AFCP Middle Mediastinum + Heart

Mediastinal shift

Deviation of the mediastinum, causing structures to get displaced

Mediastinal widening is caused by which conditions?

Tumors, aneurysms (widening of BVs), pericardial effusions (excess fluid around heart)

Tip: TAP

Mediastinal narrowing is caused by which conditions?

Lung masses, pleural effusion

The heart lies in which mediastinum?

Middle

What are the 3 layers of the pericardium (outermost → innermost)?

1. Fibrous pericardium

2. Parietal serous pericardium

3. Visceral serous pericardium

The pericardial cavity is the space between the _______ and contains _______

space between the parietal and visceral serous pericardium

contains pericardial fluid

What makes the pericardial fluid and what’s the purpose of it?

Serous pericardium

To reduce friction during heartbeats

What is the significance of the 2 sinuses of the pericardium?

They are 2 places where the visceral and parietal layers fuse (separated everywhere else) to keep the pericardial cavity closed

The transverse sinus is enclosed anteriorly by the _______ and posteriorly by the _______

Anteriorly: pulmonary trunk, aorta

Posteriorly: vena cava, pulmonary veins

The oblique sinus is a _____-shaped sinus located ______

J

behind the left atrium

During cardiac surgery, a ligature is passed through the ______ to clamp the ascending aorta and pulmonary trunk

transverse sinus

What are the 3 arterial supplies of the pericardium and which one specifically supplies the visceral serous pericardium?

1. Pericardiacophrenic artery

2. Branches from the thoracic aorta

3. Coronary arteries - supplies the visceral serous pericardium

The pericardiacophrenic a. is a branch off of the _______

internal thoracic a.

The pericardium has which 2 venous supplies?

1. Pericardiacophrenic vv.

2. Azygos venous system

The vagus nerve is also called the _____

cranial nerve X (CN X)

The phrenic nerves stem from which spinal nerves?

C3-C5

The cardiopulmonary splanchnic nerves stem from which spinal nerves?

T1-T4

What is the sensory, sympathetic, and parasympathetic innervations of the pericardium?

Sensory: phrenic nerves (C3-C5)

Sympathetic: cardiopulmonary splanchnic nerves (T1-T4)

Parasympathetic: vagus nerve (CN X)

Pericarditis is _________ and causes ____ pain. It may make the _____ rough, causing the pericardial friction rub sound.

inflammation of the pericardium

causes chest pain

serous pericardium

Cardiac tamponade is caused by hemopericardium, which is _________

blood in the pericardial cavity

What is the effect of cardiac tamponade?

Heart is compressed → cardiac output is reduced

1. Hypotension

2. Jugular - venous distention

3. Muffled heart sounds

Beck’s triad - indicative of cardiac tamponade

Pericardiocentesis is the treatment for _______, where ____ is withdrawn from the pericardial sac at the ______ intercostal space near the ____ angle.

Pericardiocentesis is the treatment for cardiac tamponade, where fluid is withdrawn from the pericardial sac at the 5th-6th intercostal space near the infrasternal angle.

The heart is located at which intercostal spaces? Which space is the apex found?

2nd - 5th intercostal space

Apex: left 5th ICS

The anterior (sternocostal) surface of the heart is formed by ______

2/3 right ventricle, 1/3 left ventricle

The posterior surface of the heart is formed by ______

2/3 left atrium, 1/3 right atrium

The inferior (diaphragmatic) surface of the heart is formed by ______

2/3 left ventricle, 1/3 right ventricle

The right surface of the heart is formed by _______

the right atrium

Dysphagia is the compression of the _____ that can result from _____-

Dysphagia is the compression of the esophagus that can result from a dilated left atrium.

What are the 4 venous supplies of the right atrium?

1. Superior and inferior vena cava

2. Coronary sinus

3. Anterior cardiac veins

A landmark for the AV node

Triangle of koch

The following make up what structure and where is this structure located?

1. Tendon of todaro

2. Ostrium (os) of the coronary sinus

3. Septal leaflet of the tricuspid valve

Boundaries of the triangle of koch

Located in the right atrium

The chordae tendineae connects which 2 structures?

The tricuspid/bicuspid valve to the papillary muscles

The moderator band contains ______

the right branch of the AV bundle

The pulmonary trunk/arteries carry _____ blood from the _____ to the ______.

The pulmonary trunk/arteries carry deoxygenated blood from the right ventricle to the lungs.

The bicuspid and tricuspid valves are _____ valves that prevent ______.

AV (atrioventricular) valves

backflow of blood from the ventricles back to the aorta

The aortic and pulmonic valves are _____ valves.

semilunar valves

Explain which structures the following valves are located between:

1. aortic valve

2. mitral (bicuspid) valve

3. tricuspid valve

4. pulmonic valve

1. aortic valve: left ventricle and aorta

2. mitral (bicuspid valve): left atrium and left ventricle

3. tricuspid valve: right atrium and right ventricle

4. pulmonic valve: right ventricle and pulmonary trunk/artery

The 1st heart sound, or the ____, is caused by closure of the _____ valves

lub

atrioventricular valves (AV valves)

The second heart sound, or the _____, is caused by closure of the ______

dub

semilunar valves

The aortic valve contains which 3 sinuses? Which 2 arteries come out of these sinuses?

