Topic 8: exchange and transport Flashcards
Give two examples of exchange surfaces in humans and describe their function.
.the alveoli in the lungs allow carbon dioxide and oxygen to diffuse in and out of the blood stream
.the villi in the small intestine Villi allow nutrients such as glucose, amino acids, mineral ions etc to be absorbed from the small intestines into the bloodstream
what are the three main things that affect the rate of diffusion explain why
.distance the less distance the quicker the rate of diffusion
.concentration difference gradient, the bigger the difference in concentration between the area that they are diffusing from to the area they are diffusing to the faster the rate of diffusion as more molecules will move across
.surface area, the more surface area there is the faster the substance can get to the other side
Fick’s law shows the relationship of the rate of diffusion its factors
what is the equation?
how are the alveoli adapted for efficient gas exchange
Their walls are only one cell thick which provides a short distance for diffusion
There are many of them giving a large total surface area
They are moist, which allows the gases to dissolve, and therefore diffuse more easily
characteristics of arteries
.thick walls as they carry blood under high pressure to other parts of the body
.thin lumen
characteristics of capillaries
.one cell thick to allow for diffusion
.large surface area for lots of diffusion
characteristics of veins
.carry deoxygenated blood back to the heart
.have valves to prevent back flow of blood
.thin walls and thick lumen as they carry blood under little pressure
pattern of the blood flow in the heart chambers
V- vena cava
A-right atrium
V-right ventricle
A-pulmonary artery
V-pulmonary vein
A-left atrium
V-left ventricle
A-aorta
compare right to left side of the heart
left: has a larger muscle than the right side as it is responsible for pumping blood throughout the body
right: only needs to pump blood to the lungs so is less muscular
what is the only vein that carries oxygenated blood and why
pulmonary vein
carries oxygenated blood back into the heart from the lungs to be pumped to the rest of the body
what are the advantages of mammals having a double circulatory system
In double circulatory systems, oxygenated blood is pumped to the body tissues at a higher blood pressure.
This faster blood flow ensures more oxygen is delivered to the body cells.
This is vital to warm-bodied, complex organisms with higher metabolic rates.
where are pacemaker cells found
right atrium
what do pacemaker cells do
directly controls the heart rate
5 uses of glucose from respiration
To combine small molecules to make larger molecules
To break large molecules into smaller molecules
For muscle contraction
To maintain our body temperature
To move substances around the cell
why is aerobic respiration
Anaerobic respiration doesn’t break down the glucose molecule completely, and so releases less energy than aerobic respiration
Anaerobic respiration produces lactic acid which can damage cells and leads to an oxygen debt
