section 5 - blood and organs Flashcards
what are the 4 main components of blood
plasma, p-latelets, red blood cells, white blood cells
what does plasma carry
- red, white blood cells and platelets
- digested food products - glucose and amino acids
- carbon dioxide
- urea
- hormones
- heat energy
what are the 2 reasons for blood clotting
stop losing to much blood and prevent micro-organisms enetering the wound
what are platelets help together by
a mesh of protein called fibrin
what are the adaptations of red blood cells
- small and biconcave shape - large SA for absorbing and releasing o2
- contains haemoglobin which contains iron to release oxygen into cells
- dont have a nucleus to free up space for more haemoglobin so they can carry more oxygen
what are the 2 types of white blood cells
lymphocytes and phagocytes
what do phagocytes do
ingest pathogens - detect foreign things and engulf the pathogens to digest them.
they are non-specific and attack anything that is not meant to be there
what to lymphoctyes do
produce antibodies
every pathogen has antigens open surface
lymphocytes produce antibodies specific to the antigen.
why are memory cells produced
in responce to the foreign antigen to remember the specific antigen. reproduce fast if same antigen enters body again. secondary immune response much faster if reinfected
how does vaccination protect from future infections
injected with dead or inactive pathogens that carry antigens. trigger an immune response and lymphocytes produce antibodies to attack them. memory cells are produces and remain in the blood so if same type of pathogen appear antibodies will be produced faster and in greater numbers to kill them
what are the 3 types of blood vessel
arteries, capillaries, veins
what are arteries for
carry blood away from heart
what are capillaries for
exchange of materials at the tissues
what are veins for
carry blood to the heart
what are artery walls like
strong and elastic. the elastic fibres allow arteries to expand. walls are thick compares to the lumen (whole) and contains a thick layer of muscle to make them strong
what are capillaries like
really tiny. they carry blood close to every cell to exchange substances with them.
they have a permeable wall so substances can diffuse in and out.
they supple food any oxygen and take away waste like co2.
their walls are one cell think which increases the rate of diffusion by decreasing the distance over which it happens.
what are veins like
capillaries join up to veins. blood at low pressure so walls dont need to be thick. they have a bigger lumen that arteries to help blood flow despite the lower pressure. have valves to keep blood flowing in the right direction . elastic fives and smooth muscle.
what kind of blood does the right atrium receive
deoxygenated blood
what vein brings the blood to the heart from the body
vena cava
where does the blood go after the right ventricle
to the lungs via the pulmonary artery
what sort of blood does the left atrium receive
oxygenated blood through the pulmonary vein from the lungs
how does the blood get pumped to the rest of the body
through the left ventricle via the aorta
why does the left ventricle have a thicker wall than the right ventricle
to pu, p blood around the whole body rather than just to the lungs. the left ventricle is under higher pressure
what do the valves in the heart do
prevent back flow of the blood
how does the heart rate increase when exercising
increases amount of co2 in the blood. the high levels are detected by the receptors In the aorta and carotid artery. these receptors send signals to the brain which sends signals to the heart causeing it to contract more frequently with more force
why does heart rate increase when excerisisng
to get more oxygen into the cells and remove more co2
how does adrenaline cause heart rate to speed up
binds to specific receptors in the heart causing cardiac muscle to contract more frequently with more force, heart rate increases and heart pumps more blood. this increases oxygen supply to the tissues, getting the body ready for action
which blood vessel carries blood to the liver
hepatic artery
which blood vessel carries blood away from the liver
hepatic vein
which blood vessel carries blood from gut to liver
hepatic portal vein
which blood vessel carries blood to the kidneys
renal artery
which blood vessel carries blood from the kidneys
renal vein
what is coronary hear disease
- coronary arteries get blocked by the layers of fatty material building up
- causes arteries to become narrow and blood flow is restricted, causing lack of oxygen which can lead to hear attack
what are risk facts for coronary heart disease
- diet high is saturated fat - leading to fstty deposits
- smoking increases blood pressure and causes damage
- being inactive - can lead to high blood pressure
what are the 3 main roles of the kidneys
- remove urea
- adjustments of salt levels in the blood
- adjustment of water content
where is urea produces
liver
what happens in ultrafiltration
blood from renal artery flows through the glomerulus. lots of blood and capillaries for high pressure
high pressure squeezes water, urea, ions and glucose into the Bowmans capsule.
called theglomerular filtrate
what happens in selective reabsorption
- glucose is reabsorbes in the proximal convoluted tubule through active transports against concentration gradient - lots of mitochondria
- sufficient ions are reabsorbed, excess ions aren’t
- sufficient water is reabsorbed from collecting duct into blood stream by osmosis
what happens to the remaining substances
continue out of nephron through the ureter and into the bladder where is is stored and released via the urethra
3 ways water is lost from body
sweating, breathing weeing
what is the regulation of water called
osmoregulation
what hormone controls amount of water reabsorbed in kidneys
ADH
what happens if more water is needed in the body
it is detected by the hypothalamus, ADH is released from the pituitary gland to make the collecting duct more permeable to reabsorb more water. causing urine to be more concentrated and less frequent
