A&P unit 2

The functions of astrocytes are to ______.

-Assist neuronal development -Regulate the composition of interstitial fluid -Help form the blood-brain barrier

Which of the following are characteristics of neurons?

-Conductivity -Amitotic -Excitability -Secretion -Extreme longevity

A resting membrane potential is essential in the normal function of which of the following type of cells?

-Nerve -Muscle

Place the events in the correct sequence. Not all items will be used.

1. Action potential reaches the synaptic knob 2. Voltage gated calcium channels open 3. Calcium enters the synaptic knob 4. Synaptic vesicles merge with synaptic knob plasma membrane 5. Neurotransmitter is released by exocytosis 6. Neurotransmitter crosses the synaptic cleft 7. Neurotransmitter attaches to receptors on a muscle, neuron, or gland cell.

The arrival of a nerve impulse at the synaptic knob of a motor neuron causes synaptic vesicles to release _____ into the synaptic cleft.

ACh Acetylcholine Neurotransmitter

The motor end plate has large numbers of ______ receptors.

ACh Acetylcholine

Which of the following are used for fast axonal transport?

ATP Microtubules Motor proteins

Each myosin head in a thick filament can bind to the protein in a thin filament called ______

Actin

Thin filaments are composed of

Actin Tropomyosin Troponin proteins

A flow of electrical current called a(n) ______ ______is generated within the initial segment of a neuron.

Action potential

The division of the nervous system that is subdivided into the sympathetic and parasympathetic divisions is the _____ nervous system.

Autonomic Involuntary ANS Visceral

The ______ is the functional division of the nervous system that controls the involuntary movement of smooth muscle.

Autonomic motor nervous system

The synapse is located ______ the presynaptic neuron and postsynaptic neuron.

Between

Unipolar neurons start out as ______ neurons during development.

Bipolar

The brain and spinal cord are part of the ______.

CNS

Which of the following are among the general characteristics of graded potentials?

Can either be depolarizing or hyperpolarizing. The degree of change in membrane potential is dependent on the stimulus magnitude. The decreased intensity with distance traveled along the membrane.

A muscle fiber is what level of organization in the body?

Cellular

The ependymal cells help produce ______.

Cerebrospinal fluid

H zone

Contains thick filaments only

What are the four types of neuronal pathways?

Converging Diverging Reverberating Parallel-after-discharge

Sarcoplasm

Cytoplasm of a muscle cell

Actin

Double stranded contractile protein Binding site for myosin to shorten a sarcomere

Numerous ______ must be generated and arrive at the initial segment at nearly the same moment if a threshold is to be reached.

EPSP's

Numerous ______ must be generated and arrive at the initial segment at nearly the same moment if a threshold is to be reached.

ESPSs

Gap junctions are found in ______.

Electrical synapses

Stages of cross-bridge cycling in order

1- Calcium binds troponin; myosin-binding site uncovered 2- Cross-bridge formation 3- Power stroke 4- Release of myosin head by ATP 5- Reset of myosin head

Voltage is a measure of relative _____ energy.

Potential or Electrical

Chromatophilic substance and Nissl bodies are both types of ____.

Ribosomes

If a skeletal muscle is injured, surrounding ______ cells may be stimulated or differentiate and assist in its repair and regeneration

Satellite (or) stem

If the sarcoplasm of a muscle cell is flooded with calcium ions, to which protein will they bind?

Troponin

The flow of sodium ions through sodium channels is best described as ______.

From outside the cell to inside

Sarcomere

Functional contractile unit of skeletal muscle

A cluster of neuron cell bodies found along a peripheral nerve is known as a(n)

Ganglia

Match the neurotransmitter to its class.

Glutamate ---> amino acid Norepinephrine -----> Monoamine

Match the neurotransmitter with its correct class.

Glycine ----> amino acid Dopamine ---> monoamine Neuropeptide --> enkephalin

A potential that is a temporary change in membrane potential which lasts only as long as the stimulus that causes it and can vary in size is called a _____ potential.

Graded

Choose which of the following can be the mechanism by which neurotoxins may do harm.

