OVERVIEW OF BODY'S DEFENCES (1ST AND 2ND LINE OF DEFENCE)

Question 1

A chemical released by virus-infected cells to protect uninfected cells is called

a.
interferons

b.
complement

c.
keratin

d.
lysozymes

Answer 1

= Interferon

Question 2

Which nonspecific defence cell specialises in attacking early cancer cells and virus-infected cells?

a.
Natural killer cells

b.
Neutrophils

c.
Mast cells

d.
Macrophages

Answer 2

= Natural killer (NK) cells

Question 3

One of the ways in which normal flora benefit the host is by:

a.
providing nutrients for the growth of microorganisms

b.
inhibiting the growth of harmful microorganisms

c.
inhibiting the production of substances harmful to the host

d.
maintaining optimum gastric pH

Answer 3

= inhibiting the growth of harmful microorganisms

Question 4

The main phagocytic cells in the body are

a.
macrophages and lymphocytes.
b.
neutrophils and basophils.
c.
macrophages and neutrophils.
d.
macrophages and natural killer (NK) cells.

Answer 4

= macrophages and neutrophils.

Question 5

Examples of first line of defense include

a.
sebum, sweat and macrophages

b.
mucous, tears and neutrophils

c.
lysozymes, vasodilation and inflammation

d.
cilia, mucous and lysozymes

Answer 5

= cilia, mucous and lysozymes

Question 6

Examples of second lines of defence include

a.
sebum

b.
lysozymes

c.
natural killer cells

d.
gastric acid

Answer 6

c.
natural killer cells

Question 7

Saliva and tears contain this enzyme that destroys certain bacteria.

a.
Amylase

b.
Sebum

c.
Salivase

d.
Lysozymes

Answer 7

= Lysozymes

Question 8

The aetiology (cause) of the acute inflammatory response could include

a.
pain, heat and swelling

b.
dust, bites and infection

c.
neutrophils, histamine and phagocytosis

d.
vasodilation, histamine and prostaglandins

Answer 8

= dust, bites and infection

Question 9

The inflammatory response is characterised by

a.
attraction of erythrocytes to the injured site.
b.
vasoconstriction of local capillaries.
c.
increased vascular permeability to serum proteins in the inflamed area.
d.
resorption of interstitial fluid into the bloodstream

Answer 9

= increased vascular permeability to serum proteins in the inflamed area.

Question 11

Which of the following is a feature of a wound that would heal by primary intention?

a.
There is some tissue loss to the wound

b.
Simple cut with no tissue loss

c.
Delayed closure of the wound

d.
Wound edges unable to come together easily

Answer 11

b.
Simple cut with no tissue loss

Question 12

Which nonspecific defence cell specialises in attacking early cancer cells and virus-infected cells?

a.
Natural killer cells

b.
Macrophages

c.
Neutrophils

d.
Mast cells

Answer 12

a.
Natural killer cells

Question 13

Which of the following is a part of the second line of defence against microorganisms?

a.
Cilia

b.
Sebum

c.
Phagocytes

d.
Gastric acid

Answer 13

c.
Phagocytes

Question 14

The main phagocytic cells in the body are
a.
neutrophils and basophils.
b.
macrophages and neutrophils.
c.
macrophages and lymphocytes.
d.
macrophages and natural killer (NK) cells.

Answer 14

b.
macrophages and neutrophils.

Question 15

Which of the following belongs to the proliferative phase of wound healing?

a.
Remodelling of collagen to increase tissue strength

b.
Formation of new epithelial tissue

c.
Vasoconstriction to stop bleeding

d.
Acute inflammatory response

Answer 15

b.
Formation of new epithelial tissue

Question 16

Swelling from Acute Inflammatory Response (AIR) is due to

a.
migration of white blood cells into injured site due to chemotaxis

b.
leakage of fluid into surrounding tissue due to increased permeability of blood vessels

c.
leakage of fluid into surrounding tissue due to vasoconstriction of damaged blood vessels

d.
migration of red blood cells into injured site due to chemotaxis

Answer 16

b.
leakage of fluid into surrounding tissue due to increased permeability of blood vessels

Question 17

chemotaxis

Answer 17

the migration of a cell in response to a chemical stimulus

Question 18

opsonisation

Answer 18

a process that uses opson (an extracellular protein) to tag foreign pathogens to be eliminated by phagocytes

Question 19

margination

Answer 19

the migration of WBC to the endothelium the membrane that lines the inside of the heart and blood vessels

Question 20

diapedesis

Answer 20

the passage of blood cells through the walls of the capillaries

Question 21

complement system

Answer 21

part of the body’s immune system that cleans up damaged cells and helps the body heal after an injury or infection

Question 22

pathogen

Answer 22

an organism causing disease to a host causing a virus

Question 23

phagocyte

Answer 23

a type of cell that engulfs and absorbs bacteria

Question 24

interferons

Answer 24

chemical released by virus infected cells to protected uninfected cells