The Human Heart Unit X

Heart Action Controlled by ANS: Medulla Beats per minute: 70/80 (normal)

Heart Action Cont. Blood cycle: One minute Blood loss: 35% Serious 50% Fatal

Heart Action Cont. Factors that affect heart rate: Age Weight Physical condition Emotional State Gender

Heart Contractions Four chambered heart Atria (atrium): Contract first Ventricle(s): Contract second “All or None Law”

Heart Contraction Cont. Vagus nerve Sinoatrial node: “SA node” “Pacemaker of Heart” Regulates heartbeat Atrialventricular node: “AV node” “Bundle of His”

Atria Ventricles SA node AV node Bundle of His Heart Contraction: Impulse Transmission

Heart Cont. Composition: Cardiac muscle Location: Pericardial cavity Pericardium (membrane) Pericardial fluid

Heart Cont. Heart structure* Blood flow* (Overhead)

Blood Vessels Veins: Carry blood to heart High in CO 2 3 tissue layers One-way valves

Blood Vessels Cont. Arteries: Carry blood away from heart High in O 2 3 tissue layers (much thicker)

Blood Vessels Cont. Capillaries: Connect arteries to veins Gas exchange

Blood Vessels Cont. Coronary Arteries & Veins: Supply the heart

Blood Pressure Two types: Systolic* Diastolic*

Systolic Contraction of ventricles Range: mmHg (120 average)

Diastolic Ventricles relax (atria fill) Range: mmHg (80 average)

Blood Pressure Cont. Major causes of high blood pressure: Heart attack Stroke (most common problem)

High Blood Pressure Factors Age Weight Emotions Physical cond. Diet Arteriosclerosis Blood viscosity Blood volume Cardiac output Gender

General Review 60, ,000 miles Heparin Hemophilia Streptokinase Epinephrine-serotonin Heart cells (size, not #)

That’s All Folks!! Quiz Tomorrow