Anatomy of the Lymphatic System

Vocabulary flashcards covering the structural components, anatomical pathways, organs, and clinical concepts of the human lymphatic system based on the lecture material.

Lymphatic System

A system responsible for the drainage of tissue fluids and leaked plasma proteins to the bloodstream, as well as the removal of cellular debris and infection.

Lymph

A colorless fluid that circulates inside lymphatic vessels alongside veins and is not visible to the naked eye.

Chyle

A milky, opaque lymph formed in the small intestine when absorbed fats are packaged by the intestinal epithelium.

Afferent Lymphatic Vessels

Lymphatic vessels that carry lymph directly into a lymph node.

Efferent Lymphatic Vessels

Lymphatic vessels that transport lymph away from a lymph node.

Right Lymphatic Duct

A major lymphatic duct that drains lymph from the right side of the head and neck, right upper limb, right side of the thorax, and right upper abdomen into the systemic venous system at the junction of the right internal jugular and right subclavian vein.

Thoracic Duct

The largest lymphatic duct in the body ($45\,\text{cm}$ in length) that drains lymph from the lower limbs, pelvis, perineum, abdomen, left side of the head and neck, left upper limb, and left thorax.

Cisterna Chyli

A dilated sac in front of the lower border of $T12$ that marks the origin of the thoracic duct.

Lymph Nodes

Small, encapsulated masses of lymphoid tissue ($0.1$ to $2.5\,\text{cm}$ long) located along lymphatic vessels that act as filters for foreign substances and contain lymphocytes and macrophages.

Axillary Lymph Nodes

A group of lymph nodes located in the armpit region that drains lymph from the upper limb and breast.

Cervical Lymph Nodes

A group of lymph nodes located in the neck that drains lymph from the head and neck.

Thymus Gland

A central lymphoid organ consisting of two unequal pyramidal lobes located posterior to the sternum; it is involved in early immune system development, grows until puberty, and later diminishes and gets replaced by fibrous and adipose tissue.

Spleen

The largest lymphoid organ in the body, reddish-brown in color, weighing about $200\,\text{gm}$, located in the left hypochondrium between the stomach and diaphragm beneath the 9th, 10th, and 11th ribs.

Superior Border of the Spleen

A distinct border of the spleen characteristically marked by a notch near its anterior end.

Visceral Surface of the Spleen

The medial surface of the spleen that features three impressions for adjacent structures: the gastric impression (stomach), colic impression (splenic flexure), and renal area (left kidney).

Diaphragmatic Surface of the Spleen

The smooth, convex lateral surface of the spleen that lies against the diaphragm and bears impressions from the 9th to 11th ribs.

Hilum of the Spleen

A fissure on the visceral surface of the spleen that transmits splenic vessels and nerves, and provides attachment to splenic ligaments.

Splenic Artery

A tortuous blood vessel supplying the spleen that divides into five or more terminal branches at the hilum to accommodate movement of the organ.