**A&P 2 Unit 20 (Lab) [Lymphatic System]

Question 1

Functions of the Lymphatic System

Answer 1

• Transports excess interstitial fluid to blood
• Assists in dietary fat absorption
• Activation of the immune system

Question 2

Structures of the Lymphatic System

Answer 2

• Lymphatic Vessels (“lymphatics”)
  
  • Transport the fluid lymph
• Lymphoid tissues and organs
  
  • Classified as: Primary or Secondary
  • Abundant lymphocytes

Question 3

Lymphatics

Answer 3

• Lymphatic capillaries collect interstitial fluid
  
  • Fluid is now called lymph
• Lymph flows inside lymphatic vessels
• Right lymphatic duct and thoracic duct (left)
  
  • Drain into right and left subclavian veins

Question 4

Absorption of Dietary Facts

Answer 4

• Occurs along small intestine
• Fatty acids are usually too large to enter blood capillaries
• Enter lacteals (lymphatic capillaries)

Question 5

Lymphocytes

Answer 5

• • Most abundant cell in the lymphatic system
• Types:
  
  • B cells
  • T cells
  • NK cells

Question 6

Development & Maturation of Lymphocytes

Answer 6

• All lymphocytes develop in the red bone marrow
• To “mature”= become immunocompetent
  
  • B cells and NK cells mature in red bone marrow
  • T cells migrate to thymus gland to mature

Question 7

After Maturation of Lymphocytes

Answer 7

• Immunocompetent lymphocytes
  
  • Re-enter bloodstream, then travel to red bone marrow and other lymphoid tissues
  • Ready to respond

Question 8

Classification of Lymphoid Tissue

Answer 8

• Primary vs. Secondary
• Encapsulated vs. Unencapsulated

Question 9

Primary Lymphatic Tissue

Answer 9

• Where lymphocytes develop and mature
• Red bone marrow
• Thymus

Question 10

Secondary Lymphatic Tissue

Answer 10

• Where lymphocytes may become activated in an immune response
• Lymph Nodes
• Tonsils
• Spleen

Question 11

Encapsulated

Answer 11

• Have distinct fibrous covering
• Lymph Nodes
• Spleen
• Thymus

Question 12

Unencapsulated

Answer 12

• Unencapsulated (no distinct covering)
  
  • Mucosal-associated lymphoid tissue (MALT)
• Along digestive, respiratory, urinary tracts
• Includes:
  
  • Tonsils
  • Appendix
  • Peyer’s Patches

Question 13

Lymph Nodes

Answer 13

• Encapsulated
• Little organs
• Contain B cells, T cells, Macrophages
• Lymph enters through afferent vessels
• Lymph node “filters” lymph
• Lymph exits through efferent vessels

Question 14

Spleen

Answer 14

• Largest lymphatic organ
  
  • Left upper quadrant
• Filters blood (and stores platelets)
  
  • White pulp: Immune responses (lymphocytes, phagocytes)
  • Red pulp: Destroys old RBCs (macrophages)
• Thin capsule can easily rupture –> life threatening emergency (bleeding)
• B cell proliferation

Question 15

B Cells

Answer 15

• Plasma Cells
• Produce & secrete antbodies

Question 16

T Cells

Answer 16

• Cytotoxic T Cells
• Helper T Cells
• Suppressor T Cells

Question 17

Cytotoxic T Cells

Answer 17

Attack foreign cells or body cells infected by viruses.

Question 18

Helper T Cells

Answer 18

Stimulate activation & function of T & B Cells

Question 19

Suppressor T Cells

Answer 19

Inhibit activation & function of T & B Cells

Question 20

Lymphatic Valves

Answer 20

• Prevent back flow
• Promotes one-way flow
• Lymph moves slowly

Question 21

Threee Types of Tonsils

Answer 21

• Pharyngeal
• Palatine
• Lingual

Question 22

Metastasis

Answer 22

The development of secondary malignant growths at a distance from a primary site of cancer.

Question 23

NK Cells

Answer 23

Control several types of tumors and microbial infections by limiting their spread and subsequent tissue damage.

Question 24

Thymus

Answer 24

Site of T cell maturation