Pancoast tumour, spinal cord, neck Flashcards
Where would pain be felt if a Pancoast tumour encases the C8 nerve root, and what would happen to the muscles in that area?
Medial two digits of the hand would be painful
The intrinsic muscles of the hand would atrophy
Describe the pain that would be felt if a tumour interferes with the T1 nerve root?
Pain which radiates down the medial aspect of the arm and forearm, stopping at the wrist
If there is a disruption to the sympathetic nerves of the eye, what symptoms occur?
- Ptosis
- Miosis
- Hemi-facial anhidrosis
- Loss of head and neck sympathetic tone
- Enophthalmos (sunken eyeball)
What happens when tumour compresses the recurrent laryngeal nerve?
Hoarse voice and bovine cough
Describe where first-order neuronal fibres arise and end in sympathetic innervation of the eye
Arise from postero-lateral hypothalamus
Descend through brainstem until termination at C8-T2
Describe when second-order neuronal fibres arise and end in sympathetic innervation of the eye
Exit through T1 root, travelling close to lung apex through sympathetic chain and cervical-thoracic ganglion
Terminate in superior cervical ganglion
Describe when third-order neuronal fibres arise and end in sympathetic innervation of the eye
Exit ganglion forming plexus around carotid internal.
Ascending into the cavernous sinus
Runs to eye via long and short ciliary nerves
Describe the superior vena cava syndrome
Obstruction of the superior vena cava by a tumour (mass effect) causes facial swelling, cyanosis and dilatation of the veins of the head and neck
Which fibres of the face cause sweating and tone to occur?
Vasomotor and sweat gland fibres - form plexus around external carotid artery
Which order of neuronal fibres are affected by a pancoast tumour to cause horners syndrome?
Second order neuronal fibres- called a second order neuronal lesion
Are pancoast tumours the only thing that can cause horners syndrome?
No - if any of the orders of neuronal fibres are affected in any way, the syndrome can appear
Why does enopthalmos occur?
Loss of sympathetic supply to the eye causes narrowing of the palpebral fissure, causing the ILLUSION of enopthalmos
How can upper limb swelling and discolouration be caused by a pancoast tumour?
Tumour growth in the lung apex can completely or partially compress the subclavian vein
What problems in the upper limb can be caused by a pancoast tumour - and why?
Upper limb swelling and discolouration Loss of vascular tone (loss of sympathetic innervation) Oedema (failure of venous drainage) Tenderness Erythema Warmth
Which anatomical structures allow the formation of three compartments within the thoracic inlet?
Insertion of the anterior and middle scalene muscle on the posterior scalene muscle (on second rib)
What is found within the anterior compartment of the thoracic inlet?
Subclavian and internal jugular veins
What is found in the middle compartment of the thoracic inlet?
Subclavian artery and some of its branches
What is found in the posterior compartment of the thoracic inlet?
Brachial plexus branches, sympathetic trunk and cervical-thoracic ganglion
What is a Pancoast tumour characterised by?
Malignant neoplasm of the superior sulcus of the lung with destructive lesions of the thoracic inlet and involvement of the brachial plexus and cervical sympathetic nerves
What are the common clinical features of a Pancoast tumour?
- Pain radiating down the arm
- Atrophy of hand and arm muscles
- Horner’s syndrome
- Compression of blood vessels
- Oedema
What type of cancer are Pancoast tumours normally?
Squamous cell carcinomas
Adenocarcinomas
What is a main difference between a Pancoast tumour and classic lung cancers?
No breathlessness or coughing up blood
How would a Pancoast tumour be diagnosed?
- Biopsy - supraclavicular incision
- Bronchoscopy
- X-ray
- CT
- MRI - spread
- PET - lymph node involvement
What is the classical treatment for Pancoast tumours and what is the 5yr survival rate?
Pre-operative radiotherapy
Removal of chest wall, lower brachial plexus and part or the entire lung
Additional chemotherapy 30%
What is the management for disseminated pancoast tumours?
