Lymphatic System

Vocabulary flashcards covering key structures, fluids, and immunological processes of the lymphatic system.

Lymphatic System

Body-wide network that drains excess interstitial fluid, transports dietary lipids, and orchestrates immune responses.

Lymph

Clear-to-milky fluid formed from interstitial fluid; about 2–3 L produced each day.

Chyle

Milky lymph rich in dietary lipids absorbed from the small intestine.

Lacteal

Specialized lymphatic capillary in the small intestine that absorbs lipids and produces chyle.

Lymphatic Capillaries

Blind-ended, highly permeable vessels that collect interstitial fluid from tissues.

Lymphatic Vessels

Channels that carry lymph from capillaries toward lymph nodes; equipped with valves.

Lymphatic Trunks

Large collecting vessels formed by convergence of lymphatic vessels; include lumbar, bronchomediastinal, subclavian, jugular, and intestinal trunks.

Lumbar Trunk

Paired lymphatic trunk that drains lymph from the lower limbs, pelvic organs, and part of the abdominal wall.

Bronchomediastinal Trunk

Paired trunk draining lymph from thoracic viscera and the thoracic wall.

Subclavian Trunk

Paired trunk draining lymph from upper limbs and superficial thoracic wall.

Jugular Trunk

Paired trunk draining lymph from the head and neck.

Intestinal Trunk

Single lymphatic trunk that drains lymph from abdominal viscera, especially the intestines.

Right Lymphatic Duct

Short duct that drains the right upper limb, right side of head, and right thorax into the right subclavian vein.

Thoracic (Left) Duct

Major duct that drains lymph from the rest of the body into the left subclavian vein.

Bone Marrow

Primary lymphatic organ where B cells mature and all lymphocytes originate.

Thymus

Primary lymphatic organ that educates T cells via positive and negative selection.

Positive Selection

Process in the thymus where T cells that recognize self-MHC molecules are allowed to survive.

Negative Selection

Thymic process eliminating T cells that bind strongly to self-antigens, preventing autoimmunity.

Lymph Node

Secondary lymphatic organ that filters lymph and houses B cells, T cells, and dendritic cells.

Cortex (Lymph Node)

Outer region of a lymph node containing follicles and germinal centers rich in B cells.

Paracortex

Middle region of a lymph node primarily populated by T cells.

Medulla (Lymph Node)

Inner region of a lymph node containing medullary cords of plasma cells and macrophages.

Germinal Center

Site within lymph node follicles where B cells proliferate, mutate, and differentiate into plasma and memory cells.

Afferent Lymphatic Vessel

Vessel through which lymph enters a lymph node.

Efferent Lymphatic Vessel

Single vessel at the hilum through which filtered lymph exits a lymph node.

MALT

Mucosa-associated lymphoid tissue that guards mucous membranes throughout the body.

Peyer’s Patches

Aggregates of lymphoid tissue in the distal ileum; part of GALT (gut-associated lymphoid tissue).

Tonsils

Ring of lymphoid tissue guarding the pharynx; provides first-line defense against inhaled or ingested pathogens.

Palatine Tonsils

Pair of tonsils located on either side of the oropharynx.

Pharyngeal Tonsil (Adenoid)

Single tonsil located in the nasopharynx.

Lingual Tonsils

Pair of tonsils located at the base of the tongue.