cardiac circulation and conducting system Flashcards
what are the two grooves of the heart which separate and left and right ventricle
- posterior interventricular groove
- anterior interventricular groove
where does the coronary arteries arise from
- arise from ascending aorta
- can be found lifting the auricles
how can be the coronary arteries structure be divided
- left and right coronary arteries
- right coronary artery is much longer than left
- right marginal branch arises from coronary artery and found near bottom of heart
- left coronary artery much shorter splits into two branches know as the circumflex which wraps posteriorly and the anterior interventricular branch
- posterior interventricular branch can arise from right or left coronary artery depends from person to person
what do most of the coronary veins drain into
- coronary sinus which drains into right atrium
- some coronary veins directly drain into right atrium
what are the 5 veins which drain into coronary sinus
- small cardiac vein
- middle cardiac vein
- great cardiac vein
- oblique cardiac veinn of left atrium
- left posterior interventricular vein
what vein of the coronary stem directly empties into right atrium
anterior cardiac vein s
what is the left marginal vein in the coronary venous circulation
- empties into great cardiac vein
what is angina and what is it caused by and triggers
- sudden crushing substernal pain
- caused by myocardial ischemia by narrowing of coronary arteries by the build up of fibrous plaque
- trigger include exercise, stress, cold
- received by rest
what is coronary artery disease and what are examples of causes
- ischameia of myocardium
- can be acute- plaque breaks away and obstructs vessels causing myocardium infarction
- can be due to artheroscleoris in the coronary arteries
coronary artery bypass what vessels can we use
- internal thoracic artery (more historical)
- great saphenous vein (superficial under skin of leg)
what are the three most common blockages of coronary arteries
- anterior interventricular branch
- right coronary artery
- circumflex branch
what is referred pain phenomenon
- where Ian is perceived from a different location to where it actual originated from
- due to somatic and visceral sensory nerves from different areas converge to the same spinal cord segment- so brain doesn’t know where innervation came from
what is the distribution of refered pain of he heart
- left shoulder, extending down to left arm, left neck and jaw
- share the same spinal nerve roots (C3-T4)
what is the conducting system
- specialised system of cardiac. muscle responsible for generating and transmitting electrical impulses ensuring coordinated rhythms and contractions
- consists of the SA node and AVN node
where is the SAN located
- junction of the SVC ad right atrium
what is the moderator band
- found in the septomarginal trabecula
- helps distribute the electrical impulse/activity
- only found in right ventricle/right bundle
where is an artificial pacemaker placed
- travels through subclavian vein through superior vena cava through right atrium through tricuspid valve to the right ventricle
- electrodes placed in contact with the endocardium
what is the cardiac plexus
- supplies innervation to the heart
- located between aorta, pulmonary trunk and the trachea
- parasympathetics include vagus nerves
- sympathetics include post synaptic fibres from superior thoracic paravertebral ganglia of the sympathetic trunks
what is the blood supply of the AVN
- supplied by AV nodal artery
- where the AV Nodal artery originates from depends from person to person
what does it mean if you are right dominant, left dominant, co dominant
- right dominant means the AV nodal artery arises from the posterior interventricular branch which arises from right coronary artery
- left dominant- AV nodal artery arises from posterior interventricular branch from circumflex of left coronary artery
- co dominant- supplies from both
what is the significance of cardiac dominance
- cardiac imaging
- cardia bypass
what is angiography for
- x ray to visualise coronary arteries
- uses dye, dark regions are densest
-can be used to find where a clot in the artery is - what the blood supply of the AVN is
whats the path of vagus nerve
- cardiac plexus
- esophagul plexus
- anterior and posterior vagal trunk (formed distal end of esophagul plexus)
what is the innervation of the vocal cords/larynx
- vagus nerve gives off a branch known as superior laryngeal nerve which supplies the larynx
- descending vagus nerve on the left Side gives off a branch which wraps around the aorta known as the left recurrent laryngeal nerve and supplies the voice box
