LYMPHATIC FINALS ANAPHY

Lymphatic System

It is a vast collection of cells and biochemicals that travel in lymphatic vessels. A network of vessels that assist in circulating fluids.

This is closely associated with the cardiovascular system

Primary Sites (Thymus and Bone marrow)

Sites where stem cells divide; location for maturation of T and B cells

Secondary Sites (Lymph nodes, Tonsils, Peyer’s patches, Spleen)

Sites where most immune responses occur, recognizes macrophages and foreign bodies.

Fluid Balance

Removes excess tissue fluid and returns it to the bloodstream.

~30 L/day

How much of fluid passing through blood capillaries to interstitial fluid?

27L

How much of fluid go back to blood capillaries?

3L

How much of fluid should diffuse with lymphatic capillaries, and go through lymphatic vessels as lymph then go back to bloodflow

Edema

If the fluid remains in the interstitial fluid, it can accumulate and cause swelling, a condition called ___, which can cause damage and death of tissues.

Lacteals

Are specialized lymph capillaries located in the villi of the small intestine, which absorb digested fat and fat-soluble vitamins

Chyle

A fat absorbed by the lymphatic system, has a milky white appearance.

Defense

Pathogens are filtered from lymph by lymph nodes and from blood by the spleen.

Interstitial Fluid

Also known as intercellular fluid; acts as the intermediary between the blood in capillaries and the tissue.

Lymph

Fluid flowing through the lymphatic system.

Clear colorless fluid, because it flows only in one direction, towards the heart and to the lymphatic vessels.

Excess fluid passes through the tissue spaces and enters lymphatic capillaries to become _____.

Water and Solutes derived from two sources (Substances derived from Plasma and Cells)

What does Lymph composed of?

Lymphatic Capillaries

Run parallel to blood capillaries in all body tissues; absorbs small chain fatty acids in the small intestine.

Allow diffusion of tissue fluid from interstitial spaces into the lymphatic pathway.

Simple squamous epithelium

What are Lymphatic Capillaries made of?

Lymphatic Vessels

Have thin walls and valves to prevent backflow; filled with lymph

Endothelial lining, Smooth Muscle, Connective Tissue

What are the three layers of Lymphatic Vessels?

Endothelial Lining

Which layer of Lymphatic Vessel is for diffusion?

Thymus

Site of T-lymphocytes maturation. A two lobed organ located posteriorly to sternum, medial to lungs, and superior to heart

Red Bone Marrow

T and B lymphocytes develop from stem cells in _____

Immunocompetent

Immature T-cells are called ____ and would go to the thymus for maturation.

Helper T-cells (CD4+)

Binds specific antigens presented by macrophages.

Killer T-cells (CD8+)

Directly kills virus-invaded body cells and cancer cells.

B cells

Produces plasma cells that secrete antibodies.

Lymph Nodes

Tiny oval-shaped structures covered by a capsule of fibrous connective tissue; ~600 located along lymphatic vessels.

Filter out potentially harmful particles from lymph.

Produce lymphocytes to destroy invading bacteria; site for the final maturation and recognition ability of T and B cells.

Trabeculae

Capsule sends inward extensions called ____.

Germinal center

When foreign materials are detected, the ______ is stimulated to produce lymphocytes, which are released into the lymph and later enter the bloodstream to produce antibodies.

Sinuses

Are present in lymph nodes that contain a network of fibers and macrophage cells.

Cortex

Outer region of Lymph Nodes which contains B-cells

Paracortex

Middle region of Lymph Nodes which contains T-cells

Medulla

Inner region of Lymph Nodes which contains phagocytes and macrophages

Cervical Lymph Nodes

Monitors lymph from the head and neck.

Axillary Lymph Nodes

Monitors lymph from the arms and breasts.

Inguinal Lymph Nodes

Monitor lymph from the legs.

Right Lymphatic Duct

Drains lymph from the head and neck region.

Thoracic Duct

Main collecting duct; drains lymph from the rest of the body.

Spleen

Largest lymphatic organ: located in the upper-left quadrant of the abdomen inferior to diaphragm.

