Chapter 11 The Lymphatic System Flashcards
Lymphatic System
is not considered a separate system, but part of the circulatory system. Lymph is derived from tissue fluid which, in turn, came from plasma that escape the blood vascular system.
Lymphatics
an extensive network of small vessels. The purpose is to collect excess tissue fluid and return it to the blood vascular system by emptying into veins. Lymphatics have no pumping system, the contents are transported by gravity and pressure of the surrounding structures compressing the vessels.
Tissue Fluid
blood plasma that escapes from through the walls of the capillaries, minus some proteins. Tissue fluid provides a fluid environment in which body cells exist. It also serves as the transportation medium by which the cells of the body receive nutrients and exchange respiratory gases and waste products.
Lymph
hen tissue fluid enters the lymphatic vessels, it becomes known as lymph.
Edema
caused when tissue fluid builds up in excess and is not carried away by the capillaries or the lymphatic vessels. This leads to swelling and distention of the tissues.
Characteristics of Lymph
- pale amber colored, oderless, salty liquid
- specific gravity of 1.015 and is slightly alkaline with a pH of 7.4
- moves slow due to gravity and pressure from surrounding structures
Vessels of the Lymphatic System
- Right Lymph Duct
- Thoracic Lymph Duct
Layers of Lymphatics
3 layers in the walls
- Intima
- Media
- Adventitia
Right lymphatic duct
drains lymph from the superior right quadrant of the body. this vessel is formed from the small lymph vessels draining this area. it is a small vessel which empties into one of the veins in the neck, generally the right subclavian or right brachiocephalic vein.
Left lymphatic duct
the thoracic duct
drains lymph from the superior left and both inferior quadrants of the body. this duct begins at the cisterna chyli in the abdomen and courses up the thoracic cavity, where it empties into the left subclavian or left brachiocephalic vein
Cisterna Chyli
is a dilated inferior end of the thoracic duct which is the collecting place for lymph coming from the abdomen and lower extremities
Lacteals
small lymph vessels which drain the lymph from the digestive tract, specifically from the ileum of the small intestine. has a milky appearance due to the presence of fats that are dissolved into the lymph. This is a special lymph called Chyle
Peyer’s Patches
a cluster of lymph nodes located in the alls of the small intestines. they help filter lymph leaving the intestinal area via the lacteals.
Major Lymph Node Cluster Locations
- Axilla
- Groin
- Breast Area
- Neck
- Along major vessels of the body
Thymus Gland
a significant mass of lymphoid tissue located behind the top of the sternum. Important to body’s immune system because it is involved with the early production of lymphocytes.