Interfere with the transmission of action potentials Induce detrimental structural change to a neuron Alter events that occur at a synapse

Because muscle cells require a huge amount of ATP in order to contract, they have a large number of which organelle?

Mitochondria

The autonomic division of the nervous system is part of the ______ nervous system.

Motor

In a motor unit, a single _____ neuron typically controls numerous muscle fibers ina muscle.

Motor Somatic

The inside of the cell is relatively more ______ than the outside of the cell.

Negative

When electrodes are placed just inside and just outside of the cell membrane, there is a relatively more ______ charge on the ______ of the cell.

Negative; inside

The thin outer layer of the neurolemmocyte is called the ______.

Neurilemma

Neurofilaments aggregate to form bundles called ______.

Neurofibrils

Clusters of neuron cell bodies called ganglia are found in the ______ nervous system.

Peripheral

Guillain-Barré syndrome is a disorder of the ______ nervous system.

Peripheral

In a unipolar neuron, the portion of the axon stretching from the dendrites to the cell body is known as the _______ ________.

Peripheral process

A ______ transmits an impulse through its axon toward the synapse.

Presynaptic

Membrane molecules that use the energy of ATP to move ions against a concentration gradient are called

Proteins Pumps

A ______ is a type of circuit that causes a cyclic response.

Reverberating circuit

Some antidepressant drugs are SSRIs. SSRI stands for ______ _______ _______ _______.

Selective Serotonin Reuptake Inhibitors

The somatic division of the nervous system that receives information from the eyes, ears, and skin is the somatic _____ division.

Sensory Afferent

A change in membrane potential insufficient to cause an action potential is known as a _______ ________.

Subthreshold Value

The process by which postsynaptic potentials are added together at the initial segment is known as

Summation

The motor end plate has folds and indentations to increase the membrane surface area adjacent to the ______.

Synaptic knob

As a result of ACh stimulation, calcium ions are released from the _____ of the sarcoplasmic reticulum

Terminal cisternae

What must happen in order for a chemical signal to change the membrane potential of a neuron?

There must be a change in ion flow across the membrane. (And) There must be a change in the number of open ion channels.

Vesicles involved in retrograde transport are moving ______ the cell body.

Toward

True or false: Facilitation and inhibition may be caused by changes in either the presynaptic neuron or the postsynaptic neuron.

True

What are the two structural examples of sensory neurons?

Unipolar Bipolar

Both Na+ and K+ are pumped by the Na+/K+ pumps ______ their concentration gradients in maintaining the resting membrane potential.

Up

______ are unique channels in that they have three states; resting, activation, and inactivation.

Voltage gated channels

______ are not commonly found in the receptive segment of a neuron.

Voltage-gated ion channels

M line

appears as a dark protein disc in the center of the H zone

Streps in neuromuscular junction

1- Nerve signal arrives at the synaptic knob 2- Calcium enters and binds synaptic vesicle 3- ACh is released via exocytosis into the synaptic cleft 4- ACh binds receptors on the motor end plate

Which two are divisions of the sensory nervous system?

1- Somatic division 2- Visceral division

Most channels have ________ gates(s), but a sodium channel has _______ Gates(s).

1. one 2. two

Thick filaments are composed of

200-500 myosin protein molecules

Membrane pumps require ______ energy.

A lot

Each myosin head in a thick filament can bind to the protein in a thin filament called _____

Actin

Sensory ______ neurons carry information ______ the central nervous system.

Afferent; toward

Current is measured in

Amps

Local _______ like lidocaine work by inhibiting impulse propagation along nerves.

Anesthetics

A substance synthesized at the cell body must undergo ______ transport to reach the synaptic knobs.

Anterograde

Substances can be moved in fast axonal transport (in) ______.

Anterograde and retrograde directions

The endoneurium is made of ______.

Areolar connective tissue

The connective tissue layers in muscle provide protection, distribution sites for blood vessels and nerves, and a means of ______ to the skeleton.

Attachment

Sympathetic and parasympathetic are divisions of the ______ nervous system.

