week 1 Flashcards
What is the name of weakness on one side of the body?
hemiparesis
What is the name for difficulty with speech?
aphasia
WHat is a dermatome?
the region of skin supplied by a single spinal nerve
Where are the preganglioic neurons in the sympathetic nervous system?
thoracic and upper lumbar spinal cord
T1-L3
Where are the preganglionic neurons in the sympathetic nervous system?
brainstem (some cranial nerves)
sacral spinal cord (S2-4)
Where are sympathetic ganglia found?
in the sympathetic chain which is next to the vertebral column
Where are the parasympathetic ganglia found?
in the walls of the viscera that they innervate
What is pain?
an unpleasant and emotional experience associated with actual or potential tissue damage
What is involved in the acute catabolic stress response?
anxiety, depression, sleep
up BP, HR
inhibits cough, hyperventilation
etc
What are the four physiologic processes of nociception?
transduction
transmission
modulation
perception
Describe nociceptors
C
polymodal (mechano-heat-chemical)
Ad mechanical, some thermal
HIGH THRESHOLD
Name substances that activate pain receptors
K+ 5HT bradykinin H+ Histamine ATP, adenosine
What can sensitise pain receptors?
prostaglandins
leukotriens
substance P
noradrenaline
What sort of fibres can morphine inhibit?
C
pathophysiology
Describe somatic pain
skin, muscle, bone well localised dermatomal radiation sharp, aching, gnawing constant or incident
Describe visceral pain
internal organs vague distribution diffuse to body surface dull, cramp, dragging often periodic sweaty
What are some common descriptors of neuropathic pain?
shooting electric shock burning tingling numbness
What method do tens machines use?
gate control therapy
How many segments of the spinal cord are there?
31 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
What is the upper limit of the spinal cord?
the junction with the medulla oblongata
What is the lower level of the spinal cord?
in newborn infants L3/L4
In adult L1/L2
What is a ganglion?
a collection of cell bodies
WHat is a fasciculus?
a bundle of axona
What is a faniculi?
tract of axons
What does the neural tube develop from?
a flat plate of cells (neurodevelopment-ectoderm)
what is the dorsal horn involved in?
sensory
What is the ventral horn involved in?
motor
What are the three layers of the meninges?
dura mater
arachnoid mater
pia mater
what is the epidural space?
separates the dura and the vertebrae
What is in the arachnoid space?
CSF
WHat is the name of the artery that supplies the lower 1/3 of the spinal cord?
artery of adamkiewicz
What does the spinal cord pass through as it leaves the skull?
the foramen magnum
WHat is the lowest part of the spinal cord called?
conus medullaris
Where does the pain pathway go?
the superficial dorsal horn
where does the gentle touch pathway go?
deep dorsal horn
WHat are a alpha fibres involved in?
proprioceptors of skeletal muscle
What are A beta fibres involved in?
mechanoreceptors of the skin
WHat are A delta fibres involved in?
pain, temperature
What are C fibres involved in?
temperature, pain, itch
What pathway is discriminative touch?
dorsal column
What pathway is pain?
spinothalamic pathway
What pathway is voluntary motor?
corticospinal and corticobulbar
WHat are the four areas of the brain?
frontal, parietal, occipital, temporal
what are the two main sulci of the brain called?
central and lateral
what is the motor area called?
pre central gyrus
what is the sensory area called?
post central gyrus
Where is the area for speech?
motor cortex
where is the visual cortex?
occipital lobe
WHat areas are involved in the motor aspect of speech?
Brocca’s areas in the inferior frontal gyrus
What side of the brain are the main broccas areas mainly found?
the left
What is the auditory association cortex called?
Wernickes areas
WHat makes up the corpus striatum?
caudate nucleus
putamen
globus pallidus
What are the basal ganglia called?
corpus striatum, sub-thalamic nuclei, substantia nigra
WHat are the boundaries of the lentiform nucleus?
claustrum internal capsule anterior limb genu posterior genu
What does the ectoderm give rise to?
CNS
PNS
sensory epithelium of the ear, nose and eye
epidermis, hair and nails
subcutaneous, mammary and pituitary glands
enamel of the teeth
What does the notochord develop from?
the primitive node
tube extends in the opposite direction from the primitive streak
What causes the ectoderm to thicken and form the neural plate?
appearance of the notochord and mesoderm
WHat is the neural plate made from?
neuroectoderm
Describe signalling in neuralation
Up regulation of FGF, inhibition of BMP-4 causes induction of the neural plate
chordin and noggin expressed
neural plate switches from E-cadgerin to N-cadherin expression
WHat do the neural crest cells give rise to?
ganglia schwann cells adrenal medulla melanocytes connective tissue in head region
once the neural tube has closed what do the neuroepithelial cells give rise to?
neuroblasts which form the mantle layer
What does the mantle layer become?
