B4 science Flashcards
Common features of transport systems:
they are made up of tubes or ‘vessels’ that carry materials from one part of the organism to another
they make close contact with cells, such as those of exchange surfaces
Other substances transported in the blood include:
antibodies
hormones
right ventricle function
pumps blood around the rest of the body
left ventricle function
pumps blood around the rest of the body
pacemaker (in the right atrium) function
controls the natural resting heart rate. artifical electrical pacemakers can be fitted to correct irregularities
coronary arteries function
carry oxygenated blood to the cardiac muscle
heart valves
prevent blood in the heart from flowing in the wrong direction
trachea
carries air to/from the lungs. rings of catilage protect the airway
bronchioles
carries air to/from the air sacs (alveoli). splits into multiple pathways to reach all the air sacs
alveoli
site of gas exchange in the lungs. maximises surface area foe efficient gas exchange
capillaries
allows gas exchange between into/out of blood. oxygen diffuses into the blood and carbon dioxide diffuses out
blood
blood is a tissue consisting of plasma, in which blood cells and platlets are suspended
plasma 55% of blood
pale yellow fluid. transports co2, hormones and waste.
red blood cells 45% of blood
carries oxygen. large surface area, no nucleus, full of haemoglobin
white blood cells 1% of blood
parts of the immune system. some produce anti bodies, others surround and engulf pathogens
platlets 1% of blood
fragments of cells. clump together to form blood clots
platlets 1% of blood
fragments of cells. clump together to form blood clots
artery
carry blood away from the heart. thick muscular walls, small lumen, carry blood under high pressure, carry oxygenated blood (except for the pulmonary artery)
vein
carry blood to the heart. thin walls, large lumen ,carry blood under low pressure, have valves to stop flow in the wrong direction, carry de oxygenated blood (exept for the pulmonary vein).
capillary
connects arteries and veins. one cell thick to allow diffusion, carry blood under very low pressure.
lung and gas exchange
the heart pumps low oxygen/high carbon dioxide blood to the lungs
coronary heart disease cause
a build up for fatty substances in the coronary arteries (artherosclerosis)
coronary heart disease effect
oxygen-ated blood cannot get to the cardiac muscle
coronary heart disease treatment
stents: inserted into the blocked artery to open it up. statins: lower harmful cholesterol
faulty heart valves cause
valves don’t open or close properly
faulty heart valves effect
blood can leak or flow in the wrong direction
faulty heart valves treatment
biological valve transplant or a mechanical valve can be instead
plant organ systems
the roots, stem and leaves from a plant organ system for transport of substances around the plant
epidermal tissues
.wavy cuticle (top layer of the leaf). Reduces water loss from the leaf.
.guard cells and stomata. guard cells open and close the stomata to control water loss and allow for gas exchange (oxygen and carbon dioxide).
palisade mesophyll
palisade cells. cells near the top surface of the leaf that are packed with choroplasts that contain chlorophyll. both adaptions maximize photosynthesis
spongy mesophyll
air spaces in the leaf between cells. increase surface area for gas exchange so that carbon dioxide can diffuse into photosynthesising cells
xylem
hollow tubes strengthened by lignin adapted for the transporation of water in the transpiration stream. allows transport of water and mineral ions from the roots to the stem and the leaves
phloem
cell sap moves from one phloem cell to the next through pores in the end walls. transports dissolved sugars from the leaves to the rest of the plant for immediate use or storage (translocation).
meristem tissue
new cells (roots and shoot tips) are made here including root hair cells. root hair cells have an increased surface area for the uptake of water by osmosis, and mineral ions by active transport.
transpiration
the rate of which water is lost from the leaves of the plant. The transpiration stream is the column of water moving through the roots, stems and leaves. temperature, humidity, air movement and light intensity affect the rate of transpiration
how does temperature affect transpiration rate
higher temperature increases transpiration rate
how does wind speed affect transpiration rate
higher wind speed increases transpiration rate
how does light affect transpiration rate
more light increases transpiration rate
how does humidity affect transpiration rate
higher humidity decreases transpiration rate
