Anatomy of CVS Flashcards
Where is the heart located?
Middle mediastinum
Where are blood vessels NOT located?
Cartilage
Where are lymphatics NOT located?
Brain
Eyes
What are the two main circulations of the CVS?
Pulmonary (heart - lungs - heart)
Systemic (heart - body - heart)
What is an additional circulation?
Hepatic portal circulation
What are the anterior relations of the heart?
Sternum
Costal cartilages 4 - 7
Anterior edges of lungs and pleurae
Thymic remnants
Posterior relations of heart
Oesophagus
Descending aorta
Thoracic vertebrae 5 - 8
Lateral relations of heart
Lungs
Phrenic nerve
Inferior relations of heart
Central tendon of diaphragm
What is the sternal angle?
T4
Layers of the heart
Endocardium (innermost)
Myocardium (Middle)
Epicardium (outermost)
Pericardial cavity
Histology of endocardium
Simple squamous
Single layer
Bit of connective tissue
Histology of myocardium
Cardiac muscle
Intercalated discs, branching fibres
Histology of epicardium
Simple squamous
One layer thick
Connective tissue underneath
What is the pericardial cavity filled with?
Fluid
What lines the heart chambers?
Endocardium
What forms valves?
Endocardium (due to projections)
What cells make up cardiac muscle?
Myocytes
What are myocytes connected by?
Intercalated discs
What are intercalated discs?
Complex junctions that connect myocytes
What do desmosomes do?
Connect at horizontal interface and bind myocytes together
What do gap junctions do?
Connect at vertical interface
What does the epicardium contain?
Main branches of coronary arteries
What may happen to the epicardium?
May become fatty
What is the mediastinum divided into?
Superior (above T4)
Inferior (T4 to diaphragm)
What is the inferior mediastinum divided into?
Anterior
Middle
Posterior
What lies in the anterior mediastinum until puberty?
Thymus gland
Surface anatomy of heart
5th L intercostal space midclavicular line
What are the heart chambers?
Right atrium
Right ventricle
Left atrium
Left ventricle
What is the direction of blood flow controlled by?
Valves
Function of heart valves
Control direction of blood flow
What are cusps?
Thin structures derived from the endocardium
What prevents valve failure?
Chordae tendinae
Papillary muscles
Definition of valve incompetence
Widening of the valves
Definition of valve stenosis
Narrowing of the valves
How many cusps does the aortic valve have?
3
How many cusps does the pulmonary valve have?
3
How many cusps does the tricuspid valve have?
3
How many cusps does the mitral valve have?
2
What is another name for the mitral valve?
Bicuspid valve
What are the tricuspid and bicuspid valves known as?
Atrio-ventricular valves
What are the pulmonary and the aortic valves known as?
Semilunar valves
What is the predominant nerve in the heart?
Vagus
What is the predominant force on the heart?
Parasympathetic system
Attachments of the heart
Sternum
Central tendon of the diaphragm
Roots of great vessels
What is the heart lined by?
Serous pericardium
What does serous pericardium secrete?
Pericardial fluid
What does pericardial fluid act as?
A lubricant
Layers of the pericardium
Visceral
Parietal
What is the visceral layer bound to?
Heart (epicardium)
What is the parietal layer bound to?
Fibrous pericardium
What do the two layers of the pericardium allow?
Freedom of movement during the cardiac cycle
How do the coronary arteries fill up?
At systole
- openings in aortic sinuses shielded by aortic valve cusps
At diastole
- elastic recoil of aorta closes the aortic valve and blood enters the arteries
Where are the coronary arteries located?
Epicardium