11.21 C Flashcards
The two main divisions of the pericardium are what?
fibrous on the outside and serous on the inside
The serous pericardium has what two layers?
parietal on the outside and visceral on the inside
Where on the heart does the pericardium attach?
above the heart, actually fusing with the adventitia of the great vessels
In addition to the great vessels, the pericardium attaches to what?
the diaphragm
What is the normal volume of liquid in the pericardial sac?
20 mL
The pericardial fluid is produced by what?
the visceral pericardium
The pericardial fluid most resembles what other fluid?
an ultrafiltrate of plasma
What are the two pericardial sinuses?
the transverse pericardial and the oblique pericardial sinuses
Where is the transverse pericardial sinus located?
- anterior to the superior vena cava and posterior to the aorta and pulmonary trunk
- it’s where you hold the heart while removing it from a cadaver
Where is the oblique pericardial sinus located?
it is the most dependent (lowest) portion of the pericardial sac in a patient lying on their back
Leaking bypasses are likely to result in excess fluid where?
in the oblique pericardial sinus
Cardiac tamponade does what to stroke volume?
it prevents the chambers from fully expanding, thus limiting diastole and stroke volume
Classic indications of cardiac tamponade are what?
- jugular venous distension
- distant heart sounds
- hypotension with dyspnea
How is a pericardiocentesis performed?
- 18G needle placed just left of the Xiphoid process
- angle at 45 degrees and pointed towards medial edge of the left scapula
Pericarditis refers to inflammation of what?
the pericardial sac lining
What are three causes of pericarditis?
- bacterial
- viral
- malignancy
What are the three ways in which acute pericarditis can be classified?
- fibrous (usually viral)
- purulent (usually bacterial)
- hemorrhagic (blood)
Describe the pain associated with acute pericarditis.
- remains substernal
- possible referral to back and shoulders but not down left arm
- worsens upon lying down or when inhaling deeply
Pericardial friction rub is highly specific for what?
acute pericarditis
Describe the sound generated by a pericardial friction rub.
- squeaky leather or a scratchy sound
- becomes louder with forced expiration
Most of the blood to and from the pericardium travels via what vessels?
the pericardiophrenic artery and vein
The pericardiophrenic artery supplies what?
the pericardium
The pericardiophrenic artery runs alongside what other structure?
the phrenic nerve
The pericardium is innervated via what?
the phrenic nerve, which carries motor efferents and sensory afferents
What is the base of the heart?
- opposite the apex, it is the posterior surface near the top
- formed largely by the left atrium
- sort of back and to the right
What is the apex of the heart?
the most inferior portion of the heart formed by the left ventricle
What is the diaphragmatic surface of the heart?
- the inferior surface
- formed largely by the left ventricle
What is the sternocostal surface of the heart?
- the anterior surface
- formed largely by the right atrium and right ventricle
What is the obtuse margin of the heart?
the rounded left margin of the heart
What is the acute margin of the heart?
- inferior border
- divides the sternocostal and diaphragmatic surfaces
What are the three margins of the heart?
- obtuse (left)
- right
- inferior
What is the coronary sulcus?
the dividing line between the atria and ventricles
The skeleton of the heart is made up of what?
fibrous connective tissue
Half of aortic valve insufficiencies are due to what?
aortic root dilatation (fibrous skeleton stretching)
What is the sinus venarum?
smooth part of the atrial wall
What are pectinate muscles?
the rough part of the atrial wall
Where is the oval fossa located?
in the right atrium
What is the crista terminalis?
the point where pectinate muscles end and the sinus venarum (smooth wall) begins
What is the coronary sinus?
a channel that collects blood from the coronary veins and delivers it to the right atrium
Where is the SA node located?
at the superior end of the crista terminalis
The fossa ovalis marks the site of what?
the embryonic foramen ovale through which blood passes from right atrium to left atrium
What is the eustachian valve?
the valve of the inferior vena cava which in the embryonic heart directs blood from the inferior vena cava through the foramen ovale and into the left atrium
What is the right atrioventricular orifice?
the site of blood flow out of the right atrium and into the right ventricle
The smooth wall of the left atrium is derived from what?
incorporation of the pulmonary veins
The rough wall of the left atrium is derived from what?
the embryonic atrium
What are papillary muscles?
- found in the ventricles
- they attach to the cusps of the mitral and tricuspid valves and contract to prevent prolapse
What are chorda tendineae?
fibrous strands connecting papillary muscles to the cusps of the atrioventricular valves
The tricuspid valve regulates what?
the flow of blood between the right atrium and ventricle
The mitral valve regulates what?
the flow of blood between the left atrium and ventricle
What are the three cusps of the tricuspid valve?
anterior, posterior, septal
What are trabeculae carneae?
irregular muscular elevations on the inner wall of the ventricles
What is the septomarginal trabecula?
