Integumentary and Immunological Systems Flashcards
Integument System
composed of the skin, hair and nails. Provides the physical barrier to prevent the entrance of pathogens into the body
Skin Microbiome
the organisms that live on the skin and make up the normal skin flora.
-Mutualistic relationship- by occupying the skin these microorganisms prevent other more harmful organisms from occupying the space. In return microorganisms get stable eviroment with access to nutrients
Skin
-nonspecific defense mechanism that protects against pathogen invasion
Sweat
secreted from other glands and helps cool the skin by evaporative cooling
-also contains enzymes that helps destroy bacterial cell walls as well as pheromones used in chemical communication among humans
How is the skin divided?
2 basic layers:
- Dermis: contains the blood supply to the skin and most of the specialized cells
-Epidermins: contains keratinocytes, which differentiate into corneocytes
The Dermis and epidermis are connected by the basement membrane
Corneocytes
protective, waterproof cells that do not undergo further replication and are routinely sloughed off and replaced
Hair
- aids the skin
- serves to direct sweat and waste away from the skin. Helping with evaporative cooling when the body is hot.
- can also trap heat preventing the body from becoming to cool
-serves as a sensory organ, allowing the detection of nearby motion
Mucus secretions of the nose and aqueous secretions of the eyes
-help prevent foreign organisms from entering the body and resist infection
Enzymes in the mouth and throat
breakdown many entering microorganisms and decrease their pathogenecity
Nails
protect the tips of our fingers and toes from physical injury, and can be used as tools
Immune System
plays a key in the destruction of internal pathogens
-the body can distinguish between self and non self and can remember non self qualities in other cells (ANTIGENS). Allowing the body to recognize pathogens it has previously encountered and to mount a quicker immune response against these antigens if exposed to them agian
Inflammatory response
- nonspecific defense mechanism
- its when WBC’s are activated and they release chemicals CALLED HISTAMINES which activates the immune response. The response dilates and increases the permeability of the blood vessels.
- This increases the flow of WBCs and other immune cells to the affected area allowing the body to more effectively ward off infection
Inflammation
accomplished by the rise of the body temp-FEVER
Lymphatic system
found int he exravascular space of most tissues
- LYMPH flows through lymphatic vessels from lymph nodes to lymph node
- the lymph nodes and spleen serve as reservoirs of WBC’s and filters for the lymph– removing antigen presenting cells and foreign matter and activating the immune system when necessary
Granulocytes
attracted to the site of injury, where they phagocytize antigens and antigenic material
- neutrophils
- eosinophils
- Basophils
Neutrophil
- most common type of granulocyte
- are the first responders to sites of inflammation
- these cells are attracted to cytokines and in turn attract additional WBC’s once they arrive at tens its of tissue damage
- help moderate various infections and environmental trauma, but mainly attack bacteria
- neutrophil counts are elevated during the active stages of inflammation
- main component of pus
Eosinophils
- much less common than neutrophils
- responsible for immune responses: allergic and asthmatic responses
- elevated eosinophil counts on complete blood count often indicates an allergic respond or infection by a parasite (endoparasites-live inside the body and include Helminths)
Basophils
- mast cells that are also involved in allergic responses and are responsible for the release
- high concentrations of basophils indicate the presence of parasites (ectoparasites-live on the surface and include fleas and ticks)
Monocytes
large, long lived immune cells that can differentiate into macrophages and dendritic cells
Macrophages
main role is to phagocytize dead cells and pathogens
-if the pathogen is ingested by the macrophage, the antigens are then presented on the surface of the macrophage to stimulate other immune cells to mount a specific immune response to the invading pathogen
Dendritic Cells
even more focused on processing antigens than macrophages and presenting them to other immune cells
- serve an important link between the innate and adaptive immune response
- are found in areas of the body where contact with the external environment is more common (skin, intestine, mucus membrane)
T-lymphocytes
(T-cells)
- important component and specific immunity
- each T cell become reactive to one antigen, if infected with an organism that displays this antigen, the antigen from the pathogen will be presented by a MHCI (major histocompatitiblity complex 1) on the surface and an antigen presenting cell–indicating the corresponding Tcell should perform its function
MHCI
cytotoxic T cells (CD8+ T-cells) recognize and respond to antigens presented by MHC 1 complexes
MHCII
T helper cells (CD4+ T cells) recognize and respond to antigens presented on MHCII. These activated T helper cells release cytokines to stimulate the immune response cause by other WBC’s to mature and attack
Natural Killer cells
behave similarly to cytotoxic T cells and TH cells, BUT respond to antigens present by other types of CELLS
Memory T cells
reactive to the same antigens are formed and remain in circulation for long periods of time, allowing for a quicker, more targeted response if the antigen reappers
Regulatory T Cells
or Suppressor T cells
-tone down T cells to self cells or following infection
T cells
begin their development in the Bone Marrow, where T lymphocyte precursor cells are formed. They then travel to the Thymus via the bloodstream where they mature.
-Once matured these cells are released into the lymph to perform their immune function
AIDs
Acquired Immunodeficiency Syndrome
-patients have very low levels of certain T-cells, thus are prone to infection
B Lymphocytes
B cells
- when stimulated, create and express antibodies (immunoglobulins) that have high affinity for the antigen expressed by the stimulating T-lymphocyte
- can also stimulate the formation of memory cells
B cells
begin their development in the blood marrow. Their development is completed here.
Antibodies
large proteins secreted by B-cells which provide specific targeted responses to a given antigen
-several types exist within the immune system and each plays a unique role in immunity
-light and heavy chains are held together by disulfide bonds
Antibody Active immunity
occurs as a result of an immune response
-can be due to exposure to a pathogen, or antigen, such as during an infections. Can also be the result of vaccination
Vaccination
when individuals are deliberately exposed to weakened, inactivated, or killed form of the antigen
Antibody Passive immunity
acquired by the transfer of antibodies from one individual to another
- can occur during pregnancy, injections of gamma goblin
- is effective immediately upon transfer of antibodies, once the antibodies are no longer circulating in the immune system the effect of immunity is lost
What is involved in the innate immune system/adaptive immune system
Innate:
- Macrophage
- Natural Killer cells
- Granulocytes (basophils, eosinophils, neutrophil)
***Natural killer cells and dendritic cells are applied in both responses
Adaptive:
- B cells
- T- cells (CD4+/CD8+ Tcells)
- Antibodies
Innate Immunity
- comprised of the body’s initial defense against pathogens
- does not require the cells of the immune system to be previously exposed to any antigen to be activated
- BUT is not a specific response and the body is limited in the types of immune response it can mount
includes:
- anatomic features (integument)
- physiological responses (fever, pH changes, enzymes)
- Phagocytic Cells (monocytes, neutrophils, and macrophages)
- Inflammation
Adaptive Immunity
- acquired or specific immunity consists of cells capable of recognizing self vs. non-self and are specific to a particular antigen
- the activity of cells that participate are increased with each exposure (memory component)
cells that are involved:
- lympocytes (B and T cells)
- Plasma Cells
- Antigen presenting cells (macrophages and B cells)
