Thorax 1 & 2 Flashcards
What is the orientation of the heart?
Placed in the thoracic cavity, the apex of the pyramid projects forwards, and inferiorly to the left.
Base: Opposite to the apex, facing the posterior direction
What are the 5 surfaces of the heart?
Diaphgrammatic (Inferior) Anterior (sternocostal) Right pulmonary surfave Left pulmonary surface Base
Which direction does the base of the heart face?
Directed posteriorly, small portion of the right atrium and proximal parts of the superior and inferior vena cavae
Great veins enter the base of heart -> Pulmonary veins enter right and left side of the left atrium
Where do the inferior and superior venae cava drain?
Drain into the right atrium
Where is the base of the heart attached to?
Pericardial wall, opposite the borders of the vertebrae (t5-t8)
Where does the oesphagus lie in relation to the heart?
Posterior
What forms the inferolateral part of the heart?
Apex, left ventricle
Where can the apex of the heart be auscultated?
The left fifth intercostal space
Which cardiac chambers form the anterior surface of the heart?
Right atrium
Right ventricle
Left ventricle
Which chambers form the diaphragmatic surface?
Left ventricle, and small right ventricle
What separates the two ventricles on the posterior surface?
Posterior inter ventricular groove
How is the poster inter ventricular groove separated from the base of the heart?
Coronary sinus
What is the left pulmonary surface?
Faces left lung, broad convex structure consisting of the left ventricle, and a portion of the left atrium.
What is the right pulmonary surface?
Faces the right lung, broad convex structure consisting of the right atrium
What are external heart sulk?
Internal partitions divide the heart into four chambers, produces EXTERNAL grooves = sulk
What is the coronary sulcus?
Circles the heart, separates the atria from the ventricles
Which vessels reside within the coronary sulcus?
Right coronary artery
Small cardiac vein
Coronary sinus
Circumflex branch o fate left coronary artery (LCA)
What do the posterior and anterior inter ventricular sulcus separate?
Separates two ventricles
Which artery resides within the posterior/anterior inter ventricular groove?
Posterior/anterior inter ventricular artery
Where does the middle cardiac vein reside?
Posterior inter-ventricular sulcus
What are the four cardiac chambers?
Right and left ventricle
Right and left atrium
How is the pressure generated for the systemic circulation achieved?
Left ventricle is thicker with greater presence cardiac muscle
Which septum separates the two ventricles?
Interventricular septum
Which septum separates the atria?
Interatrial septum
Which vein saran into the right atrium?
Superior and inferior venae cava
Which sinus is the site of blood drainage from the wall of the heart?
Coronary sinus
Which orifice does the blood from the right atrium pass into the right ventricle ?
Right atrioventricular orifice
When is the atrioventricular closed?
Closed during ventricular contraction by the tricuspid valve
Which valve closes the right atrioventricular orifice?
Tricuspid valve
What is the shallow vertical groove of the right atrium?
Sulcus terminalis cordis
What is the sulcus terminalis cordis?
Extends superior vena cava to inferior vena cava
Which division indicates the the sulcus terminalis cordis?
Crista terminalis
What is the crista terminalis?
Smooth muscular ridge at the roof of atrium, at the opening of superior vena cava, extends inferiorly along the lateral walls to anterior of IVC
What is posterior to the crista terminalis?
Sinus of the vena cava
What is the term for the right atrium proper?
Right auricle
Which muscles cover the atrial walls?
Muscle pectinate (pectinate muscles), fan from crista overlaps the ascending aorta
Where does blood from the cardiac veins drain into?
Opening of the coronary sinus
What is the intertribal septum?
Separates the right atrium from the left
What is the fossa ovalis?
Prominent margin -> Lumbus fossa ovalis
What is the formaina of the venae cordis minimae?
Opening of the cardiac veins, drains myocardium into right atrium
Which cardiac chamber is the most anterior surface of the heart?
Right ventricle, portion of the diaphragmatic surface, anterior and left of the right atrioventricular orifice
What is the outflow of the right ventricle?
Pulmonary trunk
What is attached to the right ventricular walls?
Trabecular carnea
Which muscles are located within right ventricular walls which helps close the tricuspid valve?
Papillary muscles
What is the point of attachment for the cusps of the tricuspid valves?
Chordae tendinae
What is the triscuspid valve?
The right atrioventricular orifice, is closed during ventricular contraction by the tricuspid valve. Base of the cusp secured to the fibrous ring that assist to maintain the shape of the opening.
Cusps are continuous with each other, near the base, termed commissures.
What cusps form the tricuspid valves?
Anterior, septal and posterior
What are the tricuspid cusps attached to?
To chord tendinea from tips of papillary muscles
How does the triscupid valve close during ventricular systole?
During, diastole the tricuspid valve is open, directing the blood flow into the right ventricle; three cusps project into the right ventricle. Contraction of the papillary muscles attached to the cusps by the chordae tendinea prevents the cusps from being exerted into the right atrium (Keeps the valve closed).
How many papillary muscles form one chord tendinea?
2
What happens to the triscupid valve upon myocardial infarction?
Necrosis, resulting in prolapse
Which valve controls the outflow of the right ventricle into the pulmonary trunk?
Pulmonary valve
How many semi-lunar cusps form the pulmonary valve?
3
What is the nodule of a semi-lunar cusp?
Superior edge of the lumen has a thickens portion
What are the three semi-lunar cusps of the pulmonary valves?
left semilunar
Right semi lunar
Anterior semi lunar
How do the pulmonary cusps close after ventricular contraction?
