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
artery features? [3]
-thick walls of muscle and elastic fibres + thick outer wall
–> withstand high pressure of blood
-elastic
–> stretch and recoil with each surge of blood as heart beats
-smooth lining
–> so no obstruction to flow of blood
capillary function? [2]
carry blood close to every cell in the body to exchange substances with them
–> give glucose & oxygen, take away wastes (CO2, urea)
allow exchange of substances between blood and cells
capillary features? [1]
-thin (one cell thick) permeable walls
–> shorter diffusion distance, diffusion rate increases
vein features? [3]
-big lumen
–> help blood flow even though the blood pressure is low
-thin walls
–> low pressure so walls don’t need to be thick
-contain one way valves
–> help blood flowing in right direction despite lower pressure
what are shunt vessels? function? [2]
-blood vessels that connect veins directly to arteries
-blood doesn’t need to travel through capillaries
3 types of blood vessels?
-arteries
-veins
-capillaries
where is oxygen and glucose in blood?
plasma
what does plasma become near cells?
tissue fluid
capillary adaptations for exchange of substances?
-one- cell thick capillary walls
–> short diffusion distance
-highly branched ()large surface area)
–> more place for substances to diffuse
-constantly supplied with fresh food
–> concentration gradient is constantly maintained
features of red blood cells [3]
-biconcave shape
–> surface area increases, diffusion rate of oxygen into cell and carbon dioxide out of cell increases
-contains haemoglobin
–> binds to oxygen to form oxyhaemoglobin
-no nucleus
–> more space for haemoglobin
features of plasma
-straw coloured liquid
-blood cells float in it
-over 90% of it is water
where is excess water taken to from?
from large intestines to kidneys (kidneys remove water)
2 types of white blood cells?
phagocytes
lymphocytes
phagocytes function?
-fight diseases
-change shape to engulf and digest pathogens / microorganisms by phagocytosis
lymphocytes function?
-fight diseases
-produce antibodies to fight pathogens (antibodies fight antigens on pathogens)
what do coronary arteries do?
-supply heart muscle itself with oxygen, glucose, other nutrients
-remove carbon dioxide and other waste products
how do coronary arteries get blocked?
fatty deposits called plaques
–> mainly cholestrol
what does partial blockage mean?
less blood flow to cardiac muscle cells
what is the result of partial blockage?
severe chest pains (angina)
what does complete blockage mean?
no blood flow to cardiac muscle
what is the process and result of complete blockage?
no respiration –> no oxygen and glucose to cells –> no energy –> muscle cells can’t contract
–> results in heart attack
what does ecg measure?
electrical activity of the heart
what does an ecg tell you?
rhythm of heart beat
what is an echocardiogram?
uses ultrasound to take pictures of muscles and valves
3 ways to assess regularity of heart
-ecg
–> irregular pattern of heart beat may be a sign of heart disease
-pulse rate
–> unusual changes could indicate problems with the heart’s nervous system
-heart sounds
–> less clear lub-dub sound of the heart might mean valves are leaking as the sound is caused by heart’s valves closing in sequence
