Innate Immunity: Non-specific Defenses of the Host

Question 1

_____ the ability to ward off disease and protect against environmental agents through the body.

_____ lack of immunity

Answer 1

Immunity

Susceptible

Question 2

_____ All body defenses that protect the body against any kind of pathogen.

_____ Defenses (antibodies) against specific microorganisms.

Answer 2

Innate Immunity

Adaptive Immunity

Question 3

Innate Immune Systen

Physical Barriers: Skin, organ mucosal layers

Chemical Barriers: Stomach acid, lysozymes in eye

Innate response: Inflammatory response cells

_____: Triggers swelling, redness, and calls for backup.
_____: First to attack germs.
_____: Swallow and digest germs, also clean up dead cells.
_____: Kill infected or abnormal cells.

Answer 3

Mast cells
Neutrophil
Macrophages
Natural killer cells

Question 4

Adaptive Immune System

Adaptive response:
1. Cell Mediated response - T lymphocytes
Products: CD4+ and CD8+ T cells

2. Humoral response - B lymphocytes
   Products: Antibodies

Question 5

The Concept of Immunity

_____ in plasma membranes of macrophages and dendritic cells bind to invading microbes.

Answer 5

Toll-like receptors

Question 6

First Line of Defense: Skin and Mucous Membranes

The body’s first line of defense against infections is a physical barrier and the nonspecific chemicals of the skin and mucous membranes.

Question 7

Physical Factors

The structure of intact skin and the waterproof protein keratin provide resistance to microbial invasion.

The _____ protects the eyes from irritating substances and microorganisms.

Answer 7

Lacrimal apparatus

Question 8

Physical Factors

▪_____ traps many microorganisms that enter the respiratory and gastrointestinal tracts.
▪In the lower respiratory tract, the _____ moves mucus up and out.

Answer 8

Mucus
ciliary escalator

Question 9

Physical Factors

▪flow of urine moves microorganisms out of the urinary tract.

▪vaginal secretions move microorganisms out of the vagina.

Question 10

Chemical Factors

1. Fatty acids in SEBUM and earwax inhibit the growth of pathogenic bacteria.
2. PERSPIRATION (sweat) washes microorganisms off the skin.
3. LYSOZYME is found in tears, saliva, nasal secretions, and perspiration.
4. The high acidity (pH 1.2–3.0) of gastric juice prevents microbial growth in the stomach.

Question 11

_____ change the environment, a process that can prevent the growth of pathogens.

Answer 11

Normal microbiota

Question 12

Second Line of Defense

A microbe’s penetration of the first line of defense encourages the production of phagocytes, inflammation, fever, and antimicrobial substances.

Question 13

Formed Elements in Blood

Composition:
1. Plasma
2. Red blood cells (erythrocytes)
3. White blood cells (leukocytes)
4. Platelets (Thrombocytes)

Question 14

Leukocytes:

Granulocytes
1. _____: Function “Phagocytosis”
2. _____: Function “production of histamine
3. _____: Function “Production of toxic proteins against certain parasites.

Agranulocytes
1. _____: Function “Phagocytosis (when they mature into macrophages).”
2. _____: Function “Phagocytosis and initiation of adaptive immune responses.”
3. Lymphocytes:
- _____ Destroy target cells by cytolysis and apoptosis.
-_____ Cell mediated immunity
- _____ Produce antibodies

Answer 14

GRANULOCYTES
Neutrophils
Basophils
Eosinophils

AGRANULOCYTES
Monocytes
Dendritic cells
Lymphocytes
- Natural killer cells
- T cells
- B cells

Question 15

_____ inserts into the plasma membrane and creates channels.

_____ protein-digesting enzymes induce apoptosis (self-destruction).

Answer 15

Perforin
Granzymes

Question 16

_____: ingestion of microorganisms or particulate matter by a cell.

*performed by phagocytes, certain types of white blood cells or their derivatives.

Answer 16

Phagocytosis

Question 17

Actions of Phagocytic Cells

ENLARGED MONOCYTES become wandering macrophages and fixed macrophages.
▪located in selected tissues and are part of the macrophage system.

NEUTROPHILS, predominate during the early stages of infection, whereas MACROPHAGES predominate as the infection subsides.

Question 18

MECHANISM OF PHAGOCYTOSIS

1. Chemotaxis and Adherence
2. Ingestion
3. Digestion
4. Discharge

Question 19

▪ a bodily response to cell damage
▪ characterized by pain, redness, heat, swelling, and sometimes the loss of function.

Answer 19

Inflammation

Question 20

Inflammation

▪The release of histamine, kinins, and prostaglandins causes vasodilation and increased permeability of blood vessels.

▪Blood clots can form around an abscess to prevent dissemination of the infection.

Question 21

Phagocyte Migration and Phagocytosis

*Phagocytes have the ability to:
- stick to the lining of the blood vessels (MARGINATION)
- squeeze through blood vessels (DIAPEDESIS)

*PUS: accumulation of damaged tissue and dead microbes granulocytes, and macrophages

Question 22

A tissue is repaired when the stroma (supporting tissue) or parenchyma (functioning tissue) produces new cells.

Stromal repair by fibroblasts produces scar tissue.

Question 23

FEVER
▪ an abnormally high body temperature produced in response to a bacterial or viral infection (toxins).
▪Bacterial endotoxins, interleukin-1, and TNF-α can induce fever.

▪A _____ indicates a rising body temperature
▪_____ indicates that the body’s temperature is falling

Answer 23

CHILL
CRISIS (sweating)

Question 24

ANTIMICROBIAL SUBSTANCES

The _____

▪consists of a group of SERUM PROTEINS that activate one another to destroy invading microorganisms.

▪ Complement proteins are activated in a CASCADE.
▪Complement (C3) activation can result:
✔ _____ - Breaks the germ’s cell membrane.
✔ _____ - Helps call more immune cells.
✔ _____ - Marks germs so phagocytes can eat them easily

Answer 24

ANTIMICROBIAL SUBSTANCES

The Complement System

• cell lysis
• Inflammation
• opsonization

Complement deficiencies can result in an INCREASED SUSCEPTIBILITY to disease.

Some bacteria evade destruction by complement by means of capsules, surface lipid–carbohydrate complexes.

Question 25

_____: family of cytokines ▪3 main types: ✔Alpha interferon (IFN-α) ✔Beta interferon (IFN-β) ✔Gamma interferon (IFN-γ) ▪_____: induce uninfected cells to produce antiviral proteins (AVPs) that prevent viral replication ✔Stimulate NK cells to produce "IFN-γ" produced by NK cells, activates neutrophils and macrophages to kill bacteria.

Answer 25

INTERFERONS IFN-α and IFN-β

Question 26

ANTIMICROBIAL SUBSTANCES Transport and store iron, depriving most pathogens of the available iron.

Answer 26

Iron Binding Proteins

Question 27

Antimicrobial Peptides ✔inhibit cell wall synthesis ✔form pores in plasma membranes ✔destroy DNA and RNA ▪produced by nearly ALL PLANTS AND ANIMALS, bacterial resistance to AMPs has not yet been seen