Heart & Great Vessels Flashcards
pericardium
a fibrous sac surrounding the heart and roots of the great vessels
fibrous pericardium
inelastic; very tough
fuses superiorly with the tunica adventitia of SVC, ascending aorta, and pulmonary arteries
fuses inferiorly with the central tendon of the diaphragm
what reinforces the pericardium?
2 sternopericardial ligaments (w/in the anterior mediastinum) anteriorly and posteriorly by loose CT attaches the pericardium to the tracheal bifurcation and main bronchi
attachments of the pericardium function to…
keep the heart in position & limit cardiac distension
what overlaps the pericardium?
two pleural sacs and lungs
what lies posteriorly to the pericardium?
the esophagus, descending thoracic aorta, and main bronchi
pericardium outer layer
dense CT called the fibrous pericardium
pericardium inner serous part contains:
-parietal layer
-visceral layer
pericardial cavity
-potential space b/w the parietal and visceral layers
-contains a thin film of fluid that enables the heart to move and beat in a relatively frictionless environment
fibrous pericardium function
retain the heart in position and limit its distension-prevents sudden overfilling
parietal layer of serous pericardium
closely adherent to the fibrous pericardium
visceral layer of serous pericardium
more loosely bound to the heart and is also called the epicardium
what part of the heart is not covered by the epicardium?
posterior, irregular area between the venae cavae and pulmonary vv. where myocardium contacts fibrous cardium
development of the heart and the pericardial sinuses
due to folding of embryonic heart tube
as heart tube folds, venous end moves posterior and up, so venous end then is up by arterial end, separated by transverse sinus
as veins of heart grow and expand, oblique sinus is formed, a recess, a blind sac behind posterior side of the heart
pericardial sinuses
reflections of pericardium (where 2 layers of pericardium meet each other)
-transverse sinus
-oblique sinus
transverse sinus
at arterial end where pulmonary trunk & aorta leave heart
transverse sinus clinical implication
can stop circulation to the aorta or pulmonary artery by making a stitch through the sinus
oblique sinus
at venous end where SVC, IVC pulmonary veins enter the heart
oblique sinus function
assists with frictionless movement of the heart in the pericardial cavity
blood supply to fibrous & parietal layers of pericadium
majority from pericardiacophrenic arteries
also from musculophrenic arteries, branches of the thoracic aorta and coronary arteries
bloody supply to epicardium
via the coronary arteries
venous drainage of pericardium
pericardiacophrenic vv, internal thoracic vv, and tributaries of the azygos system
somatic sensory innervation to the fibrous & parietal layers via
the phrenic nerves
visceral sensory innervation to the epicardium via
the cardiac plexuses
epicardium is insensitive to ____
pain
vasomotor innervation of pericardium
from sympathetic trunks
pericarditis
inflammation, usually causes chest pain
sharp chest pain associated with pericarditis occurs when the irritated layers of the pericardium rub against eachother
pericarditis can lead to ____
pericardial effusion
pericardial effusion
the presence of an abnormal amount of fluid and/or an abnormal character to fluid in the pericardial space
can be caused by a variety of local and systemic disorders or idiopathic
cardiac tamponade
build-up of blood or other fluid in the pericardial sac puts pressure on the heart, which may prevent it from pumping effectively
periocardiocentesis
drains fluid from pericardial sac
xiphoid approach: needle inserted b/w the xiphoid process and L costal margin
what artery runs in the anterior interventricular groove?
anterior interventricular artery
two parts of the right atrium
-sinus venarum
-pectinate muscles
sinus venarum of right atrium
the smooth thin-walled posterior part that recieves the venae cavae and coronary sinus
derived from the embryonic sinus venosus
what divides the pectinate muscles from the sinus venarum in right atrium?
crista terminalis
what divides the right and left atrium?
interatrial septum
fossa ovalis
remnant of the fetal foramen ovale and valve
what percentage of individuals have an atrial septum defect?
25%
what happens if foramen ovale is too large?
allows O2 blood to be shunted to the right atrium resulting in an overloading of the pulmonary system
subsequently, R atrium, R ventricle and pulmonary trunk will become enlarged
where does right ventricle receive blood from?
the right atrium via the right atrioventricular orifice
*guarded by the tricuspid valve
trabeculae carneae
the irregular muscular elevations on the internal surface of the right & left ventricles
*prevent prolapse
two parts of the interventricular septum
-muscular part
-membranous part that is superior and posterior
conus arteriosus
cone-shaped pouch that leads into the pulmonary trunk
pulmonary valve
semilunar valve guarding the pulmonary trunk
how many cusps does the right atrioventricular valve have?
3
*tricuspid
cusps of right atrioventricular valve
-anterior cusp
-posterior cusp
-septal cusp
tricuspid valve contains:
-papillary muscles (3)
-chordae tendinae
function of atrioventricular valves
prevent backflow into the atria during ventricular contraction
what do the papillary muscles and chordae tendinae do in the atrioventricular valves?
prevent the cusps from prolapsing into the atria
ventricular diastole=
atria contract
ventricular systole=
ventricles contract
where does the left atrium receive blood from?
receives oxygenated blood from the lungs via four pulmonary veins
structure of left atrium
smooth interior except for pectinate muscles in the left auricle
where does the left ventricle receive blood from?
the left atrium via the left atrioventricular orifice
*guarded by the mitral valve
does the R or L ventricle have a thicker wall?
left ventricle wall is 2x thicker
aortic vestibule
part that leads into the aorta from L ventrical; smooth walled
aortic valve
semilunar valve guarding the ascending aorta
ventricular septal defects
-25% of all congenital heart defects
-opening b/w L & R ventricles, associated w/ shunting of blood
-4 types based on position and severity
-most occur in muscular portion (can spontaneously connect)
-membranous defects are more commonly surgically corrected
how many cusps does the mitral valve have?
two
*biscupid valve
bicuspid valve contains:
-papillary muscles (2)
-cordae tendinae
what valve of the heart is the most commonly diseased?
mitral (bicuspid) valve
mitral valve prolapse can cause
enlargement of the L atrium
the pulmonary & aortic valves are…
tricuspid semilunar valves
tricuspid semilunar valves
-have 3 cup-like cusps that prevent backflow into the ventricles during ventricular relaxation
-NOT associated w/ chordae tendinae & papillary muscles
each cusp of a semilunar valve contains:
- a fibrous nodule at the midpoint of its free edge
-a thin CT area on either side of the nodule called the lunule
*when valves close the nodules & lunules meet in the center
coronary arteries arise from
aortic sinuses
coronary arteries fill as the aortic sinuses fill following what?
ventricular contraction
