Central nervous system Flashcards
What is the frontal lobe involved in?
Motor function, language and cognitive function.
What is the parietal lobe involved in?
Sensation, management of 5 senses, spatial orientation.
What is the temporal lobe involved in?
Processing auditory information.
What is the occipital lobe involved in?
Processing visual information.
What is the limbic lobe involved in?
Learning, memory, emotion, motivation and reward.
What is the insular lobe involved in?
Visceral sensations, autonomic control and interoception.
Layers of meninges?
Dura, arachnoid and pia mater.
Dura layers?
Meningeal and periosteum.
Where is CSF produced?
Choroid plexus.
Where is CSF found?
Ventricular system and sub arachnoid space.
Biomarkers of CSF in relation to plasma?
Lower pH, less glucose,protein and potassium than plasma.
Where are the two spinal cord enlargements?
Cervical and lumbar (C5 and L2).
What do dorsal roots carry?
Sensory information.
What do ventral roots carry?
Motor information.
Why is it called a dorsal root?
Emerges from back of spinal cord.
Why is it called a ventral root?
Emerges from front of spinal cord.
Difference between with dorsal root and ventral root?
Dorsal root has a ganglion, ventral root doesn’t.
Which nerves emerge above vertebrae?
C1 - C7
Which nerves emerge below vertebrae?
C8 - Co1
What is the conus medullaris?
Terminal end of the spinal cord.
Where is the conus medullaris?
L1 usually.
Where do nerves emerge from?
intervertebral foramina.
Main pathway for control of voluntary movement in humans?
Corticospinal tract.
What direction is the corticospinal tract?
Descending.
Where are most of the corticospinal tract fibres traveling in?
Lateral corticospinal tract.
Main pathways for sensation?
Dorsal column pathway and spinothalamic tract (Ascending tracts).
What is the dorsal column pathway responsible for?
Fine touch, pressure, vibration and proprioception from skin and joints.
What is the spinothalamic pathway responsible for?
Pain, temperature and crude touch from the skin.
What are upper motor neurones?
First-order neurons which are responsible for carrying the electrical impulses that initiate movement.
What are lower motor neurones?
The lower motor neuron is responsible for transmitting the signal from the upper motor neuron to the effector muscle to perform a movement.
Difference between corticobulbar and corticospinal?
The corticobulbar tract conducts impulses from the brain to the cranial nerves. These nerves control the muscles of the face and neck and are involved in facial expression, mastication, swallowing, and other motor functions. The corticospinal tract conducts impulses from the brain to the spinal cord.
Where do most of the corticospinal nerve fibres cross?
Medulla.
Function of vestibulospinal tract?
Head movement and position and mediates postural adjustment.
Function of tectospinal tract?
Orientation of the head and neck during eye movements.
Function of reticulospinal tract?
Movement and postural control.
Function of rubrospinal tract?
Upper limb control.
Where does crossing over occur in the dorsal column pathway?
Medulla.
What do pain and temperature sensations ascend within?
Lateral spinothalamic tract
What do crude touch sensations ascend within?
Anterior spinothalamic tract
In ascending neuronal pathways where do 2nd order neurones terminate?
Thalamus.
In ascending neuronal pathways where do 3rd order neurones terminate?
Somatosensory cortex.
Explain dorsal column pathway?
Fibres enter via the dorsal horn and enter the ascending
dorsal column pathways. Information conveyed from lower limbs and upper limbs travels ipsilaterally. First synapse in medulla. Second order axons decussate in the caudal medulla. Form the contralateral medial lemniscus tract. Second order neurones synapse in the thalamus. 3rd order neurons from the thalamus project to the somatosensory cortex.
Explain spinothalamic tract?
Primary afferent axons terminate upon entering the spinal cord. Second order neurons decussate immediately in the spinal cord and form the spinothalamic tract. 2nd order neurons terminate in the thalamus. 3rd order neurons from the thalamus project to the somatosensory cortex.