Recoil of blood fills the pulmonary sinuses forces the cusps to close
What vessels drain into the left atrium?
Four pulmonary veins
What is the intertribal septum?
Forms part of the anterior wall of left atrium, the foramen ovale prevents blood passing from the left atrium into the right atrium
How does blood enter into the left ventricle?
Through the left atrioventricular orifices, flows forward direction towards the cardiac apex
What forms the outflow of the left ventricle?
The aortic vestibule
What are the two types of papillary muscles of the left ventricle?
Anterior and posterior papillary muscles.
What forms the anterior wall separating the ventricles?
Interventricular septum
What two parts fo the inter-ventricular septum?
Muscular and membranous part
What is the muscular part of the inter-ventricular septum?
Thick, forms major part of the septum
Which valve closes the left atrioventricular orifice?
Mitral valve
Which cusps form the mitral valve?
Bicuspid valve, therefore anterior and posterior cusps
Which valve closes the aortic vestibule, the outflow tract of the left ventricle?
Aortic valve
How many semi lunar cusps form the aortic valve?
3
What are the three semi-lunar cusps of the aortic valve?
Right
Posterior
Left
Which sinus is considered to be non-coronary?
The posterior sinus
Where do the right and left coronary arteries originate from?
Right and left aortic sinus
How is blood forced into the coronary arteries?
As blood recoils, after ventricular contraction, it fills the aortic sinuses, forced into the coronary arteries
How do veins return back to the coronary sinus?
Cardiac veins
Where is the coronary sinus located?
Located in the coronary sulcus on the posterior surface between the left atrium and left ventricle, empties into the right atrium
Where does the atrial branch of the right coronary artery pass?
Passes in groove between right auricle and ascending aorta , provides the Sino-atrial branch -> Supplies the SAN
What is the main branch of the right coronary artery?
Right marginal branch
What is the right marginal branch?
Gives off as the right coronary artery descends to the inferior margin of the heart towards the apex
Where does the posterior inventricular artery arise from?
Right coronary artery
Which artery resides within the right posterior inter-ventricular sulcus ?
Right coronary artery forming the posterior inter-ventricular artery
What does the RCA supply?
Supplies the right atrium, right ventricle, SAN, AVN and the intertribal septum
Where does the left coronary artery arise from?
Left aortic sinus
Which two branches arise from the left coronary artery?
Anterior inter-ventricular artery (LAD)
Left circumflex
What is the LAD?
Left anterior descending artery, continues on the left side of the pulmonary trunk, apex of the heart int he anterior inter ventricular sulcus (diagonal branches)
What is the circumflex branch?
Courses left in the coronary sulcus and not the base/diaphgrammatic surface. Ends before reaching the interventricular sulcus, the left marginal artery arises from it and continues across around obtuse margin of the heart
What does the left coronary artery supply?
Supplies majority of left atrium
left ventricle, inter ventricular septum
Which artery is dominant and forms the posterior inter-ventricular artery in 80% of population?
Right coronary artery
What does right heart dominant mean?
Right dominant coronary artery: Posterior interventricular branch arises Supplies posterior wall of left-ventricle; left circumflex artery small contributions.
What does left heart dominant mean?
Posterior interventricular branch arises from the left circumflex artery Left coronary artery has significant supply to the posterior wall.
Which vein are received by the coronary sinus?
Four main:
Great, middle small and posterior cardiac vein
Where do the great cardiac vein ascend from?
Begins at the apex, and ascends in the interventricluar sulcus (anterior), related to the anterior inter ventricular artery. Left from coronary sulcus into base
Where does the coronary sinus drain into?
Right atrium
Where is the small cardiac vein located?
Located anterior section of coronary sulcus
Where is the heart contained?
middle mediastinum
How is the heart separated from other structures within the mediastinum?
By the pericardium
What is contained within the mediastinum?
Thymus gland Pericardial sac, heart trachea Major arteries and veins
What is the function of the mediastinum?
Functionally behaves as a passageway enabling the oesophagus thoracic duct and nerve fibres to traverse the abdomen
What is the anatomical location of the mediastinum?
Extends from the sternum and costal cartilages to the bodies of the vertebrae;
What are the vertical boundaries of the mediastinum?
From superior thoracic aperture to the diaphragm
What is the anterior mediastinum?
Is anterior to the pericardial sac, and posterior to the sternum
What is the posterior mediastinum?
Posterior mediastinum is the region posterior to the pericardial sac & diaphragm, and anterior to the vertebral bodies
What is the middle mediastinum?
Middle mediastinum includes the pericardial sac
What is the pericardium?
The pericardium is a fibroserous sac encapsulating the heart and the roots of the great vessels. Consists of two components: Fibrous pericardium, and the serous pericardium.
What are the two main layers of the pericardium?
Serous layer and fibrous layer
What is the fibrous pericardium?
Connective tissue external layer that defines the boundaries of the middle mediastinum. Base on diaphragm, apex continuous with the Adventitia of great vessels.
What forms the phrenic nerve?
C3-C5
Which nerve innervates the fibrous pericardium?
Phrenic nerve
Which vessels supply the fibrous pericardium?
Pericardiophrenic nerve
What are the two layers that form the serous pericardium?
Parietal and visceral layer
What is the parietal layer of the serous pericardium?
Lines the inner surface of the fibrous pericardium
Which layer adheres to the heart forming the outer covering?
Visceral serous pericardium
What is found within the pericardial cavity?
pericardium fluid