Anatomy of the Cardiovascular System 1 Flashcards
Where in the body are blood vessels and lymphatics not present?
Blood vessels everywhere except cartilage
Lymphatics everywhere except brain and eyes
What are the main circulations?
Pulmonary and system
Pulmonary goes heart - lungs - heart
Systemic goes heart - body - heart
What circulation begins and ends in the capillaries?
Hepatic portal circulation
What stops the heart from over-expanding?
Outer fibrous pericardium
What is the surface marking of the apex of the heart?
5th intercostal space at midclavicular line
What forms the posterior surface of the heart?
Left atrium
What makes up 2/3rds of the anterior heart?
Right ventricle
What is the difference between the lie of the heart in children vs in adults?
Lies higher and more horizontal in children
What are the anatomical relations of the heart?
Sternum Costal cartilages 4-7 Anterior ridges of lungs and pleura Thymic remnants Oesophagus Descending aorta Thoracic vertebrae 5-8 Lungs and phrenic nerves Central tendon of diaphragm
Where is the sternal angle?
Level of T4
What are the layers of the heart?
Endocardium
Myocardium
Epicardium
What is the endocardium formed of?
Epithelium
Basement membrane
Connective tissue
What is the myocardium formed from?
Muscle
What is the epicardium formed from?
Connective tissue
Basement membrane
Epithelium
What does the endocardium line?
Heart chambers
What type of epithelium is in the endocardium?
Simple squamous
What does the endocardium form?
Valves
What cell type is cardiac muscle formed of?
Myocytes
How are chamber lumen closed down?
Muscle bundles in different planes
What are myocytes connected by?
Intercalated discs
What is the function of desmosomes in the intercalated discs of the heart?
Connect at horizontal interface and bind myocytes together
What is the function of gap junctions in the intercalated discs of the heart?
Connect at the vertical interface and supply electrical communication which is essential for a co-ordinated cardiac cycle
What type of epithelium is in the epicardium?
Simple squamous
What layer of the heart contains the main branches of the coronary arteries?
Epicardium
What is direction of blood flow in the heart controlled by?
Valves
What do the chordae tendinae and papillary muscles prevent?
Valve failure
How are heart valves clinically important?
In relation to abnormalities causing incompetence or stenosis and in infection
What valves are semilunar valves?
Aortic and pulmonary
What valves are bicuspid valves?
Mitral
What valves are atrioventricular valves?
Tricuspid and mitral
What does failure of the aortic valve to close tightly cause?
Backflow of blood into the left ventricle
The cardiac skeleton provides structural support for what?
Atrioventricular septum
Roots of great vessels
Anchorage for valves
Myocytes and capillary network
The cardiac skeleton provides electrical insulation for what?
Atria from ventricles
Myocardium from great vessels
Purkinje fibres
What kind of tissue forms the cardiac skeleton?
Connective tissue
What are the attachments of the heart?
Central tendon of diaphragm
Sternum
Roots of great vessels
What is the heart lined by?
Serous pericardium
What is the serous pericardium made of?
Epithelium
What is secreted by the serous pericardium?
Pericardial fluid which acts as a lubricant
What are the visceral and parietal pericardial layers bound to?
Visceral layer bound to heart epicardium
Parietal layer bound to fibrous pericardium
The visceral and parietal pericardial layers are continuous, what does this allow?
Freedom of movement of the heart during the cardiac cycle
At systole, openings in the aortic sinuses are shielded by what?
Aortic valve cusps
At diastolic what happens to the aorta?
There is elastic recoil of the aorta which closes the aortic valve and allows blood to enter the arteries
Where are the coronary arteries located?
In the epicardium
