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.
Describe the structure of the heart and how it functions.
The heart is made of cardiac muscle and pumps blood throughout the body.
It has four chambers: two atria and two ventricles.
- Valves ensure one-way blood flow, and the cardiac cycle involves contraction (systole) and relaxation (diastole) of the heart chambers.
How does the heart receive its own supply of blood?
The heart receives its own supply of blood through the coronary arteries, which branch off from the aorta and provide oxygenated blood to the heart muscle.
Explain how factors such as poor diet and smoking can increase the risk of developing coronary heart disease.
- A poor diet high in saturated fats can lead to high cholesterol levels, increasing the risk of fatty plaques forming in the arteries.
- Smoking can narrow blood vessels and increase blood pressure, further increasing the risk of blockages in the arteries.
What is the importance of vaccination in preventing the spread of diseases?
- Vaccination not only protects individuals from disease but also helps prevent the spread of disease within a population.
- This concept, known as herd immunity, reduces the overall prevalence of a disease.
How does blood clotting prevent blood loss and the entry of microorganisms?
blood clotting, or coagulation, forms a scab over a wound, preventing further blood loss and creating a physical barrier that prevents microorganisms from entering the body.
Suggest how the fibers labelled X help in blood clot formation
Hold cells together
Explain why only one red blood cell at a time can pass through a capillary.
Red blood cell is too big
Explain the advantages of red blood cells passing through a capillary one at a time.
- More surface area exposed
- Slows flow/ more time available
Suggest how having no nucleus helps the red blood cell carry out its function
More space for haemoglobin/oxygen
