Term
| Why do the cervical and lumbar regions of the spinal cord enlarge? |
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Definition
| these areas deal with innervation of the arms (cervical) and legs (lumbar). There is a larger mass of nerve cells bodies and tracts to accomadate the innervation needs of the limbs. |
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Term
| How many spinal nerves are there? |
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Definition
| Spinal nerves (31 segmental pairs) exit via gaps between vertebrae – the intervertebral foraminae. |
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Term
| Do spinal segments and vertebra align? |
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Definition
| Spinal segments and vertebra do not align exactly. The spinal segments are specified by the level of vertebrae at which the spinal nerve exits the spinal column. |
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Term
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Definition
| regions of the CNS that are dominated by myelinated axons of ascending or descending tracts. |
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Term
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Definition
| areas in the CNS that are dominated by neurone cell bodies, neuroglia, unmyelinated axons and afferent terminals. |
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Term
| When does the ventral horn enlarge? |
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Definition
| at segments that control the limbs - motor neurones are large and numerous. |
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Term
| How can cervical be differentiated from lumbar? |
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Definition
shape: cervical is wide and squashed whereas lumbar are round
white matter: the amount of white matter relative to grey matter decreases as you go down |
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Term
| What are the rexed laminae? |
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Definition
| a system of ten layers of grey matter (I-X) identified in the early 1950s by Bror Rexed to label portions of the spinal cord. |
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Term
| What lamina exist in the dorsal horn? |
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Definition
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Term
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Definition
| 'nucleus' posteromorginalis' contains neurones tat receive pain and temperature information from dorsal root gangly |
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Term
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Definition
| 'substance gelatinosa' painful and non-painful information fro spinothalamic tract and relays to lamina III |
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Term
| Describe lamina III, IV and V |
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Definition
| 'nucleus proprius' information about touch and proprioception and relays to brainstem/brain/lamina |
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Term
| What lamina exist in the intermediate horn? |
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Definition
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Term
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Definition
| 'intermediolateral nucleus' mediates the entire sympathetic innervation of the body |
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Term
| What lamina exist in the ventral horn? |
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Definition
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Term
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Definition
| motor neurones that innervate muscles |
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Term
| What are the spinal meninges? |
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Definition
| a series of specialised membranes surrounding the spinal cord, provide the necessary physical stability and shock absorption. |
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Term
| Describe the 3 meninges layers |
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Definition
1. Dura mater: thickest outer most layer.
2. Arachnoid mater: adheres to the inner surface of the dura mater.
3. Pia mater: intimately bound to the surface of the spinal cord. |
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Term
| What is the subarachnoid space filled with? |
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Definition
| cerebrospinal fluid (CSF) which is continuous with the brain. |
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Term
| What information enters the spinal cord? |
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Definition
| sensory information via general somatic/visceral afferents that enter at the dorsal posterior root |
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Term
| What resides in the dorsal root ganglion? |
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Definition
| cell bodies of afferent neurones |
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Term
| What do interneurones do? |
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Definition
| link sensory neurones with motor or autonomic neurones |
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Term
| What information leaves the spinal cord? |
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Definition
somatic motor outflow
motor efferents innervating peripheral striated muscle exit via the ventral (anterior) root |
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Term
| Describe pre-ganglionic neurones in the ANS |
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Definition
| Visceral motor neurones in the brainstem and spinal cord are known as preganglionic neurones because they extend towards ganglia. These neurones are part of visceral reflex arcs; most of their activities represent direct reflex responses, rather than responses to commands from the hypothalamus. The axons of preganglionic neurones are called preganglionic fibres. Preganglionic neurones leave the CNS and synapse on ganglionic neurones |
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Term
| Describe ganglionic neurones in the ANS |
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Definition
| anglionic neurones – visceral motor neurones in peripheral ganglia. These ganglia are called autonomic ganglia. Ganglionic neurones innervate visceral effectors such as smooth muscle, glands, cardiac muscle and adipose tissue. The axons of postganglionic neurones are called postganglionic fibres, because they begin at autonomic ganglia and extend to peripheral target organs. |
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Term
| Describe the neurones in the sympathetic division of the ANS |
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Definition
| cell bodies of preganglionic neurones lie within the lateral horn of the spinal grey matter. Preganglionic neurones synapse with postganglionic neurones whose cell bodies reside within the sympathetic chain that runs alongside the spinal cord. |
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Term
| Describe the neurones in the parasympathetic division of the ANS |
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Definition
| cell bodies of preganglionic neurones lie within the brainstem. Preganglionic neurones synapse with postganglionic neurones whose cell bodies reside close to or within target tissues. |
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Term
| How is white matter divided? |
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Definition
1. Posterior funiculus: this area of the spinal cord includes the dorsal columns.
2. Lateral funiculus: this area of the spinal cord is the most lateral of the bundles.
3. Anterior funiculus: this area of the spinal cord is anterior to the anterior grey horn. |
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Term
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Definition
is a generic term referring to a disorder in which a cyst or cavity forms within the spinal cord.
