Lymphatic System structure consists of :
Lymph, lymphatic vessels, structures, and organs containing lymphatic tissues & red bone marrow
Functions of the lymphatics system
Drain excess interstitial fluid
Transport dietary lipids to blood stream
Carry out immune responses/ defend from microbial invasions
One way system from the tissues to the circulatory system
Vessels begin as:
Lymphatic Capillaries (they are closed at one end) They unite to form large lymphatic vessels
What's the difference between lymphatic vessels & Veins?
They resemble in structure but lymphatic vessels have thinner walls & more valves
lymphatic vessels pass through:
lymph nodes; encapsulated organs w/ masses & B & T Cells, and function as lymph filters
lie near blood capillaries
slightly large diamters
Have unique one way structure
composed of simple endothelial cells
permits interstitial fluid to flow in
*fluid not reabsorbed from blood*
Note: All extra fluid that comes out of blood into tissues if it can not be used it goes back into lymph- goes to organ of choice, to be filtered/ cleansed for T Cells/ B Cells to kill it. It is than good to go into heart & back into blood.
EZ Pass of Body
If the lymphatics fail to return lymph to blood, fluid accumulates into the tissues, what is this called?
Lymphatic Capillaries drain into larger:
lymphatic vessels which in turn merge with others, eventually forming 2 collecting ducts
The 2 collecting ducts are called:
Thoracic Duct (Left Side)
& Right Lymphatic Duct
Lymphatic vessels unite to form
The principal lymph trucks are:
Bronchomediastinal (walls of heart, lungs, thoracic wall)
Subclavian (upper arm/limb)
Passes from lymph trunks into 2 main channels before
draining into venous blood:
Thoracic duct, & Right lymphatic duct
Larger thoracic duct receives lymph from
lower extremities (abdomen, left arm, & left side of the head & neck).
Thoracic duct begins an an enlarged area in a lymph vessel called the:
cisterna chyli (it collected all the lymph below the diaphragm)
In the thorax, the thoracic duct enters the:
left subclavian vein
Right lymphatic duct goes into the:
right subclavian vein
Smaller right lymphatic duct receives lymph from
the R arm & the right side of the head & neck.
Lymph Transport: Lymph moves through the vessels much the same way blood is transported in veins. Upper parts of the body, lymph flows by gravity:
Lymph Transport Cont'd: regions below the heart, lymph is propelled largely by skeletal muscle contractions, which is assisted by valves
Small nodular organs along lymphatic vessels ( 1 inch or less)
Lymph nodes are covered by a fibrous connective tissue called a :
Lymph enters the nodes through -------------- vessels & leaves through ------------- lymphatic vessels.
Enters: Afferent lymphatic
Exits: Efferent Lymphatic vessels
Lymph Nodes: Stroma
Supporting connective tissue
Memory B Cell- it has a memory, makes a copy of viruses
B Cells replicate next time to stop you from getting sick again
Lymph Nodes: includes---?
Capsule, trabeculae, reticular fibers & fibroblasts
Parenchyma- functional part (outer cortex)
Aggregates of B Cells called lymphatic modules (follicles)
Outer Cortex is the site of
plasma cell & memory b cell formation
Inner cortex consists of
mainly T cells
Medulla consists of:
B cells, antibody producing plasma cells from cortex & macrophages
occur in a single location or in clusters/clumps around the body
Inguinal lymph nodes
in the groin area
Axillary lymph nodes
located in the arm pits & chest areas
Submandibular lymph nodes
located along the lower border of the mandible "tonsils"
Deep cervical lymph nodes
located along the internal jugular veins
True or False: The thymus gland is larger adults than children.
False: larger in children than adults (Babies need more protection that is why they have a larger thymus gland)
Thymus Gland is located :
along the trachea behind the sternum in the upper thoracic cavity
Thymus gland is divided into:
2 lobes (internally divided into many lobules)
Large # of T-lymphocytes secrete...
Thymosin, a hormone which stimulates the development of T Cells .
T Lymphocytes= immunity
True or False: You can live without the spleen.
Largest mass of lymphatic tissue in the body
Structure of Spleen: Stroma made of:
Capsule, trabeculae, reticular fibers, & fibroblasts
Structure of Spleen: Parenchyma:
White pulp- lymphatic tissue (lymphocytes& macrophages)
Structure of Spleen: B Cells & T cells carry out
RBC's, macrophages, lymphocytes,plasma cells, granulocytes
Where do your dying RBC's go?
Blood gets recycled here (macrophages, eat all worn & ruptured blood cells)
Red Pulp define:
blood filled venous sinuses and splenic (Bilroth's) cords- RBC's, macrophages, lymphocytes, plasma cells & granulocytes
Storage of up to 1/3 of body's platelet supply
embedded in the mucous membrane of the respiratory tract
phagocytize foreign substances from the lymph
How many tonsils are there?
a single tonsil (posterior wall of nasopharnyx)
If the pharyngeal tonsil is abnormally enlarged it is called:
(2) Palatine tonsils
Both sides of the posterior oral cavity
(2) Linguinal tonsils
under the tongue
Tonsils are sometimes overloaded with microorganisms flowing through them & themselves become..
enlarged or inflamed
Inflammation of the palatine tonsils
Tonsilitis is removed by (if they make breathing difficult or are chronically infected)
Tonsil Stones (White picture on tonsils)
food gets stuck in dents in crups in tonsils. forms a hard puddy from reparing after sickness too.
Aggregates of lymphatic tissue found in the wall of the ileum (3rd region of small intestine)
Peyer's Patches function:
destroy bacteria in the intestines & keep their #'s down.
Pink-Blood are highly vasular, immune RBC's, WBC's
more immunity you have