Cardio Anatomy Lectures

Question 1

What is the anatomy of the thorax?

Answer 1

Sternum
•12 pairs of ribs – costal cartilages and bone
•12 thoracic vertebrae

•The thoracic cage is semi-rigid, which allows it to move when we breathe.
•Semi-rigid structure is used to an advantage when performing CPR – the sternum can be depressed to compress the heart.
•Intercostal muscles move the ribcage for ventilation

Question 2

What is the anatomy of the lungs?

Answer 2

•Site of gas exchange (O2 in, CO2 out).
•Lobes: separated from each other by fissures
•Lobes are clinically important:
•Listen to each one when auscultating the lungs
•Pathology may affect just one lobe
•Assessing the lungs on CXR

Question 3

What is the anatomy of the pleura?

Answer 3

Vital for ventilation
•Parietal and visceral pleura held together by surface tension
•Surface tension created by a small amount of pleural fluid in the pleural cavity
•The chest wall and the lung expand and recoil together

Question 4

What is the CR of the pleura?

Answer 4

Clinically important: if the surface tension is ‘broken’, the lung does not inflate when the thoracic cage expands
•Can happen spontaneously or secondary to trauma that allows air to enter the pleural cavity.

Question 5

What is the anatomy of the heart?

Answer 5

•A sophisticated muscular pump
•Spontaneous electrical activity
•Autonomic input (symp and parasymp)
•Four chambers
•4 valves ensure unidirectional flow
•Clinically important: each valve is auscultated in a specific location on the chest wall – abnormal sounds (murmurs) indicate a problem
•Heart supplied by coronary arteries – specific branches supply different

Question 6

What are the key nerves of the thorax?

Answer 6

Left and right phrenic nerves (C3,4 and 5) – innervate the diaphragm

•Left and right vagus nerves – complex
•Vagus is a cranial nerve (leaves the brainstem)
•Parasympathetic fibres – supply the thoracic viscera
•Somatic motor fibres – supply muscles of the pharynx and larynx
•Somatic sensory fibres – supply the larynx

•Left and right sympathetic trunks / chains – complex
•Sympathetic innervation to thoracic and abdominal viscera, smooth muscle of blood vessels and glands

Question 7

What is the surface anatomy of the thorax?

Answer 7

Heart borders:

Second intercostal space

5th intercostal space

Midclavicular line

Question 8

What are the auscultation areas of the heart?

Answer 8

Aortic valve
Pulmonary valve

Tricuspid valve
Mitral valve