Immune system Flashcards
The immune system has three types of components
– Lymphoid tissues
– Various types of immune cells
– Chemical signals that coordinate responses
The immune system is able to recognize molecules as
foreign (“non-self”) and specifically attack them
Functions of immune system
Protects against pathogens – Bacteria – Viruses – Parasites Protects against foreign molecules (e.g., toxins) • Removes dead or damaged cells • Attempts to recognize and remove abnormal cells
3 types of immune system pathologies
Incorrect immune responses – Autoimmune disease (e.g., Type 1 diabetes) • Overactive immune responses – Allergies • Lack of immune response – Immunodeficiency disease (ex: AIDS)
2 lines of defense in the organism
- Physical and chemical barriers
2. Immune defenses
Examples of physical and chemical barriers
–Skin, epithelial linings, and cilia
–Acids, mucus, and lysozymes
2 types of immune defenses
Innate and Acquired/adaptive
Differences between innate and acquired immunity
–Innate immunity
• Non-specific – responds to a range of signals
• Immediate response
–Acquired/adaptive immunity
• Specific – attacks a specific pathogen or antigen
• Slower but stronger response
• Memory allows for fast responses upon re-exposure
4 examples of chemicals that act as barriers
- sebum( secreted by sebaceous glands, low pH inhibits
microbial growth - Perspiration (flushes skin of microbes, contains lysozyme
- gastric juice (low pH, presence of enzymes)
- urine: flushes preventing attachment
What is part of our innate immunity
Epithelial
Phagocytes (activate complement and NK cells)
Complement
NK cells (a type of lymphocyte)
Cells that are part of adaptive immunity
B lymphocytes that will differentiate to plasma cells that will produce antibodies upon exposure of particular antigen
T lymphocytes , cytotoxic T cell and T helper
4 steps in an immune response
- Detection and identification of the foreign
substance - Communication with other immune cells
- Recruitment of other immune cells, and
coordination of the response - Destruction or suppression of the invader
What is a lymphatic system
a vascular system that collects tissue fluid and returns it to the blood.
This lymphatic fluid (called lymph) is monitored for pathogens by immune system cells as it travels
What in lymphatic system is packed with T and B cells
Lymph nodes
What happens to lymph after certain period of time
It is going to be dumped back into the veins and thus right atrium
How much of fluid gets into the lymph system every day?
3.6L
The flow of lymph depends on
Muscle contraction, because it has no driving force
Primary lymphoid tissues
Bone marrow
Thymus
Encapsulated lymphoid tissues
Lymph nodes
Spleen
Lymphoid nodules are also called what type of lymphoid tissues
Diffuse, for example gut-associated lymphoid tissue (GALT) . they are found beneath epithelial
Where thymus gland is found
A 2-lobed organ located in thorax just
above heart
When thymus gland reaches its peak size and what happens after
adolescence, then shrinks and is replaced
by adipose
What cells are eliminated during the development in thymus
cells that would be
self-reactive in the thymus are eliminated
Thymus produces
T lymphocytes
- Peptides: thymosin, thymopoietin,
thymulin