Week 7 Lymph Part 4 Flashcards
What is the center or inner portion of a lymph node called?
Medulla
What is the most superficial or outer layer of the node called?
cortex
Explain the layers of the lymph node? (superficial to deep)
Mature exterior, immature interior, superficial cortex, deep cortex, medulla
Lymphocytes are highly migratory or not?
VERY migratory
What are the two compartments of a lymph node?
Cortex and medulla
The cortex is comprised of a dense mass of lymphatic tissue such as?
Reticular framework, dendritic cells, lymphocytes, macrophages, plasma cells
Where do blood vessels enter and leave the lymph node?
Through the hilum INTO the medulla
The medulla consists of _____ of lymphatic tissue
Cords
The medulla consists of ‘cords’ of lymphatic tissue separated by?
Lymphatic sinuses or medullary sinuses
Lymphatic sinuses or medullary sinuses
Lymphocytes, macrophages, dendritic cells, and plasma cells
Cords in the lymph node are organized around _______ fibers?
Reticular, they are NOT physically attached -loosely surrounded
The medullary sinuses converge at the _____ and drain into _______ lymphatic vessels?
Converge at the HILUM and drain into the EFFERENT lymphatic vessels
Lymphatic vessels are lined by?
Cuboidal or columnar endothelial cells that allow for lymphocytes to move
What does aquaporin 1 do?
It is a water channel. Helps maintain volume of lymph fluid. Allows transfer of fluid into the bloodstream and causes lymph to enter through afferent vessels to be drawn deep into cortex
What is the thymus??
A bi-lobed organ located in the superior mediastinum, anterior to the heart and great vessels
Is the thymus more active in adults or children?
Children
Explain the structure of the thymus?
It is surrounded by a thin capsule with trabeculae extending into the parenchyma
The trabeculae create domains called?
Thymic lobules
Each thymic lobule contains?
A cortex and medulla
The capsule and trabeculae contain _________ and _____ lymph vessels?
Blood vessels and efferent lymph vessels
Are there any afferent vessels in the thymus?
NO!
Does lymph ‘flow’ though the thymus like it does lymph nodes?
NO!
What is the thymus replaced with in an adult?
Adipose tissue
What is the thymus function?
Lymphopoiesis during fetal and postnatal life
What is lymphopoiesis?
The generation of, differentiation of lymphocytes
Lymphopoiesis is more important in adults or children?
Children. (this is why it get filled with fat and is less important in adults)
In adults, lymphocytes _____ in the thymus?
Proliferate
Why do thymphocytes ONLY proliferate in the thymus?
Bc they develop in the bone marrow
The thymic parenchyma contains developing T cells in a meshwork of ___________?
Epithelioreticular cells
What are epithelioreticular cells?
These cells have features of epithelia and fibroblasts; forming the meshword to support T-cells
Thymis or Hassall’s corpuscles are derived from?
Epithelioreticular cells
What is the function of thymic or Hassall’s corpuscles?
Unknown
