Ch 15 extra Flashcards
1
Q
Describe the functions of the lymphatic system.
A
- to collect and return tissue fluid to circulation.
- this prevents oedema
- Lymph nodes are a major site of lymphocyte productions.
- The system transports fats, fatty acids and glycerol.
2
Q
Describe the immune system in terms of phagocytosis.
A
- Neutrophils carry out phagocytosis.
- there is receptor protein on the cell wall of a neutrophil.
- the neutrophil moves towards the pathogen.
- Bacteria sticks to the CSM.
- The neutrophil membrane infolds and them flows around and engulfs the pathogen.
- The cell membrane then pinches of and forms a vacuole in neutrophil.
- The enzymes digest the pathogen.
3
Q
Describe the immune system in terms of vaccination.
A
- A vaccine contains weakened or dead pathogens.
- or poisonous toxins produced by them.
- The antigens are still present on the weakened pathogens
- Causes lymphocytes to produce antibodies
- Memory cells release the correct antibodies when the real pathogen enters the body
- The person is then immune to the disease
4
Q
Describe the immune system in terms of tissue rejection (dis ‘n lang een hierdie)
A
- Transplanted organs may be a different tissue type, which creates a chance of rejection
- The donor and recipient must be carefully matched, so that the organ has the same tissue type and blood type. Usually from a close relative
- Rejection means that lymphocytes recognise the new organ as “foreign” and release antibodies to attack the organ
- The patient is given immunosuppressant drugs to kill lymphocytes
- This causes loss of protection from other infectious diseases, and the patient is placed into isolation
- Genetic engineering can be used to clone or produce organs
- Shortage of organs for transplantation creates a black market
- Transplanting an organ is very expensive
5
Q
Describe active immunity
A
- Long term protection
- Produce own antibodies
- Body has memory cells which can produce these antibodies
- This explains getting chicken pox only once
6
Q
Describe passive immunity
A
- Temporary protection against a disease
- Given ready-made antibodies
- Given antibodies eventually disappear
- No memory cells to produce antibodies
7
Q
Describe natural active immunity
A
- Catching and recovering from a disease such as chicken pox causes the body to produce long lasting antibodies
- Memory cells “remember” the antigen and can release the correct antibody when the pathogen enters the body again
8
Q
Describe artificial active immunity.
A
- You are immunised against diseases such as polio, meningitis or TB
- Receiving an injection of a weakened strain of a disease.
- The vaccine is injected into you, and youproduce your own antibodies in response.
8
Q
Describe natural passive immunity.
A
- immunity acquired by babies from their mothers.
- Antibodies are present in mother’s blood from previous infections and immunisations.
- babies getting antibodies when feeding on breast milk.
- antibodies cross the placenta during pregnancy to the foetus.
- Memory cells do not cross the placenta, so immunity is temporary.
9
Q
Describe artificial passive immunity.
A
- Receiving an injection of a serum containing antibodies.
- Horses are injected with small doses of snake venom.
- The antibodies produced by the horses are extracted.
- Snake bite victim can be injected with these antibodies to give them temporary immunity and time for its own immune system to respond to the venom.
10
Q
Describe the transmission and symptoms of malaria, explain the reasons why the immune system may fail to eliminate malaria from the body and its importance as a major disease in many countries.
A
study page 293 the Fact about malaria.
11
Q
Describe the role of the female Anopheles mosquito in transmission of Plasmodium.
A
- Mosquitoes stab and sucks human blood.
- If the victim has malaria, parasites enter the mosquito with the blood.
- When biting a uninfected person, the female anopheles mosquito injects saliva into the person ( contains anticoagulant) into the person to prevent blood from clotting.
- the saliva contains parasites which enter the uninfected person.
12
Q
study cycle on page 294
A
Hi……This is Dog.
13
Q
Name the Symptoms of malaria.
A
- Fever ( hot spells )
- Shivering ( cold spells )
- Sweating and shaking
- Headaches
- Muscle pains
- Nausea ( NOT vomiting )
- Extreme tiredness.
14
Q
Why does malaria cause extreme tiredness?
A
- One has fewer red blood cells.
- This results in less haemoglobin to transport oxygen.
- Burst red blood cells block capillaries.
- Less oxygen is available to respiration.
- Less energy will be release.
