Immune System Flashcards
What is the primary function of the immune system?
Safeguard against disease
The immune system is a network of cells, tissues, and organs that protects the body.
What are leukocytes?
White blood cells that originate in bone marrow
Leukocytes migrate to the bloodstream and lymphatic system.
What is the normal range of leukocytes in microliter of blood?
4000 - 11000
This range indicates the number of white blood cells present in healthy individuals.
How do leukocytes detect issues in the body?
By screening for antigens
Antigens are molecular traces on pathogens that signal the presence of invaders.
What are phagocytes?
Cells that trigger immune response by destroying invaders
Phagocytes send macrophages and dendritic cells into the blood to eat invaders.
What role do macrophages and dendritic cells play in the immune response?
They destroy invaders by eating them
This action allows phagocytes to detect antigens and inform lymphocytes.
What symptoms of a cold help the immune system?
Warmer body temperature and swelling
A warmer body makes it harder for bacteria and viruses to spread, while swelling attracts phagocytes.
What occurs when body cells are damaged?
Release chemicals that make fluid leak into surrounding tissues
This process attracts phagocytes to the site of damage.
What do lymphocytes do?
Search for infected body cells and kill them
This group includes T-cells that are essential for the immune response.
What is the function of B cells and helper T cells?
Make antibodies using information gathered by phagocytes
Antibodies are specific to each antigen and help destroy them.
How do B and T cells contribute to immunity?
Recognize invaders in the future and swiftly counterattack
This process helps develop immunity to diseases.
What are autoimmune diseases?
Conditions where the body destroys healthy cells
Autoimmune diseases occur when the immune system mistakenly targets the body’s own tissues.
Innate (non specific defense system)
Responds immediately to protect the body from all foreign substances. Prevents entry and spread of micro-organisms
Acquired (specific) defence system
Immune-system — responsible for attacking against particular foreign substances by using cells to attack invaders or by releasing chemicals and antibodies
