Immunology
Leukocytes
- Neutrophils:
oearly responders come in quickly to help but die off.
ocontain bacterial and fungal pathogens through a process known as
phagocytosis.
othey release enzymes to help kill and digest these cells, ingest bacteria and other
foreign cells.
- Monocytes:
obigger and can gobble up lots more.
othey reach the tissue, mature into macrophages and dendritic cells.
omatured in the bone marrow and circulate in the blood and spleen.
ocharacterized by their ability to recognize “danger signals” from pattern
recognition receptors.
- Lymphocytes: B and T cells
oLymphocytes are cells that circulate in your blood that are part of the immune
system.
oB cells produce antibody molecules that latch on and destroy invading viruses or
bacteria. Adaptive humoral immune system and are responsible for mediating
the production of antigen-specific immunoglobulin directed against invasive
pathogens.
oT cells: focuses on specific foreign particles. They do not generically attack any
antigens rather they circulate until they encounter their specific antigen. They
replicate and keep replicating until they activate cytotoxic Ts to kill; attract other
immune cells to the area.
The Bs and Ts of Immunity
- B cells (humoral immunity) come from bone marrow while T cells (cell mediated
immunity) migrate to T cells to mature.
- T cells: CD4 helper T cell and CD8 Cytotoxic T Cells
- B cells: Plasma cell and B memory cell (persists in blood stream)
- Natural killer cells kill without protein receptor
- Dendritic cells
oare also an antigen presenting cell. Found in skin, GI and respiratory tract. They
pick up and present cells on their surface
oCapture, process, and present antigens to adaptive immune cells and mediate
their polarization into effector cells
o
- Mast cells release histamine (vasodilator)
ocontribute to homeostasis
othey serve as a first line of defense against antigens entering the body due to
their location in the skin and mucosa.
What happens when it meets an Antigen?
- Agglutination: makes pathogens clump together
- Antitoxins: neutralize the toxins produced by bacteria
- Lysis: digests the bacterial membrane, killing the bacterium
- Opsonization: coats the pathogen in protein that identifies them as foreign cells
IgG-most abundant transfers across the placenta
IgA-found in tears/ saliva/breastmilk/resp tract.
IgM-in blood and lymph(first type to develop in baby), first antibodies to appear after
immunization and in response to infection
IgD-lining of chest and abdominal cavity, needed for maturation of B cells
IgE-in lungs, skin and mucous membranes
- MHC 1: associated with CD8, warns body of pathogen
oRecognizes there is an antigen, on all nucleated cells, interact with antigen
receptor on CD8
- MHC 2: activates and directs cells to kill pathogen
oRecognizes there’s been phagocytosis, primarily on macrophages and B
lymphocytes, communicate with CD4 for reinforcement
How does the body know when its own cells are wounded by bacteria and need to be
removed??
-The antibodies(immunoglobulins) tag non-self
-Who tags or identifies “self”?MHC
Hypersensitivity
Type I:
- Immediate
- Local anaphylaxis
- Involve Mast cells and basophils
- Hay fever, hives, and bronchial asthma- also food allergies, atopic dermatitis, allergic
rhinitis
- Primary-vasodilation, vascular leakage and smooth muscle contraction (lungs)
- Secondary-Eosinophils involved, epithelial tissue destruction
Anaphylaxis-Type 1
- Rapid antigen-antibody reaction
- Release of IgE bound to mast cells and basophils leads to histamine release
- Increased vasodilation and capillary permeability swelling of bronchioles and
bronchospasm leading to
Anaphylactic shock
Treatment
- Give epinephrine-constricts blood vessels, relaxes bronchioles
- Support with oxygen, VS, antihistamine drugs and corticosteroids (decrease
inflammatory response), IV fluids
Type II:
- Immunoglobulins IgG and IgM are responsible for activation of complement
- E.g., mismatched blood
Tophat
- IgG and IgM are responsible for activation complement
- Type Three: Antibody is bound to free floating soluble antigen which leads to local and
systemic inflammation
- Type One: primary response involves vasodilation, vascular leakage and smooth muscle
contraction in the lungs
- Type Two: Example of this type of reaction is mismatched blood
- Type Four: delayed, T-cell mediated response
Diabetic Ketoacidosis
- Life-threatening problem that affects people with diabetes.
- Your body starts breaking down fat at a rate that is much to fast. The liver processes the
fat into a fuel called ketones, which causes the blood to become acidic.
- This happens when the signal from insulin in the body is so low that
oGlucose can’t go into cells to be used as a fuel source
oThe liver makes a huge amount of blood sugar
oFat is broken down too rapidly for the body to process
-The fat is broken down by the liver into a fuel called ketones. Ketones are normally
produced by the liver when the body breaks down fat after it has been a long time since
your last meal. These ketones are normally used by the muscles and the heart. When
ketones are produced too quickly and build up in the blood, they can be toxic by making
the blood acidic. This condition is known as ketoacidosis.
- 250 mg/dl or higher
- Sx/S: metabolic acidosis (kaussamal’s respirations), low bicarb, low pH, ketonemia,
moderate ketonuria, respiratory pattern
HHS
- Complication of type 2 diabetes
- Involves extremely high blood sugar level without the presence of ketones
- Conditions:
oExtremely high blood sugar level
oExtreme lack of water
oDecreased alertness or consciousness
- 600 mg/dl
- Blood is so concentrated that individual is at high risk for strokes or a cardiac event
oAbsence of ketoacidosis, extreme dehydration, may loose consciousness
- Kidneys will try to make up for a high glucose level in the blood by allowing the extra
glucose to leave the body in the urine. But then the patient becomes dehydrated.
Insulin production
- Pancreas makes a hormone called insulin. Insulin helps the glucose get into the body’s
cells. Beta cells in the islets of Langerhans in the pancreas-lower blood glucose level by
driving glucose into the cells
Chain of infection: Every link must be connected for it to be an infection
- Infectious agents: this causes the illness and call me classified as a pathogen
- Reservoir: any person, animal or substance in which an infectious agent normally lives
and multiplies.
- Portal of exit: The way a pathogen leaves a reservoir. E.g., mucuos, or saliva
- Method of transmission: Way pathogen is transmitted. E.g., sex, kissing
- Portal of entry: The way a pathogen can enter a new host. E.g., needles or inhalation
- Susceptible host: ANYONE!
