blood and organs Flashcards
main components of blood
plasma
platelets
red blood cells
white blood cells
what is plasma
liquid which carries everything that needs transporting around your body
what six things does plasma carry
blood cells
digested food products
carbon dioxide
urea
hormones
heat energy
what are platelets
platelets clot the blood in a wound, held together by a mesh of fibrin
what do red blood cells do
transport oxygen from the lungs to all cells
what adaptations do the red blood cells have
biconcave cell
no nucleus
contain haemoglobin
thin membrane
how does haemoglobin aid red blood cells
in the lungs haemoglobin reacts with oxygen to become oxyhaemoglobin, in body tissue the reverse happens to release oxygen into the cells
how do pathogens cause disease
once entered the body they reproduce rapidly
2 types of white blood cells
phagocytes
lymphocytes
how do phagocytes kill pathogens
engulf and digest pathogens
they are non-specific so they attack anything foreign
how do lymphocytes kill pathogens
lymphocytes produce proteins called antibodies, they lock onto the pathogen and mark them for destruction
what are memory cells
produced in response to a foreign antigen, remain in the body and remember a specific antigen, building immunity
how do vaccines protect from future infection
injects dead pathogens into the body, carrying antigens, these trigger an antibody attack from lymphocytes. the memory cells ensure that if they appear again, the antibodies will kill them
3 different types of blood vessels
arteries
capillaries
veins
what is the function of arteries
carry the blood away from the heart
what is the function of capillaries
involved in exchange of materials at the tissue
what is the function of veins
carry blood to the heart
why are artery walls strong and elastic
heart pumps blood at high pressure
features of arteries
thick, strong elastic walls with elastic fibres allowing the arteries to expand
features of capillaries
walls only one cell thick
permeable walls
microscopic
why are capillary walls permeable
so that substances can diffuse in and out such as food, oxygen and CO2
why are the walls only one cell thick
increases rate of diffusion by decreasing the distance over which it occurs
features of veins
thinner walls than arteries
bigger lumen
valves
why do veins have thinner walls than arteries
blood is at lower pressure
why do veins have a bigger lumen
helps the blood flow
why do veins have valves
to keep the blood flowing in the right direction
what occurs in the right atrium
receives deoxygenated blood from the body through the vena cava
what occurs in the right ventricle
pumps the deoxygenated blood to the lungs via the pulmonary artery
what occurs in the left atrium
receives oxygenated blood fro, the lungs through the pulmonary vein
what occurs in the left ventricle
pumps oxygenated blood around the whole body via the aorta
what is the difference between the left ventricle and right ventricle
the left has a much thicker wall than the right as it requires more muscle to pump the blood all the way around the body
which vein carries blood to the right atrium
vena cava
which artery carries blood to the lungs
pulmonary artery
which vein carries blood into the left atrium
pulmonary vein
which artery carries blood to the whole body
aorta
what is the valve between the right atrium and ventricle called
tricuspid valve
what is the valve between the right ventricle and pulmonary vein called
semi-lunar valave
what is the valve between the left atrium and ventricle called
bicuspid valve
what is the vein between the left ventricle and aorta called
semi-lunar valve
why does heart rate increase with exercise
when you exercise your muscles need more energy so you respire more
how does your heart rate increase with exercise
increased amount of CO2 in the blood detected by receptors in aorta and carotid artery. these send signals to the brain’s which sends a signal to the heart causing it to contact more frequently and with more force
how does the hormonal system control heart rate
adrenal glands release adrenaline. adrenaline binds to specific receptors in the heart causing the muscle to contract more frequently and with more force
what does pulmonary mean
lungs
what does hepatic mean
liver
what does renal mean
kidneys
what is coronary heart disease
when the coronary arteries that supple the blood to the heart get blocked by layers of fatty material build up
what does coronary heart disease lead to
heart attack, the arteries become narrow restricting the blood flow to the heart
3 risk factors for coronary heart disease
diet high in saturated fats
smoking
inactivity
why does a diet high in saturated fats lead to heart disease
fatty deposit aside the arteries
why is smoking a risk factor for heart disease
increases blood pressure, causing damage to the inside of arteries.
chemicals in cigarettes increase the likelihood of fatty deposit forming
why does inactivity lead to heart disease
leads to high blood pressure, damaging the lining of the arteries
what 3 main roles do the kidneys have
removal of urea from the blood
adjustment of ion levels
adjustment of water content
how do the kidneys carry out their functions (basic)
filtering things out of the blood under high pressure then reabsorbing the useful things
what occurs in nephrons
ultrafiltration
reabsorption
how does ultrafiltration occur
- blood from the renal artery flows through the glomerulus
- a high pressure squeezes water, urea, ions and glucose out of the blood and into the bowman’s capsule
what is the glomerulus
a bundle of capillaries at the start of the nephron
why are proteins not filtered out of the blood during ultrafiltration
the membrane between glomerulus and bowman’s capsule are partially permeable, meaning that big molecules stay in the blood
what is reabsorption
useful substances are selectively reabsorbed back into the blood
how does reabsorption occur
- all the glucose is reabsorbed from the proximal convoluted tubule to be used in respiration, uses active transport
- sufficient ions are reabsorbed
- sufficient water is reabsorbed from the collecting duct into the bloodstream by osmosis
where is glucose reabsorbed
proximal convoluted tubule
where is water reabsorbed
the collecting duct by osmosis
what is the regulation of water called
osmoregulation
what 3 ways is water lost from the body
urine sweat breathing
how does osmoregulation occur in the kidneys
the kidneys reabsorb more water if the person is dehydrated
what hormone controls water reabsorption
anti diuretic hormone
how does ADH control water reabsorption
makes the collecting ducts of the collecting ducts more permeable so more water can be reabsorbed into the blood
where is ADH released from
pituitary gland
when is more ADH released
dehydration
when is less ADH released
water gain/ over hydration
