Integumentary and Immunological Systems Flashcards
Integement
The skin, hair and nails
Provide a physical barrier to prevent the entrance of pathogens into the body
Skin microbiome
The microorganisms that live on the surface of human skin and make up the normal skin flora
Skin
A nonspecific defence mechanism that protects against pathogenic invasion
Sebaceous glands
Secrete oil to keep the skin pH relatively acidic (4-6) to decrease bacterial growth
Sweat
Secreted by glands
Cool skin by evaporative cooling
Contains enzymes to destroy bacterial cell walls and pheromones for chemical communication
Dermis
Contains the blood supply to the skin and most of the specialized cells
Epidermis
Contains mainly keratinocytes, which differentiate into corneocytes
Corneocytes
Protective, waterproof cells that do not undergo further replication and are routinely sloughed off and replaced
Hair
Direct sweat and waste away from the skin
Help with evaporative cooling
Trap heat
Nails
Protect the tips of the digits from physical injury
Used as tools
Immune system
The destruction of internal pathogens
2 types: humoral and cell-mediated
Humoral immunity
Antibody production to recognize pathogens previously encountered to mount a quicker immune response
Cell-mediated immunity
Cells that combat fungal and viral infections
Inflammatory response
Activated white blood cells release histamines that dilate and increase the permeability of blood vessels to increase flow of white blood cells and other immune cells to affected areas
Fever
Increases the ability to fight infection by killing temperature-dependent pathogens
Lymph
Contains white blood cells
Flows through the lymphatic vessels between lymph nodes
Lymph nodes
Reservoir of white blood cells and filter lymph, removing antigen-presenting cells and foreign matter
Active immune system
Leukocytes
White blood cells
Granulocytes
Attracted to site of injury
Phagocytize antigens and antigenic material
Basophil (1%), eosinophil (5), neutrophils (94%)
Neutrophils
First responders to sites of inflammation & main component of pus Attracted to cytokines Attrack additional white blood cells Attack bacteria Phagocytic
Eosinophil
Responsible for immune responses (allergic and asthmatic)
Fight parasites
Basophil
Mediate allergic response and parasite infections
Release histamine
Monocytes
Large, long-lived immune cells
Macrophages, dendritic cells
Macrophages
Phagocytize dead cells and pathogens
Secrete cytokines
Present antigens
Dendritic cells
Present antigens
Activate immune system
Located where contact with the external environment is more common
T lymphocytes
Each T cell is reactive to only one specific antigen
Precursor cells formed in the bone marrow, travel via the bloodstream to the thymus to mature, then released into lymph
Major histocompatibility protein complex (MHC)
A large locus on DNA containing a set of closely linked polymorphic genes that code for cell surface proteins essential for the adaptive immune system
Antigen-presenting cells indicate the corresponding T-cell response
Cytotoxic T cells
CD8+ T cells
Recognize and respond to antigens presented by MHC I complexes
From cells infected with viruses or developing tumors
Destroy cells marked for destruction
T helper cells
CD4+ T cells
Recognize and respond to antigens presented by MHC II complexes
Release cytokines to stimulate immune response, causing other white blood cells to mature and attack
Natural killer T (NKT) cells
Destroy cells marked for destruction
Memory T cells
Remain after infection so a response can be mounted more quickly if infected by a specific antigen again
Regulatory/Suppressor T cells
Tone down T cell response to self cells or following an infection
B lymphocytes
Create and express antibodies (immunoglobulins) that have high affinity for the antigen expressed by the stimulating T lymphocyte
Develop in the bone marrow
Antiboides
Secreted by B cells
Provide specific, targeted responses to a given antigen
Y shape, antigen-binding site at top, cell-receptor-binding region at bottom, light chain and heavy chain held by disulfide bonds
Active immunity
Occurs as a result of an immune response due to exposure to a pathogen or antigen that are stored in “nonself” memory
Passive immunity
Acquired by the transfer of antibodies from one individual to another
Innate immunity
The body’s initial, generalized defences against pathogens
Anatomic features, physiologic response, phagocytic cells, inflammation
Adaptive immunity
Cells capable of recognizing self versus nonself cells
Increased with each exposure
Lymphocytes (B and T cells), plasma cells, antigen-presenting cells (macrophages, B cells)
Immunocompromised
Immune system not functioning at full capacity
