T1 L3: Middle Mediastinum Flashcards
What is the superior boundary of the middle mediastinum?
T4/5 (The transverse thoracic plane)
Describe the flow of blood through the heart starting with the vena cava, including the valves
Superior and inferior vena cava go into the right atrium, and then through the tricuspid valve and into the right ventricle. Then blood goes through the pulmonary valve and into the pulmonary trunk and then the pulmonary arteries and to the lungs. From the lungs, the blood goes through the pulmonary veins and into the left atrium. Then through the bicuspid valve and into the left ventricle. It will then travel though the aortic valve and into the ascending aorta
What is the function of the auricles?
To allow extra volume of blood in the atria
Where is the atrioventricular groove?
Between the ventricle and the atrium
Where is the interventricular groove?
Between the two ventricles
Through what vessel does deoxygenated blood leave the heart?
Via the pulmonary trunk
What vessel branches into the left and right pulmonary arteries?
The pulmonary trunk
What is Sinus Venarum and where is it found?
Its the smooth walled muscle of atria found where the blood flows. Sinus because it’s close to the opening to where blood flows
Where is pectinate muscle found and what is its function?
It’s found in the atria and its function is to help with contraction
What are the 3 vessels through which deoxygenated blood flows into the right atrium?
Superior vena cava, inferior vena cava and the coronary sinus
Where is fossa ovalis located?
At the interatrial septum
What is the crista terminalis?
A boundary where the pectinate muscle becomes sinus venarum (smooth muscle)
Describe where the sinal atrial node (SAN) is located
The superior part of the crista terminales or the junction between the vena cava and the right atrium
What vessels bring oxygenated blood into the left atrium?
The pulmonary veins
What are the trabeculae carneae?
The rough muscle found in ventricles
What is the difference between pectinate muscle and trabeculae carneae?
Pectinate muscle is in atria, trabeculae is in ventricles
What is the function of trabeculae carbeae?
They help with contraction but also prevent surface adhesion between the walls of the ventricles
What is the function of the moderator band?
It connects the interventricular septum to the anterior papillary muscle in the apex and carries a current to those muscles
Where is the moderator band located?
In the right ventricular apex
What is the function of the papillary muscles?
They connect the the heart wall and help control the function of valves
What are the names of the 2 semilunar valves?
Pulmonary and aortic
What are the names of the 2 atrioventricular valves of the heart?
Tricuspid and bicuspid (mitral)
What are the only arteries in the body that have a valves?
The pulmonary artery and the ascending aorta
What are the names of the 2 cusps of the bicuspid (mitral) valve?
Anterior and posterior
What are the names of the 3 tricuspid cusps of the tricuspid valve?
Anterior, posterior and septal
Which artery is posterior, the pulmonary or the aortic?
The pulmonary
Which semilunar valve has a posterior cusp?
The aortic valve
Which cusps of the aortic valve connect to coronary arteries?
The left and right cusp
What nerve travels over the pericardium?
The phrenic
What are the 2 functions of the pericardium?
To protect the heart against overfilling and it helps to retain the heart in position
What is cardiac distension?
When the heart over fills (dilation)
Why does bleeding into the pericardium create pressure?
Because the heart cant expand further than the pericardium
What type of pericardium is external?
The fibrous pericardium
What type of pericardium is internal?
The serous pericardium
What are the 2 layers of the serous pericardium?
the parietal and visceral (epicardium) layers
Where is the pericardial cavity?
Between the parietal and visceral pleura
Where is serous fluid found within the pericardium?
In the pericardial cavity
What is the function of serous fluid in the pericardium?
It allows for some movement
What is a sinus?
A space, sac or cavity in any organ or tissue
What are the 2 pericardial sinuses?
Transverse and oblique sinuses
Where is the transverse sinus?
Located between the outflow and inflow vessels of the heart
Where is the oblique sinus located?
Between the pulmonary veins
What is the LAD artery?
The left anterior descending (anterior interventricular branch of the left coronary artery)
Which coronary artery is the most common site for a blood clot?
The LAD (anterior interventricular branch of the left coronary artery)
What are the 1st 2 branches of the left coronary artery?
The circumflex and the anterior interventricular
Where is the potential anastomosis on the heart?
Between the end branches of the anterior interventricular and the posterior interventricular artery
Why is the cardiac anastomosis potential?
Because it can only occur is the occlusion grows slowly
What coronary artery determines dominance?
The posterior interventricular
What side of the heart is most commonly dominant?
The right
What is an accessory coronary artery and how common is it?
It’s a third artery branching off the ascending aorta and 4% of people have it
Which cardiac vein runs along the posterior interventricular groove?
The middle cardiac vein
Where does the coronary sinus drain?
Into the right atrium
What is the purpose of the fibrous skeleton in the heart?
To act as an electrical insulator between the atria and ventricles
Which nervous system innervates the myocardium and what is its function?
The autonomic nervous system and it tells the heart how fast to beat
Which plexus do nerves destined for the heart enter?
The cardiac plexus
What’s the name of the nerve that carries parasympathetic information to the heart?
The vagus nerve
Where does the vagus nerve loop?
Under the subclavian artery on the right and under the aorta on the left
Where so sympathetic nerves to the heart come from?
From the sympathetic trunk
