Lymphatic System, Spleen - PDF

Lymphatic system & Axillary lymph Nodes & Spleen  Objectives   Discuss Lymph, Lymphatic vessels, Lymphatic nodules and Lymphoid organs.  Enlist functions of lymphatic System.  Explain Lymphatic circulation....

Lymphatic system & Axillary lymph Nodes & Spleen  Objectives   Discuss Lymph, Lymphatic vessels, Lymphatic nodules and Lymphoid organs.  Enlist functions of lymphatic System.  Explain Lymphatic circulation.  Discuss Main lymphatic channels.  Describe the axillary & Inguinal lymph nodes  Discuss the gross features of spleen.  Give its blood and nerve supply.  A 48-year-old woman is diagnosed with a malignant tumor in the superolateral quadrant of the right breast. If it metastasizes, this cancer will most likely spread first to which of the following locations? (A) Lateral axillary lymph nodes (B) Anterior axillary lymph nodes (C) Deep cervical lymph nodes (D) Parasternal lymph nodes (E) Contralateral breast lymph nodes LYMPHATIC SYSTEM  Definition:  Is a part of the vascular system, concerned with collection of a fluid part of blood called the plasma, which escapes from the capillaries, by filtration and or the tissue fluid or lymph. LYMPHATIC SYSTEM  The tissue fluid is returned back to bloodstream through lymph vessels.  Lymph vessels start as fine lymph capillaries that join to form lymphatics which are numerous, fine and have many valves COMPONENTS LYMPHATIC SYSTEM  Lymph.  Lymphatic vessels.  Lymphatic cells.  Lymphatic nodules.  Lymphoid organs FUNCTIONS OF LYMPHATIC SYSTEM  Remove excess fluids from body tissues & transport of tissue fluid back into the blood circulation.  Absorb & remove large Protein molecules.  Absorb fatty acid and transport fat to circulatory system from intestinal villi.  Produce immune cells (lymphocytes, monocytes & plasma cells). LYMPH  Clear, watery fluid found in the lymphatic vessels.  Much of this interstitial fluid is absorbed by tissue cells or reabsorbed by the blood, small amount of interstitial fluid is left behind.  It is twice as blood in our body. Lymphatic Vessels  Lymphatic vessels drain interstitial fluid from tissues to venous blood.  Lymphatic vessels are found in most of tissues and organs in the body but absent from: o CNS. o Eye ball. o Internal ear. o Epidermis. o Cartilage. o Bone.  Lymphatic Vesseles  Superficial lymphatic vessels: Present on the deep surface of the epithelium. They run parallel to the superficial blood vessels of the skin. They then join together to form larger vessels.  Deep lymphatic vessels: They are deep to the deep fascia. Parallel to the major blood vessels. Larger than the superficial vessels Have thick wall and valves. Lymphatic circulation  Blind ended lymphatic capillaries.  Contain valves (beaded appearance).  In the intestine the lymphatics are called lacteals.  Afferent lymphatics.  Lymph nodes.  Efferent lymphatics.  Thoracic duct/ Right lymph duct.  Blood circulation. Lymphatic organs  Primary lymphatic organs  Organs where lymphocytes become initially immunocompetent e.g. bone marrow and thymus.  Secondary lymphatic organs  Organs where immunocompetent lymphocytes form effector lymphatic tissue and organs e.g. lymphatic nodules, lymph nodes, tonsils and spleen. LYMPH NODES (GLANDS)  The lymph passes through lymph nodes before reaching the main lymph vessels.  They are present in groups  They act as filters preventing the passage of germs and their poisons to the blood stream. LYMPH NODES (GLANDS)  The most important of which are: Axillary: for the upper limb & breast. Cervical: for head & neck. Aortic: for abdominal organs. Inguinal: for the lower limbs. Iliac: for the pelvic organs. Mediastinal: for thoracic organs.  LYMPH NODES (GLANDS) Structure:  Convex (outer) surface:  Receives afferent lymphatics.  Concave (inner) surface:  It is called the hilum.  Exit to an efferent lymphatic  LYMPH NODES (GLANDS)  Functions: 1. Act as a filter as they prevent micro-organisms and certain substances from entering the blood stream. 2. Formation of lymphocytes. 3. Formation of antibodies. 4. In case of infection or malignancy, the lymph nodes become enlarged and change in consistency.  LYMPH DUCTS  Two main lymphatic vessels are present in the body, each ends into the corresponding brachiocephalic vein.  Right lymphatic duct.  Thoracic duct.  LYMPH DUCTS  Thoracic duct.  Beginning: cisterna chili in the abdomen (in front of the lumbar vertebrae)  Course: It ascends through the posterior abdominal and thoracic walls (deviating to the left side).  Termination: at the junction of left subclavian and left internal jugular veins.  Drains: lymph from all the body except the upper right quadrant.  LYMPH DUCTS  Right lymphatic duct.  Size: much smaller  Drains: lymph from the upper right quadrant (right side of the head and neck, right upper limb, and right side of the chest)  Termination: at the junction of right subclavian and right internal jugular veins  Axillary Lymph nodes Divided into 5 groups: 1. Pectoral (Anterior) group:  Site: on lower border of pectoralis minor.  Afferents: from front of upper ½ of trunk, and breast.  Efferent: central and apical groups  Axillary Lymph nodes 2. Scapular (Posterior) group:  Site: along subscapular artery  Afferents: from back of upper ½ of trunk.  Efferent: central and apical groups 3. lateral group:  Site: Along the axillary vessels.  