Autonomic (peripheral)

A fascicle is a bundle of ______.

Axons

Troponin

Bound to tropomyosin; can bind calcium ions

Ependymal cells produce and circulate cerebrospinal fluid. The ______ helps circulate the CSF.

Cilia

Thin filament

Composed of actin, troponin, and tropomyosin. Bind to thick filaments and cause contaction

Thick filament

Composed of myosin Bind to thin filaments and cause contraction

The somatic sensory division detects stimuli that are ______ perceived.

Consciously

______ is the type of neuronal circuit that is made when multiple impulses come together at a single postsynaptic neuron.

Converging

What is the movement of charged particles called?

Current

Myofibrils

Cylindrical organelles specialized for contraction Contain myofilaments that are responsible for muscle contraction

A band

Dark band containing both actin and myosin

The epineurium is made of ______ connective tissue.

Dense irregular

Another way for the neurotransmitter to be removed from the synaptic cleft is by ______ where there is uptake by surrounding glial cells.

Diffusion

A message traveling from one presynaptic neuron to multiple postsynaptic neurons is an example of a ______ circuit.

Diverging

Tropomyosin

Double-stranded regulatory protein covers the active sites on actin, preventing myosin from binding to actin when muscle fiber is at rest

Motor neurons are classified as ______ neurons.

Efferent

The gradient that is dependent on the combination of the electrical gradient and the chemical concentration gradient is the __________ gradient.

Electrochemical

The resting membrane potential is a(n) ______ gradient at the plasma membrane.

Electrochemical

in a muscle there are concentric layer of connective tissue. From deep to superficial these connective tissue layers are the ______, the ______, and the _______

Endomysium Epimysium Perimysium

The lining ventricles of the brain is a location of ______.

Ependymal cells

An increase in the response of a postsynaptic neuron to a neurotransmitter is known as ______.

Facilitation

True or false: Ion channels use the energy of ATP to maintain concentration gradients across neuron membranes.

False

True or false: Many voltage-gated channels are found in the receptive segment of a neuron.

False

A skeletal muscle cell is also called a muscle _____

Fiber

Th peripheral nervous system is made of nerves and ____.

Ganglia Ganglion

The chromatophilic substance helps create the ______ color in parts of the brain and spinal cord.

Grey

At maximal contraction of a muscle fiber, the thin filaments are pulled into the ______ zone which disappears.

H

In a sarcomere, the ______ zone (or band) is the light, central region of the A band.

H zone

What part of a myosin molecule does ATP bind to?

Head

Many local anesthetics prevent the transmission of pain by ______.

Inhibiting voltage-gated sodium channels

If you were moving across a neuron's membrane from the receptive segment toward the transmissive segment, in the ______ is where would you first encounter large numbers of voltage-gated Na+ and K+ channels.

Initial segment

Which of the following segments of a neuron contains large numbers of voltage-gated potassium channels and voltage-gated sodium channels?

Initial segment Conductive segment

Neuronal pools are made of ______.

Interneurons

The cytosol close the the plasma membrane contains relatively more ______ ion than does the interstitial fluid that is close to the plasma membrane.

K+

IPSPs

K+ and Cl- ions current with this, local currents of ions associated with the graded potentials.

The net movement of K+ and Na+ in maintaining the resting membrane potential is partially dependent upon the number of ______ channels.

Leak

In neurons, most chemically gated ion channels open in response to the binding of a(n)

Ligand

I band

Light band containing thin filaments only

Cells that wander through the CNS and replicate in response to infection are called

Microglia

The resting membrane potential is measured in ______.

Millivolts

Upon release from the synaptic knob, acetylcholine attaches to receptors on the ______.

Motor end plate

______ is caused by the destruction of oligodendrocytes.

Multiple sclerosis

Interneurons are _____ neurons.

Multipolar

The sarcoplasm of a skeletal muscle fiber contains hundreds to thousands of long, cylindrical structures called __________

Myofibrils

Muscle cells store oxygen bound to a ____ molecule.

Myoglobin

Which of the following ions have leak channels on the plasma membrane?

