Sensory and Motor Systems 1 Flashcards
Where does the spinal cord run from?
The foramen magnum and terminates between L1 and L2 as the conus medullaris.
What are the vertebral enlargements and its significance?
Cervical enlargement is where the brachial plexus exists the spinal cord. The lumbarsacral enlargement is where the lumbarsacral plexus exits the spinal cord but this is much more inferior to the enlargement than the cervical enlargement.
What is the cauda equina?
Bundle of spinal nerves continuing from the conus medullaris to the coccyx.
Where are lumbar punctures performed?
Between L3 and L4-> The cauda equina ends at level L1 and L2.
What is the subarachnoid space?
The space between the pia mater and the arachnoid mater. It contains cerebral spinal fluid and enlarged pockets of CSF called cisterns.
What is the epidural space?
The space between the dura mater of the spinal cord and the vertebral column.
Where are epidurals injected?
In the epidural space between the dura mater of the spinal cord and the vertebral column.
Where do we obtain cerebrospinal fluid?
The subarachnoid space between the pia mater and the arachnoid mater.
What is the filum terminale?
A fibrous non-neuronal extension of the pia mater from the conus medullaris of the spinal cord to the periosteum of the coccyx
What is the meninges?
The three-layered membrane enclosing the brain and the spinal cord consisting of the pia mater, the middle arachnoid mater and both are derived from neural crest cells and the outer dura mater which is derived from the paraxial mesoderm.
Why does the spinal cord terminate earlier than the vertebral column?
During development, the vertebral column grows at a faster rate.
What are the variations of the spinal cord matter in the cervical, throacic, lumbar and sacral?
Sacral has the greatest proportion of white matter ; Cervical has the greatest proportion of grey matter
What does the grey matter of the spinal cord contain?
Soma and ganglions for sensation
What does the white matter of the spinal cord contain?
Axons for stimulation
What is the role of the central canal of the spinal cord?
Transports cerebrospinal fluid from the ventricular system of the brain for nutrients.
What is funiculi?
A bundle of axons in the white matter
What is the ventral white commissure?
A bundle of axons which cross the midline of the spinal cord
What is the role of the gracile faniculus?
Bundle of axons in the spinal cord lateral to the dorsal medial fissure where first order neurons pass through without decussating to enter the medulla oblaganta and synapsse with second order neurons in the medial leminiscus. Gracile fasiculus is important for fine touch,
What is the role of the gracile faniculus?
Bundle of axons in the spinal cord lateral to the dorsal medial fissure where first order neurons pass through without decussating to enter the medulla oblaganta and synapsse with second order neurons in the medial leminiscus. Gracile fasiculus is important for fine touch, vibration and propioception.
What is the cuneate faniculus?
Bundle of axons in the spinal cord lateral to the gracile fasiculus important for fine touch, vibration and propioception where first order neurons pass through ipsilaterally without decussating to enter the medulla oblaganta and synapse with second order neurons in the medial leminiscus before decussating contralaterally.
What is the function of the fourth ventricle?
Cushion the brain from trauma and form the central canal to transmit cerebral spinal fluid to the spinal cord
What are the cerebral peduncles?
Stalks which connect the cerebrum to the midbrain for communication with the spinal cord for sensation and inducing stimuli
What are the colliculus?
Two paired structure in the rostral midbrain which receive input about environmental stimuli to co-ordinate eye and head movement. There is a superior colliculi and inferior colliculi.
What information does the superior colliculus integrate?
Present on the midbrain to receive input from the retina for vision.
What does rostral mean in the brain?
Front of the brain
What information does the inferior colliculus integrate?
Present on the midbrain to receive input from the ear for hearing
What is the tectum?
Part of the midbrain posterior to the cerebral aqueduct that contains both the superior or inferior colliculi for auditory and vision input
Why is the midbrain important for nerves?
Cranial nerves arise from the brainstem
What are the cerebellar peduncles?
Connect the cerebellum to the midbrain and the cerebrum
What is the function of the brainstem?
Breathing, heart rate, blood pressure regulation, swallowing reflex, consciousness and wakefullness.
What are the consequences of brainstem death?
Loss of ability to independently breathe, swallow, regulate blood pressure and heart rate
What is 2-point discriminative touch?
Able to locate touch in both the limb and the precisely spot,
What is superficial sensation?
Somatic afferent nerve from the skin which is highly localised.
What is deep sensation?
Somatic afferent nerve from the muscles, connective tissue and tendons which is localised.
What is visceral sensation?
Visceral afferent nerve from the organs such as hunger and nausea.
What is special sensation?
Sight, smell, hearing from the cranial nerves
What is the sensory cortex?
In the post-central gyrus which maps out areas of the body corresponding to the body parts in the somatosensorytropic map
What is the spinocerebellar tract?
Unconscious sensation to modulate balance and propioception
What is the spinotectal tract?
Unconscious sensation of vision and hearing to modulate our head and eye movement towards it
What is the spinoreticular tract?
Unconscious sensation to induces or maintains wakefullness
What is the spino-olivary tract?
Unconscious sensation to modulate cerebellar activity to environmental change
Where is the medial leminiscus?
Medial surface of the spinal cord in the medulla where first order neurons of the dorsal column pathway decussate ipsilaterally
How do lesions more medial in the dorsal horn of the spinal cord affect the body?
Pain, temperature and crude touch: Below lesion, there will be contralateral loss of these sensations in the lower limbs
Fine touch, vibration, pressure and propioception: Below lesion, there will be ipsilateral loss of these sensations in the lower limbs if below medulla
How do lateral lesions in the dorsal horn of the spinal cord affect the body?
Pain, temperature and crude touch: Below lesion, there will be loss of these sensations in the upper limbs
Fine touch, vibration, pressure and propioception: Below lesion, there will be loss of these sensations in the upper limbs