Afferents: From upper limb.  Efferent: central and apical groups  Axillary Lymph nodes 4- Central LNs:  Site: Below clavicle  Afferents: anterior, lateral, posterior groups and from upper part of breast.  Efferent: Apical group  Axillary Lymph nodes 5- Apical group:  Site: At the apex of axilla  Afferents: from anterior, posterior, lateral and central groups.  Efferent: subclavian lymph trunk which drains (thoracic duct (Lt) or right lymph trunk (Rt)  Axillary Lymph nodes Applied note: Infection or malignancy in the upper limb or breast give swelling in the axilla due to involvement of axillary LNs.  Inguinal Lymph nodes Superficial inguinal LNs:  Site: In the femoral triangle.  No: 12- 20  Two groups: 1. Horizontal group:  Medial: drains anterior abdominal wall below umbilicus, lower part of anal canal, external genitalia (male and female).  Lateral: drains buttock and back below iliac crest.  Inguinal Lymph nodes 2. Vertical group: drains the lower limb. It is present at the end of the great saphenous vein. N.B: All the above groups of LNs send afferents to deep inguinal and external iliac LNs.  SPLEEN  During a splenectomy, a surgeon carefully dissects the peritoneal ligament containing the splenic vessels at the hilum of the spleen. Which of the following peritoneal ligaments is being dissected by the surgeon? (A) Hepatoduodenal ligament (B) Coronary ligament (C) Transverse mesocolon (D) Lienorenal ligament (E) Gastrolienal ligament SPLEEN  Is the largest lymphoid organ in the body. It lies below the diaphragm.  Site: Left hypochondrium. SPLEEN Functions:  Destroys worn-out RBCs.  Acts as reservoir for blood cells of all kinds.  Produces lymphocytes in the lymph nodules.  SPLEEN Surface Anatomy  It lies parallel to the left 9th, 10th, 11th ribs.  The long axis of the spleen: parallel to the 10th rib.  The medial end: 1 1/2 inches from the spine of T 10.  The lateral end: just behind the mid-axillary line.  SPLEEN Shape: 3 borders, 2 ends, 2 surfaces.  Ends o lateral end (Broad, directed downward) o medial end (tapering, directed upward)  Borders o Upper border (Sharp & notched) o Lower border (Broad) o Intermediate border (thick, incomplete, from the medial end till the hilum).  SPLEEN Surfaces 1. Diaphragmatic surface:  Convex, Related to the diaphragm which separates it from 3 structures :------ o Lower part of left pleura, o Base of left lung, o Left 9, 10, 11 ribs.  SPLEEN Surfaces 2. Visceral surface:  Concave, irregular, directed to the abdominal cavity.  Contains the hilum and impressions for 4 abdominal organs: GRCP o Gastric impression (related to fundus of stomach): above the hilum. o Renal impression: below the hilum o Colic impression (left colic flexure): lateral end of spleen o Pancreatic impression (tail of pancreas): lateral end of the hilum  SPLEEN Peritoneal covering  The spleen is completely covered by peritoneum of the greater sac except at the hilum.  It is attached and related to the following ligaments:  Gastro-splenic ligament  Lieno-renal ligament.  SPLEEN Gastrosplenic ligament  (between hilum of spleen and fundus and greater curvature of stomach)  contains: 1. Short gastric vessels 2. Left gastroepiploic vessels 3. Lymph nodes  SPLEEN Lienorenal ligament  (between hilum of spleen and left kidney)  contains: 1. Splenic vessels 2. Tail of pancreas  SPLEEN Arterial supply  Splenic artery  Origin: from coeliac trunk  Course: wavy course at the upper border of the pancreas.  It passes with the tail of the pancreas in the lieno-renal ligament.  Termination: At the hilum it divides into 5 or 6 splenic branches.  SPLEEN venous supply  Splenic vein  Termination: unit with superior mesenteric vein to form portal vein behind neck of Pancreas  SPLEEN Splenomegaly  Enlargement of the spleen beyond its normal size.  Causes: infections, anemias.  Enlarged spleen extends downward and medially (due to the presence of the phrenico- colic ligament that prevents its direct downward descent).  The splenic notch(s) may be felt by palpation through the anterior abdominal wall.  SPLEEN Rupture of the spleen  Injury of the spleen is common due to fracture of the 9, 10, 11 ribs, thin capsule, highly vascular.  Causes: automobile accidents, during playing contact sports, or due to penetrating wounds of the lower left thorax.  SPLEEN Splenectomy  Remove a diseased or damaged spleen  Its attachments to other organs are gently cut.  The tail of pancreas is in close relation to the hilum of spleen so it could be injured during splenectomy (surgical removal of the spleen).  SPLEEN Accessory spleen  (10-15% of people).  They are found at the hilum of spleen, the lieno-renal, or the gastro-splenic ligaments.  SPLEEN  During a splenectomy, a surgeon carefully dissects the peritoneal ligament containing the splenic vessels at the hilum of the spleen. Which of the following peritoneal ligaments is being dissected by the surgeon? (A) Hepatoduodenal ligament (B) Coronary ligament (C) Transverse mesocolon (D) Lienorenal ligament (E) Gastrolienal ligament  SPLEEN  A 65-year-old woman is injured in an automobile accident. Examination indicates she suffers fractures of left ribs 8 to 10 and profuse internal bleeding. Which of the structures indicated in the given CT scan of the abdomen will likely need to be surgically removed?