BIO 253
Bio 253 Exam 2 Study Questions and
Answers Top Graded 2025
What are the two cell types in neural tissue? -Correct Answer ✔1.) Neuron
2.) Neuroglia
What are the two groups of nervous system organs? -Correct Answer ✔1.) Central
Nervous system
2.) Peripheral Nervous system
What are the general functions of the nervous system? -Correct Answer ✔-The
nervous system can process a wide variety of information from the external
environment, including sight , sounds, and touch on the surface of the skin.
What is a neuron? -Correct Answer ✔-A nerve cell, the fundamental unit of the
nervous system, responsible for receiving, processing, and transmitting information
through electrical and chemical signals.
-Contains a cell body, dendrites and an axon
How does a axon become myelinated in the PNS? -Correct Answer ✔-Schwann
cells wrap their membranes tightly around the axon, forming a myelin sheath.
Describe the types of neurons based on structural characteristics -Correct Answer
✔-Multipolar-many dendrites, 1 axon (many processes)
-Bipolar- 1 dendrite, 1 axon (two processes)
-Unipolar- Two branches that function as 1 axon
BIO 253
,BIO 253
What are the functions of sensory neurons, interneurons, and motor neurons? -
Correct Answer ✔- Sensory neurons: (afferent neurons)- Conduct impulses from
peripheral body parts into the brain or spinal cord
-Towards the brain and spinal cord
-Interneuron: Multipolar; relay information from one part of the brain or spinal
cord to another
-Motor neurons: Multipolar; conducts impulses out of the brain and spinal cord to
effectors
Astrocytes (CNS) -Correct Answer ✔-Connects neurons to blood vessels,
exchanging nutrients and growth factors
-Part of the blood barrier
Oligodendrocytes (CNS) -Correct Answer ✔-Myelinate CNS axons; also provide
structural support
Microglia (CNS) -Correct Answer ✔-Phagocytic cells; also provide structural
support
Ependyma or ependymal cells (CNS) -Correct Answer ✔- Cover choroid plexuses
-Circulate CSF
- Line central canal of spinal cord
Schwann cells (PNS) -Correct Answer ✔-Produce myelin sheath
-Speed up speed of nerve impulses;se transmission
BIO 253
, BIO 253
Satellite cells (PNS) -Correct Answer ✔- Support clusters of neuron cell bodies
(ganglia)
- Nourish and balance ionic concentrations
How is a resting membrane potential achieved? -Correct Answer ✔-The difference
in ion concentrations across the cell membrane and the membrane's selective
permeability to those ions.
-Specifically, a higher concentration of potassium (K+) inside the cell and sodium
(Na+) outside the cell, coupled with the membrane's greater permeability to K+ at
rest, leads to a negative resting potential.
How does a polarized axon respond to stimulation? -Correct Answer ✔-By
initiating an action potential, a rapid change in membrane potential, that travels
down the axon.
List the major events of an action potential -Correct Answer ✔1. At threshold,
sodium channels open and diffuse inward, depolarizing the membrane
2. At the same time, potassium channels open and diffuse outward, re-polarizing
the membrane
What is the refractory period? -Correct Answer ✔-A state of recovery that occurs
after a neuron has fired an action potential
How does impulse conduction differ in myelinated and unmyelinated axons? -
Correct Answer ✔-Myelinated axons: Covered in a myelin sheath conduct
impulses much factor than unmyelinated axons; and the action potentials jump
from one node of Ranvier to the next.
BIO 253
Bio 253 Exam 2 Study Questions and
Answers Top Graded 2025
What are the two cell types in neural tissue? -Correct Answer ✔1.) Neuron
2.) Neuroglia
What are the two groups of nervous system organs? -Correct Answer ✔1.) Central
Nervous system
2.) Peripheral Nervous system
What are the general functions of the nervous system? -Correct Answer ✔-The
nervous system can process a wide variety of information from the external
environment, including sight , sounds, and touch on the surface of the skin.
What is a neuron? -Correct Answer ✔-A nerve cell, the fundamental unit of the
nervous system, responsible for receiving, processing, and transmitting information
through electrical and chemical signals.
-Contains a cell body, dendrites and an axon
How does a axon become myelinated in the PNS? -Correct Answer ✔-Schwann
cells wrap their membranes tightly around the axon, forming a myelin sheath.
Describe the types of neurons based on structural characteristics -Correct Answer
✔-Multipolar-many dendrites, 1 axon (many processes)
-Bipolar- 1 dendrite, 1 axon (two processes)
-Unipolar- Two branches that function as 1 axon
BIO 253
,BIO 253
What are the functions of sensory neurons, interneurons, and motor neurons? -
Correct Answer ✔- Sensory neurons: (afferent neurons)- Conduct impulses from
peripheral body parts into the brain or spinal cord
-Towards the brain and spinal cord
-Interneuron: Multipolar; relay information from one part of the brain or spinal
cord to another
-Motor neurons: Multipolar; conducts impulses out of the brain and spinal cord to
effectors
Astrocytes (CNS) -Correct Answer ✔-Connects neurons to blood vessels,
exchanging nutrients and growth factors
-Part of the blood barrier
Oligodendrocytes (CNS) -Correct Answer ✔-Myelinate CNS axons; also provide
structural support
Microglia (CNS) -Correct Answer ✔-Phagocytic cells; also provide structural
support
Ependyma or ependymal cells (CNS) -Correct Answer ✔- Cover choroid plexuses
-Circulate CSF
- Line central canal of spinal cord
Schwann cells (PNS) -Correct Answer ✔-Produce myelin sheath
-Speed up speed of nerve impulses;se transmission
BIO 253
, BIO 253
Satellite cells (PNS) -Correct Answer ✔- Support clusters of neuron cell bodies
(ganglia)
- Nourish and balance ionic concentrations
How is a resting membrane potential achieved? -Correct Answer ✔-The difference
in ion concentrations across the cell membrane and the membrane's selective
permeability to those ions.
-Specifically, a higher concentration of potassium (K+) inside the cell and sodium
(Na+) outside the cell, coupled with the membrane's greater permeability to K+ at
rest, leads to a negative resting potential.
How does a polarized axon respond to stimulation? -Correct Answer ✔-By
initiating an action potential, a rapid change in membrane potential, that travels
down the axon.
List the major events of an action potential -Correct Answer ✔1. At threshold,
sodium channels open and diffuse inward, depolarizing the membrane
2. At the same time, potassium channels open and diffuse outward, re-polarizing
the membrane
What is the refractory period? -Correct Answer ✔-A state of recovery that occurs
after a neuron has fired an action potential
How does impulse conduction differ in myelinated and unmyelinated axons? -
Correct Answer ✔-Myelinated axons: Covered in a myelin sheath conduct
impulses much factor than unmyelinated axons; and the action potentials jump
from one node of Ranvier to the next.
BIO 253
