Unit 13 - Lymphatic System Flashcards
Lymphatic system consists of
- one way network of lymphatic vessels that collect approximately. 10% of the ECF that leaked out from cardiovascular capillaries and return this fluid to the venous blood
- lymph nodes along the vessel network that cleanse lymph as it passes through them
What support the functions of the lymphatic system
- lymphoid cells
- tissues
- organs
ICF
- intracellular fluid
- fluid found within cells
ECF
- fluid found outside of cells
Blood plasma
- ECF
- fluid in blood
- some exits capillaries to for ISF (interstitial fluid)
ISF
- interstitial fluid
- fluid between cells within the body (except blood cells which are surrounded by plasma)
- some moves into lymphatic capillaries to form lymph
Lymph
- approx. 1% of body weight
- fluid inside lymphatic system
- returned to blood plasma
Lymphatic circulation
Write out on whiteboard page 78 of notes
Lymphatic capillaries
Closed ended vessels that project into cardiovascular capillary beds
- lymphatic capillaries in the small intestine also play a role in fat absorption
What filters lymph
Lymph nodes along collecting vessels filter lymph (bacteria debris)
Where do lymphatic capillaries transport lymph fluid away from tissue to
- Right lymphatic duct
- Thoracic duct
Right lymphatic duct
- lymph from the right side of the head, chest and arm
- drains into right subclavian vein re-entering circulation
Thoracic duct
- lymph from below the ribs and the entire left side of body
- collecting vessels form below the ribs converge to an enlarged lymph vessel (cisterna chyli- most inferior portion of the duct)
- the thoracic duct drains into the left subcalvian vein reentering blood circulation
Summary of lymphatic circulation
One way route back to blood
Lymphatic capillaries - lymphatic collecting vessels (with valves) - lymphatic ducts - subclavian veins
Lymphoid tissues and organs contain
Many lymphocytes and play a key role in the body’s immune system
Primary lymphoid organs and tissues are the locations for what?
- where lymphoid stem cells divide and mature (become immunocompetent)
- includes:
1. Red bone marrow
2. Thymus gland
Where do mature lymphocytes go
Move into bloodstream and migrate to the secondary lymphoid organs/tissues
Red bone marrow
- all lymphocytes stem cells arise here
- site of B lymphocyte proliferation (mitosis) maturation
Thymus gland
- early in development (fetal stage) lymphocyte stem cells migrate here
- site of T lymphocyte proliferation (mitosis) and maturation
Secondary lymphoid organs and tissues
- where lymphocytes detect and remove pathogens
- locations where lymphocytes are activated and proliferate further
Secondary lymphoid organs and tissues include
- Lymph nodes
- Spleen
- Mucosal associated lymphoid tissue (MALT)
What are lymph nodes
Small masses of lymphoid tissue along lymphatic collecting vessels
Where are high concentrations of lymph nodes located
- cervical (neck)
- axillary (armpit)
- inguinal (groin)
- intestinal
- pelvic regions
Where is the spleen located
In the left side of abdominal cavity just below diaphragm next to stomach
What does the spleen do
Filters (cleans) blood by removing pathogens, old and defective blood cells and cellular debris
Pathogens
Organisms that can cause disease like bacteria or viruses
Mucosal associated lymphoid tissue (MALT)
- trap and remove pathogens at points of entry into body
- includes tonsils, appendix, and other lymphoid tissues on mucous membranes
- ex. Aggregated lymphoid nodules in the small intestine
Tonsils
- example of MALT
- form a ring around the pharynx
1. Pharyngeal (1)- in posterior nasopharynx (referred to adenoids when infected/swollen)
2. Palatine (2)- in oropharynx (used to be commonly removed)
3. Lingual (1)- bumpy nodules on posterior part (base) of tongue
