Thorax 3 Flashcards
What is the pericardium?
Give 2 functions of the pericardium
Pericardium is a fibro-serous sac that encloses the heart and the roots of the great vessels
Functions to;
Restrict excessive movements of the heart as a whole
Serve as a lubricated container in which the different parts of the heart can contract
label what u can
at the top is tunica adventitia
Parietal and visceral
Pericardial cavity
Contains pericardial fluid (lubricant)
Give the 3 attachments of the fibrous pericardium
Firmly attached below to the central tendon of the diaphragm
Fuses with tunica adventitia of great blood vessels that pass through it
Attached in front to sternum by sternopericardial ligaments
How does the heart appear in-situ?
Both atria are mainly located posteriorly
Give the 3 sources of blood to the RA
SVC
IVC
The coronary sinus is the major venous tributary of the greater cardiac venous system; it is responsible for draining most of the deoxygenated blood leaving the myocardium.
name what u can and their function
what si the crista terminalis
Ridge on inside between atrium and right
auricle
- From SVC to IVC
- Posterior to the wall is smooth
what is Musculi pectinati
- Anterior to crista
terminalis the walls are
roughened by bundles of
muscle fibres
what is Fossa ovale
- Marks location of
embryonic foramen ovale,
which allowed blood to
bypass the lungs in fetal
circulation
label what u can, and what is being shown?
right ventricle
the right atrium –> right ventricle = what valves?
right ventricle –> pulmonary trunk = what valve?
tricuspid, atrioventricular valve
pulmonary valve, 3 semilunar cusps
label what u can and note their function
what is the Trabeculae carnae
- muscular, irregular structures
- A few trabeculae carnae are known
as papillary muscles
Importance of papillary muscles
When the ventricle contracts, papillary muscles contract, preventing the cusps from turning inside out into the atrium as intra-ventricular pressure rises
In left and right ventricle
key difference between left and right atrium?
no christa terminalis
label what u can, and what is shown?
left atrium
left atrium –> left ventricle = what valve?
mitral valve, bicuspid valve
Supply of coronary arteries
As blood recoils after ventricular contraction, and fills the aortic sinuses formed by the cusps, it is forced into coronary arteries
what are the 3 aortic branches
BCS
braciocephallic - right subclavian then right cc
left cc
left subcalvian
how does the pulmponary trunk arise?
what does pulmonary trunk divide into?
Arises slightly anterior to aortic orifice
Divides into left and right
* Left: inferior to aortic arch
* Right: posterior to ascending aorta and SVC
Where does IVC pass through the diaphragm?
T8
what is Heart murmur
Where do we place the stethoscope when we want to listen to heart sounds?
what are the 4 auscultation points?
Turbulent bloodflow
Downstream of blood flow
what are the layers of the heart?
Endocardium: inner most layer. Lines Cavities and heart valves
Myocardium: composed of cardiac muscle and responsible for contraction of the heart
Epicardium: outermost layer of the heart, formed by the visceral layer of the serous pericardium. It is composed of connective tissue and fat
Structure of endocardium
2 functions of endocardium
*Structurally, the endocardium is comprised of loose connective tissue and simple squamous epithelial tissue
*Similar in its composition to the tunica intima which lines the inside of blood vessels
In addition to lining the inside of the heart, the endocardium also regulates contractions and aids cardiac embryological development
Subendocardial tissue
*Deep to the endocardium is the subendocardial tissue, which contains loose vascularized connective tissue
*Subendocardial tissue also contains nerves as well as Purkinje fibres
label what u can and what is shown?
myocardium
*This layer is highly vascularized and the cardiomyocytes contain glycogen granules as an additional energy source
Connection of cardiomyocytes
Cardiomyocytes are connected by intercalated discs, forming a cardiac syncytium to enable transmission of electrical impulses through the network and coordinate contraction of the myocardium
what is Epicardium
*The pericardium is a fibrous double layered connective sheath that encases the heart within the mediastinum
*The visceral portion of the serous pericardium (that is in contact with the heart) is called the epicardium
*It is a mesothelium derivative that is rich in adipocytes and neurovascular tissue
label what u can
label what u can
Right coronary artery
*Arises from aorta and runs forward between pulmonary trunk and right auricle
*Descends almost vertically in the right atrioventricular groove
*At inferior border continues posteriorly to anastamose with left coronary artery
*Offers a marginal branch and a posterior interventricular branch
left coronary artery
Usually larger than right
Arises from aorta and passes
forward between the
pulmonary trunk and left
auricle
Then enters atrio-ventricular
groove and divides into
anterior inter-ventricular
branch and a circumflex branch
label and what is the coronary sinus?
The coronary sinus is the major venous tributary of the greater cardiac venous system; it is responsible for draining most of the deoxygenated blood leaving the myocardium MAGS
Posterior interventricular artery
Sometimes comes from left
Clinical consequences as blockage of right or left will have different effects
what are the tributaries of the coronary sinus?
which tributary does not enter the coronary sinus?
- Great, middle, small and posterior cardiac veins
- Anterior cardiac veins are very small, draining only the anterior portion of the
right ventricle
Anterior cardiac veins are very small, draining only the anterior portion of the right ventricle
where is Valve of coronary sinus
Medial to IVC in RA
Atrioventricular groove
where the right coronary artery runs - between right auricle and pulmonary trunk
between atrium and ventricle
Interventricular groove
Anterior and posterior interventricular arteries
between left and right ventricle
