Student should be able to Describe the parts and location of

lymphatic system

Lymph

Lymph vessels

Lymph nodes

Lymph organs

Lymph is a clear watery fluid, similar in composition to plasma, except plasma proteins.

Carry large particles including bacteria which are destroyed by lymph nodes

Lympha in small intestine – Chyle

• Lined by endothelial cells

• Present in all parts of the body EXCEPT– Central Nervous System– Bones– Superficial layers of skin

• Join together to form Lymphatic vessels

• Lymphatic vessels join together to form– Thoracic duct Left subclavian vein– Right lymphatic duct Right subclavian vein

Oval or bean shaped

Functions Filtration Phagocytosis Proliferation of lymphocytes

Presence of lymph follicles with germinal centers

Covered by capsule

• Largest lymphatic organ

• Left hypochondriac region

• Functions– Phagocytosis – Abnormal cells– Storage of blood – 350 ml of blood– Immune response – enlarge during infection

(splenomegaly)– Erythropoiesis

Microscopic structure: Trabeculae

Red pulp – contains blood

White pulp – contains lymphatic tissue

Central arteriole present

• Lies in the upper part of mediastinum behind sternum

• Grows until puberty then regresses

• Functions– Production of T lymphocytes– Produce “Thymosin” hormone

• Microscopic structure:– Presence of Hassal’s corpuscle

TONSIL Located in oralcavity Tonsillar crypt present

PEYER’S PATCHES Located in small intestine

Ross & wilson anatomy & physiology 10th edition – Pgs 132 - 137