PSU Bio 141 Exam 2 Questions and Correct Answers/ Latest Update / Already Graded

Page |1


PSU Bio 141 Exam 2 Questions and
Correct Answers/ Latest Update / Already
Graded
What is acetylcholine (Ach)

Ans: the most plentiful neurotransmitter in the body, released
by nerve cells, especially active in neuromuscular junctions
(cardiac, skeletal, and smooth)
Excitatory: muscle contraction
Inhibitory: reduction of signaling, like reduction of HR


Which receptors pick up ACh

Ans: cholinergic receptors


Sarin gas

Ans: inhibits AChl; interferes with the degradation of ACh in
the synapse (neuromuscular junction); leads to muscle tetani,
inability to control the muscles.


Atropine

Ans: inhibits muscarinic ACh receptors



All rights reserved © 2025/ 2026 |

, Page |2

CNS

Ans: spinal cord and tissue, sensory info, executing motor
commands, higher functioning, both cell bodies and axons


PNS

Ans: all neural tissue except CNS, mainly composed of nerves
grouped together in bundles of axons
the only place to find cell bodies are in ganglions


Afferent neurons

Ans: sensory neurons


3 classes of afferent neurons

Ans: somatic
visceral
special


somatic afferent neurons

Ans: neurons of the bones, muscles, and skin




All rights reserved © 2025/ 2026 |

, Page |3

visceral afferent neurons

Ans: neurons of the organs


special afferent neurons

Ans: neurons involved in hearing, sight, taste, smell


interneurons

Ans: only located in the CNS


efferent neurons

Ans: motor neurons


2 classes of efferent neurons

Ans: somatic and visceral


Visceral Sensory Receptors

Ans: input from internal organs, many of these receptors are
chemoreceptors (use chemicals)


Somatic Sensory Neurons

All rights reserved © 2025/ 2026 |