UNIT 9- Circulatory, Respiratory and Endocrine Systems

Circulation ► Circulatory System- ► System responsible for the transport of materials  ex. oxygen, carbon dioxide, food, cellular wastes, etc

Circulatory System ► Two types- ► Open-  blood is not always contained in blood vessels, ex. arthropods ► Closed-  blood is always contained in vessels, ex. vertebrates

Human Circulatory System ► Consists of three parts  1. Heart  2. Blood vessels  3. Blood

Heart (p933, 934) ► Heart  Pumps blood to all parts of the body ► Chambers  atria/auricles- receiving chambers  ventricles- pumping chambers

Heart ► Valves  control the flow of blood, prevents back-flow ► Pericardium  thin protective sac around the heart ► Septum  Wall separating the right and left sides of heart  Prevents mixing of oxygen rich and oxygen poor blood

Heartbeat (p 935) ► Control ► Sinoatrial Node (SA) (pacemaker)-  Group of cells that initiate the contraction of the heart. ► Atrioventricular node (AV)  Stimulates contraction of ventricles

Pulse (p935) ► Two beats ► Systole-  Occurs when ventricles contract ► Diastole-  Occurs when ventricles relax ► Average- 70 – 90 beats per minute for adults. (Quick Lab- p 934)

Blood flow through heart ► 1. Vena cavae  ► 2.  ► 3.  ► 4.  ► 5.  ► 6.  ► 7.  ► 8.  ► 9.  ► 10.  ► 11.  ► 12.  ► 13. Aorta  ► 14. The body

Blood flow through heart ► 1. Vena cavae (a, g)  ► 2. Right atrium (d)  ► 3. Tricuspid valve (e)  ► 4. Right ventricle (f)  ► 5. Semilunar valves  ► 6. Pulmonary arteries (b, i)  ► 7. Lungs  ► 8. Pulmonary veins (c, j)  ► 9. Left atrium (h)  ► 10. Bicuspid valve (k)  ► 11. Left ventricle (l)  ► 12. Semilunar valves  ► 13. Aorta (n)  ► 14. The body

Blood Vessels ► Arteries (p 936)  Vessels that carry blood away from the heart, usually oxygen rich, have a thicker layer of smooth muscle  (take pulse from artery measure of heart rate)

Blood Vessels ► Aorta  Largest artery in the body, carries blood directly from the heart ► Arterioles  Very small arteries, lead to capillaries

Blood Vessels ► Capillaries  Smallest blood vessels  Very thin membrane walls  Actual exchange of materials occurs

Blood Vessels ► Veins (p 937)  Vessels that return blood to the heart  Thinner layer of smooth muscle  Some have valves ► Venules  Very small veins

Circulation (p 938) ► Pulmonary  Carries blood between the heart and lungs  Only circulation where arteries carry oxygen poor blood and veins carry oxygen rich blood

Circulation ► Systemic  Carries blood between the heart and all parts of the body  Arteries carry oxygen rich blood  Veins carry oxygen poor blood

Circulation ► Coronary- heart ► Renal- kidney ► Hepatic portal- liver

Blood Pressure ► A measure of the force that blood exerts on a vessel wall ► Two measurements- systolic/diastolic ► Systolic- ventricle contraction ► Diastolic- ventricle relaxation ► Normal = 120/80

Lymphatic System ► A network of vessels that collects fluid (lymph) that is lost by the blood into tissues and returns it to the circulatory system