Lecture 1 introduction

Question 1

What are some threats from outside the human body?

Answer 1

microorganisms and toxic agents

Question 2

What are some threats from inside the human body?

Answer 2

malignant transformation of normal cells to cancer cells

Question 3

What is the defense mechanism of the body?

Answer 3

The immune system,
can identify and neutralize all threats
distinguish non self organisms and cells from self.

Question 4

What is the first line of defense?

Answer 4

innate immune system

Question 5

What is the second line of defense?

Answer 5

adaptive immune system

Question 6

When is the 2nd line of defense activated?

Answer 6

If the first line is breached, then the second line is activated

Question 7

What are the physical components of the immune system?

Answer 7

1. Tissues and organs (lymphoid tissues or organs)

2. Cells (lymphoid cells)

Question 8

What are the two categories of lymphoid tissues and organs?

Answer 8

1. PRIMARY / central

2. Secondary (peripheral)

Question 9

What are the PLTs classified into?

Answer 9

• Bone marrow

- Thymus

Question 10

Functions of the PLT?

Answer 10

Origination and development or maturation of the immune cells.

Question 11

What does the BM contain?

Answer 11

• Contains connective tissue, blood vessels, fat and cells.
• Hematopoietic stem cells(pluripotent).
• Site for production and development of immune cells

Question 12

Development of the thymus

Answer 12

• First lymphoid organ to develop.

- Bilobed capsulated organ.

Question 13

Location of the thymus

Answer 13

Located in superior mediastinum anterior to heart and great vessels.

Question 14

Size of the thymus

Answer 14

• Increases in size during fetal and neonatal life.

- Progressively involutes following puberty.

Question 15

Population of the thymus

Answer 15

lymphocytes

Question 16

organization of the thymus

Answer 16

Organized into an outer region(cortex) and inner region(medulla).

Question 17

cells of the thymus

Answer 17

lymphocytes, dendritic cells, macrophages and epithelial cells.

Question 18

function of the thymus

Answer 18

forms the site for development of T-lymphocytes.

Question 19

What are the secondary lymphoid tissues?

Answer 19

• Spleen
• Lymph nodes or glands(superficial and deep)
• Mucosa associated lymphoid tissues in
• Gut (GALT)
• Respiratory(bronchus) system(BALT)
• Peyers patches
• Urogenital system
• Tonsils

Question 20

location of the spleen

Answer 20

Capsulated, found in left hypochondrium behind the stomach.

Question 21

divisions of the spleen

Answer 21

Divided into white pulp rich in lymphocytes and red pulp rich in erythrocytes.

Question 22

filtration action of the spleen

Answer 22

Filtration device ,removing foreign matter, dead cells and protein aggregates from the circulation.

Question 23

concentration of the spleen

Answer 23

Concentrates blood-borne antigens and microbes.

Question 24

contents of the spleen

Answer 24

Contain B- lymphocytes,T-lymphocytes,plasma cells.

Question 25

function of the spleen

Answer 25

Form the site for interaction of immune cells to produce an immune response.

Question 26

shape of the lymph nodes

Answer 26

Small round or oval capsulated lymphoid organ.

Question 27

locations of the lymph nodes

Answer 27

Present around large arteries and veins; Cervical L.N,axillary L.N,Coeliac and Mesenteric L.N and Inguinal L.N.

Question 28

number of lymph nodes in the body

Answer 28

400-450 L.N in normal young adult.

Question 29

divisions of the lymph nodes

Answer 29

Divided into the deeper cortex and inner medulla homing the T-lymphocytes.

Question 30

functions of the lymph nodes

Answer 30

Function as filter to purify lymph prior to return to the blood circulating system.

Question 31

What is MALT?

Answer 31

• largest mammalian lymphoid organ
• Mucosal associated lymphoid tissue
• specialized immune barrier

Question 32

What cell type is MALT comprised of?

Answer 32

40-60% of all lymphocytes

Question 33

What are the subdivisions of MALT?

Answer 33

• GALT (GI, PP, appendix)
• BALT (bronchus)
• NALT (nasopharyngeal)
• Salivary and lacrimal glanda
• Genitourinary tract