Ch 7.8 Cardiovascular System ence-channel/29732-exploring-time- heart-beat-video.htm

Heart Basics Weight- approximately 11 oz Beats- 100,000 beats /day (2.5 billion/avg. lifetime) Pumps 2,000 gallons of blood /day

Anatomy Location- surrounded by lungs, vertebral column and sternum – 2/3 to left of midline

External View

angiogram healthy heart

Enlarged heart due to alcoholism and high blood pressure

Cross section of heart

io202/heart/inthrt.htm

Layers of the heart Endocardium-smooth layer of cells that lines the interior of the heart Myocardium-muscular layer

Pericardium-sac that covers the outside of the heart Pericardial fluid-prevents friction and damage to the heart

Coronary arteries coronary veins

valves

Circulation

Blood Pressure Pulse Blood Pressure

Systolic pressure = ventricular contraction Diastolic pressure = ventricular relaxation Normal = 120 mmHg 80 mmHg Hypertension= persistently elevated arterial pressure

Arrhythmias-abnormal heart rhythm – Early contraction of the atria – Ventricle fibrillation-random contractions, can cause death – Defibrillator-shocks the heart so that is can regain its normal rhythm – Pacemaker-monitors the hearts rhythm and uses electrical impulses to the heart when necessary

Heartbeat-controlled by electrical impulses or the conduction system /hhw/hhw_electrical.html /hhw/hhw_electrical.html

P wave- atrial depolarization; prior to contraction QRS Complex- ventricular depolarization; masks atrial repolarization T wave- ventricular repolarization PROBLEMS: High P wave=enlarged atrium High Q wave= heart attack Flat T wave= not enough oxygen getting to heart

Heart sounds-lubb ( tri/bi cuspids close) dubb-(semilunars close)

Blood vessels 62,000 miles of vessels that make up a closed circuit.

Arteries Carry blood away from the heart High in oxygen except the pulmonary artery Made of muscular and elastic tissue Aorta Coronary artery Arterioles Inner layer-smooth to prevent clots Middle layer-muscle Outer-connects to surrounding tissue

Capillaries Connect arteries to veins One cell thick

Veins Return blood to heart Low in oxygen except the pulmonary vein Thin walls, less elastic compared to arteries Have valves Venules Venae Cavae – Superior vena cava – Inferior vena cava

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Blood Formed elements or Blood Corpuscles Plasma – Serum – Fibrogenin and Prothrombin

Fibrinogen and prothrombin at work

Erythrocytes Life span of 120 days Hemoglobin ry.htm

Leukocytes Neutrophils – phagocytosis Basophils – Inflammatory response Eosinophils – allergy Lymphocytes – Protection by developing antibodies Monocytes – phagocytosis

Thrombocytes or platelets Used in blood clotting-clump together to form a clot

Blood Types Rh Factor Rh positive Rh negative

Cardiologist Hematologist

Pathology of the Cardiovascular sys

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Aneurysm

Artificial Pacemakers Replace SA nodes b/c it may not be working correctly