cardiac circulation and conducting system

Question 1

what are the two grooves of the heart which separate and left and right ventricle

Answer 1

• posterior interventricular groove
• anterior interventricular groove

Question 2

where does the coronary arteries arise from

Answer 2

• arise from ascending aorta
• can be found lifting the auricles

Question 3

how can be the coronary arteries structure be divided

Answer 3

• 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

Question 4

what do most of the coronary veins drain into

Answer 4

• coronary sinus which drains into right atrium
• some coronary veins directly drain into right atrium

Question 5

what are the 5 veins which drain into coronary sinus

Answer 5

• small cardiac vein
• middle cardiac vein
• great cardiac vein
• oblique cardiac veinn of left atrium
• left posterior interventricular vein

Question 6

what vein of the coronary stem directly empties into right atrium

Answer 6

anterior cardiac vein s

Question 7

what is the left marginal vein in the coronary venous circulation

Answer 7

• empties into great cardiac vein

Question 8

what is angina and what is it caused by and triggers

Answer 8

• 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

Question 9

what is coronary artery disease and what are examples of causes

Answer 9

• ischameia of myocardium
• can be acute- plaque breaks away and obstructs vessels causing myocardium infarction
• can be due to artheroscleoris in the coronary arteries

Question 10

coronary artery bypass what vessels can we use

Answer 10

• internal thoracic artery (more historical)
• great saphenous vein (superficial under skin of leg)

Question 11

what are the three most common blockages of coronary arteries

Answer 11

1. anterior interventricular branch
2. right coronary artery
3. circumflex branch

Question 12

what is referred pain phenomenon

Answer 12

• 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

Question 13

what is the distribution of refered pain of he heart

Answer 13

• left shoulder, extending down to left arm, left neck and jaw
• share the same spinal nerve roots (C3-T4)

Question 14

what is the conducting system

Answer 14

• 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

Question 15

where is the SAN located

Answer 15

• junction of the SVC ad right atrium

Question 16

what is the moderator band

Answer 16

• found in the septomarginal trabecula
• helps distribute the electrical impulse/activity
• only found in right ventricle/right bundle

Question 17

where is an artificial pacemaker placed

Answer 17

• 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

Question 18

what is the cardiac plexus

Answer 18

• 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

Question 19

what is the blood supply of the AVN

Answer 19

• supplied by AV nodal artery
• where the AV Nodal artery originates from depends from person to person

Question 20

what does it mean if you are right dominant, left dominant, co dominant

Answer 20

• 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

Question 21

what is the significance of cardiac dominance

Answer 21

• cardiac imaging
• cardia bypass

Question 22

what is angiography for

Answer 22

• 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

Question 23

whats the path of vagus nerve

Answer 23

• cardiac plexus
• esophagul plexus
• anterior and posterior vagal trunk (formed distal end of esophagul plexus)

Question 24

what is the innervation of the vocal cords/larynx

Answer 24

• 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