Na+ K+

ESPSs

Na+ ions currents with this, local currents of ions associated with the graded potentials

The relative distributions of K+, which is more concentrated inside the cell, and Na+, which is more concentrated outside the cell, are the result of the activity of the ______.

Na+/K+ pump

Which of the following membrane transporters are present throughout the membrane of a neuron?

Na+/K+ pumps Potassium leak channels Sodium leak channels

The ability to alter the response of neurons to neurotransmitters is known as ______.

Neuromodulation

Synaptic knob, motor end plate, and synaptic cleft are parts of a ______.

Neuromuscular junction

Neuronal pools are also called ______.

Neuronal pathways and Neuronal circuits

A toxin that interferes with the activity of neurons is called a

Neurotoxin

Choose the cells that are part of the central nervous system.

Oligodendrocyte Microglia Ependymal cells Astrocyte

Na+ and K+ are moved in ______ directions to maintain the resting membrane potential.

Opposite

A fascicle is surrounded by a layer of dense irregular connective tissue called ______.

Perineurium

Sarcolemma

Plasma membrane of a muscle fiber

An inhibitory neurotransmitter may cause the opening of a ______ channel.

Potassium and Chloride

The period following an action potential in which an action potential can be initiated with a larger stimulus is known as the _____ ______ period.

Relative Refractory

The plasma membrane also functions in establishing and maintaining electrochemical gradient at the plasma membrane called _______ ________ potential.

Resting membrane

Some antidepressant drugs work by blocking the _______ of serotonin.

Reuptake

The removal of neurotransmitters from the synaptic cleft by transport into the synaptic knob is known as ______.

Reuptake

The repetitious nature of a ______ circuit ensures that we continue breathing while we are asleep.

Reverberating

After stimulation of ACh receptors, a muscle impulse spreads quickly along the ______ and into the muscle fiber along T-tubules.

Sarcolemma

The motor end plate is a specialized region of the ______.

Sarcolemma

Within a myofibril, each ______ shortens as the muscle fiber contracts.

Sarcomere

During the development of skeletal muscle cells, some myoblasts do not fuse and instead become ______ cells.

Satellite

_____ are voltage-gated ion channels that have two gates.

Sodium channels

If several EPSPs occur at different synapses, they undergo ______ at the initial segment.

Spatial summation

The expanded tip of an axon is called a ______.

Synaptic knob

A neuromuscular junction contains a(n) ______

Synaptic knob Motor end plate Synaptic cleft

Neurotransmitters are stored in ______.

Synaptic vesicles

If several EPSPs occur at a synapse over a short period of time, they undergo ______ at the initial segment.

Temporal summation

A thick cordlike structure that attaches a muscle to a bone is called a(n) ______.

Tendon

The H band (or H zone) is more lightly shaded because only ____ filaments are present

Thick (or) myosin

The all-or-none law refers to the fact that action potentials will only occur if the initial segment reaches

Threshold or -mV

True or false: Skeletal muscle is usually attached to the skeleton, but it is also found at the openings between the digestive tract and the external environment and the urinary tract and the opening to the external environment.

True

Tropomyosin

Two intertwined strands' cover myosin-binding sites Covers the active sites on actin when muscle cell is at rest

Actin

Two intertwines strands; each bead has a myosin-binding site.

Myosin protein consist of_____

Two strands; each has a globular head and an elongated tale.

Most afferent neurons are classified functionally as ______.

Unipolar

Pseudounipolar is another name for a ______ neuron Multiple choice question. multipolar

Unipolar

The ______ functional division of the nervous system transmits information from the viscera to the central nervous system.

Visceral sensory division

Ganglia are ______.

clusters of neuron cell bodies in PNS

When a nerve impulse reaches the end of an axon of a neuromuscular junction, calcium flows ______ the synaptic knob.

into

H zone

lighter region in middle of dark A band

Z disk

made of dark proteins that create a zig-zag line

The components of the somatic sensory division are ______.

-Receptors for hearing -Receptors for taste -Receptors in joints and muscles

Neurons have a resting membrane potential of ______ mV.

-70 mV