4.1.4 Non-Specific Immune Response Flashcards
1
Q
Primary methods of defence in humans
A
- Skin
- Mucous membrane
- Cilia
- Tears (Lysosomes in tears break down cell wall of bacteria)
- Sweat
- Ear wax
- Lashes
- HCL
2
Q
Secondary defence in human body
A
- Blood clotting
- Phagocytosis
- Inflammation
- Fever
- Neutrophils and Macrophages
3
Q
What does skin do
A
- Keratin
- Physical barrier
- Secrete sebum containing fatty acids with antimicrobial properties
- Evaporation of sweat leaves salty residue which has a lack of moisture and low pH, which is inhospitable for microbes
4
Q
What do mucous membranes do
A
- Line gut, airways and reproductive systems
- Epithelial cells waft with cilia
- Mucus traps microbes
- Back of throat to swallow into HCL
5
Q
What are expulsive reflexes
A
- Cough or sneeze
- Expulsion of air pushes pathogens back up respiratory tract out of mouth
6
Q
What are commensal microbes
A
- Grow on skin, in mouth and in intestines
- Do not cause disease
- Compete with pathogens
- Antibiotics can kill these which can allow pathogens to grow
7
Q
What happens during blood clotting?
A
- Endothelium cut so platelets exposed to proteins outside endothelium, activating platelets
- Platelets form plug around damaged area
- Platelets release clotting factors thromboplastin
- Thromboplastin + Calcium ions activate Prothrombin
- Prothrombin converted to enzyme thrombin
- Thrombin turns fibrinogen into insoluble fibrin
- Insoluble fibrin forms mesh, trapping blood
8
Q
What is inflammation?
A
- Surrounding area of wound becomes swollen
- Works by chemical signalling
- Phagocytes migrate to tissue and increased blood flow (why it appears red and warm)
- Mast cells secrete histamine
- Histamine stimulates vasodilation, makes vessel wall more permeable and causes cells to release cytokines
- Cytokines attract phagocytes
- Travel to hypothalamus to increase body temp making pathogens less able to reproduce
9
Q
How do scabs form?
A
- Form of blood clotting
- Under scab stem cells divide by mitosis to heal wound
- Collagen produced, granulation tissue formed filling wound
