B1.4 circulatory system in humans Flashcards
plasma function
transport of carbon dioxide
soluble food e.g glucose
urea
hormones
distributes heat
name of heart muscle
cardiac muscle
blood vessels on the heat
coronary arteries
what do the coronary arteries do
supply the heart with blood containing oxygen and glucose for aerobic respiration
acronym to remember order of valances
TSB
tricuspid
(Septum)
bicuspid
what are the two systems of the double circulatory system
pulmonary system(lungs)
systemic (for other body organs)
function of the heart
contracts to pump blood around the body
What is meant by double circulation
blood flows through the heart twice in one complete circuit
what is the advantage of double circulation
maintains blood pressure for fast flow of blood to body organs
what do valves do
prevent the backflow of blood
5 blood vessels from artery to vein
artery
arteriole
(Network of) capillaries
venule
vein
why do capillaries form extensive networks
Each body cell is near a capillary carrying blood
Why do arteries split into arterioles
In order to reach each cell
Does blood wash over the body cells?
No! Tissue fluid does!
What does tissue fluid contain
Small molecules e,g water, oxygen, glucose, hormones
NOT proteins or red blood cells
How does oxygen and dissolved food get into cells
It diffuses across their cell membranes from the tissue fluid they are bathed in
What happens once oxygen and diffused food enter body cells from the tissue fluid
Respiration takes place and waste carbon dioxide
and urea
diffuse into the tissue fluid and pressure drops
why does tissue fluid even leak out of capillary walls?
PRESSURE of blood flow is HIGH from the arteries / arterioles
why does the tissue fluid containing waste products return back to the blood after respiration in cells take place
Pressure has now dropped because of previous leaking
Is tissue fluid a PART of plasma
Yes!
What is the function of capillaries
To allow exchange of substances between blood and body cells
(They have extensive networks! They love the hustle!)
what type of the blood does the (medical) right side of the heart pump
(imagine left on the book)
deoxygenated blood
(Pulmonary artery pumps it to the lungs)
(Vena cava receives deoxygenated blood used on body organs)
what type of blood does the medical left side of the heart pump
(imagine right on paper)
oxygenated blood
(aorta pumps oxygenated blood to body organs)
(pulmonary artery receives oxygenated blood from the lungs)
What is the outer wall of both an artery and vein made of
tough fibres
artery is thicker
what’s the second layer of both an artery and vein
layer of MUSCLE and ELASTIC fibres
artery is thicker
What is the third layer of both an artery and vein
smooth endothelium lining (one cell thick)
Why does an artery have a thicker muscular wall
To resists high pressure
Why does veins have thinner muscular walls
Allow contracting skeletal muscle to squeeze vein to help blood along (low pressure)
Is an arteries lumen smaller of larger than a vein’s
smaller!
Do arteries have valves (except the aorta and pulmonary artery)
No!
How does blood flow in an artery compared to in a vein
Blood flows in pulses in artery
Blood flows smoothly in vein
How fast does blood flow in an artery
Rapidly at a higher pressure
5 risk factors of CVD
Smoking
Obesity and overweight
High cholesterol
Lack of Exercise
High blood pressure
How is smoking a risk factors
Carbon monoxide limits how much oxygen can be carried by haemoglobin
How is obesity a risk factor
Fat stored around organ/ heart so it HAS TO WORK HARDER
How is high cholesterol a risk factor
Linked to high fat diet which causes fatty deposits/ atheroma building up in the CORONARY arteries
How is lack of exercise a risk factor
Excess fat is not used for energy
How is high blood pressure a risk factor
Linked to high salt intake - can damage arteries by making them less elastic
What are atheroma
Fatty deposits that building up in the coronary arteries
What risk factor causes atherosclerosis
High cholesterol linked to High saturated fat diet
What is medical term for when there is atheroma in your coronary arteries
Atherosclerosis
What do atheroma do
Restrict the blood flow and may cause blood clots to form if a plaque ruptures
What are the cells in the heart
Heart muscle cells
How is a heart attack then caused from atherosclerosis
Narrowed arteries means less blood flow so not enough oxygen for heart to continue to contract
What is it called when u get pain in the chest due to atherosclerosis but not a heart attack
Angina
What happens when blood vessels in the brain are blocked
A stroke
The slower the flow of blood makes it more likely..
That a clot will form
3 Lifestyles changes you can make!
Stop smoking / reduce alcohol intake
Regular and more exercise
Less saturated fat and salt intake
Suggest a problem with these lifestyle changes
Require self discipline (but they have no side effects)
3 treatments for CVD!
Lifestyle changes
Statins
Angioplasty
What are statins
Daily Drugs that LOWER BLOOD CHOLESTEROL
this reduces chance of atheroma in arteries
Do statins cure or prevent?
No, do not cure or prevent. They simply reduce one of the major risk factors
Can stains have side effects
Yes
Do lifestyle changes have side effects
No!
What is an angioplasty
Surgery done in emergency to widen narrowed arteries
Do the ventricles have thicker muscular walls? Which is the thickest?
The ventures have thicker muscular walls because every time they contract they must pump blood out of the heart
Left ventricle wall is thicker because it’s connected to the aorta ( pumps all around the body)
What are attached to the valves so they don’t get pushed inside out
Tendons
Why do the atria have thin walls
they only PUMP blood to the ventricles
Do the even pump blood?
Yes! To the ventricles
What happens to the number of white blood cells in your body if you have an infection
Increase rapidly