1. Posterior aortic sinus

2. Right aortic sinus → right coronary artery

3. Left aortic sinus → left coronary artery

The _____ skeleton of the heart anchors and provides an attachment point for the _______ of the heart’s valves

The fibrous skeleton of the heart anchors and provides an attachment point for the cusps of the heart’s valves

The fibrous skeleton of the heart is made from __ ______ rings

4 dense collagen rings

Circulation of the blood through the heart:

1. O2 (rich/poor) blood flows into the _______.

2. ______ → _______.

3. _____ → lung.

4. At the lung, O2 (rich/poor) → O2 (rich/poor) blood.

5. O2 (rich/poor) blood flows into the ____.

6. _____ → ______.

7. _____ → body.

Circulation of the blood through the heart:

1. O2 poor blood flows into the superior and inferior vena cava.

2. right atrium → right ventricle.

3. pulmonary artery → lung.

4. At the lung, O2 poor → O2 rich blood.

5. O2 rich blood flows into the pulmonary veins.

6. left atrium → left ventricle.

7. aorta → body.

Auscultations of the heart are performed _______, NOT _______.

where the waves reverberate

NOT at the location of the valves

There are 4 heart auscultation sites, describe each:

1. Aortic

2. Tricuspid

3. Pulmonary

4. Mitral/bicsupid

1. Aortic: 2nd intercostal space, right parasternal

2. Tricuspid: 5th intercostal space, left parasternal

3. Pulmonary: 2nd intercostal space, left parasternal

4. 5th intercostal space, left midclavicular line

Tip: All The Pretty Men

The aortic sinuses give rise to the _______ and _______ arteries, which are the main arterial supplies of the heart.

left and right coronary arteries

What are the 3 branches of the right coronary artery?

1. Posterior interventricular artery

2. Right marginal artery

3. Sinoatrial nodal branch

Tip: P(Q)RS

In right coronary dominance, the _______ artery supplies what?

posterior intraventricular artery supplies the back of the ventricles, the right atrium, most of the right ventricle, and the SA and AV nodes

In left coronary dominance, the ____ artery supplies what?

anterior intraventricular artery supplies both ventricles, the left atrium, most of the left ventricle, and the SA and AV nodes

Which is more common, right or left coronary dominance?

Right - 80%

Left: 10%

What are the 3 branches of the left coronary artery?

1. Anterior interventricular artery (LAD)

2. Circumflex artery → left marginal artery

Great cardiac vein accompanies which artery?

The anterior interventricular branch of the left coronary artery

What are the 2 anastomoses of the coronary arteries?

1. Anterior interventricular (LAD) and posterior interventricular arteries

2. Left and right coronary arteries

The main venous drainage of the heart comes from the _______, which contains branches from the ______, ______, and ______

coronary sinus

branches from the great, middle, and small cardiac veins

The coronary sinus drains into _____

the right atrium

Coronary atherosclerosis

Narrowing of the coronary arteries due to plaque accumulation

Angina pectoris

When does it occur/relieve?

Cardiac pain that occurs during exertion and relieved by rest due to narrowing of coronary arteries

Narrowing of coronary arteries can lead to ________

myocardial infarction (heart attack)

What are the following treatments used for: bypass graft, coronary angioplasty, intravascular stenting

Treating coronary artery disease

Coronary artery bypass graft

Taking an artery/vein from a different part of your body and inserting it to bypass the damaged coronary artery and create a new blood flow

Coronary angioplasty

A catheter with a balloon tip flattens the plaque and allows blood to flow through the coronary arteries

Intravascular stenting

Stent is placed to maintain dilation of the coronary artery

“Pacemaker” that generates cardiac electrical impulses

Sinuatrial (SA) node

Slows down electrical impulses and transmits it to the ventricles

Atrioventricular (AV) node

Divides the electrical impulses to the R and L ventricles

Bundle of his

Causes ventricles to contract

Purkinje fibers

Located in the right atrium between the crista terminalis and opening of the SVC

Sinuatrial (SA) node

Located in the right atrium at the interatrial septum

Atrioventricular (AV) node

Located at the membranous part of the interventricular septum

Bundle of his/AV bundle

What artery mostly supplies the SA and AV nodes?

Right coronary artery

What mostly supplies the AV bundle/bundle of his?

Anterior interventricular artery (LAD)

_____ of the conducting system causes asynchronous contraction of the heart.

Ischemia (lack of blood flow)

What do artificial cardiac pacemakers replace?

Replaces the SA node to initiate contraction

The _____ nerve is the parasympathetic innervation of the heart and _____ heart rate.

vagus nerve (CN X)

slows heart rate

The ______ nerves are the sympathetic innervations of the heart and _____ heart rate.

cardiopulmonary splanchnic nerves (T1-T4)

increases