Summary PHYSIO 1 Lecture EXAM IV Study Guide Part 3

LECTURE EXAM IV STUDY GUIDE Part 3
- Immune System

- Identify the various pathogens your body can encounter.
o
- Differentiate innate immunity from adaptive immunity.
o Types of Immunity
 Innate (Nonspecific) Immunity
 Inherited and built in (not acquired over time)
 First line of defense against pathogens
 Acts nonspecifically
o Acts on all viruses and bacteria
 Divided into external and internal defenses
 Adaptive (Specific) Immunity
 Acts on specific pathogens
 Develops over time due to prior exposure to pathogens (vaccinations)
o Inject different pathogens into body
 Eliciting an immune response without getting sick
- Identify and describe all nonspecific external defenses.
o Innate Immunity | External Defenses
 Physical Barriers and Secretions
 1. Skin
o Barrier & lysozyme activity
 2. Digestive system
o Mucus membranes, acidity of stomach, intestinal microbiota
 Help prevent the tunics of the GI tract from being
invaded
 3. Respiratory system
o Mucociliary clearance, alveolar macrophages
 4. Genitourinary tract
o Mucus membranes, acidity of urine, vaginal lactic acid
 Above mechanisms prevent pathogens from entering underlying connective
tissues and fluids
- Identify and describe all nonspecific internal defenses.
o Innate Immunity | Internal Defenses
 Phagocytes
 Ingest and destroy bacteria, cellular debris, denatured proteins, and
toxins by phagocytosis (cellular eating and digested by lysosomes)
 Microbes display PAMPS
 Phagocytes have pathogen recognition receptors (receipt PAMPS)

,  Also participates in adaptive immunity
 Type of Phagocytes
o Neutrophils (found in blood plasma and tissues)
 First responders
o Mononuclear phagocytic cells
 Monocytes (found in blood)
 Macrophages (found in all types of tissues)
 Dendritic cells (found in CT)
o Organ-specific phagocytes
 Some are fixed phagocytes (stay within organs)





 Complement System
 A group or series of proteins that form can from on a
pathogen/bacterium and form a membrane attack complex to cause
cellular lysis
o Proteins form a hole in the bacterium
 Causing water to move into the bacterium and cause it
to “pop” (cellular lysis)
 Also participates in adaptive Immunity
 Fever
 During infection, leukocytes (white blood cells) secrete endogenous
pyrogens that act on hypothalamus
o Sets body temperature higher
 Induces sleepiness
 Plasma [iron] falls to limit bacteria activity
o Bacteria love iron
 Increased heat production from metabolism of brown adipose tissue
and vasoconstriction

,  Increases levels of interferons (reduce the activity of virus) and activity
of Neutrophils
 Interferons
 Polypeptides produced and secreted by infected cells that prevent
infection of neighboring cells
o Polypeptides inhibit viral replication and assembly
o Interferons
 During this entire process, our cell is producing
interferons (proteins).
 They are like signaling molecules that tell the
cells around them that they have been infected
 And if they do get infected, to inhibit the
replication of these viruses
 Inhibit the replication of viruses from nearby cells
 Natural killer cells (NK cells)
 Destroy cells infected with viruses, cancerous cells, and mismatched
transplanted tissue cells
o NK cells
 Secrete granzymes and perforin (proteins)
 Perforin
o Create holes in target cells
 Causing lysis of target cells
 Granzymes
o Enzymes that can enter the target cell
and breakdown the DNA
 Cell undergoes Apoptosis
(program cell death)
 Mast cells
 Release histamine and other mediators of inflammation
o Allows for
 Vasodilation
 (increase blood flow to specific area) and
 Extravasation
 (epithelial cells at the walls of blood vessels
contract and shrink allowing for different WBC
to enter through the cracks of the Epithelial
cells)
o Also participates in adaptive immunity
- Differentiate antigens from antibodies in terms of molecular composition, function, and location.
o What occurs when they interact in the body?
 Antigens & Antibodies
 Antigens vs Antibodies
o Antigens