Flashcards in Lecture 7 RH Deck (42):
What is the function of the fibrous skeleton of the heart?
The fibrous skeleton of the heart is important for anchoring the valves.
The fibrous skeleton provides structural support for the heart
What is the function of the vagus nerve?
vagus nerve decreases heart rate and force of contraction. It runs anteriorly to the root of the lung.
Where do the sympathetic preganglionic neurons that innervate the heart originate from?
Preganglionic neurons originate from T1-T4 lateral horns and synapse at the sympathetic trunk.
What nerves does the cardiac plexus contain?
Contains sympathetic and parasympathetic neurons bundled up in a hard to distinguish manner.
Where do the visceral afferent neurones that arise from the heart enter the spinal cord?
visceral afferent neurones (*bald eagle screech*) end up in T1 -T4
What are the components of the pericardium?
pericardium is a double layered membrane with a visceral layer around the heart and a parietal layer of serous pericardium.
Pericardium anchors the heart to the diaphragm's central tendon.
How does the heart beat without being inhibited by the structures around it?
Fluid around the heart within the serous membrane allows less friction to exist.
What is the endocardium?
Endo cardium is the inside layer of the heart which is in contact with the blood the heart is pumping
What is the epicardium?
Epicardium is equiavalent to the visceral pleura
What is the myocardium?
The intermediate layer between the epi and endo cardium. This layer consists mostly of the muscle.
What is a probable problem of the pericardial space?
effusion can occur into it which would limit ventricle contraction.
What nerves innervate the pericardium?
Right and left phrenic nerves give branches to the pericardium and the afferent fibers go to C3,4,5.
What are pericardial sinuses?
pericardial sinuses are spaces inside pericardial cavity.
What is the outermost layer of the pericardium?
The fibrous pericardium.
What are the types of sinuses present in the pericardium?
What is the clinical significance of the oblique sinus of the pericardium?
Deepest and most inferior part when patient is on their back which means this is the location where fluid effusion can occur. As a result of this the left ventricle and atrium can suffer.
Where does the oblique sinus of the pericardium run?
pericardial cavity behind the heart near the apex the pericardium runs obliquely and forms the oblique sinus.
Where does the transverse sinus of the pericardium run?
behind the roots of the aorta and pulmonary trunk anteriorly and the pulmonary veins inferiorly.
What is the clinical significance of the transverse sinus?
Roots in and around and behind and around the aorta and pulmonary trunk can be accessed through this sinus.
What landmarks are coronary arteries commonly associated with?
The grooves of the heart
Where do the coronary arteries originate from?
2 main arteries; taking origin from ascending aorta (first branch) directly superior to the semilunar aortic valves.
Where does the left coronary artery run and what branches does it give off?
Left coronary artery runs behind the pulmonary trunk and gets access to left atrioventricular groove and all the way around posterior aspect of the heart. It forms 2 branches; anterior interventricular branch and the circumflex branch. Left coronary artery wraps around left side of the heart and gives off a marginal branch to provide blood to the left ventricle.
What is another name for the anterior interventricular branch?
anterior interventricular branch is also known as the left descending artery.
Where does the right coronary artery run and what branches does it give off?
Right coronary artery runs through right atrioventricular groove and gives off right marginal artery as it wraps around the back of the heart and continues posteriorly to the midline of the heart. It usually gives off the posterior interventricular branch. It also gives a branch to the sinoatrial node and the atrioventricular node.
Which artery supples the posterior interventricular groove?
right coronary artery gives off the posterior interventricular artery but only in the case of a right dominant circulation. In the left dominant circulation the circumflex artery supplies the posterior interventricular groove.
What parts of the heart does the right coronary artery supply?
Most of right ventricle
diaphragmatic surface of left ventricle
sometimes gives off a branch to the sinoatrial node (55% of times)
Atrioventricular node (90% of times(
What parts of the heart does the left coronary artery supply?
Most of left atrium and ventricle
Some of right ventricle via branches from anterior interventricular artery.
In some cases a branch to the SA node (45%)
In rare cases to AV node (10%)
What are the anastomoses that exist between coronary arteries?
posterior to the apex between the posterior interventricular branch anastomoses with anterior interventricular branch of the left coronary artery
What kind of end arteries are coronary arteries?
Coronary arteries are functional end arteries. They don't actually connect unless a slow occlusion occurs because it stimulates production of more arteries. Sudden occlusions cause myocardial infarctions.
What happens during coronary heart disease?
blockages in coronary arteries prevent oxygen from reaching the heart and as a result tissues die and stimulate visceral afferent neurons which cause pain to be felt.
How is angiography carried out?
A catheter is inserted into aorta and added into the coronary arteries and radio opaque dye is injected into them and this is visible on a screen.
What is angioplasty?
angioplasty involves adding a balloon into the narrowing of the coronary artery and then inflating the balloon and this removes the blockage.
What is coronary bypass?
Coronary bypass involves getting a blood vessel from elsewhere and using it to replace the coronary arteries with it. typical arteries to be used for this are the radial artery and the small saphenous vein.
Triple bypass can involve multiple arteries that are used to replace coronary arteries.
What is the purpose of the coronary sinus?
Coronary sinus sits on the posterior aspect of the heart between left atrium and left ventricle and is a big swollen vein which has an opening in the right atrium.
Where is the great cardiac vein located?
wrrapping around the left side of the heart and going through anterior interventricular groove is the great cardiac vein.
What vein drains the right side of the heart?
right side of the heart is drained by small cardiac vein
what vein drains the left side of the heart?
left side of the heart mainly drained by left marginal vein.
How does the impulse from the SA node not affect the ventricles?
Muscles of atrium and ventricles are separated by the fibrous skeleton.
What is the benefit of having the AV node?
AV node allows the ventricles to contract after considerable time from the SA node.
Papillary muscles are distant, how do heart muscles allow them to contract in a timely manner?
left and right ventricular branches run to each individual ventricle. Papillary muscles are distant. This is fixed by the moderator band.
What happens to the AV node when the SA node stops working efficiently?
AV node can control the entire heart when SA node is damaged