Innervation of the heart wall Flashcards
Where does extrinsic innervation of the heart come from?
Parasympathetic from vagus nerve
Sympathetic from both superficial and deep cardiac plexus
Where do autonomic fibres travel?
In vagus nerve and spinal cord segments T1-4
What are autonomic fibres and what do they control?
Parasympathetic - control heart rate
What are autonomic fibres routed to the heart via?
Cardiopulmonary nerve plexus situated at the bifurcation of the trachea
Where does sensory and pain innervation come from?
Sympathetic nerves T1-4
What nerves supply the dermatomes of the inner aspect of the upper arm and why is this relevant to cardia problems?
Somatic sensory fibres about spinal nerves T1-4
Pain coming from the heart from these segments is interpreted by the brain as coming from these dermatomes instead of the heart, particularly those from the left upper arm.
What is the intrinsic innervation of the heart?
Innervation of within the heart
What do sympathetic motor fibres innervate in the heart wall?
Sinoatrial node and atrioventricular node
What is the anatomy of the special conducting system?
SA node
AV node
Bundel of His
Left/right branch bundles
Purkinje fibres
Where does the SA node lie?
Lies near the opening of the SVC in the right atrium
Where does the AV node lie?
In the inferior part of the interatrial septum
Where do the atrioventricular bundles of His lie?
Within each side of the interventricular septum
