Lymphatic System Lab 7 Flashcards

Study Notes

Lymphatic System Overview

Right lymphatic duct collects lymph from the right upper extremity, head, and thorax; empties into neck veins at the junction of the right internal jugular and right subclavian veins; present in only 20% of individuals.
Thoracic duct is the largest lymphatic vessel, draining into the left internal jugular and left subclavian veins, serving most of the body's lymphatic drainage.

Lymphatic Trunks

Five main lymphatic trunks include:
- Lumbar trunks: drain lymph from lower limbs and pelvic region.
- Intestinal trunk: collects lymph from digestive organs like the stomach and intestines.
- Bronchomediastinal trunks: gather lymph from the thoracic viscera.
- Subclavian trunks: receive lymph from upper limbs and superior thoracic wall.
- Jugular trunks: collect lymph from the head and neck.

Lymph Nodes

Cervical lymph nodes: located in the neck, filtering lymph from surrounding areas.
Axillary lymph nodes: situated in the armpit, involved in immune response from upper limbs and breast tissues.
Inguinal lymph nodes: found in the groin, filtering lymph from lower body regions.

Specialized Structures

Cisterna chyli: a dilated sac at the thoracic duct's base, receiving lymph from the intestinal and lumbar trunks, rich in chyle (fat-rich lymph).
Pharyngeal tonsil (adenoids): located in the posterior nasopharynx, plays a role in immune defense.
Palatine tonsils: situated in the oral cavity, protect against pathogens entering through the pharynx.
Lingual tonsils: located at the base of the tongue, contributing to immune function.

Key Organs

Spleen: positioned beneath the diaphragm; functions include initiating immune responses, serving as a reservoir for blood cells, and phagocytizing old erythrocytes and pathogens.
Thymus: a bilobed gland in the anterior mediastinum; vital for T-lymphocyte maturation; regresses with age, replaced by adipose tissue.

Lymphatic Structures

Lymph nodes possess two main regions:
- Cortex: outer layer containing lymphatic nodules and sinuses, where T-lymphocytes are organized.
- Medulla: inner layer with medullary sinuses and cords supporting lymphatic cells.
Germinal centers: sites within lymphatic nodules for B-lymphocyte proliferation.
Medullary cords: connective tissue fibers supporting lymphatic cells within the medulla.
Medullary sinuses: pathways through which lymph flows as it is filtered by lymph nodes.

Cells of the Lymphatic System

Lymphocytes: specialized white blood cells that recognize and attack specific antigens, crucial in adaptive immunity.

Other Structures

Vermiform appendix: a pouch extending from the large intestine, containing MALT to protect against cecal infections.
Peyer's patches: aggregates of lymphoid tissue in the ileum, initiating immune responses to intestinal antigens.

Description

Test your knowledge of the lymphatic system with these flashcards from Lab 7. Each card provides definitions and information about specific components, like the right lymphatic duct and thoracic duct, vital for understanding lymphatic function. Perfect for students studying anatomy and physiology.