NURS 5357 NEUROBIOLOGY EXAM 4 FINAL
PAPER 2026 STUDY GUIDE DETAILED ANSWERS
READY
◉ Substance P.
Answer: Pain transmitter peptide located heavily in dorsal horn of
SC, specifically located within areas of C- and A-delta fiber synaptic
termination (ex. PIS caused by spinal SP depletion).
◉ C-fibers and A-delta Fibers.
Answer: How nociception is carried to the SC; C-fibers are the only
unmyelinated ones, both terminate in superficial aspects of SC
dorsal horn and synapse immediately onto 2nd-order cells
conveying pain info; A-delta terminates more deeply and reflects
instant/sharp pain while C-fibers reflect constant/dull pain
◉ Gate Control Theory of Pain.
Answer: The substantia gelatinosa integrates pain and non-painful
signals by gating pain processing; large-fiber touch activity closes
the gate while small-fiber pain activity opens it.
◉ Descending Analgesia System.
,Answer: Electrical stimulation of a number of areas within the
brainstem will render an animal analgesic; PAG targets RVM that
includes raphe nuclei.
◉ Endorphin.
Answer: Endogenous opiate-like molecule comprised of 31 AAs in
pituitary and brain.
◉ Enkephalin.
Answer: Comprised of 5 AAs in SC and adrenal gland, co-localizes
axo-synaptically with SP in dorsal horn to produce pain control
presynaptically by inhibiting SP release and cutting off EPSPs to
2nd-order cells.
◉ Cornea and lens.
Answer: Refracts and focuses light to form an image.
◉ Ciliary muscles.
Answer: Adjusts focus by changing shape of the lens.
◉ Accomodation.
Answer: Process of focusing light to create a sharp image.
, ◉ Pupil.
Answer: An opening in the iris that controls how much light enters
the eye.
◉ Extraocular muscles.
Answer: Controls eye movement.
◉ Structure of the Retina.
Answer: 3 layers of cells, 2 layers of synapses.
◉ Photoreceptor cells.
Answer: Rods and cones.
◉ Bipolar cells.
Answer: Receives input from photoreceptors/horizontal and
omicron cells, synapses onto ganglion cells.
◉ Ganglion cells.
Answer: Receives input from omicron cells, axons form the optic
nerve.
◉ Visual field.
PAPER 2026 STUDY GUIDE DETAILED ANSWERS
READY
◉ Substance P.
Answer: Pain transmitter peptide located heavily in dorsal horn of
SC, specifically located within areas of C- and A-delta fiber synaptic
termination (ex. PIS caused by spinal SP depletion).
◉ C-fibers and A-delta Fibers.
Answer: How nociception is carried to the SC; C-fibers are the only
unmyelinated ones, both terminate in superficial aspects of SC
dorsal horn and synapse immediately onto 2nd-order cells
conveying pain info; A-delta terminates more deeply and reflects
instant/sharp pain while C-fibers reflect constant/dull pain
◉ Gate Control Theory of Pain.
Answer: The substantia gelatinosa integrates pain and non-painful
signals by gating pain processing; large-fiber touch activity closes
the gate while small-fiber pain activity opens it.
◉ Descending Analgesia System.
,Answer: Electrical stimulation of a number of areas within the
brainstem will render an animal analgesic; PAG targets RVM that
includes raphe nuclei.
◉ Endorphin.
Answer: Endogenous opiate-like molecule comprised of 31 AAs in
pituitary and brain.
◉ Enkephalin.
Answer: Comprised of 5 AAs in SC and adrenal gland, co-localizes
axo-synaptically with SP in dorsal horn to produce pain control
presynaptically by inhibiting SP release and cutting off EPSPs to
2nd-order cells.
◉ Cornea and lens.
Answer: Refracts and focuses light to form an image.
◉ Ciliary muscles.
Answer: Adjusts focus by changing shape of the lens.
◉ Accomodation.
Answer: Process of focusing light to create a sharp image.
, ◉ Pupil.
Answer: An opening in the iris that controls how much light enters
the eye.
◉ Extraocular muscles.
Answer: Controls eye movement.
◉ Structure of the Retina.
Answer: 3 layers of cells, 2 layers of synapses.
◉ Photoreceptor cells.
Answer: Rods and cones.
◉ Bipolar cells.
Answer: Receives input from photoreceptors/horizontal and
omicron cells, synapses onto ganglion cells.
◉ Ganglion cells.
Answer: Receives input from omicron cells, axons form the optic
nerve.
◉ Visual field.
