Transport And Exchange Flashcards
What do organisms need for metabolism? (3)
- dissolved food molecules
- water
- minerals
What does the metabolism produce and what are examples?
Waste products such as:
Carbon dioxide
Water
Urea
Why do the waste products need to be excreted?
They’re toxic
How do waste products get out?
Diffusion across exchange surfaces
What are features of a good exchange surface? (2)
Thin for a short diffusion distance
Large surface area for more diffusion per second
What are alveoli?
Exchange surfaces for gas exchange in the lungs
What do alveoli do?
Let oxygen diffuse from the air in the lungs into the blood, and carbon dioxide the opposite way
What does ‘surface area to volume ratio’ mean?
How big a surface area is compared to its volume
How do you work out the SA:VOL?
Surface area/volume
What kind of sa:vol ratio do small organisms have?
They have a large sa:vol ratio so they can exchange materials across their surface
What kind of sa:vol does a large organism have and why?
They have a small sa:vol ratio because diffusion across their surface would be too slow so they need exchange surfaces eg. Alveoli
Describe red blood cells (3)
- transport oxygen, haemoglobin binds to oxygen to make oxyhaemoglobin
- biconcave disc shape for a large sa:vol ratio
- no nucleus to contain more haemoglobin for oxygen
What are the 2 types of white blood cells and what do they do?
Phagocytes - engulf and digest pathogens
Lymphocytes - make antibodies which kill pathogens
What are platelets?
Fragments of cells, make chemicals which help blood clot when cut
What is plasma and what does it do?
- straw coloured liquid part of the blood
- carries RBCS, WBCS, platelets, dissolved sugars, hormones, urea and CO2
Which side of the heart pumps deoxygenated blood?
The right side
Which side of the heart pumps oxygenated blood?
The left side
What is the role of the vena cava?
Brings deoxygenated blood back from the body into the right atrium
What is the role of the pulmonary artery?
Carries deoxygenated blood to the lungs to collect oxygen
What is the role of the valves?
Open and close to prevent blood backflow
What is the role of the pulmonary vein?
Carries oxygenated blood from the lungs back to the left atrium
What is the role of the aorta?
Carries oxygenated blood around the body
What is the role of the septum?
Separates oxygenated and deoxygenated blood
What is the role of the thicket left ventricle wall?
Pumps blood at a high pressure around the whole body
What is the role of the thinner right ventricle wall?
Only pumps blood to lungs at a low pressure
Put vein artery capillary in order of biggest to smallest
Artery
Vein
Capillary
What is the role of an artery?
Carries blood away from the heart
Describe the structure of an artery
Thick muscle layer
Small lumen
What happens to an artery when the heart beats?
It stretches
What kind of pressure does an artery pump blood at?
High pressure
Describe the structure of a vein
Thin muscle layer
Large lumen
What is the role of a vein?
Carry blood to the heart
What kind of pressure does a vein pump blood at?
A low pressure
What do veins have that prevent backflow of blood?
Valves
If the muscles surrounding the vein are relaxed, what does this mean for the valves?
They are closed
If the muscles around the vein are contracted, what does this mean for the valves?
They are open
Describe the structure of a capillary
Thin muscle layer (only one cell thick)
Large lumen
What is the role of the capillary?
Exchange of materials within the tissues
What is cardiac output?
The volume of blood pumped into the aorta each minute
What is the cardiac output equation?
Cardiac output=stroke volume X heart rate
What is the equation for aerobic respiration?
Glucose + oxygen—>carbon dioxide + water
How is oxygen delivered to respiring cells?
Alveoli
How is glucose delivered to respiring cells?
Small intestine
What is the equation for anaerobic respiration?
Glucose—>lactic acid
Why is lactic acid not good for your body?
It’s toxic, causing muscles to cramp
