Chapter 4 Flashcards
What does plasma carry (3)
red blood cells, white blood cells, platelets
What makes up the human circulatory system (3)
blood, blood vessels, heart
where is waste carbon dioxide carried to
the lungs
where and how is urea formed
urea formed in your liver from the breakdown of excess proteins
How are red blood cells adapted
biconcave discs so high volume to SA ratio
they are packed with a red pigment called haemoglobin that binds to oxygen
they have no nucleus, making more space for haemoglobin
what do white blood cells do
help protect the body against infection
what are platelets
they are cell fragments that start the clotting process at wound sites.
what are the main types of blood vessels
arteries, veins, capillaries
what do valves do
the valves prevent backflow, ensuring that blood flows in the right direction
what do arteries do
your arteries carry blood away from your heart to the organs of your body
what do veins do
the veins carry blood away from the organs towards your heart
what do capillaries do
capillaries form a huge network of tiny vessels linking the arteries and the veins
what is the heart
is an organ that pumps blood around the body
what are stents used for
stents can be used to keep narrowed or blocked arteries open
what do statins do
statins reduce cholesterol levels in the blood, reducing the risk of coronary heart disease.
what happens in the heart 1) deoxygenated blood cycle
2) oxygenated blood cycle
1) deoxygenated blood enters the heart from the body -> right atrium -> right ventricle -> pulmonary artery which is going to the lungs
2) oxygenated blood enters the heart from the lungs through the pulmonary vein -> left atrium -> left ventricle -> aorta which takes blood to the body
what can be done to damaged heart valves
they can be replaced using biological or mechanical valves
what does a natural pacemaker do
the resting heart rate is controlled by a group of cells in the right atrium
what does an artificial pacemaker do
they are electrical devices used to correct irregularities in the heart rhythm
What does the alveoli do
The alveoli provide a very large surface area and a rich supply of blood capillaries. This means gases can diffuse into and out of the blood as efficiently as possible.
describe the ventilation of the lungs (breathing in, breathing out)
(breathing in) 1) as ribs move up and out and diaphragm flattens, the volume of the chest increases
2) increased volume means lower pressure in the chest
3) atmospheric air at higher pressure than chest - so air is drawn into the lungs
(breathing out) 1) as ribs fall and diaphragm moves up, the volume of the chest gets smaller
2) decreased volume means increased pressure in the chest
3) pressure in chest higher than outside - so air is forced out of the lungs
what do xylem tissue do
they transport water and mineral ions from the roots to the stems and leaves
what do phloem tissue do
they transport dissolved sugars from the leaves to the rest of the plant, including the growing regions and storage organs
what is transpiration
it is the loss of water vapour from the surface of plant leaves
how is water lost
water is loss through the stomata, which open to let in CO2 for photosynthesis
what controls gas exchange and water loss
the stomata and guard cells
4 factors that increase the rate of transpiration
temperature, humidity, air flow, light intensity
when is transpiration most effective
in hot, dry, windy or bright conditions
