Week 7 Lymphatic vessels and spleen Flashcards
What is the lymphatic system?
network of capillaries, thin vessels, valves, ducts and organs.
What is the function of the lymphatic system?
helps protect and maintain the internal fluid environment of the body
Absorbs and transports fat
Plays a vital role in Defence
How are lymphocytes added to lymph?
Added to lymph as it passes through the lymph nodes
WHere do lymphatic capillaries occur?
Where there are blood capillaries which form a closed network but with a larger mesh. They originate in the intercellular spaces of most tissues.
Where are lymphatic capillaries found?
In the skin and mucous membranes
How do pass through the spleen and liver?
through irregular spaces called sinusoids
What are lymph vessels?
Thin walled vessels which drain the networks of cappilaries.
They exist between lymphatics and veins
Have more valves than veins as hey do not have a pump system pushing fluid around the body, vavles prevent build up and backflow of fluid.
What does the lymphatic system follow?
Veins
Deep lymphatics do follow arteries though
What are lymph nodes and what is there faunction?
Flattened shape oval structures that are enclosed in a fiborous connective tissue capsule They filter lymph are a factory for lymphocytes contain antibodies can be a pathway for spread
How does lymph flow into lymph nodes?
Into via Afferent lymph vessles
Out of via efferent lymph vessels
What is lymphoid tissue?
collections of enormous numbers of migratory and semimigratory lymphocytes
Play a role in immune reactins of the body
Where does lymphoid tissue occur?
in lymph nodes tonsils follicles in the intestine appendix thymus spleen
What affect lymphatic flow?
is negligible in a non-mobile limb
active during muscular activity
intermittent pressure on vessels muscle contraction)
suction within thorax
inspiration
movements of organs surrounding lymphatics
What are the main channels of the lymphatic system?
3 trunks and 2 ducts; Trunks: Jugular Subclavian Bronchiomediastinal
Ducts:
Thoracic duct
Right lymphatic duct
What is the spleen?
A soft, highly vascular and mobile organ which is the largest lymphatic organ within the body.
What is the size of the spleen?
12 cm long, 7 cm wide and 3 cm thick
Roughly the size of a clentched fist
What are the borders of the spleen?
Anterior, superior, posterior and nferior borders
Where is the spleen found?
deep to ribs 9-11 on the left
Where does the outer convexity of the spleen lie?
against the diaphragm
What does the inner concavity have?
impressions for the stomach, kidney, splenic flexure of the colon and the tail of the pancreas at its hilum
What does the spleen rest on?
the left colic flexure
What is the spleen lined by?
A thin fiborous capsule of visceral peritoneum expect at the hilum
What sits in relation to the spleen?
Anteriorly: Stomach Posteriorly: Left aspect of the diaphragm Left ribs 9-11 Inferiorly: Left colic flexure Medially: Left kidney
What attaches to the hilum of the spleen?
The Gastrosplenic and splenorenal ligaments
What is a pulp?
There are two types of pulp, white and red.
White pulp is lymphoid tissue and is the centre for production of lymphocytes
Red pulp are blood cells that destroy old erythrocytes
They are smooth muscle and are friable in texture (easily crumbled)
What are the functions of the spleen?
Defence (produces WBC) Produces lymphocytes in new borns contains phagocytes act as a resevoir or storage for blood destruction and recycling of erythrocytes resevoir for plateletes
What is the arterial supply to the spleen?
Splenic artery
What is the nerve supply to the spleen?
Sympathetics:
abdominopelvic splanchnic nerves by the celiac ganglion
Parasympathetic:
Vagus nerve