- aka moderator band
- a trabecula carneae that conveys right branch of the atrioventricular bundle to the anterior papillary muscle
What is the conus arteriosus?
the smooth-walled outflow tract of the right ventricle to the pulmonary trunk
What is the supraventricular crest?
part of the right ventricle that separates the ventricle proper from the conus arteriosus
What are the cusps of the mitral valve?
anterior and posterior (bicuspid)
Papillary muscle rupture typically leads to what?
atriventricular valve dysfunction/insufficiency
AV valve insufficiency is often the result of what?
papillary muscle rupture secondary to MI
Left ventricular hypertrophy is most commonly the result of what two things?
- chronic hypertension
- aortic valve stenosis
What would cause left ventricular hypertrophy and chamber dilation?
volume overloading as a consequence of aortic or mitral valve regurgitation
Which is more common, mitral or tricuspid valve prolapse?
mitral valve prolapse is more common given that the left ventricle contracts at higher pressure
What are the symptoms of mitral valve regurgitation?
- chest pain
- cardiac arrhythmia
- shortness of breath with activity or when lying flat
What are the right and left aortic sinuses?
the spaces above the cusps of the leaves of the aortic valve
After development, does the pulmonary or aortic valve end up more anterior?
the pulmonary valve does
What is the posterior semilunar cusp?
the posterior cusp of the aortic valve
When is blood flow into the coronary arteries greatest?
during diastole
The coronary arteries extend from what other structure?
the right and left aortic sinuses
The most common congenital heart anomaly is what?
a bicuspid aortic valve
A bicuspid aortic valve is associated with what gene defect?
that of the Notch-1 gene
A bicuspid aortic valve is most commonly ____ but may cause what other problems?
- benign
- aortic valve stenosis
Aortic valve stenosis can cause excessive turbulence which will in turn cause what?
ascending aortic aneurysm
The right coronary artery supplies what?
- right atrium
- most of right ventricle
- diaphragmatic surface of left ventricle
- posterior 1/3 of AV septum
- SA node in 60% of people
- AV node in 80% of people
The left coronary artery supplies what?
- left atrium
- most of left ventricle
- anterior 2/3 of AV septum
- SA node in 40% of people
- AV node in 20% of people
The right/left dominance of a heart is with regards to which side does what?
which coronary artery supplies the posterior interventricular artery
In a right dominant heart, what is true?
the posterior interventricular artery arises from the right coronary artery
What is a balanced heart?
one in which the posterior interventricular artery arises from both the left and right coronary arteries
Is a left, right, or balanced heart most common?
a right dominant heart
What is the most common coronary artery occlusion?
blockage in the left anterior descending branch
What are the three most common coronary artery occlusions?
- LAD near the origin
- circumflex branch near the origin
- right coronary artery near the origin
How are anterior interventricular descending artery occlusions are usually bypassed?
using the internal thoracic artery which comes off the subclavian artery and attaching it to the LAD in a spot distal to the occlusion
Which arteries and veins are most commonly grafted for coronary artery bypass?
- radial artery (from arm)
- great saphenous vein (from leg)
Most blood coronary blood returns to the heart through what vessels?
- coronary sinus
- anterior cardiac veins
Where is the SA node located?
at the superior point of the cristae terminaleus near the superior vena cava
Where is the AV node located?
by the opening of the coronary sinus in the right atrium
Why doesn’t the AP from the SA node travel directly from the atria into the ventricles?
because the tissue is discontinuous across the annuli fibrosi (fibrous skeleton)
Blockage within the anterior interventricular artery may lead to what electrical disturbance?
- blockage leads to ischemia
- ischemia damages myocytes
- conduction is interrupted
- may lose ventricular contractions
How is a pacemaker placed?
by threading the lead down the superior vena cava
Pacemakers are generally planted in what two locations within the heart?
- at the SA node
- at the apex in the right ventricle to replace the AV node
What is the cardiac plexus?
a plexus of sympathetic, parasympathetic, and afferent nerve fibers
Why does cardiac pain get referred?
because after traveling through the cervical spinal cord, they synapse in dorsal root ganglia of the upper thoracic spinal nerves (T5 to C4) along with other afferent nerves
The cardiac plexus is a _____ autonomic nerve plexus.
mixed
Parasympathetic innervation of the heart originates from where?
the vagus cranial nerve (X)
Males typically experience what sort of pain when experiencing a heart attack?
they have very stereotypic pain which is substernal, radiating down the medial side of the left arm
In contrast to men, women experience what sort of pain when experiencing a heart attack?
more localized pain
