Chapter 21 - Cardiovascular System

What are the two circuits of the cardiovascular system

Pulmonary circuit and systemic circuit

What does the pulmonary circuit do

Carries blood between the heart and the lungs for gas exchange

What does the systemic circuit do

Carries blood between the heart and the rest of the body

How many chambers does the heart have

Four chambers

Where is the heart located relative to the midline

Slightly left of the midline

Which side of the thorax is the heart mostly on

Left side

What is the apex of the heart

The pointed inferior tip formed by the left ventricle

What is the base of the heart

The broad superior portion formed mainly by the atria

What is the pericardium

A double-walled sac that encloses and protects the heart

Name the two layers of the serous pericardium

Parietal pericardium and visceral pericardium

Which layer is also called the epicardium

Visceral pericardium

What is found in the pericardial cavity

Serous fluid

Name the three layers of the heart wall

Epicardium, myocardium, endocardium

Which layer contains cardiac muscle

Myocardium

Which layer lines the chambers

Endocardium

Identify the right vs left atrium and ventricle on a diagram

Atria are superior chambers and ventricles are inferior chambers, with right side handling deoxygenated blood and left side handling oxygenated blood

What sulcus separates the atria from ventricles

Coronary sulcus

What sulcus separates the ventricles

Interventricular sulcus

Which chambers receive blood

Right and left atria

Which chambers pump blood out

Right and left ventricles

What separates the atria

Interatrial septum

What separates the ventricles

Interventricular septum

Name the four heart valves

Tricuspid, bicuspid (mitral), pulmonary semilunar, aortic semilunar

Which valves are atrioventricular

Tricuspid and bicuspid (mitral) valves

Which valves are semilunar

Pulmonary and aortic valves

When are AV valves open vs closed

Open during ventricular relaxation and closed during ventricular contraction

When are semilunar valves open vs closed

Open during ventricular contraction and closed during ventricular relaxation

What are chordae tendineae

Fibrous cords that anchor AV valves to papillary muscles

What do papillary muscles do

Prevent AV valves from prolapsing into the atria during contraction

Where are papillary muscles found

In the ventricles

Trace blood flow through the heart

Superior and inferior vena cava and coronary sinus → right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary trunk → pulmonary arteries → lungs → pulmonary veins → left atrium → bicuspid valve → left ventricle → aortic valve → aorta

Which vessels enter the right atrium

Superior vena cava, inferior vena cava, and coronary sinus

Which vessels leave the ventricles

Pulmonary trunk leaves the right ventricle and aorta leaves the left ventricle

What do coronary arteries supply

The myocardium

What does the coronary sinus drain

Deoxygenated blood from the myocardium

Where does coronary blood ultimately return

Right atrium

What is systole

Contraction phase of the heart

What is diastole

Relaxation phase of the heart

What structure initiates the heartbeat

Sinoatrial (SA) node

Trace the electrical conduction pathway

SA node → AV node → AV bundle (bundle of His) → right and left bundle branches → Purkinje fibers

What does a P wave represent

Atrial depolarization

What does the QRS complex represent

Ventricular depolarization

What does the T wave represent

Ventricular repolarization