Lecture 9 pt 2 Flashcards
What are the major branches of thoracic aorta?
1) Coronary arteries
2) Right brachiocephalic trunk
3) Arch of aorta
4) Posterior intercostals
What are two branches of the right brachiocephalic trunk?
1) Right common carotid
2) Right subclavian
What two things come off the arch of the aorta?
1) Left common carotid
2) Left subclavian
What is inside the aortic valve?
Lateral sinuses contain the right and left coronary arteries
When are the coronary arteries perfused? Why?
During diastole; they open to the aortic valve, so if the valve is stenotic or contracting, the coronary artery has no perfusion
Describe the anatomy of the left and right coronary arteries
1) Left coronary artery is usually the main/ dominant one, has 2 branches: left anterior descending/ anterior IV septal branch (descends along anterior margin of AV septum) and the circumflex branch.
2) Right coronary artery supplies blood to right ventricle, then goes behind and forms right septum and they meet on the posterior side of the apex.
Vagus nerve runs through the mediastinum; what branches off here?
Left and right recurrent laryngeal nerves
Which recurrent laryngeal nerve has a longer course? Why is this important?
Left recurrent laryngeal nerve; more prone to injury
1) What is the carotid body and what does it do?
2) What innervates it?
1) Chemoreceptor; monitors PO2
2) CN 9 (Glossopharyngeal n.) and CN 10 (Vagus n.)
What is the baroreceptor for BP?
Carotid sinus
What nerve innervates the carotid sinus?
CN9
Where is the carotid sinus?
Where the common carotid artery branches into internal and external
What provides autonomic innervation to the heart?
Cardiac plexus’s sympathetic and parasympathetic components
1) What forms the sympathetic part of cardiac plexus?
2) What do the fibers innervate?
1) Presynaptic cell bodies: thoracic lateral horn T1-5(6)
Postsynaptic cell bodies: cervical and superior thoracic paravertebral ganglia
2) Fibers innervate SA and AV nodes, cardiac muscle cells
1) What forms the parasympathetic part of cardiac plexus?
2) Where are the postsynaptic cell bodies?
1) Presynaptic fibers of the CN10 (vagus).
2) Postsynaptic cell bodies (intrinsic ganglia) located near SA and AV node, along coronary arteries.
What does sympathetic stimulation do to the heart? What does it dilate?
Increases rate and force, dilates coronary arteries
What does parasympathetic stimulation do to the heart?
Slows heart, reduces force of ctx.
The SA node is set around ______________BPM, and can be modified by sympathetic input, but this also involves the ________________ arteries
60-100; coronary
The electrical cells of the heart pause everything to allow contraction of ________, then goes to bundle of his (anterior and posterior) and Purkinje fibers
atria
What are the two main divisions of the two coronary arteries?
1) RCA (right coronary artery) & posterior IV branch
2) LCA (left coronary artery), Anterior IV branch (LAD) & circumflex branch
What are two branches of the left coronary artery (LCA)?
Anterior IV branch (LAD) & circumflex branch