Neck and Bucal Cavity

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Lymphatic System and Thyroid Gland
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The Lymphatic System

• Many different organs and systems work together
  in an effort to keep us alive and healthy.
• In this ongoing struggle, the lymphatic system
  plays a central role it has an extensive
• drainage network that helps to
• - keep bodily fluid levels in balance
• - defends the body against infections, and
• - assists in tissue repairs.

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Main Functions of Lymphatic System

• The production, maintenance and distribution of
  lymphocytes WHITE BLOOD CELLS (WBCs)
• Basic Overview
• The Lymphocytes (WBCs), protect the body against
  antigens (viruses, bacteria, etc.) that invade
  the body.
• Lymphocytes are produced and stored within lymph
  organs, such as
• The spleen,
• The thymus and
• The bone marrow.
• Lymphocytes must be specifically made to defend
  any new or known invader that enters the body.

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Main Functions of Lymphatic System

• The return of fluid and solutes from the
  peripheral tissues of the blood.
• Lymph is the liquid that baths every cell in
  the body. This fluid, called Interstitial Fluid,
  is the transport mechanism.
• Lymph Nodes are areas within the body that
  collect waste proteins (antigens, broken up
  cells) and dispose of them.

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The Lymphatic System

• The Three Main Components of the Lymphatic
  System
• 1. Vessels-
• A network of lymph vessels (like blood vessels)
  start from the peripheral (outside) tissues and
  move internally towards local areas of holding,
  digestive sites Lymph Nodes.

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The Lymphatic System

• 2. Fluid LYMPH
• The Lymph is clear and watery. It flows through
  the lymphatic vessels.
• Lymph Fluid contains
• Fluid from the intestines (chyme), which contains
  proteins and fats.
• RBCs.
• WBCs, especially lymphocytes, the cells that
  attack bacteria in the blood.

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The Lymphatic System

• 3. Lymphoid organs-
• Lymphoid organs are connected to the lymphatic
  vessels and contain large numbers of lymphocytes.
  
• (Ex. Lymph nodes, spleen and thymus).

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Lymphatic Organs

• Lymph organs bone marrow, lymph nodes, spleen,
  and thymus.
• Human lymph nodes, called lymph glands and
  swollen glands, are bean-shaped and range in
  size from a few millimeters to about 1-2 cm in
  their normal state.
• They may become enlarged due to a tumor or
  infection. (Where does a doctor check first?)
• White blood cells are located within honeycomb
  structures of the lymph nodes.
• Spleen- The spleen, which is located in the upper
  left part of the abdomen under the ribcage, works
  as part of the lymphatic system to protect the
  body. It clears worn out red blood cells and
  other foreign bodies from the bloodstream to help
  fight off infection.

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Lymphatic Organs

• TonsilsThe tonsils are areas of lymphoid tissue
  on either side of the throat.
• Thymus- an organ located in the upper anterior
  portion of the chest cavity just behind the
  sternum.
• Hormones produced by this organ stimulate the
  production of certain infection-fighting cells.

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Thyroid Gland

• Through the hormones it produces, the thyroid
  gland influences almost all of the metabolic
  processes in your body. 
• Thyroid disorders can range from a small,
  harmless goiter (enlarged gland) that needs no
  treatment to life-threatening cancer. 
• The most common thyroid problems involve abnormal
  production of thyroid hormones. 
• Too much of these vital body chemicals results in
  a condition known as hyperthyroidism.  
• Insufficient hormone production leads to
  hypothyroidism.

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