Topic 13 -Lymphatic System

Question 1

lymphatic system include

Answer 1

lymph vessels and organs

T & B lymphocytes to protect the body against bacteria, viruses and cancer cells

Question 2

Major extracellular fluids

Answer 2

Blood plasma -fluid in blood
ISF (interstitial fluid) -bathes cells except blood cells
lymph -inside lymphatic vessels

Question 3

Lymphatic circulation for ISF

Answer 3

ISF formed by capillaries leaking plasma
90% re-enters blood in capillaries + venules
10% into lymphatic circulation (now called lymph)

Question 4

Lymphatic circulation for lymph

Answer 4

enters lymphatic capillaries (closed ended vessels)
lymphatic capillaries connect to lymphatic collecting vessels (have valves)

lymph nodes along vessels filter lymph (bacteria, debris)

Question 5

transport lymph fluid away from tissue to

Answer 5

1) right lymphatic duct (lymph from right head, chest and arm -drains into right subclavian vein, re-enters blood circulation

2) thoracic duct (lymph from below ribs and left side of body)
- collects blood from left side of body and below ribs
- collecting vessels from below the ribs converge into an enlarged lymph vessel =cisternae chyli (the beginning of the thoracic duct)
- thoracic duct drains lymph into left subclavian vein, re-enters blood circulation

Question 6

summary of lymph route

Answer 6

lymphatic capillaries -> lymphatic collecting vessels (with valves) -> lymphatic ducts -> subclavian veins

Question 7

Primary lymphatic organs and tissues

Answer 7

red bone marrow

thymus gland

Question 8

red bone marrow

Answer 8

lymphoid stem cells arise here in fetus

if they remain in red marrow they become B lymphocytes -proliferate (mitosis) and mature here
OR can migrate to thymus gland and become T lymphocytes

Question 9

Thymus gland

Answer 9

T lymphocytes -proliferate (mitosis) and mature here

Question 10

Secondary lymphatic organs and tissues (where lymphocytes proliferate)

Answer 10

lymph nodes
spleen
Mucosal Associated Lymphoid tissues (MALT)

Question 11

lymph node locations

Answer 11

cervical, axillary (armpit), inguinal (groan), intestinal, pelvic

Question 12

spleen

Answer 12

filters blood eg removes bacteria

Question 13

Mucosal Associated Lymphoid Tissue (MALT)

Answer 13

eg tonsils, appendix, lymphoid tissues in mucous membranes

tonsils -1) adenoids=pharyngeal (1) -nasopharynx
palatine (2) in oropharynx
lingual (1) base of posterior part of tongue