Flashcards in Ascending and Descending Pathways Deck (34)
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1
What is the name given to the end of the spinal cord situated at L1/2?
Conus medullaris
2
What connects the spinal cord to the dura?
Denticulate ligament
3
What is present in the white matter?
Longitudinally oriented axons, glial cells and blood vessels
4
What is present in the grey matter?
Neuronal soma
Cell process
Synapses
Glia
Blood vessels
5
What is an extra addition to the grey matter at T1-L2?
Lateral horn containing the preganglionic sympathetic neurones
6
What is the arterial supply to the spinal cord?
3 major longitudinal arteries
Segmental arteries
Radicular arteries
7
What is the origin of the major longitudinal arteries supplying the spinal cord?
Vertebral arteries
8
What is the origin of the segmental arteries supplying the spinal cord?
Vertebral
Intercostal
Lumbar arteries
9
What is the venous drainage of the spinal cord?
Longitudinal and segmental veins
10
What do the radicular arteries supply?
The dorsal and ventral roots
11
What is the epidural space?
Space between the dura and bone which contains adipose tissue and the anterior and posterior epidural venous plexuses
12
Where is the primary somatosensory cortex and the sensory cortical homunculus?
Post central gyrus
13
What does the dorsal column/medial lemniscus system detect?
Fine touch
Proprioception
14
Where do fibres from the dorsal column decussate?
Medulla
15
Describe the dorsal column
Fibres enter dorsal root ganglion where they will project into dorsal column
Ascend to the medulla where they will synapse at the nucleus gracilis/cuneatus
Decussate after synapse and ascend to the thalamus via the medial lemniscus
Synapse in thalamus and ascend to the postcentral gyrus at the somatosensory cortex
16
What does the spinothalamic tract detect?
Pain
Temperature
Deep pressure
17
Describe the spinothalamic tract
Nervce cell bodies in dorsal root ganglion
Enter spinal cord and synapse in the posterior horn in tract cells
Decussate and ascend up the spinal cord on the contralateral side
Synapse in thalamus
Ascend to the postcentral gyrus of at the somatosensory cortex
18
Where is the primary motor cortex found?
Precentral gyrus
19
What is the main motor tract?
Descending corticospinal tract which is divided into the lateral and ventral tracts
20
What movements will the corticospinal tract control?
Fine, precise movements particularly of distal limb
21
Where will the corticospinal tract decussate?
85% at the caudal medulla called the decussation of the pyramids
22
What will crossed fibres of the corticospinal tract form?
Lateral CST
23
What will uncrossed fibres form?
Ventral CST
24
What will the motor fibres pass through whilst in the brain from the motor cortex to the thalamus?
Internal capsule
25
Where are the pyramids of the medulla found?
Anterior surface of medulla
26
What can a CVA of the internal capsule result in?
Lack of descending control of the corticospinal tract resulting in spastic paralysis with hyperflexion of upper limbs
Decortical posturing
27
What is the tectospinal tract?
Input to cervical segments
Mediates reflex head and neck movement due to visual stimuli
28
Where is the tectum found?
Posterior area of midbrain
29
Where does the reticulospinal tract originate?
Areas of reticular formation in pons and medulla
30