CELLS OF THE INNATE IMMUNITY

Question 1

what is leukocytes?

Answer 1

white blood cells that contain a nucleus, lack hemoglobin and colourless cytoplasm.

Question 2

what is the two main categories of leukocytes?

Answer 2

the two categories depends on,

1. appearance of their nuclei
2. the presence or absence of granules in their cytoplasm when
   viewed microscopically

Question 3

what are the category of neutrophils, eosinophils and basophils?

Answer 3

polymorphonuclear granulocytes

nuclei are segmented into several lobes and the cytoplasm contains abundance of granules.

Question 4

how about monocytes and lymphocytes?

Answer 4

mononuclear agranulocytes

single, large, non-segmented nucleus and few/less granules.

Question 5

characteristics and functions of neutrophils.

Answer 5

1. showed no dye preferences
2. first defenders on bacterial invasion
3. sense the site of the infection migrating to it and destroying the infectious organisms by phagocytosis.
4. attach to the walls of the blood vessels, blocking the passageway of antigens that try to gain access to blood.
5. prod toxic substances (reactive oxygen species) that are released into extracellular fluids and damage host cells.

Question 6

characteristics and functions of eosinophil.

Answer 6

1. granulated cytoplasm is stained with acid dye eosin red.
2. Increase number of eosinophils are associated with allergic conditions
   (e.g. asthma and hay fever) and with internal parasitic infestations
   (e.g. worms).
3. Eosinophils are less active in terms of their phagocytic function.
4. Eosinophils attach to the worms and secrete substance to kill it.
5. Modulate the inflammatory response.

Question 7

characteristics and functions of basophil.

Answer 7

1. Granulated cytoplasm is stained with basic dye methylene blue.
2. Least numerous and most poorly understood of the leukocytes.
3. Basophils differ from eosinophils and neutrophils in that they are not
   phagocytes
4. They synthesize and store histamine; involved in allergic reactions and inflammations, as well as, increase and magnify innate immune response.

Question 8

characteristics and functions of monocyte/macrophage.

Answer 8

1. The largest leukocyte.
2. Professional phagocytes.
3. Normally the number of monocytes circulating in the blood is quite small; it increases during an infection.
4. Monocytes are called to the site by chemotactic factors released from
   damaged tissue and neutrophils.
5. Once it reach the site, they migrate out into the tissues and differentiate into macrophages (produce granules within themselves).

Question 9

characteristics and functions of monocyte/macrophage (part 2)

Answer 9

1. They can recognize, engulf, and destroy bacteria, fungi, protozoa, as
   well as, removing tumor cells, virus-infected cells, and normal cells that
   have undergone apoptosis.
2. They also function in wound healing, tissue repair and bone remodeling
3. They process the antigens to be recognized by T cell.
4. They secrete cytokines for various roles in immune system.

Question 10

explain this statement of monocyte/macrophages:

Once it reach the site, they migrate out into the tissues and differentiate into macrophages. (produce granules within themselves).

Answer 10

sebab macrophages are specialized cells with enhanced abilities to perform immune functuions.

bila dia sampai, dia jadi highly specialised for the local environment and immune needs.

Question 11

characteristics and functions of dendritic cells.

Answer 11

1. participate in both innate (by phagocytosis) and the adaptive (by Antigen Presenting Cell) immune
   response.
2. They have long membranous extensions that resemble the dendrites of nerve fibers.
3. Located in the skin and mucosal tissues associated with routes of pathogens entry such as the oral,
   respiratory and genital mucosae.
4. They help to trigger the adaptive immune response.
5. Migrates to lymph node upon activation.

Question 12

characteristics and functions of mast cells.

Answer 12

1. contains a lot of granules- synthesize and store histamine and heparin.
2. Responsible for allergic reactions and response to parasitic infections.
3. Found throughout the body but most commonly in tissues that are
   exposed to the external environment, such as mucous membranes.
4. They can rapidly and selectively produce mediators that work in host
   defense.
5. They can enhance the recruitment of effector cells that respond to infection.
6. They can influence the adaptive
   immune response.