Zusammenfassung der Ressource
Disease and Immunity
- Disease
- Causes
- Infections caused by pathogens e.g bacteria and viruses.
For example common cold, food poisoning and chest
infections
- Non infectious disease- caused
by malfunctioning of the body
e.g cancer
- Lifestyle
- Coronary Heart
Disease (CHD):
-Poor diet (high in
saturated fat or
salt) -Smoking
-lack of exercise
- All lead to high BP, which can damage the
heart and blood vessels, increasing risk of CHD
- Cancer, result of uncontrolled cell division:
-Smoking (mouth, throat and lung cancer)
-Excessive exposure to sunlight; skin cancer
-Excessive alcohol intake; liver cancer
- Risk Factor=
anything that
increases the
chance of getting
a disease
- Pathogens
- Organism that can
cause disease
- Types of Pathogen
- Viruses
- HIV-Aids + Influenza
- Bacteria
- Myobacterium Tuberculosis
- Entry into the body
- Gas Exchange System
- Mucus trap pathogens, cilia beat and move mucus
up trachea and out of the mouth
- The Skin
- Blood clots and dries to form a scab
- Digestive System
- Most pathogens killed by acidic conditions of the stomach
- How they cause disease
- 1. Production of Toxins
- 2. Cell Damage- kill host cells
- i). rupture host cell to release nutrients
- ii) Break down nutrients for own use, this starves the cell
- iii) cell dies, pathogens replicate inside cells and eventually they burst
- The Immune Response
- 1. Phagocytosis
- 1. Phagocyte recognises antigens on surface
- 2. Cytoplasm of phagocyte moves around the pathogen, engulfing it
- 3. The pathogen is now in a phagocytic vacuole
- 4. A lysosome fuses with the phagocytic vacuole, the lysosomal enzymes break down the pathogen
- 5. Phagocyte then presents the pathogens antigens on its own surface in order to activate other immune system cells
- 2. T-Cell Activation (Cellular Response)
- Type of white blood cell, has proteins on its
surface that bind to antigens on phagocytes
- Some T-cells release substances to activate B cells. Others
attach to antigens on the pathogen and kill the cell.
- 3. B-Cell Activation& Plasma cell production (Humoral Response)
- B Cells= Type of white blood cell
- Covered with antibodies
(proteins that bind antigens to
form an antigen-antibody
complex)
- Each B cell has a diff shaped
antibody on its membrane
- Meets complimentary antigen+ binds. This, together with
substances released from
T-Cells activate the B-Cells
and cause them to divide (Plasma cells)
- 4. Antibody Production
- Plasma cells are identical to B cells (clones) so they secrete loads of antibodies
specific to the antigen
- Antibody Functions:
- Coating pathogen so the phagocyte can easily engulf it
- Binding to and neutralising toxins produced by pathogen
- Antibody Structure
- Proteins- made of chains of AA
monomers, linked by peptide bonds
- Each antibody has a diff shaped variable region due to diff amino acid sequences
- Primary Response
- Vaccines
- Helps avoid a disease
- Antigenic Variation
- Monoclonal Antibodies