Term 2 Lymphatic System Flashcards
What four components does the lymphatic system consist of ?
- Lymph
- Lymphatic vessels
- Lymphatic organs
- Red Bone Marrow
What is lymph
interstitial fluid that enters and flows in the lymphatic vessels
- contains white blood cells
What are the Lymphatic organs (3)
- Spleen
- Thymus
- Lymph nodes
Red bone marrow is the site of what process?
hematopoiesis
What are the three primary functions of the lymphatic system?
- Drain excess interstitial fluid (helps maintain blood volume)
- transports dietary lipids
- Carries out immune responses
Where are lymphatic capillaries found?
between arterioles and venules
Which tissues lack lymphatic capillaries? (4)
- Avascular tissues (eg cartilage, epidermis, and cornea of the eye
- central nervous system
- portions of the spleen
- red bone marrow
What are lacteals? What do they do?
Specialized lymphatic capillaries found in the villi of the small intestine
Absorb fats from the digestive tract
What is chyle? How does its appearance differ from lymph elsewhere?
- The lymph draining from the small intestine
- Appears creamy white (due to fats) whereas lymph elsewhere is a clear pale-yellow
Lymphatic vessels begin as ______ _________
Lymphatic capillaries
Lymphatic vessels are ________ at one end and located ______________
Lymphatic vessels are closed at one end and located in the spaces between cells
Lymphatic capillaries unite to form ___________. What do these resemble?
larger lymphatic vessels
Resemble veins in structure but have thinner walls and more valves
How does lymph flow?
Lymphatic capillaries →Lymphatic vessels →Lymph nodes→ Lymph trunks →lymph ducts
What are five principle lymph trunks? What do they drain?
- Lumbar trunks → drain lymph from lower limbs, wall and viscera of pelvis, kidneys, adrenal glands and abdominal wall
- Intestinal trunks→ drain lymph from the stomach, intestine, pancreas, spleen and part of the liver
- Bronchomediastinal trunks→ drain lymph from thoracic wall, lung and heart
- Subclavian Trunks→ drain free upper limbs
- Jugular trunks → drain head and neck
____ are the largest lymphatic vessels
Ducts
The right lymphatic duct returns lymph from the __________, __________, _____________
The right lymphatic duct returns lymph from the Right subclavian, right jugular, right bronchomediastinal trunks
The thoracic duct (left lymphatic duct) begins as a dilation (________) that receives lymph from:
- _________
- _________
- _________
The thoracic duct (left lymphatic duct) begins as a dilation (cisterna chyli) that receives lymph from:
- The right and left lumbar trunks
- The intestinal trunk
- Left jugular, subclavian and bronchomediastinal trunks
Why does interstitial fluid contain only a small amount of protein?
Most plasma proteins are too large to leave blood vessels
How is lymph flow regulated?
- Skeletal muscle pump
- Respiratory pump
What two groups are lymphatic organs and tissues classified into and what is the basis of this classification?
Grouped based on function
- Primary lymphatic organs
- Secondary lymphatic organs
What are primary lymphatic organs?
Sites where stem cells divide and become immunocompetent
-Thymus and Red Bone Marrow
What are secondary lymphatic organs and tissues?
Sites where most immune responses occur
Each thymus lobule consist of a _________ (superficial) and _______ (deep)
Cortex
Medulla
Lymph nodes are covered by a _______ of ___________
a capsule of dense connective tissue
The capsule of lymph nodes extends and become _______, dividing the node into compartments
The capsule of lymph nodes extends and become trabeculae, dividing the node into compartments
What are two functions of the trabeculae of lymph nodes?
- give support
- provide a route for blood vessels into the interior of the node
The parenchyma (________) of a lymph node is divided into a _________ and a __________
The parenchyma (functional tissue) of a lymph node is divided into a superficial cortex and a deep medulla
Most nodules in the outer cortex are:
secondary lymphatic nodules
The inner cortex does not contain?
Lymphatic nodules
The largest mass of lymphatic tissue in the body is ?
the spleen
The superior surface of the spleen is ______, ______ and conforms to the concave surface of the _________
The superior surface of the spleen is smooth, convex and conforms to the concave surface of the diaphragm
The spleen has a hilum. What is this?
The large tortuous splenic artery and splenic vein
What is “white pulp” in the image below; what is the “red pulp”?
White pulp: Lymphatic tissue
Red pulp: blood-filled venous sinuses
What are lymphatic nodules?
masses of lymphatic tissue not surrounded by a capsule
