HONDROS BIO 253 EXAM 2
QUESTIONS WITH COMPLETE
SOLUTIONS 2025/2026
Neurons (Chapter 18) - ANSWERCommunicating Cells
Cell body - ANSWER-contains ribosomes, rough endoplasmic er, Golgi apparatus
-Neurotransmitters are packaged into vesticles
-provide proteins for nerve fibers
Axon - ANSWER- each neuron has 1 axon
-carries impulses to target cells
Axon Hillock - ANSWERIntegrates incoming signals
Cytoskeleton - ANSWER-microtubules of microfilaments, as well as neurofibrils (budles
of neufilaments)
-allows transport of small organelles
Classifications of neurons - ANSWER-Multipolar (motor are typically multipolar)
Bipolar(rare, think of retina)
Unipolar(pseudounipolar)(sensory are usually unipolar
Neurons have a limited capacity to repair themselves - ANSWER-If the damage is not
extensive, the cell body and the neurilemma are intact, and scarring has not occurred
than nerve fibers can be repaired
Stages of neuron repair - ANSWER-after injury distal portion of the axon and myelin
sheath degenerate
-Macrophages remove debris
-remaining neurilemma and endoneurium form a tunnel from the point of injury to the
effector
-new Shawanna cells can grow in the tunnel to maintain a path of regrowth for the axon
Glia - ANSWERThe supporting cells of the central nervous system / 5 types
Astrocytes - ANSWER-Starshaped, Largest and most numerous type of glia
-cell extensions connect to neurons and capillaries
-transfers the nutrients from the blood to the neuron.
-helps form and operate synapse
Microglia - ANSWER-small usually stationary cells
,-phagocytes
Ependymal cells - ANSWER-lined fluid filled cavities in the CNS
-make and circulate Cerebrospinal fluid
Oligodendrocytes - ANSWER-smaller than astrocytes and have fewer processes
-hold the nerve fibers together
-producer the myelin sheath
Neuroglia: Schwann Cells - ANSWER-Found only in Peripheral neurons
-Supportive nerve fibers and form the myelin sheaths
Myelin sheaths - ANSWER-gaps between the segments and the Nodes of Ranvier
-Made is segments by glia cells
oligodendrocytes - ANSWERlocated in the CNS
Schwann Cells - ANSWERLocated in the PNS
central nervous system - ANSWER-consists of the brain and spinal cord
-structural and center of the entire nervous system
-Main function is evaluation
peripheral nervous system - ANSWERNerves that are the outlier of the body
-Cranial nerves originate from the brain
-spinal nerves originate from the spinal cord
Afferent Division - ANSWER(sensory) brings signals into the CNS
-consist of all incoming pathways
somatic sensory division - ANSWERcarries feedback information to the somatic
integration center in the CNS.
- these include the skin muscles and joints
Efferent Division - ANSWER(motor)- carries signals to the effectors outside the nervous
system
Consist of all outgoing motor pathways
-sympatric division
parasympathetic division
somatic motor division / ans - ANSWERcarries information to somatic effectors such as
the skeletal muscles
- carries information to autonomic and visceral effectors like smooth and cardiac
muscles , adipose tissue
interneurons - ANSWERintegrate signals
, Reflex Arc - ANSWERThe path of which something is sensed and then the effect
Reflex arc path order - ANSWERreceptor -> afferent sensory neutron -> interneuron->
efferent neuron ->effector
Ipsilateral reflex arc - ANSWERSensory in & Motor out ON THE SAME SIDE OF THE
BODY
contralateral reflex arc - ANSWERSensory enters in one side of the body and MOTOR
EXITS THE OPPOSITE SIDE OF THE BODY
White matter - ANSWERBundles of nerve fibers in the cns (no connective tissues
covering)
Pns- Myelinated Nerves
Cns-Myelinated tract
gray matter - ANSWERPns- referred to as ganglia
Cns-Referred to as nuculi
Sensory Nerves - ANSWER-nerves with predominantly sensory neurons
-Motor nerves - ANSWER-Nerves with predominantly motor neurons
-Tumors in the cns - ANSWER-neuroma and glioma
disorders of nerve cells - ANSWERAdtrocytoma
-glioblastoma multiform
-ependynomama
Tumors in the PNS - ANSWERAcoustic Neuroma, and neurofibromatosis
(Chapter 19) Nerve signaling - ANSWERstarts here -- you gunna love it
Membrane Potentials - ANSWERslight deficiency of positively charged ion on the inside
of the membrane
difference in electrical charge is called - ANSWERIs called the potential because its a
type of stored energy
polarized membrane - ANSWERA membrane that has membrane potential not zero
Resting membrane potential - ANSWER-membrane potential maintained by the
neurons plasma membrane
-slight excess of positive ions on the outer surface of the membrane (typically 70 MV)
Membrane channels maintian resting membrane potential