the gray matter of the spinal cord
What does the marginal layer become?
white matter in the spinal cord
myelination of nerve fibres
WHat are the three primary brain vesicles called?
forebrain - prosencephalon
midbrain - mesencephalon
Hindbrain - rhombencephalon
WHat does the prosencephalon divide into?
the telencephalon and the diencephalon
WHat does the mesencephalon divide into?
the mesencephalon
What does the rhombencephalon divide into?
the mesencephalon and the myelencephalon
What does the telencephalon become?
the cerebrum
What does the diencephalon become?
eye cup
thalamus, hypothalamus and epithalamus
WHat does the mesencephalon become?
the mid brain
What does the mesencephalon become?
the pons and the cerebellum
What does the myelincephalon become?
the medulla oblongata
What are the different types of spina bifida?
oculta
meningocele
myelomeningeocele
What causes hydrocephaly in spina bifida?
CSF build up in heat due to obstruction of the foramen magnum by the cerbellum
What causes the resting membrane potential?
a difference in charge between the inside and outside of the neuron at rest
What is the typical RMP of neurons?
-60 - -70mV
What is an action potential?
a brief but dramatic change in membrane potential
Describe depolarisation and depolarisation and hyperpolarisation
depolarisation related to increased permeability to Na+ cells
repolarisation and hyper polarisation due to increased permeability to K+ ions
In what ways can bolted - gated sodium channel drugs be used?
local anaesthetics
pain treatment
epilepsy
What type of cells are found in the CNS?
oligodendrocytes
WHat sort of cells are found in the PNS?
schwann cells
What are the areas that are unmyelinated called?
nodes of ranvier
What is saltatory conduction?
action potential “jumps” form node to node in myelinated axon
Describe synaptic transmission
AP enters presynaptic terminal
Ca2+ entry through voltage-gated channels
docking of synaptic vesicles containing NTs
NTs released and bind to and activate receptors on postsynaptic membrane
Ions enter cell and cause depolarisation or hyperpolarisation
What is an excretory post synaptic potential?
EPSP
brings the post synaptic membrane closer to the threshold for depolarisation
What is an inhibitory postsynaptic potential
IPSP
moves the post synaptic membrane further away from the threshold
What are the two types of summation of post synaptic potentials?
spacial (firing at multiple sites) and temporal (frequency of firing)
WHat is the main inhibitory neurotransmitter?
gamma-aminobutyric acid
How does botulism affect synaptic transmission?
disrupts exocytosis preventing Ach release
How does myasthenia gravis affect synaptic transmission?
antibodies bind to Each receptors in the postsynaptic motor end plate
In what ways can cerebral function be investigated?
EEG
PET
fMRI
TMS
How can a pancoast tumour affect the upper limb?
superior extension of the tumour may result in encasement of the C8 nerve root and cause pain in the medial 2 digits of the hand
Causes atrophy of intrinsic muscles of the hand - particularly the interosseous muscles
Infiltration of the T1 nerve root causes pain which radiates down the medial aspect of the arm and forearm as far as the wrist
What are the results of horner’s syndrome?
ptosis mitosis hemifacial / unilateral anhidrosis loss of head and neck sympathetic tone enophthalmos
Describe the first order neruronal fibres in the sympathetic pathway to the eye
arise from the poster-lateral hypothalamus
descend through brain stem to terminate in the spinal cord at the ciliospinal centre (C8-T2)
Describe the second- order neuronal fibres in the sympathetic pathway to the eye
exit through the T1 root and travel close to the lung apex through the paravertebral sympathetic chain and the stellate ganglion
This is the level where a pancoast tumour could interrupt the pathway
Describe third order neuronal fibres in the sympathetic pathway to the eye
exit the ganglion to form a plexus surrounding the internal carotid aftery
plexus then ascends into the cavernous sinus, runs a short course on CN VI and then follows the ophthalmic division of C5 in the orbit
Supplies the iris dilator muscles and the smooth muscle fibres if the upper and lower lid
vasomotor and sweat gland fibres follow the external carotid artery to supply the ipsilateral side of the face
Describe the anterior compartment of the thoracic inlet
from the sternum to the anterior scalene muscle
contains subclavian and internal jugular veins
Describe the middle compartment of the thoracic inlet
from the anterior to the posterior scalene muscle
contrains subclavian artery and branches of the subclavian artery
Describe the posterior compartment of the thoracic inlet
beyond the middle scalene muscles
contains branches of the brachial plexus, the sympathetic chain and stellate ganglion
What is a pancoast tumour?
a 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 is the most common type of pancoast tumour?
squamous cell carcinomas (non small cell)
How are pancoast tumours diagnosed?
biopsy
imaging - CT, PET
How are pancoast tumours managed?
surgery
radiation
chemo
very low 5 year survival rate
