Compendium 10. Immunity Flashcards
What are the 3 main functions of the lymphatic system?
- Fluid balance
- Fat absorption
- Defence against infection
What is a lymph?
Clear fluid made up of water and solutes. It drains through the lymphatic system and back into the blood via veins.
What are lymphatic vessels?
They are one way, beaded vessels that carry lymph away from tissues and back to the heart.
The movement of the lymph is aided by the contractions of skeletal muscles.
What are 4 features of the lymphatic capillaries / blind ended capillaries?
- They are more permeable than blood capillaries.
- It has one way flow
- Epithelial cells do not have basement membranes
- Found in all parts of the body except for nervous system, bone and avascular
What are lymphatic trunks?
Large lymph vessels where smaller lymph vessels join
They drain lymphs and are named according to where they are situated in the body.
Where is the Jugular lymphatic trunk?
Head and neck
Where are the Subclavian lymphatic trunks?
Upper limbs, thoracic wall and mammary glands
Where are the Bronchomediastinal lymphatic trunks?
Thoracic organs and deep thoracic wall
Where are the Intestinal lymphatic trunks?
The abdominal organs
Where are the lumbar lymphatic trunks?
Lower limbs and organs in the pelvis
What are lymphatic ducts?
They drain tissues into major veins. There are 2 ducts :
- The right lymphatic duct
- The thoracic duct
What parts of the body do the two lymphatic ducts drain?
- Right lymphatic duct drains the right side of the body, right-upper limb and right thorax.
- Thoracic duct drains the rest of the body
What are some examples of encapsulated tissue?
- Lymph nodes
- Spleen
- Thymus
What are some examples of non-encapsulated tissue?
Mucosa-associated tissue
What are diffuse lymphatic tissue?
- Has dispersed lymphocytes and macrophages
- It does NOT have clear boundaries
What are lymphatic nodules?
- Is denser that diffuse lymphatic tissue
- numerous in loose connective tissue in the digestive, respiratory and urinary system
What are lymph nodes?
- Filter lymphs
- They activate the immune system
- The site in which lymphocytes will proliferate
What are tonsils?
- Large groups of lymphoid tissue in the nasopharynx and oral cavity
- They provide protection against pathogens that enter the mouth and nose cavity
What are the 3 different sets of tonsils?
- Palantine - The ones you can see at the back of the throat
- Pharyngeal - They sit in the posterior walls of the nasopharynx
- Lingual - Located at the base of the tongue
What is the spleen and what are it’s main functions?
The largest lymphatic organ in the body.
- It monitors blood by detecting and responding to foreign antigens
- Destroys defective red blood cells
- Contains a reserve of red blood cells.
Describe the difference between the red and white pulp of the spleen
Red pulp - associated with the veins and makes up 75% of spleen. It contained many red blood cells and macrophages.
White pulp - associated with arteries and makes up around 25% of spleen. It is full of lymphatic tissue.
What is the thymus?
It is the site of the maturation of T cells.
What are trabeculae?
A series of parturitions formed by bands or columns of connective tissue
Describe the process of the lymphatic system
- Lymphatic capillaries remove fluid from tissues. This fluid becomes the lymph.
- Lymph flows through lymphatic vessels.
- Lymph nodes filter lymph and respond to infections where necessary.
- Lymph enters thoracic duct or the right lymphatic duct.
- The lymph enters the blood stream
