The Lymphatic System and Lymphoid Organs Overview

Lymphatic System

Network returning fluids from tissues to blood.

Lymphatic Vessels

Drainage vessels collecting interstitial fluid.

Lymph

Fluid within lymphatic vessels.

Lymph Nodes

Structures cleansing lymph during circulation.

Spleen

Organ filtering blood and supporting immunity.

Thymus

Site for T cell maturation.

Tonsils

Lymphoid tissues guarding throat area.

Interstitial Fluid

Fluid surrounding tissue cells.

Hydrostatic Pressure

Pressure exerted by fluid in capillaries.

Colloid Osmotic Pressure

Pressure due to proteins in blood.

Lymphatic Capillaries

Blind-ended vessels collecting excess interstitial fluid.

Glymphatic System

Brain's drainage system for interstitial fluid.

Minivalves

One-way valves in lymphatic capillaries.

Chyle

Fatty lymph from intestinal absorption.

Lacteals

Specialized lymphatic capillaries in intestines.

E C F

Extracellular fluid, including interstitial fluid.

Pathogens

Microorganisms causing disease.

Cell Debris

Dead cells and waste in tissues.

Cancer Cells

Malignant cells that can spread throughout the body.

Collagen Filaments

Structures anchoring lymphatic capillaries to tissue.

Degenerative Diseases

Conditions like Alzheimer's linked to lymphatic malfunction.

Fluid Leakage Prevention

Minivalve closure prevents backflow of lymph.

Lymphatic Capillaries

Smallest vessels that collect lymph from tissues.

Collecting Lymphatic Vessels

Thicker-walled vessels with valves, similar to veins.

Lymphatic Trunks

Larger vessels formed from collecting lymphatic vessels.

Paired Lumbar Trunks

Drain lymph from lower limbs and pelvis.

Bronchomediastinal Trunks

Drain lymph from thoracic organs and mediastinum.

Subclavian Trunks

Drain lymph from upper limbs.

Jugular Trunks

Drain lymph from head and neck.

Intestinal Trunk

Single trunk draining lymph from digestive organs.

Right Lymphatic Duct

Drains right upper body into venous circulation.

Thoracic Duct

Drains rest of body, including lower limbs.

Cisterna Chyli

Enlarged sac at thoracic duct's origin in some.

Vasa Vasorum

Blood vessels supplying larger lymphatic vessels.

Lymphangitis

Inflammation of lymphatic vessels causing red streaks.

Lymph Transport

Movement of lymph through low-pressure lymphatic vessels.

One-Way Valves

Prevent backflow of lymph in lymphatic vessels.

Milking Action

Skeletal muscle contraction aiding lymph flow.

Pressure Changes

Thoracic pressure changes assist lymph movement.

Pulse Pressure Waves

Arterial pressure waves help propel lymph.

Lymphedema

Localized swelling due to insufficient lymph return.

T Lymphocytes

Manage immune response and destroy infected cells.

B Lymphocytes

Produce antibodies marking antigens for destruction.

Macrophages

Phagocytize foreign substances and activate T cells.

Dendritic Cells

Capture antigens and activate T cells in nodes.

Reticular Cells

Produce reticular fibers supporting lymphoid tissues.

Lymphoid Tissue

Component of the immune system for lymphocyte activity.

Reticular Connective Tissue

Loose tissue that supports lymphoid cells.

Macrophages

Cells that reside on reticular fibers, phagocytizing pathogens.

Diffuse Lymphoid Tissue

Loose arrangement of lymphoid cells in organs.

Lymphoid Follicles

Spherical structures of packed lymphoid cells.

Germinal Centers

Sites of B cell proliferation in lymphoid follicles.

Peyer's Patches

Aggregations of lymphoid follicles in the ileum.

Primary Lymphoid Organs

Sites where T and B cells mature.

Red Bone Marrow

Location where B cells mature.

Thymus

Organ where T cells mature.

Secondary Lymphoid Organs

Sites where lymphocytes encounter antigens.

Lymph Nodes

Filters lymph and house lymphocytes.

Spleen

Organ involved in filtering blood and immune response.

Mucosa-Associated Lymphoid Tissue (MALT)

Tissue including tonsils and Peyer's patches.

Cortex of Lymph Node

Outer region with densely packed B cell follicles.

Medulla of Lymph Node

Inner region containing B cells and plasma cells.

Lymph Sinuses

Capillaries in lymph nodes for lymph flow.

Dendritic Cells

Present antigens to T cells in lymph nodes.

Lymph Cleansing

Lymph nodes filter lymph to remove pathogens.

Immune System Activation

Process where lymphocytes respond to antigens.

Trabeculae

Fibers extending inward to compartmentalize lymph nodes.

Lymphatic Capillaries

Small vessels that collect lymph from tissues.

Afferent lymphatic vessels

Vessels that bring lymph to lymph nodes.

Efferent lymphatic vessels

Vessels that carry lymph away from lymph nodes.

Subcapsular sinus

Large sinus lymph travels through in lymph nodes.

Medullary sinuses

Smaller sinuses in lymph nodes before exiting.

Hilum

Indented region where lymph exits the lymph node.

Lymphadenopathy

Swollen lymph nodes due to infection or disease.

Buboes

Infected lymph nodes, often pus-filled.

Spleen

Largest lymphoid organ, cleanses blood and pathogens.

Splenic artery

Artery supplying blood to the spleen.

Splenic vein

Vein draining blood from the spleen.

White pulp

Immune function area in the spleen.

Red pulp

Area in spleen for destroying old blood cells.

Trabeculae

Fibrous tissue structures within the spleen.

Macrophages

Cells that engulf pathogens and old blood cells.

Lymphocyte proliferation

Increase in lymphocytes for immune response.

Iron recycling

Process of reusing iron from red blood cells.

Fetal erythrocyte production

Spleen's role in producing red blood cells in fetuses.

Cancer-infiltrated lymph nodes

Lymph nodes with trapped metastasizing cancer cells.

Inflamed lymph nodes

Swollen nodes due to infection or immune response.

Splenic cords

Reticular tissue separating blood-filled splenic sinusoids.

Blood platelets storage

Function of spleen to store platelets for release.

Spleen

Organ that filters blood and supports immune function.

Splenectomy

Surgical removal of the spleen.

Homeostatic Imbalance

Disruption of body's stable internal environment.

Peritoneal Cavity

Space within the abdomen containing organs.

Liver

Organ that performs many metabolic functions.

Bone Marrow

Tissue producing blood cells and immune cells.

MALT

Mucosa-associated lymphoid tissue protecting body entryways.

Tonsils

Lymphoid tissue forming a ring around pharynx.

Palatine Tonsils

Largest tonsils, often infected, located in oral cavity.

Lingual Tonsil

Lymphoid tissue at the base of the tongue.

Pharyngeal Tonsil

Adenoid when enlarged, located in nasopharynx.