Heart and Mediastinum Flashcards
What part of the mediastinum holds the heart?
middle
The superior mediastinum lies right behind the breast plate, what major vessels are in this space?
ascending aorta, aortic arch into right brachiocephalic trunk (splits into right common carotid and right subclavian) and left subclavian and left common carotid
superior vena cava, left and right brachiocephalic vein
ABCs - seems like eveyrhing but IVC
Superior mediastinum contents
Which one is most anterior?
thymus gland
trachea
esophagus
great vessels - BC veins, SVC, arch of aorta, carotid and subclavian artery
thymus is most anterior
Inferior mediastinum contents
*heart
thoracic aorta
esophagus
trachea
Contents of the anterior mediastinum
connective tissue and sternopericardial ligaments
(remember hard to get these off when taking off chest wall)
Contents of the middle mediastinum
Heart
Aortic Arch
Root of lung
Posterior Mediastinum contents
aorta
vena cava and azygos veins
thoracic duct
esophagus
sympathetic ganglia and splanchnic nerves
The visceral layer of the pericardium is also called the
epicardium
The phrenic nerve is asymmetrical because
the heart is offset
What vessels supply the pericardial sac?
pericardiacophrenic artery and vein
parent structure of the pericardiophrenic artery
internal thoracic artery
Pericarditis - causes and symptoms
viral and bacterial infections, systemic illness or after MI
chest pain with UE referral but relieved with sitting forward
What is constrictive pericarditis?
excessive thickening of the pericardial sac - usually only the parietal
can compress the heart and lead to heat failure
apex of the heart lies where from anterior view?
deep to which intercostal space?
inferior lateral aspect of left ventricle
deep to the 5th intercostal space
be careful of orientation on posterior view
describe the orientation of the interventricular septum
goes between ventricles and through apex on an oblique axis
Difference between coronary sulcus and coronary sinus (and where are they?)
coronary sulcus is posterior depression for the coronary sinus (vein) to run through
horizontal
vein that takes deoxy blood from the heart muscle
azygous vein parent structure
SVC?
Describe blood flow through the heart
Deoxygenated blood enters through the IVC or SVC into the right atrium, through the tricuspid valve into the right ventricle, then through the pulmonary valve into pulmonary arteries which go to the lungs, blood becomes oxygenated and returns to heart via pulmonary veins into the left atrium, then through the mitral valve into left ventricle, then through aortic valve and out through the aorta
A blood clot traveling from the body would first enter what structure of the body?
right atrium
T/F: the RV and LV eject the same volume of blood per beat
T
SVC drains blood from _____
IVC drains blood from ______
above diaphragm
below diaphragm
The right brachiocephalic vein is oriented ___ and the left brachiocephalic vein is oriented ___
The join together via the _____
vertical
horizontal
SVC
How many pulmonary arteries come off of the pulmonary trunk?
2 on the right side (superior and inferior)
1 on left side, left is longer
What are the parts of the aorta and what major vessels come off of it?
Root, ascending aorta, aortic arch, descending/thoracic artery
right brachiocephalic trunk
left subclavian
left common carotid
Viewing the heart posteriorly, which side is the apex on?
true left side along with left ventricle
the base of the heart consists of mainly the ___ ___ and proximal great veins
think about the pyramid diagram!
left atrium
Base is NOT the floor, its the back
The diaphragmatic surface of the heart is
(bottom portion of pyramid)
the heart rests on the diaphragmatic surface in anatomical position, consists of left ventricle and small portion of right ventricle
On an EKG, the LUB sound refers to
the DUB sound is…
LUB = closure of tricuspid and bicuspid valves
DUB = pulmonary and aortic valves closing
Systolic pressure is measured between
LUB and DUB
ventricular contraction, so mitral and tricuspid valves close (LUB), then ventricles contract, and then the aortic and pulmonary valves open as blood is pushed through, then they close with DUB (beginning diastole)
Diastolic pressure is measured between
DUB and next LUB
diastole is relaxation of ventricles, so closure of aortic and pulmonary valves (DUB) after pushing out blood, AV valves open and atrium contraction, and then closure of tricuspid and bicuspid valves (LUB)
Where does the RCA come from and where does it lie?
comes from the right aortic sinus of the ascending aorta
lies between right atrium and ventricle
branches of the right coronary artery
SA node branch and right marginal branch
(also posterior interventricular branch)
know where to find these!
branches of left coronary artery
circumflex branch (wraps around to posterior side)
left marginal branch
anterior interventricular branch of artery or LAD (left anterior descending)
What is the widow maker?
anterior interventricular branch of left coronary artery
or
LAD - left anterior descending
What is left dominant coronary artery referring to?
