Module 9: Lymphatic System

Question 1

Organization of the lymphatic system

Answer 1

lymph
lymphatic vessels
- lymphatic capillaries, right lymphatic duct, thoracic duct
Lymphoid organs
- lymph nodes
- thymus
- tonsils
- spleen

Question 2

Lymph

Answer 2

Sequence of fluid flow
- blood capillaries (blood plasma) > interstitial spaces (interstitial fluid) > lymphatic capillaries (lymph plasma) > lymphatic vessels (lymph plasma) > lymphatic tracts or ducts (lymph plasma) > junction of the internal jugular vein and subclavian veins

Question 3

Lymphatic vessels

Answer 3

Lymphatic capillaries
- microscopic
- simple squamous epithelium
- “loose fit” between adjacent cells
Right lymphatic duct
- drains lymph from the right upper extremity and right side of head, neck, and upper torso
Thoracic duct
- major lymph drainage pathway in the body
*cisterna chyli

Question 4

Lymphoid Organs Lymph Nodes

Answer 4

Location and structure
- cluster formations along lymphatic vessel pathways
- lymphoid tissue
Function
- immune defense
*biological filtration
- immune cell development
* WBC (leukocytes)

Question 5

Lymphoid organs Thymus

Answer 5

location and structure
- mediastinum and extending upward in midline of the neck
- lymphocytes in reticular fibre framework

Function (major role in immunity)
- production of T Lymphocytes (T cells)
- secretes thymosin

Involution
- infiltration of fat and connective tissue

Question 6

Lymphoid organs
Tonsils

Answer 6

Structure and location
- masses of lymphoid tissue around mouth and throat
* palatine tonsils
* Pharyngeal tonsils (adenoids)
*lingual tonsils

First line of defense from the exterior of the body

Question 7

Lymphoid organs
Spleen

Answer 7

location
- upper left quadrant of the abdomen
*white pulp (lymphoid tissue)
*red pulp (venous sinuses and splenic cords)

Function
- phagocytosis
- monocyte reservoir
- blood reservoir

Question 8

Immune system

Answer 8

function of the immune system
innate immunity
adaptive immunity
immune system molecules

Question 9

Innate (nonspecific) immunity

Answer 9

rapid first response that can trigger a slower, specific response
- cytokines
- skin, tears, and mucus
Inflammation
- inflammatory response
- fever
Complement
- blood plasma enzymes

Question 10

Adaptive (specific) immunity

Answer 10

types of adaptive immunity
- cell-mediated (T cell activation)
- antibody-mediated (B cell activation)

Natural immunity
- active
- passive

Artificial immunity
- active
- passive

Question 11

Immunity System molecules

Answer 11

cytokines
- coordination of immune responses
Antibodies
- antigen-antibody complexes
- humoral (or antibody-mediated) immunity
Complement proteins
- inactive protein enzymes
-complement cascade
- inflammatory response

Question 12

immune system cells

Answer 12

Phagocytes
- neutrophils
- monocytes
- macrophages
- dendritic cells (DCs)
*macrophages and dendritic cells also act as antigen-presenting cells (APCs)

Question 13

Immune system cells cont

Answer 13

Lymphocytes
- natural killer (NK) cells
*innate immunity
- B cells (B lymphocytes)
*indirect production of humoral immunity
- T cells (T lymphocytes)
*cytotoxic T cells
*helper T cells
*regulatory T cells