Lyphatic System

Question 1

Functions of the lymphatic system

Answer 1

Transport ISF, filter lymph, immune response, transport lipids

Question 2

Components of Lymphatic System

Answer 2

Lymphocytes, lymphatic vessels, lymph nodes, thymus, spleen, bone marrow, tonsils

Question 3

Types of lymphocytes

Answer 3

B lymphocyte & T lymphocyte

Question 4

B lymphocyte

Answer 4

• Develop and mature in the bone marrow
• 10-15% of circulating lymphocytes
• mediate humoral or “liquid” immunity aka antibody-mediated immunity

Question 5

What activates B lymphocytes

Answer 5

Free floating bacteria

Question 6

What does an activated B lymphocyte become

Answer 6

Plasma Cell

Question 7

T Lymphocyte

Answer 7

• Mature in thymus gland
• 85-90% of circulating lymphocytes
• responsible for cell-mediated immunity

Question 8

What activates T lymphocytes

Answer 8

Infected or cancer cells

Question 9

Lymph Formation Steps

Answer 9

1. Fluid leaves plasma and remains in the ISF
2. Capillaries pick up waste, hormones. CO2 and other substances from the ISF
3. Lymphatic capillaries pick up excess fluid in the capillary beds and once inside the lymphatic capillaries, it is called lymph

Question 10

How does lymph differ from plasma

Answer 10

1. Doesn’t contain proteins.
2. Lymph is located in the lymphatic vessels
3. Function - lymph collects and removes WBC, viruses, and bacteria

Question 11

Composition of Lymph

Answer 11

Electrolytes, lymphocytes, other WBC, bacteria, cancer cells and viruses.

Question 12

Flow of Lymph

Answer 12

lymphatic capillaries > lymphatic collecting vessels > lymphatic trunks > lymphatic ducts > venous blood supply

Question 13

Lymphoid tissue

Structure, function and location

Answer 13

1. structure: made of lymphocytes, macrophages and reticular connective tissue
2. Function: t and b lymphocytes mount an immune response. Macrophages phagocytize pathogens and initiate an immune response. Reticular protein fibers in the reticular CT form a loose connective network that physically supports the immune cells.
3. Location: lymph nodes, bone marrow, and spleen

Question 14

Lymphoid nodules (aka lymphoid follicles)

Answer 14

clusters of lymphoid tissue NOT surrounded by a fibrous capsule

Question 15

What leads to the development of a lymph nodule?

Answer 15

When a b lymphocyte is activated. It will replicate itself forming a nodule.

Question 16

Where are nodules found?

Answer 16

lymphoid organ (such as lymph nodes) 
mucous membranes. Lymphoid nodules in mucous membranes are called: mucosa associated lymphoid tissue AKA MALT

Question 17

Nodule Germinal Center

Answer 17

lighter region with dividing lymphocytes.

Question 18

Largest Collections of MALT

Answer 18

1. Peter’ s patch aka GALT

2. Tonsils

Question 19

Peyer’s patch location and function

Answer 19

Location: wall of distal end of the small intestine
Ilium of the small intestine - terminal end that leads to the large intestine

function: to respond to any bacteria that may enter the small intestine from the large intestine

Question 20

Tonsils location and function

Answer 20

Location: Opening for the digestive system and respiratory system - Pharyngeal (adenoids), palentine, lingual

function: Respond to any pathogen that may enter the body through eating/drinking or inhaling.

Question 21

Primary lymphoid organs

Answer 21

generate lymphocytes and play a part in early in lymphocyte development.

Bone marrow and thymus

Question 22

Secondary lymphoid organs

Answer 22

house large number of lymphocytes that initiate destruction of pathogens.

Spleen and lymph nodes

Question 23

Bone marrow

Answer 23

site of initial production of lymphocytes, but only the B lymphocytes will mature here.

Question 24

Thymus

Answer 24

Does not directly fight pathogens. Only functions in the development of t lymphocytes

Does not contain true lymphoid tissue.

About 5% active by 40 years of age

Question 25

Spleen

Answer 25

largest lymphoid organ and only one to filter blood directly

a. Location – left upper quadrant. Right below the diaphragm and protected by the ribs
b. Function – filter blood. Has macrophages and lymphocytes that respond to the antigens in the blood. Macrophages also play a major role in removing worn out and defective RBC. Storage of blood and platelets

Question 26

Lymph nodes –

Answer 26

a. function: filter lymph

b. 3 areas where nodes are superficial
Cervical nodes - neck
Auxiliary nodes - armpit
Inguinal nodes - groin/upper thigh