QUESTIONS WITH COMPLETE
SOLUTIONS 2025/2026
Neurons (Chapter 18) - ANSWERCommunicating Cells
Cell body - ANSWER-contains ribosomes, rough endoplasmic er, Golgi apparatus
-Neurotransmitters are packaged into vesticles
-provide proteins for nerve fibers
Axon - ANSWER- each neuron has 1 axon
-carries impulses to target cells
Axon Hillock - ANSWERIntegrates incoming signals
Cytoskeleton - ANSWER-microtubules of microfilaments, as well as neurofibrils (budles
of neufilaments)
-allows transport of small organelles
Classifications of neurons - ANSWER-Multipolar (motor are typically multipolar)
Bipolar(rare, think of retina)
Unipolar(pseudounipolar)(sensory are usually unipolar
Neurons have a limited capacity to repair themselves - ANSWER-If the damage is not
extensive, the cell body and the neurilemma are intact, and scarring has not occurred
than nerve fibers can be repaired
Stages of neuron repair - ANSWER-after injury distal portion of the axon and myelin
sheath degenerate
-Macrophages remove debris
-remaining neurilemma and endoneurium form a tunnel from the point of injury to the
effector
-new Shawanna cells can grow in the tunnel to maintain a path of regrowth for the axon
Glia - ANSWERThe supporting cells of the central nervous system / 5 types
Astrocytes - ANSWER-Starshaped, Largest and most numerous type of glia
-cell extensions connect to neurons and capillaries
-transfers the nutrients from the blood to the neuron.
-helps form and operate synapse
Microglia - ANSWER-small usually stationary cells
,-phagocytes
Ependymal cells - ANSWER-lined fluid filled cavities in the CNS
-make and circulate Cerebrospinal fluid
Oligodendrocytes - ANSWER-smaller than astrocytes and have fewer processes
-hold the nerve fibers together
-producer the myelin sheath
Neuroglia: Schwann Cells - ANSWER-Found only in Peripheral neurons
-Supportive nerve fibers and form the myelin sheaths
Myelin sheaths - ANSWER-gaps between the segments and the Nodes of Ranvier
-Made is segments by glia cells
oligodendrocytes - ANSWERlocated in the CNS
Schwann Cells - ANSWERLocated in the PNS
central nervous system - ANSWER-consists of the brain and spinal cord
-structural and center of the entire nervous system
-Main function is evaluation
peripheral nervous system - ANSWERNerves that are the outlier of the body
-Cranial nerves originate from the brain
-spinal nerves originate from the spinal cord
Afferent Division - ANSWER(sensory) brings signals into the CNS
-consist of all incoming pathways
somatic sensory division - ANSWERcarries feedback information to the somatic
integration center in the CNS.
- these include the skin muscles and joints
Efferent Division - ANSWER(motor)- carries signals to the effectors outside the nervous
system
Consist of all outgoing motor pathways
-sympatric division
parasympathetic division
somatic motor division / ans - ANSWERcarries information to somatic effectors such as
the skeletal muscles
- carries information to autonomic and visceral effectors like smooth and cardiac
muscles , adipose tissue
interneurons - ANSWERintegrate signals
, Reflex Arc - ANSWERThe path of which something is sensed and then the effect
Reflex arc path order - ANSWERreceptor -> afferent sensory neutron -> interneuron->
efferent neuron ->effector
Ipsilateral reflex arc - ANSWERSensory in & Motor out ON THE SAME SIDE OF THE
BODY
contralateral reflex arc - ANSWERSensory enters in one side of the body and MOTOR
EXITS THE OPPOSITE SIDE OF THE BODY
White matter - ANSWERBundles of nerve fibers in the cns (no connective tissues
covering)
Pns- Myelinated Nerves
Cns-Myelinated tract
gray matter - ANSWERPns- referred to as ganglia
Cns-Referred to as nuculi
Sensory Nerves - ANSWER-nerves with predominantly sensory neurons
-Motor nerves - ANSWER-Nerves with predominantly motor neurons
-Tumors in the cns - ANSWER-neuroma and glioma
disorders of nerve cells - ANSWERAdtrocytoma
-glioblastoma multiform
-ependynomama
Tumors in the PNS - ANSWERAcoustic Neuroma, and neurofibromatosis
(Chapter 19) Nerve signaling - ANSWERstarts here -- you gunna love it
Membrane Potentials - ANSWERslight deficiency of positively charged ion on the inside
of the membrane
difference in electrical charge is called - ANSWERIs called the potential because its a
type of stored energy
polarized membrane - ANSWERA membrane that has membrane potential not zero
Resting membrane potential - ANSWER-membrane potential maintained by the
neurons plasma membrane
-slight excess of positive ions on the outer surface of the membrane (typically 70 MV)
Membrane channels maintian resting membrane potential
