Topic 8 - Transport Sytsems Flashcards
What does the red blood cell do and how is it adapted?
Red blood cells (erythrocytes):
• Transport oxygen from lungs to all cells in body - haemoglobin binds to oxygen to form oxyhemoglobin
• Biconcave disk - large surface area to volume ratio for more oxygen to diffuse in per second
• No nucleus - contains more haemoglobin to carry more oxygen.
What are the 2 types of white blood cells?
Phagocytes
Lymphocytes
What do the phagocytes do and how are they adapted?
• Large flexible membranes
• Engulf (surround) and digest pathogens
What do the lymphocytes do and how are they adapted?
• Produce antibodies and antibodies which stick to pathogens and help destroy them.
What do platelets do and how are they adapted?
• Fragments of cells with no nucleus
• Make chemicals that help blood clot at a wound
What does plasma do and how is it adapted?
• Straw coloured liquid part of the blood
• Carries RBCs, WBCs, platelets, dissolved glucose, carbon dioxide and hormones.
How is the alveoli adapted to gas exchange?
• Large surface area for quicker gas exchange maintaining steep concentration gradient.
• Very thin for a shorter diffusion pathway
• Good blood supply to maintain a steep concentration gradient
How does carbon dioxide move in the alveoli?
• Carbon dioxide moves from the blood to the alveoli
• Carbon dioxide moves from an area of high concentration to a low concentration
• Carbon dioxide moves down a concentration gradient
How does oxygen move in the alveoli?
• Oxygen moves from the alveoli to the blood
• Oxygen moves from a high concentration to a low concentration
• Oxygen moves down the concentration gradient
What are the 3 blood vessels?
Veins
Capillaries
Arteries
What do the veins do?
Carry blood to the heart.
What are features of the veins?
• Carry blood under lows pressure so walls don’t need to be as thick as artery walls
• Don’t need to be as strong
• Bigger lumen than artery to help blood flow
• Valves to stop blood flowing backwards
What do the capillaries do?
Carry blood close to cells for exchange of materials.
What are features of the capillaries?
• Arteries branch into the capillaries
• Really small
• Narrow so can squeeze into gaps between cells to exchange substances
• Permeable walls for substances to diffuse in and out
• One cell thick to increase rate of diffusion by decreasing distance over which it occurs
• Supply nutrients and oxygen, take away CO2
What do the arteries do?
Carry blood away form the heart.