Cardiovascular Anatomy Flashcards
Where is the mediastinum located?
- the centre of the thoracic cavity
What is the major component of the mediatsinum?
- the heart, lying within the pericardium
List the divisions of the mediastinum.
- superior
- inferior - subdivided into anterior, middle and posterior
What forms the anterior border of the mediastinum?
- the first rib
What forms the superior border of the mediastinum?
- the fifth rib
What separates the superior from the inferior mediastinum?
- transverse thoracic plane
List the structures of the mediastinum.
- arteries: aortic arch, brachiocephalic artery and left subclavian artery
- veins: brachiocephalic vein, superior vena cava
- nerves: vagus and phrenic
- trachea
- oesophagus
List the structures of the middle mediastinum.
- heart
- pericardium
- great vessels
- descending aorta
- oesophagus
List the structures of the posterior mediastinum.
- thoracic duct
- sympathetic chain
Where can the apex of the heart be located?
- left fifth intercostal space
- approx. 9cm form the median plane
Which structures form the right border of the heart?
- right atrium
- right ventricle
Which structures form the left border of the heart?
- left atrium
- left ventricle
Which structures form the inferior border of the heart?
- right ventricle
- left ventricle
Which structures form the superior border of the heart?
- right atrium
- left atrium
At which vertebral levels does the heart lay?
- T5-T8
- posterior to the sternum
- however, if the body was in the upright position then the heart will hang further down
At which vertebral level is the beginning and termination of the aortic arch?
- T4
At which vertebral level does the bifurcation of the abdominal aorta occur?
- L4
At which vertebral level does the bifurcation of the common iliac arteries occur?
- L5
Name the vessels that branch off the aortic arch in order from right to left.
- brachiocephalic trunk
- left common carotid artery
- left subclavian artery
Name the arteries which branch off the descending aorta.
- bronchial arteries
- oesophageal arteries
- pericardial arteries
- posterior intercostal arteries
Where do the common iliac arteries arise?
- L4
True or False?
The external iliac arteries arise at L5/S1 and become the internal iliac arteries.
False.
- they become the femoral arteries
True or False?
Internal iliac arteries arise at L5/S1 and supply the pelvic viscera.
True.
Name the tributaries of the superior vena cava.
- left and right brachiocephalic vein
- azygos vein
- right internal jugular vein
Name the tributaries of the inferior vena cava.
- left and right common iliac veins
True or False?
The azygos vein drains blood from theposterior intercostal vein.
True.
What vein drains into the azygos vein at T8/T9?
- the hemiazygos vein
State which vein the posterior intercostal vein drains into.
- the azygos vein
State which artery the posterior intercostal arteries drains into.
- the descending aorta
Where do veins/arteries from the thorax and abdomen drain into?
- the internal thoracic vein/artery
Where does the thoracic duct drain into?
- the medial end of the left brachiocephalic vein
Where does the right lymphatic duct drain into?
- the medial end of the right subclavian vein
Where does the subclavian artery become the axillary artery?
- the lateral border of the first rib
What happens to the axillary artery at the posterior axillary fold?
- it becomes the brachial artery
True of False?
The popliteal artery is a distal continuation of the femoral artery.
False.
- the iliac artery is a distal continuation of the femoral artery
What are two superficial veins in the lower limb?
- great saphenous
- small saphenous
What is the pericardium?
- a pleural membrane which covers the heart
List, in order from inside to outside, the layers that surround the heart.
- endocardium
- myocardium
- epicardium
- pericardial cavity
- parietal layer of serous pericardium
- fibrous pericardium
What type of tissue is the inner endocardium comprised of?
- a single layer of squamous epithelium
What type of tissue is the middle myocardium comprised of?
- many layers of cardiac muscle
What type of tissue is the out epicardium comprised of?
- single layer of squamous epithelium
What prevents the overexpansion of the heart?
- the fibrous pericardium
Where does the visceral pericardium receive innervation from?
- T1-T4 nerves and vagus nerve via the cardiac plexus
What is the main innervation of the parietal and fibrous layers?
- the phrenic nerve
What is the fossa ovalis?
- remnant of the foramen ovale in the foetus
- it allowed blood to move between the chambers while bypassing the lungs
Describe atrial septal defect.
- defect in the interartirial septum which allows pulmonary venous return from the left atrium to pass directly to the right atrium
What tissue surrounds the heart valves and why?
- fibrous connective tissue rings
- origin and insertion for cardiac muscle
- blocks electrical signals between atria and ventricles, acting as an electrical insulator
Describe the atrioventricular valves.
- formed from thin flaps of tissue joined at the base to the fibrous connective ring
- flaps are slightly thickened at the edge
- connect at the ventricular side to collagenous tendons called the chordae tendinaea
Where do the chordae tendinaea attach?
- mound-like extensions of ventricular muscle, called papillary muscles
What is the function of the papillary muscles?
- provide stability
- cannot actively open or close the valves
Name the two atrioventricular valves.
- tricuspid - three flaps
- mitral - two flaps
Name the two semilunar valves.
- aortic valve
- pulmonary valve
Define ventricular septal defect.
- a hole in the wall between the two ventricles in the interventricular septum
When would ventricular septal defect be more common?
- in children with other genetic problems, such as Drown’s syndrome
What supplies the heart wall with blood?
- the left and right coronary arteries and their branches
How does blood drain from the heart wall?
- cardiac veins
- then drained into coronary sinus
- then to the right atrium
Describe the coronary sinus.
- a wide, venous channel on the posterior surface of the heart
Where do the lymphatics from the heart drain to?
- the tracheobronchial and mediastinal lymph nodes
How are coronary nerves innovated?
- autonomic nerves travelling in the vagus nerve and the spinal cord segments T1-T4 are routed to the heart and coronary arteries via the cardiac plexus, situated at the bifurcation of the trachea
Describe the histological plan in the heart and blood vessels.
- innermost epithelium
- middle muscle layer
- outer connective tissue layer
These layers are known respectively as; - tunica intima
- tunica media
- tuncia adventitia
What are the three main histological types of arteries?
- elastic
- muscular
- arterioles
Where does the atrioventricular node lie?
- the inferior part of the right septum.
