Anatomy 2- Differential Diagnosis of Chest Pain Flashcards
What are the 3 links that can be made between the heart and nerves?
Dual motor control of the heart (sympathetic and parasympathetics)
Visceral afferent nerves
Conducting system of the heart and arrhythmia
How does the autonomic innervation reach the heart? - sympathetics, parasympathetics and visceral afferent nerves
Via the cardiac plexus
What is the effective the sympathetic nerves on the heart? (2)
Increases heart rate
Increases contractility
What is the effect of the parasympathetic nerves on the heart?
Decreases heart rate
What types (2) of viscera afferent nerves are involved in the heart?
Pain fibres
Visceral reflex afferents (e.g. from baroreceptors)
How do pain fibres travel to the spinal cord?
Alongside sympathetic nerves
Where do visceral reflex afferents mainly travel in?
The vagus nerve
For sympathetic innervation, what is the neurotransmitter than synapses between the axon of the presynaptic neurone and cell body of postsynaptic neurone?
Acetylcholine
For synaptic innervation, what is the neurone that connects between the ganglion and organ?
Noradrenaline
What do presynaptic sympathetic fibres from the brain do?
Travel inferiorly within spinal cord tracts and then exit the spinal cord in one of T1-L2/3 spinal nerves (thoracolumbar) and then can do 1 of 5 options
What are the 5 things that sympathetic signals which have traveled within the spinal cord and exited in one of T1-L2/3 can do?
What are the 3 options that are involved with the sympathetic stimulation of the heart?
Go into the ganglion (in sympathetic chain) 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 synpase
Pass through the sympathetic chain ganglion without synopsis, as abdominopelvic splanchnic nerves, to synapse in one of the pre-vertebral ganglia of the abdomen
Pass straight to the adrenal medulla without synapsing as an abdominopelvic splanchnic nerve
Top 3 are options for stimulation of heart
What are the names of the cervical sympathetic ganglia?
Superior
Middle
Inferior cervical sympathetic ganglia
What are the names of the postsynaptic fibres which provide sympathetics to the heart and lungs?
Cardiopulmonary splanchnic nerves
What ganglia have nerves that come out of them to produce the cardiopulmonary splanchnic nerves?
T1-T5 ganglia and cervical ganglia
For essentially midline organs such as the heart is there unilateral or bilateral sympathetic innervation?
Bilateral
What is the cardiac plexus made up of?
Sympathetic fibres
Parasympathetic fibres
Visceral afferent fibres
What is the neurotransmitter released by both the presynaptic and postsynaptic fibres of parasympathetic fibres?
Acetylcholine
How do the parasympathetic reach the organs?
Through cranial nerves III, VII, IX, and X and the sacral spinal nerves
How many parasympathetic ganglia are in the head?
4 (1 for occulomotor nerve , 2 for facial nerve and 1 for glossopharyngeal nerve)
How does the presynaptic parasympathetic fibres from the vagus nerve reach the organs?
Synapse onto postsynaptic neurones (with short axons in ganglia within the walls of the organs of the chest and upper abdomen)
What provides parasympathetic innervation to the organs of the lower abdomen, pelvis and perineum?
The pelvic splanchnic nerves
What does the vagus nerve innervate?
All the organs from the neck, chest and abdomen as far as the end of the midgut
Where does the vagus nerve attach to the heart?
At the SA node
What travels in the cardiopulmonary splanchnic nerves?
Postsynaptic cardiac sympathetic efferent
Cardiac visceral afferent
Where are the visceral afferent nerve endings in the heart located for stretch and chemicals? (8)
Inner aortic arch Pulmonary trunk Vena cavae Around the SA node Outflow tracts from both ventricles Papillary muscles Root of aorta IV septum