1. Lymphatic System

2. Overview: 2. Works with the circulatory system
1. Lymphatic system consists of lymph, lymph vessels, lymph nodes, and lymph tissue
2. Works with the circulatory system
3. Removes waste and excess fluid from the tissues

3. Lymph 1. Thin, watery fluid
2. Composed of intercellular or interstitial fluid that forms when plasma diffuses into tissue spaces.
3. Composed of water, digested nutrients, salts, hormones, oxygen, carbon dioxide, lymphocytes, and metabolic wastes such as urea
4. When fluid enters lymphatic system, be comes known as lymph

4. Lymphatic Vessels/”Lymphatics”
1. Located throughout the body in almost all tissues that have blood vessels

5. Lymphatic Capillaries
a. Small, open-ended lymph vessels
b. Act like drainpipes
c. Pick up lymph at tissues throughout the body
d. Capillaries join together to form larger lymphatic vessels

6. Lymphatic Vessels cont:
Lymphatic vessels carry lymph
Contractions of skeletal muscles against lymph vessels cause lymph to flow through vessels
Vessels pass through lymph nodes
Contain valves that keep the lymph flowing one way – towards the heart

7. Lacteals
Specialized lymphatic capillaries, called lacteals, located in area of small intestine
a. Pick up digested fats or lipids
b. When lymph is mixed with the lipids it is called chyle
c. Lacteals transport the chyle to the blood stream through the thoracic duct

8. Lymph Nodes Popularly called “glands”
Located all over the body usually in groups or clusters – principal groupings are located in the neck, armpits, chest, abdomen, pelvis, and groin
Small, oval masses ranging in size from a pinhead to an almond

10. Lymph Nodes cont: Lymph vessels bring lymph to the nodes
Nodes filter the lymph and remove impurities such as:
Carbon
Cancer cells
Pathogens or disease producing organ
Dead blood cells

11. Lymph Nodes cont:
Lymphatic tissue in nodes also produces substances such as:
Lymphocytes: a type of leukocyte or white blood cell
Antibodies: substances used to combat infection
F. Purified lymph, with lymphocytes and antibodies added, leaves the lymph node by one or two lymphatic vessels

12. Lymphatic Ducts
As lymphatic vessels leave the lymph nodes, they continue to join together to form larger lymph vessels
Eventually they drain into one of two lymphatic ducts: the right lymphatic duct or the thoracic duct

13. Right Lymphatic Duct Short tube
Receives all the purified lymph from the right side of the head and neck, the right chest, and the right arm
Empties into the right subclavian vein, returning the purified lymph to the blood

14. Thoracic Duct Much larger tube
Drains the lymph from the rest of the body
Empties into the left subclavian vein
Enlarged pouchlike structure called the cisterna chyli is located at the start of the thoracic duct

15. Cisterna Chyli Serves as a storage area for purified lymph
Receives chyle from the intestinal lacteals

16. Lymph Tissue
Located throughout the body in addition to being in the lymph nodes
Tonsils, spleen, and thymus are examples of lymphatic tissue

17. Tonsils Masses of lymph tissue Filter interstitial fluid
Three pairs of tonsils
Palatine tonsils on each side of the soft palate
Pharyngeal tonsils (also called adenoids) located in the nasopharynx (upper part of the throat)
Lingual tonsils on the back of the tongue

18. Spleen
Organ located on the left side in back of the upper part of the stomach
Produces leukocytes and antibodies
Destroys old erythrocytes or red blood cells

19. Spleen
Stores erythrocytes to release into blood stream if excessive bleeding occurs
Destroys thrombocytes or platelets
Filters some metabolites and wastes from tissues
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20. Thymus Mass of lymph tissue located in the center of the upper chest
Atrophies or wastes away after puberty and is replaced by fat and connective tissue

21. Thymus Functions during early life Produces antibodies
Manufactures lymphocytes to fight infection
Function is taken over by lymph nodes after it atrophies
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