Respirator, Middle Mediastinum Flashcards
Where is the sinoatrial node found? Atrioventricular?
SA = group of cells positioned on the wall of the right atrium, near the entrance of the superior vena cava. AV - between the RIGHT atrium and RIGHT ventricle
What are the 4 boundaries of the MIDDLE Mediastinum? What is found within this structure?
- Superiorly = STERNAL ANGLE (T4 –> 2nd rib) 2. Inferiorly = XIPHISTERNUM (T9) 3. Laterally on the left = 5th intercostal space in midaxillary line* (where Bicuspid valve is) 4. Laterally on the RIGHT = Along sternal border HEART IS INSIDE THE MIDDLE MEDIASTINUM (mediastinum = space between right & left pleural cavities of the lungs)
What is the pericardium? What is the progression of the layers of the pericardial sac?
- closed sac containing serious fluid for lubrication Pericardial Sac: Fibrous Layer –> Parietal –> Serrous Fluid/ Pericardial Cavity –> Visceral layer
What two layers are continuous with one another within the pericardial sac? They are both composed of a _______ epithelium.
Visceral (Epicardium) & Parietal* SEROUS Epithelium
At what two areas are the visceral and parietal layers continuous with one another?
Transverse Sinus - at the entry of 4 pulmonary veins & Oblique Sinus - below the pericardial reflection between the pulmonary veins
Where are both sinuses located and how can they be accessed?
located POSTERIORLY - accessed ONLY from the LEFT SIDE* (the pericardial reflections of the superior and inferior vena cavae block the right side)
Describe the pathway of blood circulation within the heart (include the valves in the progression and where blood is oxygenated & deoxygenated)
1 –> Superior & Inferior Vena Cavae [Deoxygenated blood] 2 –> goes into the RIGHT ATRIUM 3–> through the TRICUSPID valve 4 –> enters the RIGHT VENTRICLE 5–> Exit via the PULMONARY SEMILUNAR Valve* 6 –> [Oxygenated] blood returns to the LEFT ATRIUM via R_ight and Left Pulmonary VEINS_ 7 –> through the BICUSPID VALVE enters the 8 –> LEFT VENTRICLE 9–> exits left ventricle through AORTIC SEMILUNAR VALVE into the 10–> AORTA
What are the 6 major structures found in the RIGHT Atrium?
- Fossa Ovalis –> remnant of foramen vale = fetal shunt
- Musculi Pectini –> ridges on the walls of the atria
- Opening of the CORONARY SINUS
- Crista Terminalis –> SA Node & origin for pectinate muscles
- Valve of Inferior Vena Cavae
- Openings for Superior and inferior Vena Cavae
What are the 5 major structures of the Right VENTRICLE?
- Tricuspid Vlaves (anterior/posterior/septal*mostmedial)
- Chorda Tendinae –> string like & arise from papillary muscle
- Papillary Muscles
- Trabeculae Carnae
- Moderator Band (septomarginal trabeculae)
What are the two major components of the LEFT ATRIUM?
- Valve of foramen ovale
- Openings for PULMONARY VEINS
What are the 4 major structures of the LEFT VENTRICLE?
- Bicuspid Valves (anterior & posterior)
- Chorda tendinae
- Papillary Muscles
- Trabeculae Carnae
Where are the papillary muscles, chorda tendinae, and trabeculae carnae found in the heart?
BOTH right and left VENTRICLES
What is the one component of the RIGHT VENTRICLE that is not found anywhere else in the heart? What does it connect?
Moderator Band (Septomarginal Trabeculae)
-connects the interventricular septum to the anterior papillary muscle
Where would one find the opening to the coronary sinus?
Right Atrium
What node inititates contraction of the heart?
SA Node
What is the function of the papillary muscles?
prevent prolapse of the tricuspid valve leaflets during ventricular SYSTOLE
(aka: blood from pushing back up into the atrium)
What two structures does the chorda tendinae connect?
Papillary Muscles to the tricuspid & bicuspid valve
Where is the only place that the Pectinate Muscles are found? Where do these muscles originate from?
RIGHT ATRIUM
- originate fromCrista Terminalis (SA Node ridge)
Name the branches of the Left Coronary Artery.
- Left Anterior Descending Artery/ Interventricular A. (LAD)
- Circumflex Artery
- Left Marginal Artery
Name the branches of the RIGHT Coronary Artery.
- Right Posterior Descending/ Interventricular Artery
- RIGHT MARGINAL ARTERY (tagged often)
What are the 4 main Cardiac veins?
- Great Cardiac V.
- Middle Cardiac V.
- Cardiac Sinus
- Small Cardiac V.
The Great Cardiac Vein travels with what Artery?
LAD
Left Anterior Descending / Interventricular
What artery dos the Middle/Marginal Cardiac Vein travel with?
Posterior Interventricular/Descending
What artery does the Small Cardiac Vein Travel with?
Right Marginal Branch
All Cardiac Veins drain into the Coronary Sinus. True or False
FALSE
all BUT Anterior Coronary Veins (branches of Small Cardiac Vein)
Where does the coronary sinus drain into?
RIGHT ATRIUM
Which artery travels within the CORONARY SULCUS?
Circumflex branch of LEFT CORONARY Artery