8: Transport in Humans Flashcards
Why do small organisms not need a transport system?
The substances are transported throughout their body by diffusion or streaming of the cytoplasm.
Why do large multicellular organisms need a transport system?
Cells in different parts of the body are far away from each other. Diffusion is too slow and becomes inefficient. Therefore, to ensure the supply of useful substances to target cells and removal of waste from the body, a transport system is developed in them.
What are the systems included in the human transport system?
Circulatory system, lymphatic system
What are the three main parts of the human circulatory system and their functions?
Blood: it carries useful substances and waste to and from body cells.
Blood vessels: they form a system of tubes that distribute blood throughout the body; the smallest blood vessels allow exchange of materials between blood and body cells.
Heart: it acts as a pump to give the force to drive blood throughout the body.
What are the four components of blood?
Plasma, red blood cells, white blood cells, blood platelets
What are the properties and functions of plasma?
Plasma contains mostly water with various substances dissolved or suspending in it.
It is the medium for transporting substances throughout the body, and it helps distribute heat throughout the body to maintain body temperature.
List 7 substances that the plasma transports.
Water, carbon dioxide (both as a gas and in the from of hydrogen carbonate ions), nutrients, urea, hormones, antibodies, and fibrinogen.
What are the shapes of red blood cells, white blood cells, and blood platelets?
Red blood cells have a biconcave disc shape, while white blood cells and blood platelets have irregular shape.
What are the sizes of red blood cells, white blood cells, and blood platelets?
Phagocytes are the largest type of cell, followed by lymphocytes and red blood cells having similar size. Blood platelets have the smallest size.
Rank the number per volume of red blood cells, white blood cells, and blood platelets in blood.
Red blood cells are the most abundant, followed by blood platelets and lastly white blood cells.
Compare the nuclei of mature red blood cells, white blood cells, and blood platelets.
Mature red blood cells and blood platelets have no nuclei. Phagocytes have a lobed nucleus while lymphocytes have a large round nucleus.
Rank the lifespan of mature red blood cells, white blood cells, and blood platelets.
Red blood cells have the longest lifespan, followed by blood platelets and lastly white blood cells.
Compare the colour of mature red blood cells, white blood cells, and blood platelets.
Mature red blood cells are red in colour due to the presence of haemoglobin. White blood cells and blood platelets are colourless.
Compare the sites of production and destruction of red blood cells, white blood cells, and blood platelets.
Red blood cells and blood platelets are produced in the bone marrow and destroyed in the liver and spleen. White blood cells are produced in the bone marrow and spleen; some of them are killed by germs and passed out through faeces.
What is haemoglobin in red blood cells broken down into?
Iron, which is reused to make red blood cells, and bile pigment, which is excreted as part of bile.
What are the characteristics of a blood smear of a patient with anaemia?
There is a reduced number of red blood cells, since anaemia is the deficiency of haemoglobin or red blood cells.
What are the characteristics of a blood smear of a patient with leukaemia?
There is an increased number of white blood cells, since leukaemia usually leads to the production of a large number of abnormal white blood cells.
What is the function of red blood cells?
They contain haemoglobin which carries oxygen from the lungs to all parts of the body.
What is the function of white blood cells?
They protect our body against diseases by killing germs.
What is the function of blood platelets?
They are involved in blood clotting which prevents further blood loss and the entry of germs into our body through the cut wounds.
What are 5 types of blood vessels in humans?
Arteries, arterioles, capillaries, venues, and veins
What is the largest artery in humans?
Aorta
What is the largest vein in humans?
vena cava
What are the layers of the walls of arteries and veins?
There are 4 layers:
The outer layer is fibrous tissue, the middle layers consist of smooth muscles and elastic tissues, while the inner layer is the endothelium.