Anatomy Flashcards
How is the location of the phrenic nerve different to the vagus nerve near the heart
The phrenic nerve is anterior to the lung hilum while the vagus nerve is posterior to the lung hilum
Layers of the pericardium from outside to inside (5)
Fibrous pericardium - For protection Parietal Serous pericardium Pericardial cavity Visceral Serous pericardium Epicardium - Secretes fluid lubricant and makes anterior surface of heart
Cardiac tamponade
When the pericardial cavity fills with blood (haemopericardium) causing the pressure to increase and prevent cardiac contraction
Pericardiocentasis (2)
Drainage of fluid from the pericardial cavity
Done via needle inserted at infrasternal angle and directed superoposteriorly, aspirating continuously
Heart surfaces (3)
Anterior (sternocostal) surface
Base (posterior) surface
Inferior (diaphragmatic) surface
Heart borders (4)
Right (lateral) border
Left (lateral) border
Inferior border
Superior border
Location to palpate apex beat of the heart and indication (2)
Left 5th intercostal space in the midclavicular line
Cardiac enlargement often moves beat to the left
Which structure separates the base border from the diaphragmatic border
The coronary sinus in the atrioventricular groove posteriorly
Coronary arteries function and implication
Arterial blood supply to epicardium and myocardium
Blockage results in myocardial infarction
Where do the coronary arteries arise from
Ascending aorta
What is the coronary sinus
A short venous conduit which receives deoxygenated blood from most of the cardiac veins and drains into the right atrium
Septum and its parts (3)
Divides the heart into right and left
Interatrial septum - Part of septum between the 2 atria
Interventricular septum - Part of the septum between the 2 ventricles
Septal defect types and implications (3)
Atrial septal defect - Hole in the interatrial septum
ventricular septal defect - Hole in the interventricular septum
Allows mixing of arterial and venous blood in the heart causing hypoxaemia due to a decrease in oxygen content of systemic arterial blood in the aorta
Role of papillary muscles and tendinous cords
Prevents prolapse of the tricuspid and mitral valves during ventricular contraction
Function of moderator band (septomarginal trabecula)
Carries fibres of right bundle branch to the 3 papillary muscles of the anterior cusp to ensure uniform contraction
Presynaptic sympathetic fibres from the brain (2)
Travel inferiorly within spinal cord tracts
Then exit the spinal cord in one of T1-L2/3 spinal nerves (thoracolumbar)
Fates presynaptic sympathetic fibres (5)
Go into the ganglion of that level and synapse
Travel superiorly in the sympathetic chain to another ganglion and synapse
Travel inferiorly in the sympathetic chain to another ganglion and synapse
Pass straight through the sympathetic chain ganglion without synapsing, as abdominopelvic splanchnic nerves ,to synapse in one of the prevertebral ganglia of the abdomen
Pass straight to the adrenal medulla without synapsing as an abdominopelvic splanchnic nerve
How do postsynaptic sympathetic fibres reach the heart and lungs(2)
By cardiopulmonary splanchnic nerves
In a midline organ there will be bilateral sympathetic innervation
Cardiopulmonary splanchnic nerves location
Postsynaptic fibres from cervical and upper thoracic sympathetic chains
The cardiac plexus contains (3)
Sympathetic fibres
Parasympathetic fibres
Visceral afferent fibres
Where are the parasympathetic ganglion synapse located
On the surface of organs
Vagus nerve function in the heart
Supplies presynaptic parasympathetic fibres onto postsynaptic neurones on the surface of the heart
Somatic chest pain origins and description
Muscular, joint, bony, nerve, pericardial, intervertebral disc
Nature is sharp, stabbing and well localized