Functions of lymphatic system
Removes excess fluid away from the interstitial fluid comp
Participates in the body’s immune response by producing lymphocytes
Transports fats from the digestive system to the bloodstream
A network of lymph vessels, tissues and organs distributed all over the body and connected to the circulatory system
Lymphatic System
These are the exta-nodal lymphatic tissues
MALT
Tonsil
Thymus
Spleen
The single cell wall of the capillaries is called the
Endothelium
It enables the interchange of water, oxygen, carbon dioxide, other nutrient and waste chemicals
Endothelium
In most capillary beds more filtration occurs where and less reabsorption
Arterial end
Smallest tube of the lymphatic network
Lymphatic capillaries
Excessive interstitial fluid results into
Edema
Lymph coming from the digestive system milky in appearance is called
Chyle
TRUE OR FALSE
Presence of valves permit the lymph to moe only in the direction of the bloodstream
True
TRUE OR FALSE
One-way lymph valves ensure flow is only toward the VENOUS SIDE of the circulation
True
Clinically edema is manifested by
Swelling
Lymphatic block by infestation of nematodes of the Filariae family
Elephantiasis
When lymphatic capillaries merge it form the
Collecting vessels or lymphatic vessels
There are 3 distinct layers that could be seen in a lymphatic vessel
Inner layer: elongated endothelial cells
Middle layer: smooth muscle and fine elastic fibers
External layer: connective tissues
TRUE OR FALSE
Lymphatic vessels differ from the veins
True
Difference of lymphatic vessels from the veins
Layers are thinner than those of the veins
Valves in LV are mire numerous and placed at much shorter intervals
They anastomose more than the veins
Large collecting vessels merge to form
Lymphatic trunks
The principal lymphatic trunks are
Lumbar trunks Intestinal trunk Broncho-mediastinal trunks Jugular trunks Subclavian trunks
Lumbar trunks drain
L&R, lower limbs, pelvis and abdomen except digestive sys
Intestinal trunk drains
Part of the digestive system below the diaphragm
Broncho-mediastinal trunks drain
Throrax
Jugular trunks drain
L&R part of the head and neck
Subclavian trunks drain
L&R, upper limbs
Lymphatic trunks drain into 2 main lymphatic ducts the
Right lymphatic duct and
Thoracic duct
Largest diameter of lymphatic vessels directly emptying into the venous system
Lymphatic ducts
Right lymphatic duct and thoracic duct
This duct drains the right side of the body above the diaphragm
(Right face, head, neck, upper limb and thorax)
Right lymphatic duct
Opens into the right brachiocephalic vein at the junction of the right internal jugular and subclavian veins
Right lymphatic duct
Drains the rest of the body except the right side above the diaphragm
(Left head, neck, upper extremity, thorax, abdomen, pelvis and 2 lower extremities)
Thoracic duct
Drains chyle-lymph from the digestive system containing emulsified fats and free fatty acids
Thoracic duct
A triangular lymphatic dilatation in the abdomen anterior to the L2 vertebral body to the right and posterior to the aorta
Cisterna chyli
TRUE OR FALSE
Thoracic duct possesses a BICUSPID valve which faces into the vein to prevent reflux of blood into the duct
True
Small, oval or bean-shaped bodies
Lymph node
T or F
There are approx 500-600 lymph nodes in the body
True
The lymph node is surrounded by a dense CT
Capsule
Extend inward incompletely dividing the node io compartments
Trabeculae
Extending from the capsule and trabeculae are
Fine reticular fibers
Lymphocytes are tightly packed within the network
3 different zones of the lymph node with their corresponding immune cells
Cortex- mostly B cells
Paracortical zones- T cells
Medulla- B cells and plasma cells are found
In the cortex lymphocytes group together into nodules
Primary germinal center
Secondary germinal center - B cells divide by cell division
In the medulla lymphocytes mainly B cells and plasma cells are arranged in
Medullary cords
It contains immobile macrophages (histiocytes) that trap foreign particles and filter lymph
Medullary sinuses
Produced in the BM transported in the blood and lymph circulation differentiate into plasma cells
B cells
Develop in the thymus transported in the blood and lymph circulation accumulate in lymphatic tissue
T cells
Directly kill pathogens
T-cytotoxic cells
Engulf pathogens get their antigens and present them to the T-cells and B-cells to facilitate action
Dendritic cells
Lymph flow
- Afferent lymph vessels at the convex part of the node
- Subcortical sinus
- Cortical sinus
- Medullary sinus
- Efferent lymph vessels at the hilum
Lie above and beneath the SCM m
Drain internal struc of the throat part of the posterior pharynx, tonsils and thyroid gl
Anterior cervical lymph nodes
In front of the trapezius from the level of the mastoid portion of the temporal bone to the clavicle
Enlarged during upper respi infection
Posterior cervical lymph nodes
