Nakamura Human Anatomy Ch 21

Question 1

Main components of the immune system

Answer 1

Lymphocytes, lymphoid tissue, lymohoid organs

Carry lymphatic fluid white color

Question 2

The lymphatic system

Answer 2

Lymphatic vessels collect lymph from loose connective tissue
–Fluid flows only toward the heart
-collect dead cells, proteins, spread out cancer cells
-connect with circulatory system
-lymph capillary, then lymphatic collecting vessels, then lymph nodes, then lymph trunk, then lymph duct

Question 3

Lymph capillaries

Answer 3

Located near blood capillaries
•Receive tissue fluid from connective tissue
–Increased volume of tissue fluid
•Minivalve flaps open and allow fluid to enter
•Highly permeability allows:
–Uptake of tissue fluid
–Entrance of bacteria, viruses, and cancer cells

Question 4

Functions of lymphatic vessels

Answer 4

.•Collect excess tissue fluid and blood proteins

•Return tissue fluid and blood proteins to bloodstream

Question 5

Lacteals

Answer 5

-specialized lymphatic capillaries
–Located in the villi of the small intestines
–Receive digested fats
–Fatty lymph: chyle

Question 6

Lymphatic collecting vessels

Answer 6

.Accompany blood vessels
•Composed of the same three tunics as blood vessels
•Contain more valves
–Helps direct the flow of blood

Question 7

Lymph nodes

Answer 7

-Cleanse the lymph of pathogens
•Human body contains approximately 500
•Lymph nodes are organized in clusters
-cervical nodes
-tracheobronchial nodes
-axillary nodes
-aortic nodes 
-iliac nodes
-inguinal nodes

Question 8

The immune system

Answer 8

-Recognizes specific foreign molecules
•Destroys pathogens effectively
•Key cells:lymphocytes
•Also includes lymphoid tissue and lymphoid organs

Cancer cell is extremely active, phagocytised by lymphocytes, by the time lymphocyte dies, cancer cell still alive

Question 9

Lymphocytes

Answer 9

-Infectious organisms attacked by inflammatory response
–Macrophages, then lymphocytes
•B lymphocytes: become plasma cells
–Secrete antibodies
•Cytotoxic T lymphocytes: Destroy antigen-bearing cells

Question 10

Lymphocyte activation

Answer 10

-Lymphocytes originate in bone marrow
•Some travel to the thymus gland
       –T lymphocytes
•Some stay in bone marrow
       –B lymphocytes
•Able to recognize a unique antigen

Question 11

Lymphoid organs

Answer 11

•Designed to gather and destroy infectious microorganisms

• tonsils (in pharyngeal region)
• thymus (in thorax, most active during youth)
• spleen (curves around left side of stomach)
• aggregated lymphoid nodules in intestine (ileum)
• appendix

Question 12

Spleen

Answer 12

-Largest lymphoid organ
•Two main blood-cleansing functions
–Removal of blood-borne antigens
–Removal and destruction of old/defective blood cells
•Site of hematopoiesis in the fetus
***The old red cells are removed from the body by the spleen and liver

Question 13

Lymphocyte activation more in depth

Answer 13

1. Lymphocytes destined to become T cells migrate to the thymus and develop immunocompetence there. B cells develop immunocompetence in the bone marrow
2. After leaving the thymus or the bone marrow as naive immunocompetent cells, lymphocytes seed the infected connective tissue, where the antigen challenge occurs and the lymphocytes become fully activated
3. Mature immunocompetent lymphocytes recirculate continuously in the blood stream and lymph and throughout the lymphoid organs of the body

Question 14

Main structures of the lymphatic system

Answer 14

Lymphatic vessels