Differential diagnosis of chest pain

Question 1

what do Sympathetic nerves do

Answer 1

Increase heart rate
Increase contractility

Question 2

what do Parasympathetic nerves do

Answer 2

Decrease heart rate

Question 3

how does the autonomic innervation Reaches the heart

Answer 3

viacardiac plexus

Question 4

Plexus

Answer 4

intertwining of nerves

Question 5

Cardiac plexus

Answer 5

intertwining of sympathetic, parasympathetic and visceral afferent nerves

Question 6

what is a Ganglion:

Answer 6

synapse between axon of presynaptic neurone and cell body of postsynaptic neurone

Question 7

what is the Neurotransmitter at the presynaptic neurone in the sympathetic nervous system

Answer 7

acetylcholine

Question 8

what is the Neurotransmitter at the postsynaptic neurone in the sympathetic nervous system

Answer 8

noradrenaline

Question 9

describe the Thoracolumbar outflow:

Answer 9

presynaptic sympathetic fibres from brain travel inferiorly within spinal cord then exit spinal cord in a T1-L2/3 spinal nerve

Question 10

• what can Sympathetic fibres which have left spinal nerve do:

Answer 10

1. Go into ganglion of that level and synpase
2. Travel superiorly in sympathetic chain and synapse (in higher ganglion)
3. Travel inferiorly in sympathetic chain and synapse (in lower ganglion)
4. Pass straight through sympathetic chain ganglion without synapsing
5. Pass straight to adrenal medulla without synpasing as an abdominopelvic splanchnic nerve - directly stimulating adrenaline releas

Question 11

what is the neurotransmitter at both presynaptic and postsynaptic neurone in the parasympathetic nervous system

Answer 11

acetylcholine

Question 12

what cranial nerves are used to help the signals reach their organs

Answer 12

3,7,9,10

Question 13

what does the Cranial nerve X (vagus nerve) do:

Answer 13

carries parasympathetic nerves to heart

• Synapses with postsynaptic neurons which have short axons in walls of organs of chest and upper abdomen

Question 14

describe craniosacral outflow:

Answer 14

spinal nerves in sacral level also carry parasympathetic nerves to lower abdomen pelvis and perineum)

Question 15

what are Pelvic splanchnic nerves

Answer 15

PARAsympathetic

Question 16

what does somatic pain feel like

Answer 16

Sharp, stabbing, well localised pain

Question 17

what is the Central sulcus -

Answer 17

important in differentiating the motor and sensory parts of brain

Question 18

Precentral gyrus:

Answer 18

somatomotor, APs originating here bring about contractions of body wall (skeletal muscle)

Question 19

Postcentral gyrus:

Answer 19

area of the brain which deals with somatosensory information

Question 20

Sensory homunculus:

Answer 20

illustration of where sensations from somatic structures reach the cerebral neocortex

Question 21

what are the sources of somatic pain

Answer 21

• Shingles (can be referred from T4/T5 posterior root dermatome)
  
  • Herpes zoster virus can be reactivated in the posterior root ganglion
• Muscular, joint, bone, IV disc
• Fibrous pericardium (pericarditis)
• Parietal pleura (pleurisy)

Question 22

what are Visceral Afferents:

Answer 22

neurons that sense events occurring within internal organs

Question 23

where do Visceral afferent APs travel

Answer 23

alongside sympathetic pass bilaterally to thalamus then diffuse areas of the cortex

Question 24

what do Visceral afferent APs at the spinal cord -

Answer 24

enter via posterior roots, as do the somatic sensory nerves → radiating and referred pain

Question 25

what is radiating pain

Answer 25

Pain felt at site of pathology AND felt spreading from there

Question 26

radiating Pain from somatic structure:

Answer 26

radiation is along the affected dermatome

Question 27

radiating Pain from heart:

Answer 27

radiation is to dermatomes supplied by the spinal cord levels at which the cardiac visceral afferents enter sympathetic chain/spinal cord - bilaterally to cervical and upper thoracic dermatomes

Question 28

radiating Visceral radiating pain:

Answer 28

is ‘visceral’ in nature (dull etc.) even though it is felt in a dermatomal pattern

Question 29

what is referred pain

Answer 29

Pain felt only at a site remote from the area of injury

Question 30

how does referred pain occur

Answer 30

• Due to afferent (sensory) fibers from the soma and afferent (sensory) fibres from the viscera entering the spinal cord at the same levels
  
  • Brain chooses to believe that pain signals coming from organ are coming from soma

Question 31

how does somatic pain work

Answer 31

1. AP carried from skin mechanoreceptors through anterior or posterior ramus (usually anterior)
2. pass into the spinal nerve
3. Travel through the dorsal root ganglion and into dorsal root/rootlets
4. Synapses within spinal cord segment specific to dermatome which experienced pain
5. AP crosses in spinal cord to ventral side
6. AP moves up left side of spinal cord to the cerebral cortex

Question 32

what is a myocardial infarction

Answer 32

irreversible death (necrosis) of part of the myocardium due to occlusion of it’s arterial blood supply

Question 33

what is Coronary Artery Bypass Grafting (CABG)

Answer 33

grafts anastomosed proximally to the ascending aorta and bypassing the area if blockage in order to return normal blood supply to the area of myocardium