Lecture 10: Heart Flashcards
Left recurrent laryngeal nerve hooks around what structure?
the ductus arteriosus in foetus and the ligamentum arteriosum in adults
Right recurrent laryngeal nerve hooks around what structure?
Right subclavian artery
Coronary sinus delivers what where?
Deoxygenated blood from myocardium to right atrium
Function of papillary muscles?
Contracts, pulls down on chordinae tendinae which pulls down on valves, closing them
What kind of valve is in the right atrium?
Tricuspid valve
What the sympathetic Innervation of the heart? Include pre-synaptic and post-synaptic
Pre-synaptic from T1-T5 IML
Post-synaptic from cervical and superior thoracic sympathetic ganglia, end in SA and AV nodes
Increases HR and force of contractions
What’s the parasympathetic Innervation of the heart? Include pre-synaptic and post-synaptic
Pre-synaptic fibres from vagus nerve
Post-synaptic fibres from intrinsic ganglia to SA and AV nodes and coronary arteries
Decrease HR and decrease force of contractions
What is the first function system is the embryo?
Cardiovascular
How old is the embryo when the heart starts beating?
21-22 days old
The heart begins to develop at what age?
Mid third week
What is the fossa ovalis?
Depression in intra-atrial septum; former site of foramen ovale
Which atrium is thicker right or left?
Left
Septa develop to separate atrium and ventricle, this is complete by what week?
5th week
1st pair of aortic arches become what?
Maxillary artery in the head
What happens to the second pair of aortic arches?
Disappears
Third pair of aortic arches become what?
Common carotid and internal carotid
Four pair of aortic arches becomes what?
Right subclavian and aortic arch
Fifth pair of aortic arches becomes what?
Degenerates
Sixth pair of aortic arches becomes what?
Ductus arteriosus and part of the pulmonary artery
At 8 weeks the fifth and six aortic arches degenerate therefore the right recurrent laryngeal nerve moves superior to hook around what structure?
Right subclavian artery
Left recurrent laryngeal nerve hooks around the sixth aortic arch known at what?
Ductus arteriosus
Foetus receives oxygenated blood from the mother via?
Umbilical vein
Most blood bypasses the liver via what structure?
Ductus venosus
Blood from IVC enters right atrium and some flows to left atrium directly through which structure?
Foramen ovale
Most blood in the pulmonary trunk is shunted to the aorta to bypass the lungs via what structure?
Ductus arteriosus
Which nerve provides sensory Innervation to the pericardium of the heart?
Phrenic nerve
Pain sensation carried by phrenic nerve are referred to what dermatome?
C3-C5
Which ventricle occupies most of the anterior surface of the heart?
Right ventricle
What is the epicardium?
Serous membrane that forms the innermost layer of the pericardium, attached to the Muscle of the wall of the heart
What is the myocardium?
Muscle of the heart
What do the right and left coronary artery supply?
Myocardium and epicardium
Where do the coronary arteries originate from?
Base of ascending aorta
Coronary arteries are function end arteries, if there is a blockage what can happen?
Myocardial infarction
The left coronary artery branches into what two structures?
Left circumflex artery and the anterior inter-ventricular artery
The right coronary artery sends out a sinoatrial nodal branch to supply what?
SA node
What is the function of the pulmonary veins?
Deliver oxygenated blood from lungs into left atrium
The coronary sinus delivers de oxygenated blood from what?
Myocardium to right atrium
Wat is the function of papillary muscle?
To pull chordinae tendinae, therefore closing valves
The right atrium has a remnant know as fossa ovalis, what did this use to be?
Foramen ovale
What is another name for the moderator band and what is its function
Septomarginal trabecula- shortcut for conduction from interventricular septum to anterior papillary muscles for synchrones contraction of right ventricle
How quick does the SA node fire
70 times/min
Heart conduction summary: SA node fires, cardiac muscle of right atrium conducts and contracts, impulse reaches AV node, travels from AV node down the interventricular septum via AV bundles. AV bundles branch to purkinje fibres that supply papillary muscles and walls of ventricles
,
Sympathetic Innervation provides more oxygen to the myocardium at what time?
During increased activity
The phrenic nerve passes…….. To the lung root
Anterior
The vagus nerve passes …… To the lung root?
Posterior
Explain cardiac referred pain including visceral and somatic fibres
Visceral afferent fibres carrying pain travel with sympathetic fibres to the T1-T5 spinal cord which synapse in dorsal root ganglion.
Somatic (skeletal muscle) afferent fibres carrying pain also synapse in the dorsal root ganglion. Confuses the brain
The umbilical vein becomes what in a new born?
Ligamentum teres
The ductus venous becomes what in a new born?
Ligamentum venosum
The umbilical arteries become what in a new born?
Medial umbilical ligaments
What is another name for the pacemaker and what does it do?
Sinoatrial node, sets the rhythm of the beating of the heart
