KIN 103 Midterm (Lecture 8) Flashcards
Immunity (Definition)
IMMUNITY: the body’s ability to protect itself from:
▫ Itself.
▫ Bacteria, Viruses, & other Disease-causing
entities.
The Immune System three main functions
1) Recognize and Remove abnormal cells.
2) Remove dead and damaged cells.
3) Protects the body from disease-causing
invaders. (pathogens)
Autoimmune diseases cause?
INCORRECT RESPONSE
▫ Cannot distinguish SELF vs. NON-SELF.
▫ .e.g. Type I Diabetes.
Allergies cause?
OVERACTIVE RESPONSE.
▫ Response out of proportion with the threat of pathogen.
▫ e.g. Bee sting.
Inherited or acquired disease cause?
LACK OF RESPONSE.
▫ Some component(s) of the immune system fail to
function.
▫ e.g. HIV then AIDS
Pathogens
Pathogens: the invaders that can cause sickness
- Can be protozoal and fungi
- Can be multicellular
Bacteria
- Cells usually have a cell wall
- Most can survive and reproduce outside a host
- Most can be killed or inhibited by antibiotics
Viruses
- Not cells nucleic acid core with protein coat
- Parasitic. Must have a host cell to reproduce
- Cannot be killed with antibiotics some can be inhibited with antiviral drugs
Barriers (What are the two primary ones?)
Barriers:
▫ Physical – skin & mucous membranes.
▫ Chemical – glandular secretions & stomach acid.
Lymphoid tissues (What are they?)
- Lymphoid Tissues
▫ Primary: Thymus & Bone Marrow.
▫ Secondary:
Spleen & Lymph Nodes (encapsulated).
Tonsils & GALT (unencapsulated or diffuse).
Immune cells (What are they?)
- Immune cells
○ White blood cells (WBCs) or leukocytes
§ 1L of blood contains 5 trillion RBCs and 7 billion WBCs
Granulocytes (What are they?)
Granulocytes
▫ Granules in cytoplasm.
▫ Basophils, Eosinophils, Neutrophils
Phagocytes (What are they?)
Phagocytes
▫ Engulf & ingest their target cells by
phagocytosis.
▫ Neutrophils, Macrophages, Monocytes,
Dendritic Cells
Cytotoxic Cells
Cytotoxic Cells
▫ Kill target cells.
▫ Eosinophils and some Lymphocytes.
Antigen Presenting Cells (APCs)
Antigen Presenting Cells (APCs)
▫ Present fragments of foreign proteins on
their surface.
▫ Marcophages, Monocytes, Dendritic
cells, B Lymphocytes
What are the most abundant type of WBC?
Neutrophils
Innate Immunity (What is it?)
Innate Immunity
▫ Nonspecific immune response.
▫ e.g. Inflammation.
Acquired (Adaptive) Immunity
Acquired (Adaptive) Immunity
▫ Specific immune response.
Cell-Mediated: Immune cell binds to
target.
Antibody-mediated: Antibodies are
secreted and combine to target cells.
4 Basic steps of the immune response (What are they?)
The 4 basic steps:
1) DETECT and IDENTIFY the foreign
substance.
2) COMMUNICATE with other immune
cells.
3) RECRUIT assistance and coordination
of the response.
4) DESTROY or SUPPRESS the invader.
NK cells (What are they?)
Natural Killer (NK) Cells
* Recognize virus-infected cells and induce
them to commit suicide (apoptosis) before
they can replicate.
* NK cells also attack some tumor cells.
* These cells secrete antiviral cytokines
(interferons) that interfere with viral replication
and activate other immune cells.
The Inflammatory Response (What are the 3 main purposes?)
1) Attracts immune cells and chemical
mediators to the site.
2) Create a physical barrier to slow the
spread of infection.
3) Promote tissue repair once infection is
controlled.
The Inflammatory Response (What is it initiated by?)
The Inflammatory Response
* This response is initiated when
macrophages release cytokines,
which:
▫ Attract other immune cells.
▫ Increase capillary permeability.
▫ Cause fever.
Innate immune response (What do interleukins do?)
Interleukins
▫Leukocyte-secreted cytokines that act
on other leukocytes.
▫Several types, multiple effects.