RCA typically supplies the SA and AV node branches, but rarely someone left circumflex branch of left coronary artery will supply them
What are the three most common sites of occlusion leading to Myocardial Infarction?
- LAD - Anterior interventricular branch of LCA (40-50%)
- RCA (20-40%)
- Circumflex branch of the LCA (15-20%)
Branches of the coronary sinus
left marginal vein and left posterior ventricular vein
also great, middle and small cardiac veins
What do the papillary muscles do and where are they?
in the ventricles, connected to mitral and tricuspid valves via tendinous cords, preventing valves from flipping up into atrium during ventricle contraction
aka hold valve cusps in place during systole
Sinus Venarum is in the _____ chamber of the heart and receives ____ (what vessels?)
easy - just think about what enters the RA
right atrium
IVC, SVC, coronary sinus
“sinus of veins”
Coronary Sinus is in what heart chamber and receives what?
right atrium
receives venous return from the heart
Atrial septum vs atrioventricular septum
artial - separates right and left atrium
atrioventricular septum - separates atria from ventricles and houses the bi or tri valves
The oval fossa is in what chamber, specifically located where?
Right atrium, in interarterial septal wall
remnant of the foramen ovalis
Where are the SA and AV nodes located? Which one is the pacemaker?
right atrium
SA (pacemaker) then AV
SA is in top corner of RA
AV is in atrial septum
Cardiac neck pain could be caused by
an open foramen ovalis
(never closed during development)
What chamber forms the largest part of the anterior surface of the heart?
Right ventricle
What are the trabeculae carneae?
muscular ridges on right and left ventricular lumen that gives a sponge look
Infundibulum
smooth outflow tract in RV leading to pulmonary valve and trunk
Tricuspid valve prevents retrograde (backflow) during ventricle ____
while pulmonary valve prevents backflow during ____
contraction of ventricle
relaxation of ventricle
What feature on the left atrium receives blood from the 4 pulmonary veins?
left auricle
Which chamber of the heart heart works hardest? What is the result?
LV works harder than RV in adult
walls on left side are twice as thick as right
Aortic vestibule
fibrous ring to which the 3 cusps of the aortic valve attaches
Heart borders
superior
right
inferior
left
you need to look at this again lol
superior - two atria, L costal cartilage b/w 2nd and 3rd rib
right - R atrium, R third costal cartilage
inferior - RV, 6th costal cartilage, mid costal portion
left - L ventricle, 5th intercostal space at L midclavicular line**
Describe the pathway of the conduction system of the heart
SA node impulse to→ Atria myocytes (atrial contraction) → AV node (between atria and ventricle) → Bundle of His (interventricular septum)→ Bundle branches (L and R ventricles) → Purkinje fibers → Ventricles (contraction)
What is cardiac auscultation?
listening to heart to assess heart rate, rhythm and regularity
Where is classic cardiac referred pain? (spinal levels)
C5 shoulder and C8 TI down the entire middle arm
lower cervical upper thoracic
Female variation in cardiac referred pain location
more jaw and chin and neck pain
The vagus nerve course is the longest course and is _______
asymmetrical
what is the vagus nerves motor and sensory innervation?
motor - voluntary muscles of larynx and superior esophagus and other visceral innervation - tracheobronchial tree, heart and alimentary canal
sensory - pharynx larynx and same areas above
Left recurrent laryngeal nerve is a branch of ____ and when compressed can cause hoarseness
left vagus nerve
Phrenic nerve innervates each half of diaphragm and does sensory to what 3 things?
diaphragm, central tendon and pericardium
What area does the diaphragm refer pain to?
R half goes to R shoulder
L goes to left shoulder
The phrenic nerve is “pinned” to what structure? Then what structures does it follow?
anterior scalene
right reavels along with SVC and IVC
left travels over pericardium
Which nerve is more anterior, phrenic or vagus?
phrenic
Cardiac muscle innervation is via
sympathetic NS
parasympathetic NS
and visceral afferents from the cardiac plexus
Describe Para and Sym NS effect on HR, force of contraction and coronary arteries (contract/dilate)
Para = decrease HR and force of contraction, constrict coronary arteries
Sym = increase HR and contraction force, dilate coronary arteries
visceral nerves from the cardiac plexus use _______ and _____ nerve to send cardiac pain
sympathetic and vagus
T/F: there is a superficial and deep cardiac plexus
T
The thoracic duct is a lymph channel from ___ and feeds into the ____ system
LE
venous
