Anatomy of the CVS 1 Flashcards
Where is the heart located?
Middle of the mediastinum
Where are arteries not found?
cartilage
Where are lymphatics not found?
brain, eye
What are the main circulations of the cardiovascular system?
PULMONARY
-heart-lung-heart
SYSTEMIC
-heart -body-heart
Also the
- hepatic portal circulation
- lymphatic system
Between which thoracic vertebrae does the heart lie when in recumbent position
T5-T8
Where does the apex (left ventricle) of the heart lie?
5th intercostal space in the midclavicular line
Where does the left atrium (base) of the heart lie?
Wholly posterior lies anterior tot he oesophageal
Where can the heart drop to when standing?
T6
What is dextrocardia?
Situs-Inverses of the heart meaning that the apex points towards the right instead of left
What lies anterior to the heart?
- Sternum & costal cartilages 4-7
- Ant. edges lungs and pleurae
- Thymic remnants (thymus gland)
What useful landmark marks the top of the heart?
T4
What lies posterior tot he heart?
- Oesophagus
- Descending aorta
- Thoracic vertebrae
What lies lateral to the heart?
lungs
Phrenic nerves
What lies inferior to the heart?
central tendon of the diaphragm
What are the layers of the heart?
Endocardium (innermost)
-Epithelium + *BM + connective tissue
Myocardium (middle)
-Cardiac muscle
Epicardium (outermost)
-Connective tissue + *BM + Epithelium (visceral layer of the serous pericardium)
What are the layers of the pericardium?
Epicardium epithelium - visceral layer of the pericardium
Parietal layer of the serous pericardium
Fibrous pericardium (outermost)
What is the structure and the functions of the endocardium?
Simple squamous epithelium sitting on basement membrane
Sits on connective tissue
- Lines heart chambers
- Forms valves
What is the structure of function of the myocardium?
Thick middle layer of heart wall
Cardiac muscle (Myocytes) – branching fibres
Striated muscle, lots of mitochondria, single central nucleus
Rich capillary bed
Muscle bundles in different planes to close down chamber lumen
Myocytes connected by intercalated discs forming a functional syncytium
What is the structure and functions of the epicardium?
Outer layer of heart wall
Simple squamous epithelium + BM + Connective tissue
Epicardium contains main branches of coronary arteries
What are the functions of the valves?
Control direction of blood flow
What is the structure of the heart valves?
Cusps - thin structures derived from endocardium
What is the function of chordae tendineae
Chordae tendineae and papillary muscles prevent valve failure (only in AV valves)
The chordae tendineae join the cusps of the valve with papillary muscles.
Papillary muscle contraction prevents the valves from upturning when ventricles contract.
What are the 4 valves of the heart?
- tricuspid (right artrioventicular)
- mitral (left artrioventicular)
- aortic valve (semilunar)
- pulmonary valve (semilunar)
Describe the fibrous skeleton
Provides structural support to
- Atrioventricular septum
- Roots of great vessels
- Anchorage for valves
- Myocytes/capillary network
Electrical insulation
- Atria from ventricles
- Myocardium from great vessels
Composed of dance connective tissue
