Chapter 10 - Integumentary and Immunological Systems Flashcards
What is the body highly dependent on to resist infection?
Integumentary and immunological systems.
What does the integumentary system serve as?
An initial barrier to infection and prevents a large proportion of environmental micro-organisms from entering the body.
What happens if organisms pass the integumentary system?
The immunological system has several mechanisms to protect the body from infection and destroy the invading organism.
What is the integumentary system composed of?
1) Skin
2) Hair
3) Nails
What does the integument system do?
Provides a physical barrier to prevent entrance of pathogens into the body.
What is the skin micro biome? Can it be pathogenic - if so, how?
Micro-organisms live on the surface of the skin to make up the normal skin flora
- The prevent other, harmful organism from occupying the same space
- Can become pathogenic if they penetrate the integument
What do sebaceous glands do?
Secrete oil onto surface of skin to keep pH relatively acidic (pH 4-6) to decrease bacterial growth
- Keep skin cool and moist
What is sweat?
Sweat is secreted to help cool via evaporative cooling
- Contain enzymes to destroy bacteria and has pheromones for chemical communication
What are the layers of skin? What are they connected by?
1) Dermis
- Contains blood supply to skin and most specialized cells (keratinocytes)
2) Epidermis
- Outer protective layer
*They are connected by the basement membrane
How does hair protect the body?
Directs sweat and waste away, evaporative cooling, traps heat, and sensory organ
What does mucous secretion do?
Prevent foreign particles from entering
- Enzymes great down organisms
What do nails protect against?
Protect finger tips and toes from physical injury and used as tools
What does the immunological system do? How?
Key role in destruction of the internal pathogens
- The body recognizes self and non-self (anti-gens)
- Can recognize previous pathogens
What are the two types of immunity?
1) Humoral: Anti-body production
2) Cell-Mediated: Cells that combat fungal/viral infections
What is the inflammatory response?
White blood cells become activated and release chemicals (histamine) to activate the immune response
- Dilates and increased permeability of blood vessels to increase flow of WBC and other immune cells to affected area to ward off infection
What is inflammation accompanied by?
Rise in body temperature (fever)
- In theory = fight infection by killing temperature dependent pathogens and speed up healing process
Describe the lymphatic system and its components:
Found in the extravascular space of most tissues
- Lymphs - flows through lymphatic vessels from lymph node to lymph node
- Lymph nodes and spleen - serves are reservoirs for WBC and filters lymph, removing antigen-presenting cells and foreign matter AND activates immune system when necessary
What type of WBC (leukocytes) does cell-mediated immunity include?
1) Granulocytes: Attracted to injury site and phagocytize antigens and antigenic material
- Neutrophils: Most common, first responders to inflammation, attracted to cytokines which attract WBC, moderate various infections and environmental trauma, adapted to attack bacteria, elevated when inflammation or pus present
- Eosinophils: Less common, allergic and asthmatic reactions, elevated on CBC during allergic/asthmatic or parasite infections
- Basophils (Mast Cells): allergic responses and paratactic infection, release histamine, dilates blood vessels
2) Monocytes: Large, long-lived, differentiate into macrophages and dendritic cells
- Macrophage: Phagocytize dead cells/pathogens, antigens from pathogen/cell presented on surface of macrophages to stimulate further immune response
- Dendritic cells: Processing antigens and presenting them to immune cells. important link between innate and adaptive immune system
3) T-Lymphocytes: Specific immunity, become reactive to specific antigen, if antigen is displayed ten the antigen from pathogen is presented by MHC on surface of an anti-gens presenting cell indicating the T-cell should perform its function
- Majority are deactivated for undergo apoptosis
- Can only respond to one specific antigen
- Cytotoxic T cells recognize and respond to antigens present on MCH I - come from cells infected with virus or developing tumors -
- T- Helper cells recognize/respond to antigens present on MCHII that release cytokines to stimulate immune response to cause WBC to mature/attack
- Natural killer cells respond to antigen presented by other types of cells
- Memory T- cells reactive to same antigen are formed and remain in circulation for long period of time to increase a quick target response if same antigen appears
- Suppressor cells tone down T-cell response
- T-cells develop in bone marrow, mature in thymus, released into lymph
- Ex. AIDS = deficiency in T-cells; subject to infection
4) B-Lymphocytes: Stimulated, create and express antibodies that have high affinity for the antigen expressed by stimulating T-cell
- Particular structure and utilize specificity to target and destroy pathogens
- Stimulate formation of memory cells
- Develop and complete in bone marrow
What is humoral immunity?
- Antibodies?
Chemical, hormones, and enzymes that supplement the action of cells, and serve equally important roles
Antibodies:
- Proteins secreted by B-cells provide specific targeted response to a given antigen
- Several types exist and play unique role in immunity
- Structure is relative the same = “Y” shape, each side consists of two chains (light and heavy) that are held together with disulfie bond, the only variable portion is the antigen-binding region
- Antigen-binding region in unique to each antigen
What does antibody-mediated immunity include?
Includes both active and passive immunity:
1) Active: occurs as a result of an immune response; could be due to exposure to a pathogen or antigen (ex. vaccination)
- Stimulates body to make immune response against antigen presented
- Takes a period of time to build up
2) Passive immunity: Acquired by transfer of antibodies from one individual to another
- Ex. Pregnancy; antibodies crossing placenta to fetal circulation
What are the two types of immunity?
1) Innate: Comprised of bodies initial, generalized defences against pathogens - does not require previous exposure
- Not a specific response
- Limited response
- Includes: Anatomic features (integument), physiologic response (pH, fever), phagocytic cells (monocytes, neutrophils, macrophages), and inflammation
2) Adaptive: Consists of cells capable of recognizing self vs. non-self
- Memory components; cell recognizes antigens previousy exposed to and immune response mounted against increase in magnitude with each repeat exposure to the antigen
- Includes: lymphocytes (T and B), plasma cells, and antigen presenting cells (macrophages, B cells)
What do innate and adaptive immunity do together?
Work together to protect host and depend pathogens
- Phagocytic cells stimulate production of T-lymphocytes to assist in pathogen killing/destruction
- T-lymphocytes in turn release cytokines to increase killing activities of phagocytes
- Both work to increase function and efficacy of immune system
