heart vasculature and innervation Flashcards
coronary arteries
- supply the myocardium and epicardium
- supply blood to heart tissues
- originated from aorta
- right and left cornary artery
what do the right and left coronary arteries arise from?
right and left aortic sinuses
right coronary artery
-Right marginal artery
–Posterior interventricular artery
what will the posterior interventricular artery give rise to?
atrioventricular nodal artery
left coronary artery
- circumflex artery
- anterior interventricular artery
coronary arteries are ____ end arteries
functionally
end artery definition
=(terminal artery)
an artery that is only supply of oxygenated blood to a tissue portion
Characteristics of end artery
- do not anastomose with other arteries or arterial branches of the same artery.
- branches are not true end arteries
why do end arteries not have true branches?
because numerous anastomoses take place between the left and right coronary arteries (intercoronary anastomoses)…and between branches of the same artery
coronary arteries send branches to what?
heart on either side of their path and to any portion of septum dep to their path
coronary arteries blood supply is easy to deduce with exception of what?
SA and AV node
right coronary artery contains what 4 branches?
- SA nodal
- Right marginal
- AV nodal
- Posterior interventricular
right coronary artery supplies what?
-right atrium
- right ventricle
- post. 1/3 interventricular spetum
SV and AV nodes
left coronary artery contains what 2 branches?
- anterior interventricular
2. circumflex
left coronary artery supplies what?
- left atrium
- left ventricle
- portion of right ventricle
- interventricular spetum (ant. 2/3)
- AV node
- SV node (40% of pop from circumflex)
SA nodal artery
- right coronary artery
- SA nodal a.
- right marginal a.
coronary artery dominance
artery that gives rise to the posterior interventricular artery
codominance
both right and left coronary arteries give rise to branches that course in or near the posterior interventricular groove occurs in about 18%
coronary artery variations
- right dominant
- left dominant
- right dominant: no circumflex
- left dominant: no right coronary artery
coronary atherosclerosis
lipid deposits in intima (lining) of coronary arteries
coronary artery disease (CAD) treatment
- balloon angioplasty
- surgical therapy
- lifestyle changes
- medications
myocardial infarction (MI)
- sudden occlusion of a major artery (by an embolus)
- region of heart supplied by occluded vessels become infarcted and necrotic
infarcted
rendered bloodless
myocardial infarction cause
coronary artery insufficiency from atherosclerosis
how is the heart mainly drained?
by veins that empty into the coronary sinus
where do anterior cardiac veins drain directly into?
right atrium
coronary sinus runs towards what and drains where?
right side of the heart and drains into the right atrium
location of SA node
located in the wall of the right atrium near the opening of the superior vena cava and superior end of the crista terminals
function of SA node in conducting system of the heart
initiates cardiac muscle contraction and determines heart rate
location of AV node
interatrial septum just superior to the coronary sinus opening
AV bundle
passes from the AV node in the membranous part of the interventricular septum and divides into right and left bundle branches
conducting system
- network of specialized tissue that stimulates contraction
- modified cardiac myocytes
- heart can contract without any innervation
Purkinje fibers
carry signal into papillary muscle to coordinate their contraction with systole
preganglionic sympathetic neuron cell bodies location
lateral horns of spinal cord segments T1-T5
In sympathetic cardiac innervation, postsynaptic fibers are carried by what?
- carried in cardiopulmonary splanchnic nerves
- contributing to the cardiac plexus and ending in the SA and AV nodes and in relation to the termination of parasympathetic fibers on the coronary arteries.
sympathetic innervation
responsible for increasing heart rate, impulse conduction, force of heartbeat, and blood flow in coronary arteries
parasympathetic stimulation
responsible for decreasing heart rate, force of contraction, and constricting coronary arteries
how is the parasympathetic innervated?
via preganglionic fibers in the vagus nerve
Presynaptic parasympathetic fibers
contribute to cardiac plexuses
postganglionic cells locations
in cardiac tissue
where do postsynaptic fibers end?
SA and AV nodes & directly on the coronary arteries
Visceral pain pathway follows what path?
heart follow the path of the sympathetics backward.
Visceral sensory pathways
- can participate in reflex actions that lower blood pressure and slow the heart rate are carried in the vagus nerve (CN X).
- The vagus nerve does not transmit any visceral pain fibers originating in the heart.
does the vagus nerve transmit any visceral pain?
no.
what 3 vessels does the umbilical cord contain?
2 umbilical arteries
1 umbilical vein
2 umbilical arteries
- carry unoxygenated blood awayfrom the fetus.
- become the medial umbilical ligaments of the anterior abdominal wall. They are branches of the internal iliac arteries.
1 umbilical vein
- carries oxygenated blood from the placenta to the fetus.
- drains into the ducutus venosus which drains into the IVC and bypasses the liver.
blood flow that ultimately circulates to the fetus’ head, neck, and upper extremities.?
Blood from the inferior vena cava flows into the right atrium, toward the foramen ovale and into the left atrium.
Blood from the superior vena cava flows into (fetal circulation)
the right atrium, toward the tricuspid valve and into the right ventricle and pulmonary trunk.
blood flow that ultimately circulates to the fetus’ thorax, abdomen, pelvis, and lower extremities.
Blood in the pulmonary trunk is shunted to the aorta via the ductus arteriosus.
