Immune/Lymphatic System Flashcards
What is an organ system?
A collection of organs, tissues and processes which carry out a specific function
What is the function of the non-specific immune system?
To protect the body against a range of issues, although the response from the body is the same regardless of the threat
Give 6 non-specific defence mechanisms
1) Physical Barriers – Includes the skin and mucous membranes
2) Chemical Barriers – Includes lysozyme and hydrochloric acid
3) Phagocytosis – Process of engulfing and digesting the pathogen
4) Fever – Process of temperature rising to kill invading bacteria
5) Natural Killer Cells – Process of reacting against and destroying another cell without prior sensitisation to it
6) Inflammation – Process which promotes healing and aims to isolate the damage and inactivate the cause
Give 2 ways the skin is a barrier to infection
1) Produces sebum and sweat which contain antimicrobial properties
2) Epithelial membranes secrete antibacterial agents which stop infection from occurring until epidermal renewal takes place
Give 2 ways lysozyme and hydrochloric acid is a barrier to infection
1) Lysozyme – Secretes antibacterial agents in tears
2) Hydrochloric Acid – Strong pH kills most ingested microbes apart from parasites
How is phagocytosis a defence mechanism?
Chemicals produced by the pathogen cause the phagocyte to move towards them. Phagocytes attach to the surface of the pathogen. They engulf the pathogen to form a vesicle called a phagosome. Lysosomes move towards the vesicle and fuse with it to form a phagolysosome. Enzymes within the lysosome breakdown the pathogen by hydrolysis. Soluble products of the pathogen are absorbed into the cytoplasm of the phagocyte or excreted by the cell using exocytosis.
How is fever a defence mechanism?
Rising of body temperature kills invading bacteria and allows chemical reactions to happen faster
How is natural killer cells a defence mechanism?
Lymphocytes police the body looking for invaders and abnormal cells. Once an invader is detected, the lymphocyte destroys foreign or damaged cells by apoptosis.
How is inflammation a defence mechanism?
Harmful substance enters the body, causing red, hot, swelling and pain to occur which is a sign of healing
What is the function of the specific immune system?
To protect the body against a specific threat or pathogen
Give 2 specific cells which respond to the specific immune system
1) T Lymphocytes – Mature in thymus
2) B Lymphocytes – Mature in bone marrow
Where are these specific cells located?
Lymph nodes
Which specific cell produces antibodies?
B Lymphocytes → Plasma B Cells
What cell of the non-specific immune system activates the specific immune system?
Dendritic
How do antibodies work?
Antibodies have a complimentary shape to the antigens from the pathogens. Once the antibody fits the shape of the antigen, they destroy the pathogen.
