Cardiovascular System pt 1 & 2

Mediastinum

The middle section of the chest cavity.

What is the mediastinum bordered by?

• Thoracic inlet (on top)

• diaphragm (bottom)

• sternum (in front)

• lungs (on either side)

• vertebral column (in back)

3 parts of mediastinum

anterior, middle and posterior

organs in mediastinum

heart, aorta, thymus, chest portion of trachea and esophagus

Heart

A muscular organ that pumps blood through the circulatory system.

Capillaries

Permit the diffusion of oxygen and nutrients from the blood into the tissues, and diffusion of waste products of the metabolism from the tissues into the blood.

Tricuspid Valve

Between Right Atrium and Right Ventricle

Pulmonic Valve

Between Right Ventricle and Pulmonary Artery

Mitral Valve

Between Left Atrium and Left Ventricle

Aortic Valve

Between Left Ventricle and Aorta (semilunar)

blood flow through heart (start at lungs oxygenated blood)

lungs - pulmonary veins - left atrium - mitral valve - left ventricle - aortic valve - aorta - capillaries - vena cava - right ventricle - tricuspid valve - right atrium - pulmonary valve - pulmonary artery - lungs

Cardiac Conduction System

The heart has specialized muscle cells here that send signals to the heart muscle that cause it to contract

Conduction System Components

SA node, AV node, bundle of His, bundle branches, and Purkinje fibers

Conduction Path

• Starts in the SA node (anatomical pacemaker) causing the atrial muscles to contract

• AV node

• bundle of His down

• Purkinje fibers, causing the ventricles to contract.

three main layers of heart

superficial to deep

• epicardium

• endocardium

• myocardium (main part)

Lub

First heart sound (S1) – Mitral and Tricuspid valve closing

Dub

Second Heart sound (S2) – Pulmonic and Aortic valves closing

S1-S2

Systole - heart emptying

S2-S1

Diastole - heart filling

Systolic pressure

Pressure released slowly until first sounds are heard.

Diastolic pressure

When sounds disappear, blood is free flowing.

Coronary Artery Disease (CAD)

Narrowing of the arteries - stops nutrients and oxy from getting to heart

Arrhythmia

An irregular or abnormal heartbeat.

Heart Failure

The heart does not pump as well as it should, leading to salt and water retention, causing swelling and shortness of breath.

Heart Valve Disease

Examples include mitral valve prolapse, aortic stenosis, and mitral valve insufficiency

• when valves don’t close correctly - blood flow problem

Heart Muscle Disease (Cardiomyopathy)

valve muscles get too strong and blood can’t enter

Peripheral Artery Disease

Similar to CAD but in the body

Coronary artery disease

• plaque build up in arteries blocking blood flow and causing heart attack

  • body tries to destroy fat and instead inflames it more

  • clot continues to grow over time

• generally caused by blood vessel problems - hypertension/ diabetes