Topic 13: Lymphatic system

Question 1

LYMPHATIC SYSTEM

Answer 1

includes:
o lymph vessels + organs
o T & B lymphocytes
-> protect body against bacteria, viruses, cancer cells

Question 2

List the Major Extracellular Fluids

Answer 2

1) blood plasma
 fluid in blood

2) ISF (interstitial fluid)
 bathes cells (except blood cells)

3) Lymph
 inside lymphatic vessels

Question 3

Describe Lymphatic Circulation

Answer 3

1. ISF (Interstitial Fluid) – formed by capillaries leaking plasma
   o 90% re-enters blood in capillaries + venules
   o 10% into lymphatic circulation (now called lymph)
2. Lymph
   o enters lymphatic capillaries (closed ended vessels)
   o lymphatic capillaries connect to lymphatic collecting vessels (have valves)
    lymph nodes along vessels filter lymph (bacteria, debris)
    transport lymph fluid AWAY from tissues to:
   1) Right lymphatic duct (lymph from Right head, chest, + arm)
    drains into right subclavian vein reentering circulation
   2) Thoracic duct (lymph from below ribs + Left body)
    collecting vessels from below the ribs converge to an enlarged
   lymph vessel = cisterna chyli (most inferior portion of the thoracic
   duct)
    thoracic duct drains into L. subclavian vein reentering blood circ.

Question 4

Primary lymphatic organs + tissues:

Answer 4

a) red bone marrow
 lymphocytes arise here
 B lymphocytes mature and proliferate (mitosis) here

b) thymus gland
 T lymphocytes mature and proliferate (mitosis) here

Question 5

Secondary lymphatic organs + tissues

Answer 5

a) lymph nodes
b) spleen
c) Mucosal Associated Lymphoid Tissue (MALT)

(where lymphocytes proliferate)

Question 6

lymph nodes

Answer 6

 locations:

o cervical, axillary (armpit), inguinal (groin), intestinal, pelvic

Question 7

spleen

Answer 7

filters blood

o e.g. removes bacteria

Question 8

Mucosal Associated Lymphoid Tissue (MALT)

Answer 8

 e.g. tonsils, appendix, lymphoid tissues on mucous membranes
 tonsils:
i. adenoids = pharyngeal (1) – nasopharynx
ii. palatine (2) – in oropharynx – commonly removed
iii. lingual (1) – base of posterior part of tongue