Internal anatomy of the heart Nov1 M3 Flashcards
how muscle changes when heart contracts
twists a little
lumen size of LV
very small
heart on ultrasound what we can see
4 chambers of the heart + sometimes 5 if right orientation to get the aorta
where RA receives blood from (3)
SVC, IVC, coronary sinus
valves present upstream of RA
valve of IVC (IN EMBRYO. prevents back flow in IVC)
valve of coronary sinus
name of muscles in RA + function
pectinate muscle. help eject blood towards ventricle
muscle other than pectinate in the RA + its function
right auricle or appendage (push blood in RV too and stop it from pooling in the dead end where this muscle is located)
embryologic remnant found in RA: 2 names
fossa ovalis (after birth) foramen ovale (before birth)
fossa ovalis composition and function of foramen ovale
is a membrane. previously RA to LA shunt
cusps orientation in the tricuspid valve
one A, one P, one towards septum
name of muscle in RV + special characteristic
trabeculae carnae. pushes blood with a torsion
pulmonary valve cusps orientation
one A, one left, one right
papillary muscles projection and attached to what
project to the lumen of the ventricle and attach to the cusps of the AV valves
papillary muscles function
when ventricle contracts, contract too to keep AV valve from collapsing in atrium bc of the pressure
how many papillary muscles in the LV and how they attach to mitral valve
2 but both attach to each cusp
name of structure between papillary muscles and attachment to the cusp
chorda tendinae
mitral valve cusps orientation
one A, one P
aortic valve number + cusps orientation
3 valves. one cusp right, one left, one posterior
only place where can listen to blood coming towards stethoscope
apex of the heart. at midclavic line at 5th intercostal space (hear blood through mitral valve)
how to hear blood from tricuspid valve
5th intercostal space, just on the left of the sternum
how to hear blood going in aortic valve
steth on 2nd intercost space just on right of the sternum
how to hear blood going in pulmonary valve
steth on 2nd intercos space just to the left of the sternum
something particular about aortic and pulm valves positionning
pulm valve is more to the left and to the top than the aortic valve
where coronary arteries exit from aorta is located
just above aortic valve
what aortic valve does at systole and why
open and lie against the opening of coronary arteries holes. prevents their damage bc of the high pressure and their small diameter (4 mm vs 3-4 cm in aorta)
how aortic valve closes at diastole
backflow of blood from aorta to LV fills out each cusp and valve closes
where nervous tissue is in the heart
imbedded inside the heart
SA node location
at junction of SVC, IVC and rest of RA
AV node location
on septal wall of right atrium, where it is close to the ventricle
name of nervous fibers transmitting AP from SA to AV nodes
internodal bundles
name of fiber right after AV node and location
Bundle of His. In ventricular septum
only nervous tissue visible in the heart, location and origin
moderator (or septo-marginal) band. comes from bundle of His
destination of moderator or septo-marginal band
reaches anterior papillary muscle of RIGHT ventricle
why called moderator band
bc ensures specific pattern of contraction of papil muscle so it contracts at same time as ventricle
SS input to the heart originates where
T2 to T4 spinal cord levels
T2 to T4 input on what 3 ganglia before signal reaches the heart
- superior cervical sympathetic ganglion
- middle cervical ganglion
- inferior cervical ganglion
Name of superior, middle and inferior ganglia projection to heart
cardiac nerves
name of region where cardiac nerves project + location
cardiac plexus. at level of RA (near SA node)
how does SS and PSS change HR specifically
increase or decrease frequency of depolarization at SA node
PSS innervation to the heart: origin
medulla (or medulla oblongata)
location wise, what’s the importance of the medulla oblongata
junction between the brain and the spinal cord
nerve originating from medulla and going to the heart
vagus nerve
what can bypass the effect of the SS and PSS
pacemaker, defibrilator
pacemaker location and mechanism
under subclavian vein. penetrates there, travels in SVC, stimulates specific parts of the conducting system in the heart (SA, bundle of His, etc.)
edema, high jugular pressure, leg swelling, ultrasound echo shows valve problem: which valve
tricuspid valve
