2 Flashcards
explain how the nervous innervation of the heart travels around the heart
Starts at SA node where the vena cava joins R atrium
Atria depolarization by SA node then AV node entre atria and ventrcieles
Goes to bundle of his which splits in the L and R bundle branches
Purkinje fibres go up the ventricles and innervate muscles of ventricular wall
what is the role of the cardiac plexus?
up and downregulates the nervous system in the heart
what are the three components of the ardaic plexus
vagus nerve
sympathetic nerves
general visceral afferent nerves
what kind of nerve is the vagus nerve
motor nerve
parasympathetic
what kind of nerve are sympathetic nerves
motor nerve
what kind of nerve are the general visceral afferent nerves
sensory nerve
what is the effect of vagus nerve on HR
decreases HR because it is parasympathetic nerve fibres
what is the effect of sympathetic nerve on HR
increaes HR
from what cranial nerve does the vgaus nerve branch from
cranial nerve 10
from what spinal cord level do the sympathetic nerves that contribute to cardaic plexus arise form
T1 to T5
they leave spinal cord synapse to sympathetic chain and preganglionic neurones run into cardiac plexus to innervate teh heart
where do general visceral afferent nerves run
alogn with sympathtic fibres so T1 to T5
how come cardiac pain is referred to the medial aspect of the arm
because somatic afferent (sensory) nerves that run along the chest also runs along the arm because teheyr are the dermatomes T1 to T5
They share somatic regions
through which artieries does the heart get its blood uspply
left coronary artery
right coronary artery
what are the branches of the RCA
posterior interventricular (descending) artery
marginal branch
what are the branches of the LCA
circumflex branch
Left marginal branch of circumflex artery
Left anterior Descneding
