Multicellular Organisms: Animal Transport Systems Flashcards
What are the 4 components of blood?
Red blood cells
White blood cells
Plasma
Platelets
What is the main function of red blood cells?
Carry oxygen.
What is the function of white blood cells?
Involved in defence against pathogens.
What is the function of plasma?
Carry dissolved nutrients and carbon dioxide.
What is the structure of a red blood cell?
Small + flexible
Filled with red pigment haemoglobin
No nucleus: allows for more haemoglobin and therefore, more oxygen.
Bio-concave shape: to increase surface area for increased oxygen-carrying.
When does haemoglobin combine with oxygen to produce oxyhaemoglobin?
When oxygen concentration of surrounding cells are high.
When does oxyhaemoglobin dissociate to become oxygen + haemoglobin?
When oxygen concentration of surrounding cells are low.
What is the chemical equation of (dis)association of oxyhaemoglobin?
Haemoglobin + Oxygen ⇌ Oxyhaemoglobin.
NOTE: associates in lungs, disassociates in tissues.
NOTE: Oxyhaemoglobin is taken to body cells.
What are the 2 types of white blood cells?
Phagocytes and Lymphocytes.
What is a pathogen?
A disease-causing organism.
What is the function of phagocytes?
Engulfs pathogens and digests them using enzymes.
What is the function of lymphocytes?
Produces specific antibodies to bind the pathogen, helping immune system to destroy it.
After being exposed to a certain pathogen once, how does the second response differ to the first one?
Faster antibody production
Higher concentration of antibody production.
Higher antibody concentration for longer
What are the names of the four heart chambers?
Right atrium, right ventricle, left ventricle, left atrium
What is the function of arteries?
Carries blood away from the heart to body organs + tissues.
What’s the function of veins?
Carries blood from organs + body tissues to the heart.
What is the function of capillaries?
Exchanges materials between the blood and body cells.
What is the structure of arteries?
Thick muscular walls
They don’t contain valves.
Narrow central channel.
What are the features and functions of capillaries?
Thin walls: faster absorption + removal of substances.
Large surface area, maximising the exchange of materials at the cellular level
Extensive blood supply: allows absorption of more materials
What is the advantage of having thin alveolar walls?
Fast diffusion of gases from blood to alveoli and vice versa
What is the structure of veins?
Wider central channel (than arteries)
Blood carried at low pressure, which is why veins have valves to prevent backflow of blood.
Thinner muscular wall (than arteries)
What is the advantage of having large surface areas in alveoli?
Allows for maximum absorption of oxygen
What is the advantage of having a dense capillary network in alveoli?
Maximum diffusion of gases
Usually, veins carry deoxygenated blood. Why is the pulmonary vein an exception?
The blood that is carried by it, has already been to the lungs for oxygenation.
What is the definition of digestion?
Breakdown of large insoluble molecules to smaller soluble molecules for absorption through the small intestine
Usually, arteries carry oxygenated blood. Why is the pulmonary artery an exception?
The blood carried by it, has not entered the lungs for oxygenation.
What is the function of thin walls in the villus?
Fast diffusion of nutrients
Describe the pathway of blood through the heart and associated structures.
vena cava → right atrium → right ventricle → pulmonary artery → LUNGS (oxygenation) →
pulmonary vein → left atrium → left ventricle → aorta → BODY
What is the function of the small intestine?
- Designed for maximum absorption and quick transport of absorbed food molecules
- Long, folded and contains villi which increase surface area
- Large blood supply and vessels leading to the lymphatic system
What is the function of the dense capillary network in the villus?
Transports glucose and amino acids
What is the function of the lacteal in the villus?
Absorbs fatty acids and glycerol
What are carbohydrates broken down into and what part of the villus absorbs it?
- Broken down to glucose
- Absorbed by capillaries
What are fats broken down into and what part of the villus absorbs it?
- Broken down to fatty acids + glycerol
- Absorbed by lacteal
What are proteins broken down into and what part of the villus absorbs it?
- Broken down to amino acids
- Absorbed by capillaries
Describe the process of gas exchange in alveoli.
Blood arrives in the lungs deoxygenated. The air breathed into the alveolus contains a high level of oxygen.
So, oxygen diffuses from a higher concentration in the alveolus to a lower concentration in the blood.
Deoxygenated blood contains higher levels of carbon dioxide than the air in the alveolus.
So, carbon dioxide diffuses from a higher concentration in the blood to a lower concentration in the alveolus.