Palliative radiotherapy or surgery
What causes ptosis
Damage or lack of nerve supply to levator palpebrae superioris muscle and superior tarsal muscle
Give cause of miosis
The iris dilator muscle - responsible for dilatation of the pupil loses sympathetic innervation -inactivated
Which two sources do motor neurons receive input from?
Local sources - segmental reflexes
Descending tracts from brain - voluntary movement
Where does the lateral corticospinal tract decussate?
In the medulla
Where does the anterior corticospinal tract decussate?
At the level at which it leaves the spinal cord
Where in the white matter does the lateral corticospinal tract travel?
Immediately lateral to the dorsal horn
Where in the white matter does the anterior corticospinal tract travel?
Lateral to the anterior median fissure
Which two parts of the brain does the corticospinal tract travel through?
Internal capsule
Cerebral peduncle of the midbrain
Where do the axons of the corticospinal tract form ventral bulges, and what are they called?
In the medulla oblongata - known as pyramids
What is the difference in function between the lateral and anterior corticospinal tracts?
- Anterior - control trunk and proximal limb movement
- Lateral - precise, agile and highly skilled movements of hands and feet
What is the function of the corticobulbar pathway?
Controls skeletal muscles of the head
Which two areas of the brain does the corticobulbar tract pass through?
Internal capsule
Cerebral peduncle of the midbrain
Which nine cranial nerve motor nuclei, do axons of the corticobulbar tract terminate in?
- Oculomotor
- Trochlear
- Trigeminal
- Abducens
- Facial
- Glossopharyngeal
- Vagus
- Accessory
- Hypoglossal
What is the function of the tectospinal pathway?
Maintains balance and posture
Which neurons does tectospinal modulate the activity of?
Alpha and gamma motor neurons innervation muscles of the neck
What is the function of the vestibulospinal pathway?
Maintains balance and posture
What are the two parts of the reticulospinal tract?
- Pontine (extensor)
- Medullary (flexor)
What is the function of the reticulospinal tract?
Maintains balance and posture
What is the function of the rubrospinal tract?
Regulates upper limb muscle tone and movement
Where do the upper motor neurons arise in the rubrospinal tract?
The red nuclei of the midbrain
Where do upper motor neurons of the rubrospinal tract decussate?
Midbrain
Where in the White matter of the spinal cord will you find the dorsal column (medial lemniscus pathway)?
Posterior and medial to the dorsal horn
Why is the dorsal column/medial lemniscus path called this?
Dorsal column of the spinal cord
Medial lemniscus of the brainstem
Where do first order neurons of the dorsal column arise from and terminate at?
Arises from sensory receptors in limbs, trunk, neck, etc
Travels into the spinal cord, ascends up the ipsilateral side and terminates at the medulla (still ipsilaterally)
Where are the cell bodies for the first order neurons of the dorsal column found?
Dorsal root ganglion
What are the two dorsal columns in the white matter - and what sensations are carried in each?
Gracile fasciculus - touch, pressure and vibration from lower limbs Cuneate fasciculus - touch, pressure, vibration and conscious proprioception from the upper limbs, trunk and neck
Where do first and second order neurons synapse in the dorsal column?
In either the gracilis or cuneate nucleus
Where do the second order neurons of the dorsal column arise and terminate?
Arise in the cuneate of gracile nucleus, then decussate (in the medulla still) and enters the medial lemniscus Terminates in the ventral, posterior nucleus of the thalamus
Where do tertiary axons of the dorsal column arise and terminate?
Arise in the ventral, posterior nucleus of the thalamus
Terminates in the primary somatosensory area of the cerebral cortex
What sensations does the medial lemniscus pathway transmit?
Tactile sensations Proprioception
Where in the white matter is the spinothalamI c tract located?
Anterio-lateral to the ventral horn
What sensations does the spinothalamic tract carry?
- Pain
- Temperature
- Itch
- Tickle
Where do the first order neurons in the spinothalamic tract arise and decussate?
