CH 5 The Circulatory System transports materials throughout the body

The body’s transport system consisting of the heart, blood, blood vessels and lymph vessels

• Transporting oxygen and nutrients to all cells to the body • Transporting carbon dioxide and other waste products away from the cells • Transporting chemical messengers, called hormones to the cells • Maintaining the pH of body fluids • Distributing heat and maintaining body temperature • Maintaining water content and ion concentration of the body fluids • Protecting against disease causing mirco-organisms • Clotting when vessels are damaged, preventing blood loss

Any cell of cell like structure in blood

• 55% • The fluid part of the blood in which cells are suspended • Function: transport the components of blood, including cells, nutrients, wastes, hormones, proteins and antibodies throughout the body

• 45% • One of the formed elements of the blood that contains haemoglobin • Function: transport oxygen from the lungs to cells through the body

The ratio of red blood cels to the total volume of blood

Shaped concave on both sides dipping inwards in the centre

• less than 1% • One of the blood cells containing a nucleus • Function: protecting the body from infection

Form other cells including macrophages that engulf pathogens and ages or damaged cells by phagocytosis

Involved in the immune response; cell mediated immunity uses T-lymphocytes and antibody- mediated immunity uses B- lymphocytes

Responsible for allergic reactions producing heparin and histamine to defend the body against parasites and bacteria

Lead to inflammatory responses; they respond to larger parasites such as worms

• very small % • A fragment of cytoplasm enclosed in a membrane but lacking a nucleus • Function: adhere to the lining and form a scaffold for the coagulation of the blood to form a clot

• The pigment in red blood cells - it is involved in the transport of oxygen and carbon dioxide through the body

Oxygen combined with haemoglobin

Blood containing a lot of oxygen

Blood that contains little oxygen

A molecule resulting from a combination of carbon dioxide and haemoglobin

Air sacs in the lungs

Substances produced by cells that cannot be used and that would be harmful if allowed to accumulate

• Vasoconstriction: the muscles in the walls of the small arteries that have been injured constrict immediately to reduce blood flow and blood loss • Platelet plug: The internal walls of blood vessels are normally very smooth but any damage creates a rough surface to which the platelets stick. Sticking platelets attract others and so a plug is built at the site of the injury. The platelets release substances that act as vasoconstrictors which enhance the constriction of damaged vessels. For many of the small tears that occur in capillaries the plugging action and constriction is sufficient to stop any bleeding. • Coagulation: The formation of a blood clot is a complex process involving a number of chemical substances or clotting factors that are present in the blood plasma. The series of reactions results in the formation of threads of a protein called fibrin. The fibrin threads form a mesh that traps blood cells, platelets and plasma. This mesh is the clot. the threads stick to the damaged blood vessels and hold the clot in position.

Formation of a blood clot and the blood becoming gel-like

Chemical substances in blood plasma that allow blood to clot

An insoluble protein that forms blood clots by holding blood cells, platelets, plasma together in a mesh