Human Transport Flashcards
What are the four main things found in the blood?
Red/white blood cells, platelets and plasma
What is plasma?
- a straw coloured liquid
- carries all of the different substances found in the blood
- since it is liquid, some substances are carried by being dissolved directly into the blood plasma
- for example, carbon dioxide is produced as a waste product in cells in body tissues and it is dissolved into the blood plasma so it can be transported to the lungs and removed from the body
- glucose is also carried to the body tissues by being carried by the blood plasma
- it carries digested food products from the small intestine to the body tissues (e.g glucose and amino acids)
- it carries urea from the liver to the kidneys from where it is removed via urine
- it carries hormones from the glands to all around the body to different target organs affected by different hormones, which act as chemical messengers
Why is it important for blood plasma to carry heat energy?
- it carries heat energy away from rapidly respiring cells (such as exercising muscles) and prevents them overheating
- it also provides heat energy to regions of the body where respiration takes place more slowly.
- by increasing the diameter of blood vessels in the skin, heat energy can be transported more rapidly to the environment during exercise to prevent the whole body from overheating
How are red blood cells adapted to transport oxygen?
Biconcave disk shape:
-increases surface area to volume ratio, increasing the rate of diffusions in and out of the cell
Contain haemoglobin:
-these carry the oxygen in the cell
-in areas of high oxygen concentration (e.g in a capillary next to alvioli) haemoglobin binds with oxygen
-this reaction is reversible, because in areas of low concentration (e.g a capillary running through respiring tissue) the oxygen is released from the haemoglobin
No nucleus:
-maximises volume that can be filled with haemoglobin, but means they cannot divide to make new cells when they get older- they are cleaned out of the blood by the liver, and new ones are released into the blood from the bone marrow in long bones (e.g femur)
Small and flexible:
-makes it possible for them to get through the smallest blood vessels (capillaries) that are sometimes no wider than a single blood cell
What are the two types of blood cells?
Phagocytes and lymphocytes
What system are white blood cells part of?
The immune system
What are phagocytes?
- several types of white blood cell belong to this category, but they all kill pathogens by ingesting them
- they engulf pathogens by pushing a sleeve of cytoplasms completely around them until they are completely enclosed, and then digest them with enzymes
- different types of pathogens kill different types of pathogens, such as bacteria, fungi and protoctist parasites
What are lymphocytes?
- this type has a very big nucleus and is responsible for producing chemicals called antibodies
- when a pathogen infects the body, lymphocytes produce antibodies that specifically match the antigers of the pathogen
- the antibodies attach to the antiger and either attract phagocytes to engulf the pathogen or cause the pathogen to break open and die
- they also produce memory cells to remember what kind of antibody is needed for a faster reaction to the infection
How do vaccines work?
- vaccination is a way of preventing disease by making the body respond as if it had already been infected
- The vaccine is prepared from small amounts of material from the pathogen which is either dead or weakened so that it cannot cause infection
- lymphocytes in the immune system respond by making antibodies to the pathogen and also memory cells
- these memory cells remain in the blood after the pathogen has been destroyed, sometimes for the rest of the persons life
- if you are ever infected by the live pathogen the memory cells recognise it very rapidly and stimulate lymphocytes to produce huge quantities of antibodies very quickly
- this response kills off the pathogen quickly, often before you develop symptoms and realise you have been infected
- this rapid response makes you immune to that pathogen
What are platelets?
- Platelets are small fragments of much larger cells that are also important in protecting from infection
- when there is damage to a blood vessel (such as from a cut) the platelets respond by releasing an enzyme that causes the formation of a fibrous protein called fibrin
- fibrin traps blood cells and forms a blood clot
- this is essential for staying healthy as it seals the cut and prevents blood from leaking out and pathogens and carbon dioxide from getting in
Draw and label a diagram of a heart
Include:
Aorta
pulmonary artery
left atrium
pulmonary vein
biscupid valve
left ventricle
muscle
interventricular septum
right ventricle
tricuspid valve
inferior vena cava
right atrium
pulmonary artery
superior vena cava
How many chambers are there in the heart?
4
What are the bottom two chambers in the heart called?
Ventricles
What are the top two chambers in the heart called?
Atriums
On a diagram draw the direction of blood in the heart (show different colours for oxygenated and deoxygenated)
-Deoxygenated into heart via vena cava
-deoxygenated out of heart via pulmonary artery
-oxygenated into heart via pulmonary vein
Oxygenated out of heart via aorta
