Monday April 5, 1999
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Lecture notes:

There are about 5 quarts of blood in a 150 lb. Man.

Blood is a transport fluid:

1. it carries raw materials to cells.
2. It carries products and wastes from cells.
3. It helps maintain an internal environment favorable for optimum cellular activity.

Blood is divided into 2 portions: cellular and plasma.

Plasma portion contains: Function

Water solvent

Plasma proteins immunity, blood clotting, maintenance of blood volume,
liquid transport.

Other solutes ions, hormones, micronutrienst, dissolved gasses.

Cellular portion is 40-50% of the volume of blood.

The original source of all blood and lymphoid cells is the bone marrow. The cells that differentiate to produce these cells are called hemopoietic stem cells.

More fluid leaves the capilaries than returns. The excess returns via the vessels of the lymphatic system. Once tissue fluid enters the vessels of the lymphatic system, it is called lymph.

Purpose:

1. return of excess filtered fluid to the blood.
2. Return of small amounts of proteins that leave the capillaries.
3. Transport of fats absorbed from the digestive tract.
4. Transport of foreign particles and cellular debris to disposal centers. (the lymph nodes)

The lymphatic circulation is a one way blind ended system, which directs tissue fluid back to the systemic circulation. The thoracic ducts empty tissue fluid into the blood stream, at the subclavian veins.

Thymus: located behind the sternum (breast bone). It is an endocrine gland which secretes hormones regulating lymphocyte maturation. The T lymphocytes mature in this organ.

Spleen: located behind the stomach, high in the abdominal cavity. It clears old and damaged red blood cells. Macrophages clean up debris and bacteria. It is a holding station for large numbers of lymphocytes.

Lymph Nodes: located along lymph vessels. Macrophages here clear lymph of bacteria and cellular debris.

Bone Marrow: original production site for all lymphocytes.

Tonsils and other "nodules of lymphoid tissue" are located throughout the respiratory and digestive tracts as production centers for lymphocytes and for defense.

Size: slightly larger than your own fist.

It rests only between beats.

Layers of the heart: Myocardium: muscle layer
Pericardium: tough fibrous outer layers
Endocardium: smooth inner layer

The heart is two pumps, divided by a septum.

The right side pumps blood to the lungs.

The left side pumps blood to the body.

The heart has 4 chambers. The two upper chambers are called atria. The two lower chambers are called ventricles.

**** notice the thickness of each