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HLT31507 CERTIFICATE III IN NUTRITION & DIETETIC ASSISTANCE. THE CARDIOVASCULAR SYSTEM delivered by: Mary-Louise Dieckmann. A closed system of the heart and blood vessels The heart pumps blood Blood vessels allow blood to circulate to all parts of the body
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HLT31507 CERTIFICATE III IN NUTRITION & DIETETIC ASSISTANCE THE CARDIOVASCULAR SYSTEM delivered by: Mary-Louise Dieckmann
A closed system of the heart and blood vessels The heart pumps blood Blood vessels allow blood to circulate to all parts of the body The function of the cardiovascular system is to deliver oxygen and nutrients and to remove carbon dioxide and other waste products The Cardiovascular System
Location Thorax between the lungs Pointed apex directed toward left hip About the size of your fist The Heart
The Heart Figure 11.1
External Heart Anatomy Figure 11.2a
Right and left side act as separate pumps Four chambers Atria Receiving chambers Right atrium Left atrium Ventricles Discharging chambers Right ventricle Left ventricle The Heart: Chambers Figure 11.2c
Blood Circulation Figure 11.3
Aorta Leaves left ventricle Pulmonary arteries Leave right ventricle Vena cava Enters right atrium Pulmonary veins (four) Enter left atrium The Heart: Associated Great Vessels
Taking blood to the tissues and back Arteries Arterioles Capillaries Venules Veins Blood Vessels: The Vascular System Figure 11.8a
The Vascular System Figure 11.8b
Walls of arteries are the thickest Lumens of veins are larger Skeletal muscle “milks” blood in veins toward the heart Walls of capillaries are only one cell layer thick to allow for exchanges between blood and tissue Differences Between Blood Vessel Types
Capillary beds are where the exchange of nutrients, respiratory gases and wastes take place between the blood and the cells of the body Capillary Beds Figure 11.10
Diffusion at Capillary Beds Figure 11.20
Major Arteries of Systemic Circulation Figure 11.11
Major Veins of Systemic Circulation Figure 11.12
The only fluid tissue in the human body Classified as a connective tissue Living cells = formed elements Non-living matrix = plasma Blood
Color range Oxygen-rich blood is scarlet red Oxygen-poor blood is dull red pH must remain between 7.35–7.45 Blood temperature is slightly higher than body temperature It is highly viscous and slightly denser than water. Normal blood volume in males is 5-6 L and 4-5 L in females. Physical Characteristics
Composed of approximately 90 percent water – non-living substance of blood Includes many dissolved substances Nutrients Salts (metal ions) Respiratory gases Hormones Proteins Waste products Blood Plasma
Albumin – regulates osmotic pressure Clotting proteins – help to stem blood loss when a blood vessel is injured Antibodies – help protect the body from antigens Plasma Proteins
Erythrocytes = red blood cells Leukocytes = white blood cells Platelets = cell fragments Blood Cells (formed elements)
The main function is to carry oxygen Anatomy of circulating erythrocytes Biconcave disks Essentially bags of hemoglobin Anucleate (no nucleus) Contain very few organelles Erythrocytes
Outnumber white blood cells 1000:1 4-6 million per mm3 Live for 90-120 days Erythrocytes
Crucial in the body’s defense against disease These are complete cells, with a nucleus and organelles Able to move into and out of blood vessels (diapedesis) Can move by ameboid motion Can respond to chemicals released by damaged tissues Leukocytes (WBC)
All blood cells come from stem cell – hemocytoblast They become either lymphoid stem cells or myeloid stem cells Types of Blood Cells Figure 10.4
Derived from ruptured multinucleate cells (megakaryocytes) Needed for the clotting process Normal platelet count = 300,000/mm3 Platelets
Thrombus A clot in an unbroken blood vessel Can be deadly in areas like the heart Embolus A thrombus that breaks away and floats freely in the bloodstream Can later clog vessels in critical areas such as the brain Undesirable Clotting