the human heart unit x heart action controlled by ans: medulla beats per minute: 70/80 (normal)
TRANSCRIPT
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 CO2
• 3 tissue layers• One-way valves
Blood Vessels Cont.• Arteries:• Carry blood away from
heart• High in O2
• 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: 90-140 mmHg
• (120 average)
Diastolic• Ventricles relax (atria fill)
• Range: 60-90 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• 60,000-100,000 miles
• Heparin
• Hemophilia
• Streptokinase
• Epinephrine-serotonin
• Heart cells (size, not #)
That’s All Folks!!
Quiz Tomorrow