This cyst, called a syrinx, can expand and elongate over time, destroying the spinal cord. The damage may result in pain, paralysis, weakness, and stiffness in the back, shoulders, and extremities. Syringomyelia may also cause a loss of the ability to feel extremes of hot or cold, especially in the hands. The disorder generally leads to a cape-like loss of pain and temperature sensation along the back and arms. |
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Term
| What is Brown-Sequard syndrome? |
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Definition
a loss of sensation and motor function (paralysis and anaesthesia) that is caused by the lateral hemisection (cutting) of the spinal cord.
- Loss of pain and temperature from contralateral side of spinal cord damage.
- Loss of touch, proprioception, vibration from ipsilateral side of cord damage. |
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Term
| Define Autonomic Dysfunction (Dysautonomia) |
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Definition
any disease or malfunction of the autonomic nervous system (ANS).
-severe postural hypotension (loss of consciousness)
-incontinence
- impotence
- lateral horn atrophy |
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Term
| Define motor neurone disease |
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Definition
| a debilitating disease with varied etiology (causes), characterised by rapidly progressive weakness, muscle atrophy and fasciculations (involuntary muscle twitch), muscle spasticity, difficulty speaking (dysarthria), difficulty swallowing (dysphagia), and difficulty breathing (dyspnea). |
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Term
| What makes up the hindbrain? |
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Definition
| the medulla oblongata (the myelencephalon) and the pons (metencephalon). |
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Term
| What makes up the brainstem? |
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Definition
| hindbrain and the midbrain |
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Term
| What is Wallenbergs syndrome? |
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Definition
thrombosis of vertebral artery
wide ranging sensory/motor deficits |
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Term
| What are the deficits caused by Wallenbergs syndrome? |
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Definition
1. contralateral loss of pain and temperature sensitivity (anterolateral system: an ascending pathway that conveys pain, temperature and crude touch from the periphery to the brain).
2. ipsilateral loss of pain and temperature sensitivity from face (trigeminal system – nerve V).
3. Vertigo and/or nystagmus: involuntary eye movements from damage to vestibular system.
4. ipsilateral loss of taste from damage to the solitary tract: a compact fibre bundle that extends longitudinally through the posterolateral region of the medulla. It is made up of primary sensory fibres and descending fibres of the vagus, glossopharyngeal, and facial nerves.
5. Dysphagia: difficulty in swallowing due to damage to the ambiguus nucleus in the lateral portion of the rostral medulla. The nucleus gives rise to efferent motor fibres of the glossopharyngeal and vagus nerves. |
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Term
| What is a brainstem glioma? |
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Definition
a cancerous glioma tumour (so, consisting of glial cells) that arises in the brainstem.
They account for 10-20% of all childhood brain tumours! |
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Term
| Symptoms of a brainstem glioma |
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Definition
Common presenting symptoms include:
double vision
weakness
unsteady gait: movements of limbs difficulty in swallowing
drowsiness
nausea
vomiting |
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Term
| What are the functions of the ascending system of reticular formation? |
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Definition
| controls arousal, sleep, attention, awareness and wakefulness |
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Term
| What are the functions of the descending system of reticular formation? |
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Definition
| forms reticulo-spinal tract which contributes to posture and postural reflexes |
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Term
| What are the raphe nuclei |
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Definition
cluster or nuclei found in the brainstem (extend bilaterally rostra-caudally along brainstem adjacent to midline)
uses serotonin as its transmitter |
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Term
| What nuclei make up the raphe nuclei? |
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Definition
1. nucleus raphe pallidus (within medulla)
2. nucleus raphe obscurus (within medulla)
3. nucleus raphe magnus (within pons) |
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Term
| Describe the medullary nuclei |
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Definition
| project to spinal cord and modulate pain transmission, movement and autonomic control |
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Term
| Describe the rostral nuclei |
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Definition
| project to diverse higher brain areas to modulate pain, mood, sleep-wake cycles |
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Term
| Name some 5-HT disorders and the pharmacological interventions |
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Definition
depression
TCA (block uptake)
MAO inhibitors (prevent breakdown) |
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