flashcards
What is the function of the heart muscle?
contracts rhythmically without getting tires to pump blood around the body
which vein takes blood from the small intestine to the liver?
hepatic portal vein
do arteries carry blood towards or away from the heart?
away
what route does the blood take through the heart?
vena cava —> right atrium —> right ventricle —> pulmonary artery —> pulmonary vein —> left artium —> left ventricle —> aorta
during one beat of the heart what do the muscular walls do?
contract and relax once
where are the cardiac muscles found?
the heart
which artery takes blood to the liver?
hepatic artery
which artery takes blood to the kidneys?
renal artery
which artery takes blood to the lungs?
pulmonary artery
which vein doesn’t carry deoxygenated blood?
pulmonary vein why does blood slow down when it travels through capillaries?
why does blood slow down when it travels through capillaries?
it allows time for exchange of materials between blood and cells
why are capillary walls so thin?
so substances can diffuse in and out of them easily
in which vessels can a pulse be felt?
arteries
which artery doesn’t carry oxygenated blood?
pulmonary artery
what pressure does blood flow at in veins?
low pressure
what is the space like inside of veins?
wide
do veins have a layer of muscle?
yes - they have a thin layer
do veins have valves?
yes - valves stop the back flow of blood
do veins carry oxygenated or deoxygenated blood?
deoxygenated
what is the function of veins?
they carry blood back to the heart
what pressure does blood flow through capillaries?
low pressure
do capillaries carry oxygenated or deoxygenated blood?
both
what are capillary walls like?
very thin
do capillaries have valves?
no
what do valves do?
stop the back flow of blood
what is the function of the pulmonary vein?
carry oxygenated blood from the lungs to the heart
what is the function of the right atrium?
receives deoxygenated blood from the venae cavae
what is the function of the left ventricle?
VERY muscular chamber which pumps oxygenated blood to the rest of the body
what is the function of the aorta?
artery that carries oxygenated blood to all parts of the body
what is the function of the pulmonary artery?
carries deoxygenated blood to the lungs
what is the function of the left atrium?
receives oxygenated blood from the pulmonary artery
what is the function of the venae cavae?
returns deoxygenates blood to the heart from the body
what is the function of the right ventricle?
less muscular chamber which pumps deoxygenated blood to the lungs
do arteries carry oxygenated or deoxygenated blood?
oxygenated
what pressure does the blood flow tin arteries?
high
do arteries have muscle?
yes - they have a thick layer of muscle
do arteries have valves?
no
what is the space inside an artery like?
narrow
what is the function of capillaries?
connect arteries and veins
name some characteristics of white blood cells
- made in bone marrow and lymph nodes
- have a nucleus
- don’t contain haemoglobin
- two types : PHAGOCYTES which engulf and destroy microbes and LYMPHOCYTES which make antibodies
name some characteristics of platelets
- no nucleus
- small fragments of cells
- made in bone marrow
- involved in blood clotting
name some characteristics of red blood cells
- biconcave disc
- red cell
- no nucleus
- large surface area
- made in bone marrow
- contain haemoglobin
what is the function of white blood cells?
they fight disease
what is the function of red blood cells?
they carry oxygen
what are the substances dissolved in plasma?
glucose amino acids salt hormones urea carbon dioxide
what is plasma?
water and dissolved substances
what is blood made of?
50% blood cells
50% plasma
list some lifestyle factors that increase the risk of CHD
- genetics
- high cholesterol
- high fat diet
- lack of exercise
- smoking
- stress
how can lipids damage arteries?
they lay down in the artery wall. This causes the arteries to become stiff - this is called hardening of the arteries
what is CHD?
coronary heart disease
why do multi cellular organisms such as large fungi, animals and plants have circulatory systems?
to transport oxygen and glucose for respiration
what is a double circulation system?
when blood is pumped from the heart to the body and back.
do unicellular organisms need circulation systems?
no - they use diffusion because the diffusion distance us so short.
what is adrenaline?
a hormone what affects the heart and blood vessels
when is adrenaline produced?
to prepare the body for action
what does adrenaline do?
- increases heart rate
- widens blood vessels going to the brain and muscles
- narrows blood vessels to the digestive system organs