They arise at the receptor (in trunk, limbs, neck, posterior head)
They terminate in the dorsal horn on the ipsilateral side
Where do the second order neurons in the spinothalamic tract arise and decussate?
They arise in the dorsal horn, and then decussate to the contralateral side They pass up the spinal cord They terminate in the ventral, posterior nucleus of the thalamus
Where do the third order neurons in the spinothalamic tract arise and decussate?
They arise in the ventral, posterior nucleus of the thalamus and travel to the primary somatosensory area (on the same side as the thalamus)
Where are the pre-ganglionic neurons of the sympathetic nervous system located?
Thoracolumbar region - T1-L3
Where are the pre-ganglionic neurons of the parasympathetic nervous system located?
The brainstem - CN III, VII, IX and XSacral region- S2-4
Where are the ganglia of the sympathetic nervous system located?
In the sympathetic trunk - next to the vertebral column from T1 to the coccyx
Where are the ganglia of the parasympathetic nervous system located?
Near the targets organ - in the walls of the viscera they innervate
What is the function of the sympathetic nervous system?
Increased heart rate Decreases gut activity Dilates pupils
What is the function of the parasympathetic nervous system?
- Decreased heart rate Increased gut motility
- Pupil constriction
- Increase in secretions
What organs are only supplied by the sympathetic nervous system?
- Sweat glands
- Adrenal medulla
- Hair follicles
- Spleen
- Iris dilator
What organs are only supplied by the parasympathetic nervous system?
Ciliary muscles - focusing the eyeIris sphincter
Outline the basic segmental organisation of the spinal cord nerves
- Cervical (8)
- Thoracic (12)
- Lumbar (5)
- Sacral (5)
- Coccygeal (1)
Each segment gives rise to a pair of nerves
What is the lower limit of spinal cord?
- L1/2 in adults
- L3/L4 in newborn
Where do the spinal nerves leave the spinal cord?
Through intervertebral foramen C1 to C7 above their appropriate vertebrae C8 to Coc1 below ther appropriate vertebrae
What does the spinal cord develops from?
Neuro-ectoderm
From what does dorsal horn develop and what fibres it contain?
From alar plate, incoming sensory fibres
From what does ventral horn develop and what fibres it contain?
Basal plate, motor outputs to the periphery
Name the meninges from innermost to outermost layer
Pia mater, Arachnoid mater, dura mater
Describe dura mater
Thick elastic membrane, fuses with the endosteum of cranium at the foramen, epidural space separates the dura and the vertebrae
Describe arachnoid mater
Thin, fibrous membrane
Bridges the subarachnoid space which contains cerebrospinal fluid
Describe pia mater
Unicellular membrane
Forms 21 denticulate ligaments laterally
Separated from the cord by the subpial space
What is the cerebrospinal fluid?
A filtrate of blood made in the choroid plexus within the ventricular system of the brain
Affords mechanical and immunological protection to the brain and spinal cord
Reabsorbed into the venous drainage system of the head
How much cerebrospinal fluid is produced each and how much circulates at one time?
500 ml each day 140 ml within the subarachnoid space
What bridges the subarachnoid space?
Trabeculae
Describe the venous drainage of the spinal cord
By Batson veins which form vertebral/Batson plexus in the epidural spae and invade the pia mater
What arteries supple the spinal cord?
Intercostal arteries give of 2 posterior spinal arteries and one anterior spinal artery
What is the artery of Adamkiewicz?
Artery given of by left posterior intercostal artery that supplies lower 1/3 of the spinal cord
Also called major anterior segmental medullary artery
What is foramen magnum?
Opening in the ocipital bone for the spinal cord
What is the lowest point of spinal cord called?
Conus medullaris
What is the collection of nerves below the spinal cord called?
Cauda equina
What is filum terminale?
Ligament that attaches to the sacrum and holds the spinal cord in place
What is the difference between epidural and spinal tap?
Epidural injection only goes to epidural space Spinal tap involves piercing the subarachnoid space to either draw CSF or administer drugs
name the types of axons
Aα
Aβ
Aδ
C
What are the properties of Aα axons?
