PNB EXAM 3 QUESTIONS AND
ANSWERS WITH COMPLETE
SOLUTIONS 100% CORRECT
GRADED A+
Ventral Ramus - CORRECT ANSWES -- -Sensory:general sense (touch, pressure,
pain, heat, cold, etc.) to the skin of the trunk (except the back) and extremities; visceral
pain via the white rami of the sympathetic nervous system; proprioceptive sense from
muscles, tendons and joints (T1-L2)
-Motor:to skeletal mm. of the neck, trunk and extremities; sympathetic innervation to the
skin
Ventral Root - CORRECT ANSWES -- no sensory
-Motor:to skeletal mm.; preganglionic sympathetic axons (T1-L2); preganglionic
parasympathetic axons (S2-S4)
Protection of the Brain - CORRECT ANSWES -- 1) bones of the cranium
2) cranial meninges
3) cerebrospinal fluid
Cranial Meninges - CORRECT ANSWES -- First layer under cranium: Dura mater
Second: Arachnoid
Third: Pia mater
Dura Mater - CORRECT ANSWES -- - Two fibrous layers
- Space between the two layers contains tissue fluids and blood vessels
Arachnoid - CORRECT ANSWES -- Arachnoid membrane: Epithelial layer
- Subarachnoid space contains CSF
- Does not follow the brain's underlying folds
Pia Mater - CORRECT ANSWES -- - Follow the brain's underlying folds
-Accompanies the branches of cerebral blood vessels
, Cerebral Spinal Fluid - CORRECT ANSWES -- - Around and inside brain and spinal
cord
- Cushion and protection
- Maintain chemical stability
- Makes brain weigh less
-CSF is renewed everyday
Circulation of CSF - CORRECT ANSWES -- - Produced by choroid plexus in the
ventricles (ependimal cells)
-Leaves the 4th ventricle via paired lateral apertures or the single median aperture
-Flows through the subarachnoid space
-Flows into the arachnoid villi, then drains into the dural venous sinuses
Where would you expect to find an inhibitory synapse such as the one in the figure
(Green, yellow, purple synapses) - CORRECT ANSWES -- Nucleus cuneatus
What loss would result from cutting through the right side of the medial lemniscus? -
CORRECT ANSWES -- -Loss of fine touch sensation on the left side of the body
Pain - CORRECT ANSWES -- Unpleasant sensory and emotional experience
associated with actual or potential tissue damage.
Physiologic (acute)
Pathologic (chronic- inflammatory or neuropathic pain)
Pain Transmission - CORRECT ANSWES -- =Receptors are free nerve endings.
Slower- conducting afferents:
* AD(delta) fibers : prickling sensation ( much faster signal because they are
myelinated)
* C fibers : Burning or aching
= Anterolateral system: project elsewhere in cord and brainstem, as well as to thalamus
and cortex
Dorsal Horn - CORRECT ANSWES -- -found in dorsal part of spinal cord. Gray matter
- Gate-control mechanism
- Application: transcutaneous electrical nerve stimulation (TENS); Opioids
Gate-control mechanism - CORRECT ANSWES -- Nociception (pain reception)
happens when there is more small-fiber stimulation or only small-fiber stimulation. This
inactivates the inhibitory neuron, and the projection neuron sends signals to the brain
informing it of pain (gate is open).
ANSWERS WITH COMPLETE
SOLUTIONS 100% CORRECT
GRADED A+
Ventral Ramus - CORRECT ANSWES -- -Sensory:general sense (touch, pressure,
pain, heat, cold, etc.) to the skin of the trunk (except the back) and extremities; visceral
pain via the white rami of the sympathetic nervous system; proprioceptive sense from
muscles, tendons and joints (T1-L2)
-Motor:to skeletal mm. of the neck, trunk and extremities; sympathetic innervation to the
skin
Ventral Root - CORRECT ANSWES -- no sensory
-Motor:to skeletal mm.; preganglionic sympathetic axons (T1-L2); preganglionic
parasympathetic axons (S2-S4)
Protection of the Brain - CORRECT ANSWES -- 1) bones of the cranium
2) cranial meninges
3) cerebrospinal fluid
Cranial Meninges - CORRECT ANSWES -- First layer under cranium: Dura mater
Second: Arachnoid
Third: Pia mater
Dura Mater - CORRECT ANSWES -- - Two fibrous layers
- Space between the two layers contains tissue fluids and blood vessels
Arachnoid - CORRECT ANSWES -- Arachnoid membrane: Epithelial layer
- Subarachnoid space contains CSF
- Does not follow the brain's underlying folds
Pia Mater - CORRECT ANSWES -- - Follow the brain's underlying folds
-Accompanies the branches of cerebral blood vessels
, Cerebral Spinal Fluid - CORRECT ANSWES -- - Around and inside brain and spinal
cord
- Cushion and protection
- Maintain chemical stability
- Makes brain weigh less
-CSF is renewed everyday
Circulation of CSF - CORRECT ANSWES -- - Produced by choroid plexus in the
ventricles (ependimal cells)
-Leaves the 4th ventricle via paired lateral apertures or the single median aperture
-Flows through the subarachnoid space
-Flows into the arachnoid villi, then drains into the dural venous sinuses
Where would you expect to find an inhibitory synapse such as the one in the figure
(Green, yellow, purple synapses) - CORRECT ANSWES -- Nucleus cuneatus
What loss would result from cutting through the right side of the medial lemniscus? -
CORRECT ANSWES -- -Loss of fine touch sensation on the left side of the body
Pain - CORRECT ANSWES -- Unpleasant sensory and emotional experience
associated with actual or potential tissue damage.
Physiologic (acute)
Pathologic (chronic- inflammatory or neuropathic pain)
Pain Transmission - CORRECT ANSWES -- =Receptors are free nerve endings.
Slower- conducting afferents:
* AD(delta) fibers : prickling sensation ( much faster signal because they are
myelinated)
* C fibers : Burning or aching
= Anterolateral system: project elsewhere in cord and brainstem, as well as to thalamus
and cortex
Dorsal Horn - CORRECT ANSWES -- -found in dorsal part of spinal cord. Gray matter
- Gate-control mechanism
- Application: transcutaneous electrical nerve stimulation (TENS); Opioids
Gate-control mechanism - CORRECT ANSWES -- Nociception (pain reception)
happens when there is more small-fiber stimulation or only small-fiber stimulation. This
inactivates the inhibitory neuron, and the projection neuron sends signals to the brain
informing it of pain (gate is open).
