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