Lymphatic System

Question 1

What are the functions of the lymphatic system?

Answer 1

Return tissue fluid to bloodstream, transport fats from digestive tract to bloodstream, surveillance and defense

Question 2

Components of the system?

Answer 2

Lymph in the fluids, vessels to lymphatics, structures and organs

Question 3

What does the system do?

Answer 3

Vessels circulating bodily fluids, transporting excess fluid away from interstitial spaces between cells in tissues and return to bloodstream
-Organs helping defend against disease
- Works closely with cardiovascular system

Question 4

What are lacteals?

Answer 4

Vessels on the lining of the small intestine that absorb fats and transports fats to circulatory system

Question 5

What do lymphatics do?

Answer 5

Ultimately deliver lymph into the two main channels
- Originate as lymph capillaries
- Capillaries unite to form larger vessels (vein like structure) connecting to lymph nodes

Question 6

What are the two main channels?

Answer 6

Right lymphatic duct and thoracic duct

Question 7

What is the right lymphatic duct

Answer 7

Drains the right side of the head and neck, right arm and thorax, empties into the right subclavian vein (smaller than thoracic duct

Question 8

What is the thoracic duct?

Answer 8

Drains the rest of the body, emptying into the left subclavian vein

Question 9

How does lymph become lymph?

Answer 9

Due to the heart pumping blood, some fluid leaks out of the circulatory system via force/muscular movements. Tissue fluid surrounding the cells (plasma) mixed with cell outside of capillaries leaks because of the permeability of the veins, which the lymphatics bring tissue fluid back into circulation

Question 10

Order of lymphatic pathway?

Answer 10

Lymphatic capillaries, lymphatic vessel, lymph nodes, lymphatic vessel, lymphatic trunk, collecting duct, subclavian vein

Question 11

What is lymph?

Answer 11

Fluid squeezed out of the circulatory system, containing only watery plasma (RBCs, WBCs, platelets= too large to seep through). Only called lymph once it enters the lymphatic pathway
- ~3L lymph/day

Question 12

How do lymphatics clean tissue fluid

Answer 12

Infection remains local in the tissues/tissue fluid, but it can travel into the blood stream
- Pathogens enter the lymphatic system, not the circulatory
- Travel to the lymph nodes to be processed (broken down by killer T cells, B cells, and macrophages)
- It then reenters the circulatory via lymphatics to subclavian veins

Question 13

Another name for interstitial fluid?

Answer 13

Tissue fluid

Question 14

Hemocytoblast definition?

Answer 14

Produce lymphatic stem cells with two different paths
- Path one: remains in the marrow, creating NK/B cells
- Path two: migrates to the thymus, creating t cells (told to kill)
- All circulate blood, the NK naturally kill, while t cells are told to kill

Question 15

Three types of lymph tissue?

Answer 15

Diffuse lymphatic, lymphatic nodules, lymphatic organs

Question 16

What is diffuse lymphatic tissue?

Answer 16

Found in connective tissue of majority of organs

Question 17

What is lymphatic nodule tissue?

Answer 17

Found in one or more clusters, oval shaped masses

Question 18

What are the lymphatic organs?

Answer 18

Lymph nodes, tonsils, spleen, thymus, bone marrow

Question 19

Describe the function of lymph nodes

Answer 19

Oval structures along lymphatics, lymph enters nodes through afferent lymphatics, flowing through sinuses, then exiting through efferent lymphatic
- Cells found: macrophages (digest unwanted pathogens in lymph) and lymphocytes (starts at large lymphatic nodules)

Question 20

Describe the function of tonsils

Answer 20

Multiple groups of a large lymphatic nodules (location: mucous membrane of oral and pharyngeal cavities) filter and kill germs entering the body

Question 21

List and describe the three types of tonsils

Answer 21

Palatine: posterior and lateral to the walls of oropharynx
Pharyngeal: posterior wall of nasopharynx
Lingual: base of tongue

Question 22

Describe the function of the spleen

Answer 22

Largest lymphatic organ, filters the blood removing the damaged old/RBCs, removing pathogens and uses them to activate cells (lymphocytes), and stores blood
- Between stomach and diaphragm

Question 23

Describe the function of the thymus gland

Answer 23

Differentiates and matures T cells, divided into two lobes
- Behind sternum in the mediastinum
- Glandeur organ near heart, where T cells learn to do their job

Question 24

Describe the function of the bone marrow

Answer 24

Blood producing tissue located inside of certain bones, stem cells transform themselves into WBCs/RBCs, and platelets (essential for immunity and circulation)