Lymphatic System Flashcards
What does the lymphatic system consist of?
Lymph
Lymphatic vessels
Lymphoid tissues and organs
What do lymphoid tissues and organs include?
Lymphatic nodules
Lymph nodes
The thymus
The spleen
Where in the body is lymphatics not found?
Bone marrow
Teeth
Epidermis of the skin
What are the functions of the lymphatic system?
- Maintenance of blood volume.
- Generation of immune response.
- Transportation of dietary lipids.
Describe the flow of lymph through the body?
- Excess interstitial fluid is reabsorbed by lymphatic plexuses made of lymphatic capillaries.
- The capillaries merge into larger collecting lymphatic vessels.
- Collecting lymphatic vessels drain into fewer larger vessels called lymphatic trunks.
- The trunks then converge to form two large lymphatic ducts, which drain into large veins at the base of the neck.
- The two lymphatic ducts drain into large veins at the base of the neck on either side. Therefore, these two lymphatic ducts return lymph to the venous circulation, which eventually drains into the right atrium of the heart.
Describe the location, structure and function of lymphatic capillaries?
Location:
They form lymphatic plexuses that are interspersed amongst the blood capillary beds in the tissues of the body.
Structure:
1. Overlapping endothelial cells creates flap-like mini valves that are easily opened = to prevent lymphatic capillaries leaving.
2. Large junctions between endothelial cells = allows larger molecules to past through.
Function (lymphatic capillaries, [lacteals] inside the villi of the small intestine):
Absorbs dietary lipids and lipid-soluble vitamins, as these are too large to be absorbed directly into the blood.
Label the parts of the lymphatic capillaries?
Label the parts of an individual lymphatic capillary?
How are collecting lymphatic vessels formed & what are they referred to as?
Formed by the union of lymphatic capillaries.
Name = lymphatics
Describe the location, structure and function of lymphatic vessels?
Location:
Superficial lymphatic vessels follow the superficial veins within the subcutaneous tissue.
The superficial lymphatic vessels drain into the deep lymphatic vessels, which accompany deep arteries.
Structure:
Composed of tunica intima, tunica media and tunica externa & they have valves.
Function:
Afferent lymphatic vessels carry unfiltered lymph from the body tissue to the lymph nodes.
Efferent lymphatic vessels carry filtered lymph from lymph nodes to lymph nodes and lymphatic vessels upstream.
Label the lymphatic vessels?
Label the lymphatic trunks of the body?
Explain where the lymphatic trunks receive their lymph from?
Jugular trunks:
Receive lymph from the head and neck.
Subclavian trunks:
Receive lymph from the upper limbs, breasts and superficial thoracic wall.
Bronchomediastinal Trunks:
Receive lymph from the deep thoracic structures.
Intercostal Trunks:
Receive lymph from the thoracic wall.
Intestinal Trunk:
Receives lymph from most abdominal structures.
Lumbar Trunks:
Receive lymph from the lower limbs, abdominopelvic wall and pelvic structures.
What is the relationship between the lymphatic trunks and lymphatic ducts?
The lymphatic trunks eventually converge to form two major lymphatic channels: the right lymphatic duct (on the right side of the body) and the thoracic duct (on the left side of the body).
What is the function of the lymphatic ducts?
They return lymph to the venous circulation by emptying it into the junction of the internal jugular vein and subclavian vein on their respective sides of the body.
What is the venous angle?
The union of the internal jugular vein and subclavian vein to form the brachiocephalic vein on either side of the body.
What areas of the body do the lymphatic ducts drain?
The right lymphatic duct receives lymph from the ‘right upper quadrant of the body’ (right side of the head, neck and thorax).
The left lymphatic duct drains lymph from the rest of the body.
What is the cisterna chyli?
The sac-like structure where the left lymphatic duct originates from.
Where is the right lymphatic duct formed & where does it return the lymph received?
Formed at the convergence of the right bronchomediastinal, jugular, and subclavian trunks.
It returns the lymph received by these trunks to the venous circulation at the junction of the right subclavian and right internal jugular veins (i.e. the right venous angle).
What is the location of the left thoracic duct?
Enters the thorax by passing through the aortic opening of the diaphragm.
Termination point is at the junction of the left subclavian and left internal jugular veins (I.e. the left venous angle).
Label the lymph node structure?
Label the human lymph node?
Identify examples of major groups of lymph nodes?
Identify the location of the thymus in young children?
Located in the inferior neck and extends into the anterior part of the mediastinum where it partially overlies the heart.
Most of the thymus is found directly posterior to the sternum, covering the origins of the great vessels.
Identify the location of the spleen?
Located in a region of the abdominopelvic cavity called the left upper quadrant.
–> Sits directly underneath the left dome of the diaphragm.
–> Is posterolateral to the stomach and lateral to the pancreas.
–> Is superior to the large intestine.
–> Is lateral to the left kidney.
Name and identify the location of the different type of tonsils?
Pharyngeal tonsil (referred as the ‘adenoids’):
In the posterior wall of the nasopharynx.
Palatine tonsils:
On either side of the soft palate.
Lingual tonsil:
On the posterior aspect of the tongue.
Tubal tonsils:
Surrounding the openings of the auditory tubes.
Identify the labelled lymphoid structures?
Identify the flow of lymph through the body?
