Chapter 11: Nervous Tissue & Neurophysiology

The nervous system: monitors internal and external stimuli. transmits information in the form of action potentials interprets or assesses information maintains homeostasis All of these choices are correct

All of these choices are correct

Identify the two functional subdivision of the peripheral nervous system. -Brain -Motor division -Parasympathetic division -Sensory division -Spinal cord -Sympathetic division

Brain; Spinal cord.

The inside of the cell membrane becomes negative at the time of an action potential. True or False

False

The nervous system functions in detecting ____ some of which we are aware and others of which we are not aware.

Sensory inputs

The somatic nervous system directs ____ activities

conscious

When traveling along an axon, the cell membrane immediately ahead of an action potential depolarizes because of ____. membrane receptors the sodium/potassium pump potassium efflux diffusion of sodium current decreased membrane permeability

diffusion of sodium current

Finally, the nervous system is able to ____ information in order to either respond to or ignore it.

integrate

The nervous system functions in mental activities such as solving ____.

problems

In the PNS(Peripheral Nervous System), the ____ , division transmits action potentials from sensory receptors to the CNS.

sensory

An action potential arriving at the presynaptic terminal causes: acetylcholine to diffuse into the cell. voltage-gated sodium ion channels to open, and sodium ion to diffuse into the cell. voltage-gated calcium ion channels to open, and calcium ions to diffuse into the cell. ligand-gated sodium channels to open, and sodium ions to diffuse out of the cell. voltage-gated sodium ion channels to open, and sodium ions to diffuse out of the cell.

voltage-gated calcium ion channels to open, and calcium ions to diffuse into the cell.

____ pathways typically consist of two neurons, with their cell bodies (somas) located in the CNS (central nervous system) and PNS (peripheral nervous system), respectively.

ANS (autonomic nervous system)

check all of the factors that would increase the speed of an action potential Axons with larger diameters Axons with smaller diameters Decreased thickness of myelin sheath increased thickness of myelin sheath presence of myelin absence of myelin

Axon with larger diameters; Increase thickness of myelin sheath; Presence of myelin.

What effect does acetylcholine have on the postsynaptic neuron? -voltage-gated sodium ion channels open and sodium diffuses in. -voltage-gated calcium ion channels open and calcium diffuses in -Ligand-gated sodium ion channels open and sodium diffuses in. -Ligand-gated calcium ion channels open and calcium diffuses in. -Terminal vessels migrate to the plasma membrane.

Ligand-gated sodium ion channels open and sodium diffuses in.

The ____ has two functional subdivisions, the sensory division ans the motor division.

PNS (peripheral nervous system)

Hyperpolarization, or afterpotential, occurs because: potassium ions continue to diffuse out of the cell after the inactivation gated of the voltage-sodium ion channels begin to close the increase potassium ion permeability lasts slightly longer than the time required to bring the membrane potential back to its resting level the inactivation gates of the voltage-gated sodium channels begin to open, and the diffusion of sodium ions decreases. more sodium ions diffuse into the cell than potassium ions diffuse out of it. the extra efflux of potassium ions causes the membrane potential to become slightly more positive than the resting value.

The increased potassium ion permeability lasts slightly longer than the time required to bring the membrane potential back to its resting level.

What is produced when depolarization of a cell membrane reaches threshold? a new action potential is produced. the absolute refractory period ends. Voltage-gated ion channels close. An existing action potential is stopped.

a new action potential is produced.

A recently deplorarized area of a cell membrane cannot generate an action potential because of the: the high concentration of potassium ions in the cytoplasm. high concentration of sodium ions in the extracellular fluid. absolute refractory period. presence of receptor sites on the membrane

absolute refractory period.

The division of the peripheral nervous system that transmits electrical impulses from sensory receptors to the CNS is the ____ division, while the ____ division of the peripheral nervous system transmits electrical impulses from the CNS toward muscles and glands

afferent; efferent

The division of the nervous system responsible for problem solving is the ____.

central nervous system

check all that apply to chemical synapses. - chemicals synapses are the numerous type of synapse in the human body. -chemical synapses are found primarily in smooth muscle cells. -chemicals synapses are unidirectional (one way). - chemical synapses allow two-way signaling.

chemical synapses are the most numerous type of synapse in the human body; chemical synapses are unidirectional (one way)

The peripheral nervous system includes the ____. blood-brain barrier spinal cord cranial nerves brain cerebellum

cranial nerves

Structures called ____ are involved in electrical synapses

gap junctions

identify the statement that best differentiates grey matter and white matter -grey matter consists of neuron cell bodies, dendrites, and axons, whereas white matter is mostly composed of glial cells. -grey matter consists of cell bodes and dendrites, whereas white matter consists mostly of myelinated axons. -gray matter consists axon bundles, whereas white matter consists of clusters of cell bodies and dendrites.

grey matter consists of cell bodies and dendrites, whereas white matter consists mostly of myelinated axons.

The nervous system receives information both internally and from the environment, responding so as to maintain ____.

homeostasis

Depolarization occurs because the increased potassium ion permeability lasts lightly longer than the time required to bring the membrane potential back to its resting level. the extra efflux of potassium ions causes the membrane potential to become slightly more positive then the resting value. more sodium ions diffuse into the cell than potassium ions diffuse out of it. potassium ions continue to diffuse out of the cell after the inactive gates of the voltage-gated sodium ion channels begin to close. the inactivation gates of the voltage-gated sodium ions channels begin to open, and the diffusion of sodium ions decreases.

more sodium ions diffuse into the cell than potassium ions diffuse out of it.

The ____ division of the PNS (Peripheral Nervous System), is divided into somatic nervous system and the autonomic nervous system

motor

The nervous system can respond to stimuli using ____ and secretory ____.

muscles; glands

The ____ of a neuron release(s) neurotransmitters.

presynaptic terminals

The cell bodies of ____ motor neurons are located in the CNS (central nervous system) and their axons connect with skeletal muscle cells.

somatic

The ____ nervous system communicates with the skeletal muscles and the ____ nervous system communicates with the smooth and cardiac muscles as well as glands.

somatic; autonomic

The autonomic nervous system controls ____ activities

subconscious

As a result of calcium ions diffusing into the presynaptic cell,: synaptic vessels migrate to the plasma membrane and release acetylcholine acetylcholine is actively transported from the presynaptic neuron. sodium ions diffuse into the cell. ligand-gated sodium channels open. acetycholine is active transported to the postsynaptic neuron.

synaptic vessels migrate to the plasma membrane and release acetylcholine.

For each ATP used, the sodium-potassium pump transports two Na+ into the cell and three K+ out of the cell two K+ into the cell and three Na+ out of the cell. two K+ out of the cell and three Na+ into the cell. two Na+ out of the cell and three K+ into the cell.

two K+ into the cell and three Na+ out of the cell.