Cells And Tissues Of The Lymphatic System Flashcards
What makes up the lymphatic system ?
- lymphatic tissues organs
- lymphatic vessels
- lymph
- cells contained within the lymphoid tissues and organs
What is lymph
- a thin fluid that resembles plasma
- has a pH of 7.4
- but with lower amounts of protein
What is chyle
- lymph that arises in the GI tract
- it is a white , cloudy substance
- contains fats and dissolved lipids
- ie chylomicrons
- fat soluble vitamins
What are the 4 fat soluble vitamins ?
- A
D
E
K
What are two similarities between a vein and lymphatic capillary?
- low pressure system
- valves present
What is a difference between lymphatic capillary and vein ?
- lymphatic capillary contains no cells inside whereas veins do.
Where are the main lymph nodes found ?
- neck ( cervical);
- groin ( inguinal)
- armpit ( axillae)
Describe the structure of a lymph node
- shaped like a kidney bean
- has multiple afferent lymphatic vessels that enter via convex surface
- a SINGLE efferent lymphatic vessel that leaves via the concave hilum.
- each lymph node has a feeding artery and draining vein that leave and enter via the hilum.
- lymphoid follicles that contain immune cells such as dendritic , t, B, and macrophages
-
Where are the lymphoid follicles found in the lymph node?
In the cortex region
Is the hilum surrounded by the cortex ?
No
What is the centre of the lymphoid follicle called ?
Germinal, centre
What is the main connective tissue fibre found in the lymph node ?
Recticulin ( collagen 111)
- made by reticular cells which are special types of fibroblasts found in the lymphatic system.
Which lymphocytes recognise antigens and which need to be presented to an antigen ?
B cells Can recognise antigens
- T cells need to be presented to antigens
How many lymph nodes are found in the lymphatic system ?
600-700
What is the cause of lymphadenopathy ( enlarged lymph nodes )
- the germinal centres fill with increasing numbers of lymphocytes causing the lymph nodes to swell too much.
- can cause considerable amount of pain
What is a difference between lymphoma and leukaemia?
- lymphoma refers to cancer that arises from lymphatic tissue itself (malignancy of the lymphoid tissue itself) whereas leukaemia is cancer where the malignant lymphoid tissue appears in the blood but arises from the bone marrow.
What are the two types of lymphoma?
Hodgkin and non-Hodgkin
What is the difference between Hodgkin and non-hodgkin lymphoma ?
- Hodgkin lymphoma is characterised by the presence of a Reed-Sternberg cell visible under microscope whereas non-Hodgkin lymphoma is a cancer characterised by increased proliferation of B or T cells- occurs in old aged people.
List all 5 lymphatic organs
- thymus
- appendix
- tonsils
- spleen
- payers patches
-
Where is the location of the thymus
Superior mediastinum ( space between both lungs )