Located below the angle of the mandible and drain the tonsillar and posterior pharyngeal regions
Tonsillar lymph nodes
Along the underside of the jaw on either side and in the floor of the mouth
Sub-mandibular lymph nodes
Found below the chin and drain the teeth and intra oral cavity
Submental lymph nodes
Above the clavicle, lateral to where it joins the sternum which drain a part of he thoracic cavity and abdomen
Supraclavicular lymph nodes
Left supraclavicular lymph node which receives the lymph drainage from most of the body especially the abdomen via the thoracic duct
Virchow’s node
Placed above the medial epicondyle of the humerus and drain the vessels that accompany the basilic vein (ulnar digits and medial arm)
Supratrochlear (cubital) lymph nodes
Found beside the cephalic vein, bet pectoralis major and deltoid m
Drain the lymph vessels that accompany the cephalic v (radial digits and lateral arm)
Delto-pectoral nodes
Accompany the basilic and cephalic veins into the axillary lymph jodes
Superficial lymph vessels
Accompany deep veins and drain into the lateral (brachial) axillary lymph nodes
Deep lymph vessels
Embedded in the fat contained in the popliteal fossa
Popliteal nodes
Located below the inguinal lig approx 20 in number
Superficial inguinal nodes
Receive afferents from the external genitalia (except testes) perineum, anus, buttocks and abdominal wall below the umbilicus
Horizontal (Superior) lymph nodes
Drain vessels that accompany the long saphenous vein
Vertical (inferior) lymph nodes
Found under the fascia lata, on the medial side of the femoral vein
Deep inguinal nodes of the lower limbs
Pre-aortic nodes (in front of the aorta) is composed of
Celiac nodes
Superior mesenteric
Inferior mesenteric
Lymph nodes of the pelvis
External iliac nodes Internal iliac nodes Common iliac nodes Sacral nodes Lumbar (lateral aortic) nodes
Drain the internal and external iliac nodes
Common iliac nodes
Lymph nodes that receive lymphatics from the pelvis
Sacral nodes
Extra-nodal lymphatic tissues has a ___ CT stroma serving
Reticular
T or F:
only the lymph nodes have afferent & efferent lymphatic vessels
True
What are the extra-nodal lymphatic tissues?
Mucous membranes-associated lymphatic tissue “MALT”
Tonsils
Thymus
Spleen
Line the internal organs and the various body cavities that are exposed to the external environment like the respiratory, digestive and genito-urinary system, nose, eyes and ears
MALT
Give examples of mucous membrane associated lymphatic tissue (MALT)
GALT (gut-associated lymphoid tissue, e.g. Peyer’s patches)
BALT (bronchus-associated lymphoid tissue)
NALT (nose-associated lymphoid tissue)
LALT (larynx-associated lymphoid tissue)
SALT (skin-associated lymphoid tissue)
VALT (vascular-associated lymphoid tissue)
CALT (conjunctiva-associated lymphoid tissue
aggregations of lymphoid tissue that are usually found in the most distal portion of the small intestine, the ileum
Peyer’s patches
Partially encapsulated lymphatic tissues Covering epithelium invaginates to form crypts where bacteria are trapped & attacked
Tonsils
What ring does the tonsils form around the entrances of the respiratory and digestive passages
Waldeyer’s ring
T or F:
The tonsils atrophies with age?
True
Enlarged pharyngeal tonsils
Adenoids
Enlargement of the tonsils from infection or tumor
Tonsillar hypertrophy-
Soft, lobulated, grayish-pink organ and increases to its maximum size, weight and function at puberty
Thymus
T or F:
The thymus is an encapsulated organ.
True
What are the 3 encapsulated lymphatic organs?
Thymus
Spleen
Lymph Nodes
Thymic corpuscles that consists of hyaline material surrounded by layers of flattened epithelioid cells
Hassl’s bodies
T or F
At birth the thymus is found at the neck then descends into the mediastinum
True
Facilitates T-lymphocyte maturation
Thymus
Loss of this organ at an early stage results in severe immunodeficiency and high susceptibility to infection
Thymus
Because majority of the T-cell maturation happens in childhood
Autoimmune disorder of the neuromuscular junction presenting with fluctuating periods of easy fatigability and weakness of voluntary muscles of the face and limbs
Myasthenia gravis
Largest lymphatic organ in the body
Located at the left upper quadrant of the abdomen
Spleen
2 surfaces of the spleen
A convex posterior diaphragmatic surface facing superiorly and laterally
An anterior visceral surface
3 areas of the anterior visceral surface
Gastric- in contact with the greater curvature of the stomach
Renal- in contact with the upper anterior surface of the left kidney
Colic- in contact with the left splenic flexure of the colon
Attaches the spleen to the stomach
Gastrosplenic ligament
Attaches the spleen to the left kidney
Splenorenal (lienorenal) ligament
Largest br of the celiac trunk (1st br of abdominal aorta)
Splenic Artery
Exits the hilum
Drains into the hepatic portal vein
Travels posterior to the pancreas
Splenic vein
One of the most commonly injured abdominal organ
Ruptured spleen
