Transport (Humans) Flashcards
Describe the composition of blood.
Blood consists of red blood cells, white blood cells, platelets, and plasma.
What is the structure of red blood cells?
- biconcave discs
- no nucleus but plenty of hemoglobin.
What is the role of plasma in blood transport?
Plasma transports glucose, amino acids, urea, lactic acid, hormones, carbon dioxide, antibodies, and cholesterol.
How do red blood cells transport oxygen?
Red blood cells transport oxygen by carrying haemoglobin, which picks up oxygen and forms oxyhaemoglobin, delivering oxygen to respiring cells and tissues.
Explain the role of white blood cells in the immune system.
- White blood cells, including phagocytes and lymphocytes, defend the body against pathogens.
- Phagocytes engulf and digest pathogens, while lymphocytes produce antibodies specific to the pathogen.
How does vaccination result in the production of memory cells?
- Vaccination triggers an immune response, leading to the production of memory cells and antibodies specific to the pathogen.
- This enables faster and greater antibody production upon future exposure to the pathogen.
How are platelets involved in blood clotting?
- Platelets are fragments of cells involved in blood clotting.
- They help form fibrin, which is needed for blood clotting, preventing blood loss and the entry of microorganisms.
Describe the structure of arteries and veins.
- Arteries have a thick, elastic wall to maintain high pressure, while veins have a thin wall and valves to prevent backflow.
- Both are involved in blood circulation.
Explain how the heart rate changes during exercise and under the influence of adrenaline.
- During exercise, the heart rate increases to deliver more oxygen to muscles.
- Adrenaline further increases the heart rate in response to stress or danger.
What factors may increase the risk of developing coronary heart disease?
- poor diet
- smoking
- stress
Describe the process of phagocytosis by white blood cells.
- Phagocytes engulf and digest pathogens.
- They detect chemicals produced by pathogenic cells, engulf the pathogen, and release digestive enzymes to digest it.
How does the structure of red blood cells make them suitable for oxygen transport?
- The biconcave shape of red blood cells provides a large surface area for oxygen diffusion.
- Their lack of a nucleus allows them to carry more haemoglobin, which binds to oxygen
Explain the importance of blood clotting.
Blood clotting prevents excessive blood loss from wounds and forms scabs to protect against microorganisms/pathogens entering the body.
- It involves platelets and the formation of fibrin.
How does the structure of capillaries relate to their function?
Capillaries have a thin, one-cell-thick wall to allow for easy diffusion of substances between the blood and tissues.
What is the role of antibodies in the immune response?
- Antibodies are proteins produced by lymphocytes that specifically target and neutralize antigens on pathogens.
- They mark pathogens for destruction by other immune cells.