Lesson 14 And 15- The Local Support And Defense System Flashcards
First Line of Defense
Nonspecific physical and chemical surface behaviours
Second Line of Defense
Nonspecific internal cellular and chemical defense
What is the first and second line of defense also known as
Innate Immune System (for foreign substances)
Third Line of Defense
Specific Defense - Immune Response
What is the third line of defense also known as
The adaptive immune system (exposed to something new then antibodies are developed)
First line of defense examples
External Physical Barriers
- Tears
- Skin
- Bladder
- Stomach
- Saliva
- Respiratory Tract
- Large Intestine
Second Line of Defense - Defensive Cells (Examples and Function)
Examples
- Phagocytic cells such as macrophages
- Natural Killer cells
Function
- Engulf invading organisms
- Kill Parasites
- Kill invading organisms and cancer cells
Second Line of Defense - Defensive Proteins (Examples and Function)
Examples
- Interferons
- Complement System
Function
- Slow the Spread of Viruses in the Body
- Stimulates histamine Release
- Promotes phagocytosis
- Kills Bacteria
- Enhances Inflamation
Second Line of Defense - Inflammation (Examples and Function)
Example
- Widening of blood vessels and increased capillary permeability
Function
- Brings in defensive cells and speeds healing
Second Line of Defense - Fever (Examples and Function)
Example
- Abnormally high body temperature
Function
- Slows the growth of bacteria
- Speeds up body defenses
(Second Line of Defense) Cell-Based Defense - Destruction by Phagocytosis
- Phagocytes
- Non-phagocytes
- Macrophage
- Natural Killer Cell
Macrophage
Pseudopod about to engulf a bacterium
Natural Killer Cell
Attacking a cancer cell
Phagocytes - Neutrophils and Macrophages
Neutrophils: First on scene and consume bacteria
Macrophages: Consume almost anything
Non-Phagocytes
Target pathogens and invade organisms that are too large for phagocytosis
Non-phagocytes - Eosinophils and Natural Killer Cells
Eosinophils: Discharge enzymes that digest a non-self target
Natural Killer Cells: Constantly circulate for non-self and release perforin (holes in membrane) and proteases to destroy cells
(Second Line of Defense) Protein-Based Defense - Complement System
- 20+ proteins synthesized in the liver (inactive)
- Deactivates by blood proteins and surface of body’s own cells
- Promotes antibodies and phagocytic cells to clear microbes and damaged cells from the body
- Promotes inflammation and attacks the pathogen’s cell membrane
What 2 things can activate the complement system
- Polysaccharides on bacteria surface OR
- Antigen/Antibody complexes
(Second Line of Defense) Defensive Process - Inflammation
4 signs
- Redness
- Heat
- Swelling
- Pain
Strategy to treat inflamed area
RICE - not always the best as it can prevent the body from healing
2 Steps to how the complement system responds to inflammation
- Complement destroys bacteria
- Phagocytes engulf bacteria
Acute Inflammation
- Bruises
- Torn tissue
- delayed onset muscle soreness
Chronic Inflammation
- Arthritis
- Obesity
(Second Line of Defense) Defense Processes - Fever
Body raises temperature to kill off bacteria
- this is good for immune systems
- can be benificial not to give medication that will suppress the fever as it counteracts effects
Parenchymal Cells
- The critical ‘functional’ portion of the tissue
- Usually the most prominent cell type in terms of mass
Parenchymal Cell Examples
- Liver cells
- Skeletal Muscle cells
- Heart cells
- Brains cells
- Adipose tissue cells
- Pancreas cells
Stromal Cells
- Support the Parenchymal cells forming the LSDS
Examples of Stromal Cells
- Neurons
- Astrocytes
- Cepillary Endothelial Cells
- Lymphoid cells
- Bone cells
- Fibroblasts
- Stem cells
- Gap junctions
Pancreas - Exocrine function
Digestion
Pancreas - Endocrine Function
Releases Insulin
Other functions of the LSDS
- Always on
- Local tissue damage by processes that are not due to infectious pathogens
- Normal Tissue Turnover (cell death and tissue repair during healing)
- Looks out for appearance of transformed cell populations (cancer)
Migration and Memory in the LSDS (Adaptive Immune Response)
- After exposure once, body can trigger response during next exposure
MHC (Major histocompatibility complex)
- proteins expressed on the surface of a cell
- Used in recognition of pathogens (attack), immune responses but also ‘self’ (support)
Support Cells
A self MHC marker label’s the body’s cells as ‘self’
Attack cells
An antigen is a molecule, on the surface of a pathogen that the immune system recognizes as ‘non-self’
3 Attack Steps
- Threat: invader enters the body
- Detection: macrophages encounters, engulfs and digests the invader
- Alert: The macrophage presents to a helper T cell and secretes a chemical that activates the helper T cell
Two signals that activate the helper T cell
- Recognition
- Verification
(To be sure it’s responding to non-self)
COVID-19 Vaccines and Antibodies
Body develops antibodies to recognize and develop an immune response
Where are memory cells stored
Bone Marrow of Thymus
Which Response is more robust (first or second)
Second - uses memory
(The first has to go through all the steps)
T suppressor cells
- Supress the activation of the immune system
- important in allowing tolerance to self antigens
What does too little t suppressor response mean
- autoimmune diseases
- allergies
- graft rejection
- inflammatory bowl disease
What does too much t suppressor response mean
Cancer and increased incidence of infection diseases
