Cardiovasclar System Flashcards
Where does the heart sit?
Immediately on top of the diaphragm
Describe the location of the heart?
- Base is at rib 2
- Apex point to the left and is anterior to the base
What is the middle third?
The mediastinum
What is the Epicardium?
Simple squamous epithelium or otherwise known as mesothelium.
It is the same as the visceral pericardium
What is the Endocardium and what is it continuous with?
Simple squamous epithelium. It is continuous with the tissue lining the blood vessels called endothelium.
The serous fluid in the pericardial cavity allows for what?
The slippage of the heart as it is beating.
What are the layers of the sac covering the heart and what is it’s function?
Fibrous pericardium- adheres to the diaphragm and the roots of large vessels. It is connective tissue that provides a skeleton inside the heart for where the cardiac myocytes need to be arranged.
Parietal pericardium- adheres to the inner surface of the fibrous pericardium
Visceral pericardium = epicardium
What makes the heart wall?
Endocardium, myocardium, epicardium.
What separates the atriums from each other?
A bit of myocardium and cardiac skeleton called the interatrial septum. Keeps the blood separated.
What are the atria?
Receiving chambers
What are the ventricles?
Pumping chambers
What separated the ventricles?
The interventricular septum which is myocardium.
Do the ventricles or the atria have thicker walls?
Ventricles
What delineates the ventricles from the atria?
The coronary sulcus
Where does the coronary sulcus travel?
All the way around the circumference of the heart.
Where does the anterior interventricular sulcus run? Posterior interventricular sulcus?
Runs along the interventricular septum on the anterior side of the heart
-Along the posterior
What dumps into the right and left atrium?
Right - IVC, SVC, Coronary Sinus
Left - Right and left pulmonary veins
What does the pulmonary trunk bifurcate to?
Right and left pulmonary arteries
How many pulmonary veins and arteries are there?
Veins = 4 Arteries = 2
What are pectinate muscles and where are they located?
- organized comb-like horizontal ridges
- located only on the interior of the anterior surface of the right and left atria.
What is the crista terminalis?
-C-shaped ridge used as a landmark to find the openings for the IVC, SVC, and coronary sinus into the right atrium.
What is the Fossa Ovalis?
Dark oval shaped sturucture in the right atrium.
It is the remenant of the Foramen Ovale.
What is the Foramen Ovale and it’s purpose?
It is a hole that you have in utero in the interatrial septum. A blood shunt for before you are born.
-In utero, you are not using your lungs, so blood coming back from the systemic circuit does not need to go to the lungs so it just skip over to the left atrium. There is intermingling of the blood here.
Does the systemic circuit include the lungs?
No.
Describe the posterior walls of the atria?
Smooth
What ia trabeculae carneae?
Meaty columns, ridges found towards the edges in the lower portion of the ventricles,
What are the papillary muscles?
Nipple like muscles that contract and pull the chordae tendinae tightly preventing the atrial ventricular valves to flap back up into the atria.
What type of blood flow do the atrioventricular valves allow?
Flow towards the ventricles but not into the atrium.
What are Chordae tendinae?
Fibrous bands of connective tissue that are anchoring the AV valves to the papillary muscles
On what side of the heart does it mainly sit on and where in the body does it make contact?
Heart sits on the left ventricle and it makes contact with the diaphragm.
Which ventricle makes up most of the wall of the interventricular septum?
The left ventricle
Which valve is the most anterior?
Pulmonary semi-lunar valve is the most anterior because the pulmonary trunk is the most anterior vessel on the anterior side of the heart.
-posterior to that is the Aortic semi-lunar
How many cusps to the semilunar valves have and what are they made out of?
Cartilaginous cusps and both the aortic and pulmonaru semiluna valves have 3 cusps.
What kind of blood flow do the valves of the heart allow?
Unidirectional
How does the blood in the ventricles not go back up into the atria?
Papillary muscles contract and pull the chordae tendinae down, basically anchoring the edges of these flaps down so blood doesn’t go back up.
How do the semi-lunar valves work?
Blood can push them open when its going out of the ventricles but when it falls back, it causes the cusps to close.
What is the job of the specialized cardiac myocytes?
Muscles cells with a function to create a spontaneous depolarization which will trigger muscle contraction in the myocardium of the heart.
What is the sino-atrial (SA) node?
Collection of cardiac myocytes that live in a close knit bundle in the superior poster wall of of the right atrium.
(Near the opening of the SVC)
-It is the pacemaker of the heart. It generates impulses.
How does the electrical circuit generated by the SA node spread throughout the atria?
Via gap junctions
What is the atrioventricular node (AV)?
Similar to the SA node.
- depolarizes much slower than the SA node, so it’s not in charge of when the heart contracts or not.
- when activated by the SA node, it sends it’s impulse down the bundle of His.
What is the bundle of His/ atrioventricular bundle?
a large strip of cardiac myocytes in which the AV node sends its electrical impulse down.
What are the bundle branches?
1/3 of the way down the Bundle of His or atrioventricular bundle separates into two branches.
-cardiac myocytes that carry the electrical impulse from the bundle of His down to the apex of the heart.
What are Purkinje Fibers?
Branches coming in the apex coming off of the bundle branches.
-terminal point for the conduction system.
What is the difference between normal cardiac myocytes used for contraction and the specialized cardiac myocytes used for electrical impulse such as the bundle branches and purkinje fibers?
Specialized are much larger in diameter and very long. they do not contract. their job is to send electrical conduction very quickly.
Do the ventricles and atria contract together?
No. Atria, then ventricles.
What happens when the electrical impulse has reached the purkinje fibers?
The electrical information is sent to all of the individual cells of the heart and they contract.
Are there neurons in the electrical conduction system of the heart?
NO
Describe the right coronary artery?
Begins from the base of the Aorta
Runs along the coronary sulcus and runs on the posterior side of the heart
Describe the right marginal artery?
A 90 degree branch off of the right coronary artery. Sometimes called just the marginal artery.
Describe the left coronary artery
comes from behind the pulmonary trunk and immediately bifurcates
What is the anterior interventricular artery?
Branch off of the left coronary artery runs in the interventricular septum.
-also called the Left Anterior Descending artery (LAD)
Describe the circumflex artery
Branch off of the left coronary artery
-goes around the back of the heart and meets with the right coronary artery on the posterior side to form an anastomosis
Describe the posterior interventricular artery
runs along the posterior interventricular sulcas and joins the right coronary artery to form an anastomosis
What is an anastomosis?
not a capillary bed just a junction of the same type of vessel
Describe the small cardiac vein
runs directly beside the the right marginal artery
Describe the middle cardiac vein
Runs along the posterior interventricular sulcus and dumps into the coronary sinus
Describe the great cardiac vein
Runs with both branches of the Left coronary artery (circumflex, left anterior descending
Is the coronary sinus supply blood to the heart?
yes
What is Coronary Artery Disease? What can you get from Coronary artery disease?
Athlerosclerosis- fatty deposits in the inner lining of the arteries that can block blood flow
Angina pectoris: chest pain from tissue hypoxia in the myocradium or from a spastic artery.
What is a myocardial infarction?
When you have athlerosclerosis and have a total blockage in an artery and that tissue is not receiving any blood so it dies and can cause death if serious enough.