Largest diameter 13-20 um
Speed - 80-120 m/sec
Sensory receptors: proprioceptors of skeletal muscle
What are the properties of Aβ axons?
Diameter: 6-12 um
Speed: 35-75 m/sec
Sensory receptors: mechanoreceptors
What are the properties of Aδ axons?
Diameter 1 -5 um
Speed: 5-30 m/sec
Pain and temperature
What are the properties of C axons?
Diameter: 0.2 -1.5 um
Speed: 0.5 - 2 m/sec
Temperature, pain, itch
What are the borders of the posterior triangle of the neck?
- Posterior: Trapezius muscle
- Inferior: Omyhyoid muscle
- Anterior: Sternocleidomastoid muscle
Name the arteries that pass through the posterior triangle of the neck
- Transverse cervical artery
- Suprascapular artery
- Subclavian artery
Name the nerves that can be spotted in the posterior triangle of the neck
- Transverse cervical nerve
- Great auricular nerve
- Accessory nerve
- Phrenic nerve
- Brachial plexus
What lymph nodes are found in the posterior triangle of the neck
Superficial cervical nodes and supraclavicular nodes
What veins are associated with the posterior triangle of neck?
External jugular vein and subclavian vein
What does transverse cervical nerve supply?
Skin of the anterior neck triangle
Where does the phrenic nerve lie within the posterior triangle of neck
On the scalenous anterior muscle
Where does the brachial plexus lie within the posterior triangle?
Behind the scalenous anterior muscle
What is the origin and insertion of the scalenous medius muscle?
Cervical vertebrae to 1st rib
What do the superficial cervical nodes drain?
Skin area of posterior triangle and some anterior parts
Where is the stellate ganglion located?
Lies on the neck of the 2nd rib
What layers divide the lung from the other structures in the root of the neck?
Pleura and connective tissue
What are the boundaries of the root of the neck?
Top of the manubrium of the sternum + superior margin of the clavicle anteriorly,
Top of the thoracic vertebra TI + the superior margin of the scapula to the coracoid process posteriorly
What is the relationship of the lung with the root of the neck?
Upward projection of the pleural cavity, including the cervical part of the parietal pleura and the apical part of the superior lobes
To what vertebral level does the lung go?
Anteriorly: Above the the superior border of rib I Posteriorly: Below top of rib I
Where does the right subclavian artery begin?
Posterior to the sternoclavicular joint as a branch of brachiocephalic trunk
Where does the subclavian arteries become axillary?
As they cross the lateral border of rib I
How is the subclavian artery divided based on its relations to ___ muscle?
Anterior -> posterio -> lateral to anterior scalene muscle
What are the branches of the subclavian artery?
Vertebral artery, thyrocervical trunk, internal thoracic artery, costocervical trunk
Outine the course of vertebral artery
1st to branch 1. transverse foramen of C VI 2. crosses posterior arch of C I 3. enters the foramen magnum
Name the branches of the thyrocervical trunk
Inferior thyroid artery, transverse cervical, suprascapular arteries
Name the branches of costocervical trunk
Deep cervical artery, supreme intercostal arteries
Describe the course of the subclavian veins
Begin at lateral margin of rib I Anterior to scalene muscle Joined by internal jugular vein to form brachiocephalic trunk Tributary - external jugular veins
What is the origin of phrenic nerves
Cervical plexus - C3, C4, C5
Describe the course of the vagus nerve in the neck
Travels within the carotid sheath Posterior and in between the common carotid and internal jugular Gives of cardiac branches
How are the cervical ganglia of the sympathetic trunk connected to each spinal nerve?
By a gray ramus communicans
Name the cervical ganglia of the sympathetic trunk
Superior cervical ganglion Middle cervical ganglion Cervicothoracic ganglion / stellate ganglion
What fibers meet in the ganglia of the sympathetic chain? esp the cervical ganglia
Ascending preganglionic sympathetic fibres from upper thoracic spinal cord levels synapse with postganglionic sympathetic fibers
What does the superior cervical ganglion supply?
