Anatomy of The CVS Flashcards
What is the cardiovascular system?
Where is the heart placed?
Middle mediastinum
What is a portal system?
Capillary - vain - capillary
What is the base of the heart?
The left atrium
What is the right border foromed from?
The right atrium
What is the sternal surface formed from?
The right ventricle
What is the name of the great vessels from left to right?
Superior vena cava, ascending aorta, pulmonary trunk?
What are the veins of the base?
Pulmonary veins
What is the vein that cardiac vein drains into before reaching the right atrium?
Coronary vein
Define mediastinum
= Area of thoracic cavity between pleural sacs (around lungs)
What is contained within the superior mediastinum?
Above T4, inferior is below T4
Where is the anterior mediastinum, middle mediastinum, posterior mediastinum?
Anterior - front of the heart
Middle - heart
Posterior - behind the heart
When does the thymus invilute?
Puberty or before puberty, proliferation in later life invades the lungs - asymptomatic, doctor performs thymectomy to cure.
Where is the apex of the heart?
•Apex - 5th left intercostal space in the midclavicular line (some references say 4th) - This is lying down
What does surface anatomy of the heart refer to?
Surface of the body, not the heart
Where is the apex of the heart in children?
•Higher in children and lies more horizontal
What is the name given to the inversion of organs? Situs invertus
What is anterior to the heart?
Ant. * Sternum & l. costal cartilages 4-7
* Ant. edges lungs and pleurae
* Thymic remnants
What is posterior to the heart?
Post. * Oesophagus
* Descending aorta
* Thoracic vertebrae 5-8
What is lateral to the heart?
Lungs and the phrenic nerves (also supply the pericardium as well as the diaphragm).
What is inferior to the heart?
Central tendon of the heart
What is the endocardium?
Innermost surface of the heart - simple squamous epithelial cells
What forms the middle surface of the heart?
•Myocardium (middle)
–Muscle
What is the epicardium?
•Epicardium (outermost)
–Connective tissue + *BM + Epithelium
*(BM = Basement Membrane)
Epithelium of the epicardium is the?
Visceral pericardium
What separates the parietal from the visceral pericardium?
Pericardial cavity
What is the function of the fibrous layer?
Stops the ballooning of the parietal pericardium?
How does the endocardium form the valves of the heart?
Forms projections which enter the lumen
How would you describe the myocardium?
- Thick middle layer of heart wall
- Cardiac muscle (Myocytes)
- Striated muscle, lots of mitochondria
- Rich capillary bed
- Muscle bundles in different planes to close down chamber lumen
- Myocytes connected by intercalated discs
Why is the myocardium described as a functional syncitium?
Cells functinon as a unit
What is the function of desmosomes?
–Connect at horizontal interface
–Bind myocytes together
What is the purpose of gap junctions?
Connect at the vertical interface
Electrical communication
Essential to co-ordinated cardiac cycle
What are intercalated disks made from?
Desmosomes and gap junctions
What is the outer layer of the heart called?
The epicardium
What is the epicardium made from?
Connective tissue, basement membrane and simple squamous epithelium
What is the epithelium of the epicardium referred to as?
It is also the visceral layer of the serous pericardium
What is the purpose of blood valves?
Control direction of blood flow
Where are the cusps derived from?
The endocardium
Do valves work actively or passively?
Passively
How is valve failure prevented?
Chordae tendinae and pipillary muscle prevent inversion
What is meant by incompetence and stenosis of heart valves?
Incompetence - widening
Stenosis - narrowing
Where do you find the mitral and the tricuspid valces?
Mitral = Left atriventricular valve
Tricuspid = right atrioventricular valve
What is the result of the failure of the valves to close tightly?
Back flow of blood into the left ventricle
What is the cardiac skeleton comprised of?
Connective tissue
What is the purpose of the cardiac skeleton?
Structural suport (atrioventricular septum)
Electrical insulation
(separates atria from ventricles, separates myocardium from great vessels
What are the two main coronary arteries?
Left and right
Describe the relationship between the cusps of the heart and the aortic sinuses
Systole - Sinuses sheilded by cusps
Diastole (relaxation) - aortic valves become closed due to elastic recoil of the aorta and so blood enters capillaries
What holds the heart in place?
Hangs by great vessels within fibrous pericardium
Pericardium is essentially a bag of fibrous tissue
Attatchments of the heart - central tendon of diaphragm, sternum and roots of great vessels
Lined by serous pericardium
What does the serous pericardium secrete?
Pericardial fluid - lubricant
What are the attachments of the viseceral and parietal layer of the serous pericardium?
Visceral - epicardium
Perietal - fibrous pericardium