Filters blood by removing old or damaged RBCs and foreign substances.

Produces lymphocytes and macrophages for immune defense.

Stores a large amount of RBCs

White Pulp

A tissue in the Spleen that contains compact masses of lymphocytes and macrophages.

Red pulp

A tissue in the Spleen that consists of a network of erythrocyte-filled sinuses and cords of splenic tissues of phagocytic cells.

Lymphatic Nodules

Egg-shaped masses of lymphatic tissues that are not surrounded by capsules; dense aggregations of lymphatic cells that lack a distinct boundary.

Tonsils

Group of lymphatic nodules in the oral cavity and nasopharynx.

Capable of producing lymphocytes and filtering inhaled or ingested substances and bacteria before they enter the body.

Divided according to location: Palatine, Pharyngeal, and Lingual

Palatine

Location of Tonsil for soft palate

Pharyngeal

Location of Tonsil for adenoids

Lingual

Location of Tonsil for tongue

Peyer’s Patches

Located in the digestive tract in the lumen of the terminal part of ileum, also known as aggregated lymphatic follicles.

Produces macrophages to destroy bacteria and prevent it from penetrating the walls of the small intestine.

Lymphatic Pathway

Lymph travels in only one direction; lymphatic circulation is an open system unlike the closed circulation of the circulatory system.

Hydrostatic Pressure

It is a pressure of tissue fluid drives the lymph into the lymphatic capillaries.

cells and blood capillaries

Lymphatic capillaries collect fluid between ____ and ____.

Intercellular spaces containing interstitial fluid

Lymphatic Capillaries

Lymphatic Vessels

Afferent Lymph Vessels

Lymph Nodes

Efferent Lymph Vessels

Lymphatic Trunks

Collecting Ducts

Subclavian Veins

What is the Flow of Lymph?

Collecting Ducts

Formed by the convergence of larger lymphatic vessels (lymphatic trunks); responsible for returning lymph to the venous circulation.

Lymphadenitis

Inflammation of the lymph nodes.

• Occurs when harmful substances enter the lymphatic system in large quantities that cannot be destroyed by the lymphocytes.

• Symptoms: tenderness of the lymph nodes and may be associated with fever or local pain.

Tonsillitis

 Inflammation of the tonsils

• Usually caused by bacterial infection, though it may also be viral.

• Symptoms: severe sore throat, difficulty swallowing and breathing, and fever.

• Treatment: antibiotics, proper hydration, and rest.

Lymphedema

Edema; swelling of the tissues due to an abnormal collection of lymph.

• Blockage or damage in the lymphatic vessels prevents normal lymph drainage, leading to fluid buildup in the affected area.

• Symptoms: swelling in the arms or legs, heaviness or tightness in the affected limb, and restricted movement or discomfort.

Infectious Mononucleosis

Disease caused by the Epstein-Barr virus.

• Sometimes called the kissing disease, because it is transmitted through saliva; it affects the lymph

  nodes, spleen, and white blood cells.

• Symptoms: fever, sore throat, fatigue, swollen

  lymph nodes, and enlarged spleen in severe cases.

Lymphoma

Cancer of lymphocytes; a malignant tumor that develops in the lymphatic tissues.

• Lymphocytes change and grow out of control, often beginning in lymph nodes.

• Begins as a painless enlargement of lymph nodes, which may compress nearby structures, causing complications.

Hodgkin’s Lymphoma

A type of Lymphoma that has the presence of Reed–Sternberg cells, which are large, abnormal (cancerous) lymphocytes.

Non-Hodgkin’s Lymphoma

A type of Lymphoma that lacks Reed–Sternberg cells; can arise in multiple lymph nodes or organs simultaneously and spreads more unpredictably.

Lymphatic Filariasis

A parasitic disease caused by Wuchereria bancrofti or Brugia malayi, carried by mosquito bites.

• Effects:

  • Severe swelling (commonly in legs, arms, or genital area)

  • Elephantiasis, or the permanent tissue enlargement

  • Hydrocele (in males), or the fluid accumulation in the scrotum