The internal and external carotid arteries Cervical spinal nerves C1 to C4 Pharynx Heart - superior cardiac nerves
What does the middle cervical ganglion supply?
Cervical spinal nerves C5-6 Heart - middle cardiac nerves
What does the cervicothoracic ganglion supply?
Spinal nerves C7-T1 Vertebral artery Heart - inferior cardiac nerves
What does the autonomic nervous system supply?
Eyes GI tract and glands Heart and blood vessels Lungs Reproductive and urinary systems Skin
What are the 2 divisions of the ANS?
Parasympathetic Sympathetic
What are the general roles of the sympathetic NS?
Dilates pupils Heart rate increased Constricts blood vessels Relaxes airways Stimulates secretions of epinephrine and norepinephrine Releases urinary bladder Stimulates male orgasm Gut activity decreased
Outline the general roles of the parasympathetic NS
Constrict pupils Decreased heart rate Increased gut motility and secretion Constricts airways Stimulates urinary bladder to contract Stimulates sexual arousal
What is the general anatomy of the fibres of ANS?
Preganglionic neuron and postganglionic neuron meet in ganglion where the body of the postganglionic neuron lies
Describe the anatomy of the sympathetic nervous system
T1-L3 Ganglia in sympathetic chain Axons enter ganglions through white rami comunicantes, Collateral ganglia - join spinal nerves through gray rami comunicantes and travel within their branches
Describe the anatomy of the parasympathetic nervous system
cranial nerves, sacral spinal cord S2-4, Ganglia in the walls of the viscera
Outline the sympathetic NS by its neurotransmitters
Preganglionic neuron - cholinergic (Ach) Postganglionic - Adrenergic, noradrenaline
Outline the parasympathetic NS by its neurotransmitters
Both neurons cholinergic
Outline the sympathetic supply to the eye
Cervical ganglions Internal carotid plexus 1. Branch of the ophtalmic nerve through the nasociliary root to become long ciliary nerve Through the sympathetic route to become short ciliary nerve Pupil dilation 2. Branch of occulomotor - superior tarsal muscles
What spinal nerves supply the brachial plexus?
C5, C6, C7, C8 and T1 = 5 roots
Name the trunks of the brachial plexus and what nerves supply them
- Upper/Superior - C5, C6
- Middle - C7
- Lower/Inferior - C8, T1 = 3 roots
How do the trunks of brachial plexus divide and what they produce?
Each trunk has posterior and anterior division = 6 divisions
What do the divisions of brachial plexus form?
3 cords
- Posterior cord - all the posterior divisions
- Lateral cord - anterior div of upper and middle trunks
- Medial cord - anterior division of lower trunk
What are the main branches of the posterior cord of the brachial plexus?
Axillary nerve and radial nerve
Other: upper and lower subscapular, thoracodorsal
Which branch of the brachial plexus is formed by lateral and medial cords?
Median nerve
What branches does the lateral cord of brachial plexus give of?
Musculocutaneous nerve
Median nerve
What branches does the medial cord of brachial plexus give of?
Ulnar nerve, median nerve
Others; medial cutaneous nerve of forearm and mc of arm
Describe the position of brachial plexus in relation to the clavicle
Roots and trunks are superior
Cords and their branches are inferior
What cervical nerve supplies elbow flexors?
C5
What cervical nerve supplies wrist extensors?
C6
What cervical nerve supplies elbow extensors?
C7
What cervical nerve supplies finger flexors?
C8
What cervical nerve supplies small finger?
T1
Draw and label a diagram of the posterior triangle of the neck
Draw and label a diagram of the root of the neck
Label the diagram, name the part of the spine and say what type of fibres is found in the area
Name the area of the spine, the circled area and what fibres are found there
What type of spine it is and what is the circled area
Name the are of the spine, the circled area and what nerve fibres are found there
Label
Name the vertebrae, label and state function of A and B
What are the dermatomes of the arm and where are they located? Draw a diagram
