Physiology of the Spinal Cord

Question 1

Physiological functions of the spinal cord

• Initial processing of … input by the CNS
• Final processing of … output by the CNS

Answer 1

• Initial processing of somatosensory input by the CNS
• Final processing of motor output by the CNS

Question 2

Spinal Nerves

• Highways of both somatosensory information traffic to the spinal cord (… pathways) and motor information traffic from the spinal cord to the muscles (… pathways)

Answer 2

• Highways of both somatosensory information traffic to the spinal cord (afferent pathways) and motor information traffic from the spinal cord to the muscles (efferent pathways)

Question 3

• …: Detection by receptors
• …: interpretation by spinal cord and brain circuits

Answer 3

• Sensation: Detection by receptors
• Perception: interpretation by spinal cord and brain circuits

Question 4

• Receptors are cells specialized in the … of energy generated by external stimuli
• Receptors are … for a narrow range of input
• Neurones in sensory systems signal events by a combination of rate, … and temporal codes

Answer 4

• Receptors are cells specialized in the transduction of energy generated by external stimuli
• Receptors are specific for a narrow range of input
• Neurones in sensory systems signal events by a combination of rate, spatial and temporal codes

Question 5

Convergence and divergence:

• … spatial resolution required: low convergence (e.g., cones and bipolar cells in retina)
• Detection of … signals required: high convergence (e.g., rods and bipolar cells in the retina)
• Input is used for complex or multiple functions: high … (e.g., vestibulo-ocular reflex)

Answer 5

• High spatial resolution required: low convergence (e.g., cones and bipolar cells in retina)
• Detection of weak signals required: high convergence (e.g., rods and bipolar cells in the retina)
• Input is used for complex or multiple functions: high divergence (e.g., vestibulo-ocular reflex)

Question 6

Two main kinds of primary (1st order) sensory receptors

• Most common type - stimulus, sensory neuron - receptor potential, threshold, AP along …, towards synaptic ending - transmitter release
• Type found in sense organs for …., equilibrium and … - stimulus, no …, generator potential, directly lead release of transmitter onto second order neuron - transmitted in same way as before - same end result

Answer 6

• Most common type - stimulus, sensory neuron - receptor potential, threshold, AP along axon, towards synaptic ending - transmitter release
• Type found in sense organs for taste, equilibrium and hearing - stimulus, no axons, generator potential, directly lead release of transmitter onto second order neuron - transmitted in same way as before - same end result

Question 7

Main cutaneous receptor types and modalities of the somatosensory system

Answer 7

Question 8

Main cutaneous receptor types and modalities of the somatosensory system

Answer 8

Question 9

Mechanisms of sensory stimulus discrimination I. different types of receptors for the same modality

• Meissner’s corpuscle - … forces
• Merkel disk - … contact
• Ruffini’s corpuscle - t…, folding
• Pacinian corpuscle - deep …, v…
• Free nerve endings - hair movement, …

Answer 9

• Meissner’s corpuscle - shear forces
• Merkel disk - light contact
• Ruffini’s corpuscle - tension, folding
• Pacinian corpuscle - deep pressure, vibration
• Free nerve endings - hair movement, pricking