b3.2 Flashcards
parts of the capillaries
- blood cells
- blood plasma
- endothelium (single layer)
- nucleus of endothelium
- basement membrane
- pore
adaptions of capillaries - large surface area
- short diameter
- blood moves in single file
- capillaries have a large total length
- large SA for exhange
adaptions of capillaries - thin walls with pores
- endothelium cell wall wich is thin with a permeable layer
- extracellular fibrous proteins to protect
- basement membranes filters macromolecules but allows small and medium inside
- blood plasma can pass out and form tissue fluid
- this is allowing substance exchange
- it leakes due to concentration gradients and then re enters
adaptions of capillaries - fenestrations
- large pores in walls
- allows for lager volumes of tissue to be produce and increased exhnage
- in kidneys it allows for large filtration of urine
arteries
oxygenated blood away from the heart to the body
- thicker walls
- narrow lumen
- circular
- inner surface corrugated
- fibres visible in the wall
veins
deoxygenated blood towards the heart
- thinner walls
- wider lumen
- circular/flatted
- inner surface smooth
- no fibres visible
arteries detialed
middle tunica media - thick layer containing smoothe muscle and elastic fibres to help pump blood by transmitting the pulse
centre tunica intimia - smoothe endothelium to line the artey and reduce resistance to the flow
outer tunica externa - outer coat of connective tissues with touch collagen fibres to prevent bursting
narrow lumen
styosic pressure
-peak pressure when blood is pumped out of the arteries
-wall stretches
- potential energy stored
diastolic pressure
- lowest pressure point
- elastic fibres recoil
- blood moved onwards
vascodilation
increasing diameter of arteries
vascocontriction
derecreasing diameters
muscles vs fibres
muscles contract and relax
fibres stretch and recoil
veins detailed
tuna media -thin layer with few elastic fibres and collagen beacuse blood pressure is low
tuna intimia - smoothe endothelieum to reduce resistance
- thin wall for flexbility and ability to flatted
- tunica externa - touch outer coat of connective tissue. to prevent leaks
veins have 3 valves that prevent backwards blood flow cause pressure is low.
skeletal muscles help to squish veins smaller and increase pressure if needed
corteroid artery
kneck
radical artery
thumb
the first two arteries are
coronary arties wich give oxygenated blood to the walls of the heart
lipids and fats on heart
they deposit atheroma (plague) making the lumen narrower causing occulsion - narrowing of arteries due to blocking
pain is called angina
risk factors of chronary heart disease
- diabetes
- high blood p
- smoking
- obesity
- inactiveness
- hertiage
- age
- cholesteral
epidemiological research
- studies of health and diease
- shpuld only try to study one variable at once
transpiration stream
- water is lost from the leaeves
- nearest xylem tries to replace the water
- cells adhere to the plant cell walls and form hydrogen bonds with the cellulose
- water is drawn. through pores in celluose
- CAPILLARY ACTION
loss of water from xylem
- creates a negative tension
- cohesion creates a pulling force and there is a pull against gravity
- rope like tension
wall thickening and lignification - xylem
- thickened by cellulose
- imprganated with a polymer called lignin
- provivdes strength
- more transpiration means water pulled up. this creates more tension. the pore tension there is there isless pressure in xylem
lack of end walls and cell content - xylem
- all the cells in xylem have merged, therefore there is no walls and contents and its a long tube
- unimpeded flow
- xylem is dead
dicotylendons
plants with 2 embryo seeds in its leaves
dicotylendons stem arrangements
looks like a circle witin a circle of vascular bundles inside
- phloem on the outside of the vascular bundle to transferr organic solutes to the plant
- cambium: small cells, thin wall, divides by mitosis. lies between phloem and xylem
- epidermis : outer layer to prevent water loss
- pith : in the middle to prevent water loss
- cortex: medium sized thin walled cells that strengthen cell
- xylem: large and thick to transferr water
dicotylendons roots
like like a circle with a star in
- phloem on the outside of the star
- cortex is large to bul root and widen surface area
- epidermis uses rot hairs to aborb water and minerals
