B9 - transport in animals Flashcards
circulatory system definition
system of blood vessels with a pump and valves to ensure one-way flow of blood
functions of the heart? [2]
-contraction of muscles of the atria and ventricles
-action of the valves
what is the activity of the heart monitored by? [3]
-ECG (electrocardiogram)
-pulse rate
-listening to sounds of valves closing
what is a coronary heart disease?
blockage of coronary arteries
risk factors of coronary heart disease? (factors that could lead to coronary heart disease) [6]
-diet
–> eating more saturated fat increases cholesterol levels, increases chance of plaque buildup
-lack of exercise
-stress
–> hormones are produced, may increase blood pressure, increases chance of blockage
-smoking
–> nicotine causes blood vessels to become narrower, increasing blood pressure, leading to buildup of fat globules (if build up is in heart = coronary heart disease)
-genetic predisposition
–> partly genetic basis
–> people with a history of coronary heart disease in their family are likely to develop it themselves
-age
–> older = risk of developing
coronary heart disease increases
-sex
–>males are more likely to develop coronary heart disease than females
what can reduce the risk of coronary heart disease?
-diet
–>reducing saturated fat and salt
–> lots of fruits and vegetables
-exercise
–>lowers blood pressure
what are the 4 components of blood?
-red blood cells
-white blood cells
-platelets
-plasma
function of red blood cells?
transporting oxygen around the body
function of white blood cells? [2]
-antibody production
-fighting diseases
function of platelets
-clotting of blood
function of plasma [2]
transport dissolved substances
–> they are dissolved in plasma
–> minerals, blood cells, ions, nutrients, urea, hormones, carbon dioxide
what are the roles of blood clotting? [2]
-prevents blood loss
-prevents entry of pathogens
what is a single circulatory system? who has it?
one loop until its back to heart
fish has it
what is a double circulatory system? who has it?
2 circuits from heart, blood passes through heart twice for every circuit of the body
mammals have it
2.5 advantages of a double circulation system?
-blood can be pumped at a higher pressure to the body
-blood can be pumped faster to the body
–> oxygen delivered quicker for respiration (also to keep body temperature constant)
what is diastole?
relaxed / at rest
what is systole
contracted
pulse definition
stretch and recoil of the artery wall
–> every time ventricles contract and push out a surge of blood
why do athletes have slower heart rates?
exercise makes heart stronger, more force, more blood pushed out in one beat than unfit person
–> same blood pumped, less beats
what is recovery time?
time taken for the pulse rate to return to the resting rate
how can recovery time be used?
it shows how well the heart is working / how fit you are / fitness levels
what is the heart made of? why?
cardiac muscle because it doesn’t fatigue
what is the effect of physical activity on heart rate?
-during physical activity, muscles need to contract more
-more energy is needed
-more respiration needs to happen
-more oxygen and glucose is needed from blood
-heart has to pump the blood faster
-increases pulse rate
-eventually oxygenated blood is delivered to the muscles
circulatory system order?
arteries –> arterioles –> capillaries –> venules –> viens