Lymphatic system

Clare Hargreaves-Norris

Lymphatic System

NVQ Level 3 Beauty Therapy


Introduction

The lymphatic system is the secondary circulatory system that drains away tissue fluids and waste products and filters the lymph protecting against infection. It is a one way drainage system that drains excess tissue fluid and transports it back into the venous system of the blood supply. It also returns to the blood any large protein molecules that were unable to pass back through the capillary walls. Unlike the circulatory system, the lymphatic system does not have a heart to pump it around the body; instead its onward movement is assisted by the pumping action of the muscles that surround the lymph vessels, the position of valves to prevent backflow and the negative pressure created in the thorax during inspiration.


Functions of the lymphatic system

The lymphatic system: Filters bacteria, foreign materials, toxins and any

harmful materials. Drains away excess fluid to prevent water clogging of

the tissues and cells. Transports proteins back into the blood supply. Produces lymphocytes which protect and defend the

body against infection. Produces antibodies to fight bacteria. Absorbs fat from the intestine and transport it to the

liver.


Did you know?

When the body is ill with an infection, your glands swell up. Many of these glands are lymph nodes. When you are healthy they are about the size of a pea or grape, but during illness they can be as big as golf balls.

Lymph nodes contain billions of white cells, multiplying rapidly to fight the invading germs. During illness they fill with millions of extra white cells and also dead germs.


Structures of the lymphatic system

The lymphatic system is comprised of: Lymph fluid Lymph capillaries Lymph vessels Lymph nodes Lymph ducts Spleen


Lymph fluid

Lymph fluid is a transparent, colourless, watery fluid that is similar to blood plasma, however contains more waste products and fewer nutrients. Lymph usually contains the larger particles that could not re-enter the blood supply. Lymph is made up of:

Plasma (watery substance) Proteins Waste products and toxins Fats Urea Gases Lymphocytes


Lymph capillaries

Lymph capillaries are fine, hollow elastic tubes which are similar to blood capillaries in structure, however, they are wider. The cell walls are made from a single layer of epithelial tissue and are more permeable than blood capillaries, therefore allowing larger substances to pass through their walls. Lymph capillaries are blind ended and transport the lymphatic fluid away from the cells and tissues.


Lymph vessels

These larger vessels run closely alongside veins and transport the lymphatic fluid through one or more sets of lymph nodes. They have collapsible walls, carry lymph at a steady pressure, and are similar to veins in structure, as they contain valves called semi lunar valves. The lymph enters the node through the afferent vessel and leaves through the efferent vessel.


Lymph nodes

Lymph nodes are tiny clusters of glands, which filter out bacteria and toxins, therefore, protecting the body against infection. Lymphocytes, macrophages and phagocytes are numerous here; these white blood cells produce antibodies and ingest bacteria and foreign materials to fight against infection. When a person is suffering from an infection the lymph nodes swell and become tender, as the white blood cells fight the infection.


Lymph ducts

The lymph ducts are the vessels that allow the collected tissue fluid to return back into the blood stream. The right lymphatic duct drains lymph from the right side of the head, neck, chest and right arm, the thoracic duct drains from the left side of the head and neck, left arm, left side of chest area and both legs.Area drained by right

lymphatic duct

Area drained by thoracic duct


The spleen

The spleen is situated behind the stomach and is responsible for producing antibodies and lymphocytes, and destroying old red blood cells.


Lymph nodes of the head and neck


Lymph nodes of the body


The Location & Function Of The Main Lymph Nodes


Lymph Nodes

Node Location Function

Buccal nodes Face, cheek region Drains the eyelids, nose and the facial skin

Parotid nodes In the face, infront of the ear

Drains the eyelids, nose and ears

Posterior auricular

nodes

Behind the ear Drains behind the ear and temple

Occipital nodes

Back of head Drains the back of the scalp and the upper neck region

Submental nodes

Under the chin Drains lower lip, chin and the

floor of the mouth

Submandibular

nodes

Under the jaw line Drains the chin, lips, nose, cheeks and tongue

Superficial cervical

nodes

In the neck, below the ear

Drains lower part of ear, parotid area and neck

Deep cervical nodes

In the neck Drains the back of the scalp and neck


Lymph Nodes

Node Location Function

Axillary nodes In the underarms Drains the pectoral area and

the upper arm

Supratrochlear lymph nodes

In the elbow Drains the fingers, thumb, hand and forearm

Intestinal lymph

nodes

Inside the abdominal

cavity

Drain abdominal viscera

Iliac nodes Hip area Drains the pelvic area including reproductive organs and the bladder

Inguinal nodes In the groin Drains the pelvic area & legs

Popliteal nodes Behind the knees Drains the toes, feet and lower legs

Cisterna chyli Sack like chamber in

the abdomen

Receives lymph from the lower abdomen, lower

limbs, and pelvis and conveys it

into the thoracic duct


Interaction between blood and lymph

The blood and lymph supply work closely alongside each other and interact at numerous points:

Primary interaction occurs within capillary exchange. Small lymph vessels run alongside the arteries and

veins collecting lymph from tissues. Lymph vessels transport lymph fluid to the lymph

nodes for filtering, thereby preventing foreign substances entering the blood stream.

Production of fresh lymphocytes are activated which circulate around the body in both lymph and blood vessels.

Lymph transports fat from the digestive tract to the blood.

Lymph returns to the blood supply via the lymphatic ducts and into the subclavian veins.


Diagram to illustrate the interaction between the blood and lymph

Arteriole

Red blood cells

Blood capillary with semi permeable walls

Venule

Tissue fluid bathing cells and tissues

Lymph fluid

Cells and tissues

Lymph capillary with semi permeable walls


Factors affecting lymphatic drainage

General blood circulation - a good strong circulation ensures that the flow of tissue fluid into the lymph vessels is maintained.

Exercise - the action of the muscles speeds up the movement of lymph through the vessels.

Massage - enhances the drainage by forcing the movement of lymph through the vessels.

Education

Lymphatic system