Chapter 20 - The Heart

Fibrous pericardium

tough connective tissue preventing overstretching of the heart, protection and anchors the heart to the mediastinum

Serous pericardium

Contains parietal and visceral layers separated by the pericardial cavity

Visceral pericardium (epicardium)

covers the heart's outer surface

Parietal pericardium

fused to and lines the fibrous pericardium

Epicardium

serous membrane covering the hearts surface

Myocardium

middle layer of the heart composed of cardiac muscle

Pericardial cavity

between the parietal and visceral pericardiums, containing serous fluid reducing friction while heart is beating

Endocardium

a thin layer of connective tissue covering the inner surface of the heart and valves

Right atrium

receives deoxygenated blood from the venae cavae and coronary sinus

Superior vena cava

transports low oxygenated blood from the upper portion of the body to the heart

Inferior vena cava

carries low oxygenated blood from lower regions of the body to right atrium

Right ventricle

receives blood from the right atrium and pumps it into the pulmonary artery

Left atrium

receives oxygenated blood from pulmonary veins

Flow of the blood

superior and inferior vena cava - right atrium - right ventricle - atrioventricular valve -

Myocarditis

Inflammation of the myocardium

Endocarditis

Inflammation of the endocardium

Acute pericarditis

acute inflammation of the pericardium

Chronic pericarditis

gradual inflammation of the pericardium

Left ventricle

receives oxygenated blood from the left atrium and sends it through the aorta

Pulmonary fibrous ring

surrounds pulmonary valve

Left atrioventricular fibrous ring

surrounds bicuspid valve

Right atrioventricular fibrous ring

surrounds tricuspid valve

Aortic fibrous ring

surrounds aortic valve

Tricuspid valve

prevents backflow of blood from right ventricle into the right atrium

Bicuspid valve

prevents backflow of blood from the left ventricle into the left atrium

Pulmonary semilunar valve

prevents backflow of blood from the pulmonary arteries into the right ventricle

Aortic semilunar valve

prevents backflow of blood from the aorta into the left ventricle

Coronary arteries

blood vessels that branch from the aorta and carry oxygenated blood to the heart muscle (myocardium)

Coronary veins

Blood vessels that removes carbon dioxide and wastes from the heart muscle (myocardium)

Myocardial ischemia

Reduced blood flow to the myocardium

Myocardial infarction

Heart attack due to blocked blood flow

Treatments for heart attack

thrombolytic injection, coronary angioplasty (balloon), and coronary artery bypass grafting

Structure of cardiac muscle tissue

involuntary, striated, 1-2 centrally located nuclei, includes intercalated discs

Functions of cardiac muscle tissue

circulates blood, maintains blood pressure

SA node

Primary pacemaker of the heart.

Artificial pacemaker

a device that sends out small electrical currents to stimulate the heart to contract

P wave

atrial depolarization

QRS complex

ventricular depolarization

T wave

ventricular repolarization and relaxation

Factors regulating stroke volume

1. preload 2. contractility 3. afterload

Factors regulating heart rate

1. autonomic nervous system 2. hormones 3. ions 4. age 5. gender 6. fitness 7. temperature