Chapter 10 Cardio

Properties of the myocardium and the cardiac cycle

What is the anatomy of heart

It is hollow, has 4 chambers, muscular and roughly fist sized. 

Where does the heart lie

behind the sternum, two thirds to the left, between the second though the sixth ribs.

Where is the Apex

It is the lowest part of the heart, located at the fifth intercostal space

What are sulci

They are the grooves that mark the boundaries between its chambers and contain the coronary blood vessels.

Coronary sulcus

Is the atrioventricular groove, it circles around the heart and represents the separation of the atria from the ventricles. 

Anterioventricular sulcus

Located on the anterior surface of the heart and represents the separation of the left and right ventricle.

Posterior interventricular sulcus

Located on the posterior surface of the heart and represents the separation of the left and right ventricle.

How does the sulci protect the heart from damage

The fatty tissue within the sulci cushions the heart. 

What is pericardium

Double-walled sac enclosing the heart.

What is the pericardium’s structure

Fibrous pericardium and serous pericardium

What is the fibrous pericardium

Tough, loose-fitting, and inelastic sac surrounding the heart

Serous Pericardium has two layers

Parietal Layer

Visceral layer

What is the parietal layer

Inner lining of the fibrous pericardium

Visceral layer/epicardium

Covering the outer surface of the heart and great vessels. 

What is pericardial fluid

Thin layer of fluid separating parietal and visceral pericardium. It helps minimize friction during contraction and expansion.

What is pericardial effusion

Abnormal amount of accumulated fluid between layers

What causes Pericardial effusion

Infections 

• Myocarditis

• Bacterial (tuberculosis)

Cancer

Trauma

Metabolic disorders 

• Kidney failure, hypothyroidism, liver failure.

What is Cardiac Tamponade

Large pericardial effusion that may affect pumping function. can cause serious drop in blood flow to body (Shock)

What is pericarditis

Inflammation of the pericardium

What is the heart wall composed of

Epicardium, Myocardium, Endocardium

What is the epicardium

THe outer layer of the heart wall

What is the myocaridum

Comprises bulk of heart and is composed of muscle tissue

What is the endocardium

Inner layer of the heart wall, forms thin continuous tissue with blood vessels.

What are the atrioventricular valves

They lie between the atria and the ventricles.

What is the tricuspid valve

It is the exit of the right atrium

What is the Mitral valve

It is at the left atrium exit. is also known as the bicuspid valve.

How does ventricular contraction influence the AV Valves

It forces the valves closed, preventing back flow of blood into atria

Chordae Tendineae

Where the lower ends of valves anchor to ventricular papillary muscles attach to. 

How is papillary contraction in the AV valves important

During systole pulls on the chordae, preventing valve reversing into atria.

Semilunar valves

Consist of three half-moon shaped cusps. separates the ventricles from their arterial outflow tracts. (pulm art. and aorta)

What is systole

Cardiac contraction.

What happens during systole

valves open, allowing ventricular ejection into arteries (pulmonary artery adn aorta)

Diastole

Valves close, preventing back flow of blood into ventricles

Regurgitation

The backflow of blood through an incompetent of a damaged valve.

Stenosis

A pathological narrowing or constriction of a valve outlet, which causes increased pressure in the proximal chamber and vessel.