Innate immune response (What do Complement proteins do?)
Complement proteins
▫Can act as opsonins, chemotaxis, and
membrane attack complex.
Innate immune response (What does Bradykinin do?)
- Bradykinin
▫Stimulates pain receptors & vasodilator.
Innate immune response (What do Acute phase proteins do?)
Acute phase proteins
- Act as opsonins that coat pathogens and enhance the inflammatory response.
Innate immune response (What does histamine do?)
Histamine acts as a:
▫Vasodilator – hot, red, swollen
infection/wound site.
▫Bronchoconstrictor – congestion, stuffy nose.
What is the high risk level for CVD?
High Risk Levels for CVD:
hsCRP level above 3mg/L
What is the acquired immune response mediated by?
- Mediated primarily by lymphocytes.
Passive Immunity (What is it?)
Passive Immunity
▫ Acquired antibodies made by another
person or animal.
Lymphocytes (What do they do?)
Lymphocytes
* Primary cells involved in acquired immune response.
* Each lymphocyte has membrane receptors that binds only one specific ligand.
▫ All lymphocytes that are specific for a
ligand form a group known as a clone.
* Clones with identical receptor react to a
specific pathogen.
What activates clonal expansion?
Exposure to an antigen activates the clone and stimulates clonal expansion
In immune response what are effector cells?
▫ Effector cells – immediate response, short lived
In immune response what are memory cells?
Memory cells – long lived = quicker and more rapid response to subsequent antigen exposure.
B Lymphocytes (B cells) (What are they?)
B Lymphocytes (B cells)
▫ Develop in bone marrow.
▫ Antibody Immunity defending against
extracellular pathogens.
▫ Mature B cells insert antibody molecules
into their cell membranes.
Antibodies become surface receptors
marking the members of each clone.
Antibodies (What are they?)
Antibodies
▫ Most antibodies are found in the blood.
▫ Antibodies make antigens more visible to the immune system.
▫ Antibodies (Ab) are also called
immunoglobulins (Ig) or gamma globulins
Antibody functions (What are the 5?)
- Activate B lymphocytes
- Act as opsonins to tag antigens for phagocytosis
- Activate antibody dependent cellular activity
- Activate compliment proteins
- Trigger mast cell degranulation
What is the Fab region?
It is where antigens bind
Vaccinations (What do they do?)
Vaccinations
* Contain a pathogen that is not harmful to
individual but will be recognized as foreign by the immune system.
* Initiates formation of memory cells with
specific antibody to particular pathogen
antigen.
* Should induce a stronger and more rapid
secondary immune response upon infection
T Lymphocytes (T cells) (What are they?)
T Lymphocytes (T cells)
▫ Develop in Thymus gland.
▫ Cell-mediated immunity defending against intracellular pathogens.
▫Insert T-cell receptors into their cell
membranes.
▫ T cells bind to cells that display foreign antigen fragments as a part of major
histocompatibility complex (MHC).
T Lymphocytes (T cells) (What are the 3 subtypes?)
T Lymphocytes (T cells)
▫Subtypes:
Cytotoxic T Cells (TC) – induce apoptosis.
Helper T Cells (TH) – secrete cytokines.
Natural Killer (NK) Cells – similar to TC
.
Major Histocompatibility Complex (MHC)
Major Histocompatibility Complex (MHC)
- basically when your body rejects an organ
* Named when found to be major cause of rejecting organ or tissue transplant.
* A family of membrane proteins, MHC proteins are on the cell membrane of all nucleated cells in the body.
* MHC proteins combine with antigen fragments (MHC-antigen complex) and then insert into the cell membrane and are visible on the extracellular surface.
MHC class I (Where are they found?)
MHC class I ▫ Found on all nucleated
human cells.
▫ Recognized by Cytotoxic T cells
- kills infected cell
MHC class II (Where are they found?)
MHC class II ▫ Found primarily on antigen
- presenting cells (APCs; macrophages, B
lymphocytes, and dendritic cells).
▫ Recognized by Helper T cells
– secretes cytokines
What is the relation between stress and exercise?
- it has been shown that too much exercise is not beneficial to our health but too minimal can be harmful too, moderation is ideal for the best health levels.
