Cardiovascular System
Shape of Heart
• Male 310 g - female 225g
• Apex - blunt point
• Top - base
• 2/3 to the left
• Rest on diaphragm
• 5th & 6th rib
Size of things
• Infant 1/130 of total weight
• Adult 1/300 of total weight
• 4 ¾ long, 3 ½ wide, and 2 ½ deep
Valves
Blood pathway
Blood Vessels
• All Blood vessels– Smooth muscle– Elastic- collagen– 3 layers
• Arteries
• Capillaries
• Veins
Arteries
• Carries blood away from heart
• Largest vessels
• Arterioles are smallest
• Precapillary sphincters– Regulate blood flow to capillaries
Capillaries
• Microscopic
• Over 1 billion
• Some organs have more and some avascular
• 3 types
• Transfer of– O2, CO2 & nutrients
Veins
• Carries blood to heart
• Smallest venules
• Get larger as they move blood to the heart
• Stretch to accomodate blood
• One-way valves
EKG or ECG
• Electrocardiography
• Measures the electrical activity of the heart.
• Shows contraction of the heart
• Speed
PQRST Wave
PQRST
• P wave –SA node (pace maker) starts stimulus and atria contract.
• QRS wave – moves to Purkinje fibers and contract the ventrical
• T- wave repolarizes- muscles go back to normal and expand back to shape
Nodes
• 1. SA node (Sinoatrial) – pace maker
• 2. AV node (Atrioventricular) base of Rt Atrium.
• 3 Purkinje fibers – go down the septum to apex then up the side of the ventricles.
Hole in Heart
Heart Structure
• Murmur (valves)– Rheumatic fever- Streptococcal infection
• Atherosclerosis
• Angina Pectoris
• Coronary bypass
• Pulmonary Edema (right side)
• Congestive heart failure (CHF) left side
Cardiomyopathy
• Abnormal large heart
• Hypertrophic cardiomyopathy– Death of young athletes
Blood Vessels
• Varicose Veins
Cardovascular Disorder
• Hypertension – high blood pressure 140/90
• Heart beats– Heart block AV node is block– Brachycardia – slow below 60– Tachycardia – fast over 100– Sinus dysrhythmia- inhaling & exhaling
Disease of the Heart
• Fibrillation: Contraction in not rhythmic
• Septic shock – infectious agents releases toxins into blood