Unit 3 - BIO 223 (Chapter 10-11)

Choose the neuroglial cell types found in the peripheral nervous system (select all that are correct)

- Schwann cells - Satellite cells

Steps of muscle relaxation in order

1. Nerve signal ceases 2. AChE breaks ACh down 3. Calcium releases from troponin 4. Active transport pumps in the sarcoplasmic reticulum begin to pump calcium back into the cisternae 5. Tropomyosin covers the myosin binding sites

After a nerve cell responds to a stimulus, the period of time when the cell can not respond again, regardless of the stimulus, is called the ______ refractory period

Absolute refractory period

Nerve

Bundles of axons and their sheaths

True or false: The myelin sheath consists of connective tissue wrapped around the cell body and axon of a neuron?

False

Another name for a single skeletal muscle cell is a skeletal muscle _____?

Fiber

Fast glycolytic fiber

Fibers with fewest capillaries and mitochondria and highest anaerobic capacity

Groups of related nerve cells bodies that are located outside of the central nervous system are called ______

Ganglia

Communication between cells is very, very rapid in cardiac muscle because of ___ _________?

Gap junctions

Electrical synapses allow ions to diffuse quickly from cell to cell via?

Gap junctions

A protein channel that opens are closes in response to a stimulus is classified as a _____ channel?

Gated

What is the nature of the signal that propagates along neurons that ultimately regulates and coordinates the functions of the body

It is electrical.

What is the neuromuscular junction?

It is the site where the nerve fiber innervates the muscle fiber.

When a neuron is at rest, ____ channels are open?

Leak

Where is myosin located in this structure?

Letter B - green leafy like structure in middle of the structure.

________ gated ion channels open or close when a molecule such as hormone or neurotransmitter binds to them.

Ligand

Skeletal muscle cell characteristics

Long, cylindrical non-branching with many peripherally located nuclei.

What cells are responsible for producing the myelin sheath in the PNS?

Schwann cells

What cells are responsible for producing the myelin sheath in the peripheral nervous system? (PNS)

Schwann cells

The type of muscle that is predominantly responsible for the production of body heat to maintain temperature is ________ muscle?

Skeletal

During an action potential of a neuron,the type of ion that enters the cell and causes depolarization is the _____ ion

Sodium

The opening of gated ion channels at the postsynaptic membrane (following the binding of acetylcholine) results in the influx of

Sodium

The opening of gated ion channels at the postsynpatic membrane (following the binding of acetylcholine) results in the influx of?

Sodium

In the sodium-potassium pump, three ______ ions are transported out of the cell while two ________ ions are transported into the cell.

Sodium, potassium

The cell body of a neuron is also known as the ____?

Soma

The division of the peripheral nervous system that includes the skeletal muscles is the _____ division

Somatic

The division of the peripheral nervous system that includes the skeletal muscles is the ______division

Somatic

Smooth muscle cell characteristics

Spindle shaped cells with a single centrally located nucleus.

astrocyte

Star-shaped neuroglia that help to form the blood-brain barrier.

Cardiac muscle general description

Striated, uninucleate, branching and possessing intercalated discs.

Sensory Receptors

Structures that are specialized to detect temperature, pain, touch, and other stimuli

Sensory receptor

Structures that are specialized to detect temperature, pain, touch, and other stimuli.

Smooth muscle general description

Surrounds hollow organs, spindle shaped, nonstriated

A junction between a neuron and another cell is called?

Synapse

Structure labeled C in this figure

Synaptic cleft

The structures that are located in the presynaptic terminals and contain neurotransmitters

Synaptic vesicles

The structures that are located in the presynpatic terminals and contain neurotransmitters are called ________?

Synaptic vesicles

True or False: The nervous system and the endocrine system are the major control systems of the body?

True

True or False: inhibitory postsynpatic potentials (IPSPs) cause hyperpolarization of the plasma membrane

True

True or false: Isometric contraction in important in postural muscles?

True

What are T-tubules

Tube-like invaginations of the sarcolemma that extend inward through the muscle cell

The portions of the central nervous system (CNS) that are composed primarily of myelinated axon bundles are often referred to as _____ matter?

White

Name the molecule used to store energy that can be used to synthesize ATP.

creatine phosphate

When the neuron membrane becomes more positive than the resting membrane potential, it is said to be

depolarized

When the neuron membrane becomes more positive than the resting membrane potential, it is said to be ______.

depolarized

Increasing stimulus strength results in an increase in the _______ of action potentials

frequency

Neurons that are found between an afferent pathway and an efferent pathway are called?

interneurons

Myelin has a high _____ concentration

lipid

The concentration of sodium is _____ in the cytosol of a resting cell than it is in the Extracellular fluid.

lower

Because of their phagocytic function, large numbers of __________ are found in areas of the CNS damaged by an infection

microglia

A neuron that innervates skeletal muscle fibers is called a _______ neuron

motor

Action potentials are conducted more rapidly along ___________ axons

myelinated

Each G-actin monomer has an active site for the binding of what molecule?

myosin

When the resting membrane potential becomes more _____ the condition is referred to as hyperpolarization.

negative

The category of cells of the nervous system that support and protect neurons are called

neuroglial cells

Excitable cells operate through the movement of ions across _______.

plasma membrane

Excitable cells operate through the movement of ions across _______?

plasma membrane

When a charge difference exists across the plasma membrane, this difference is referred to as the membrane ________.

potential

At a synapse, what is the neuron that releases a neurotransmitter referred to as?

presynaptic

With which phase are the following associated: myosin releases thin filaments, muscle tension declines, and cytoplasmic calcium levels fall?

relaxation

The difference in electrical charge across the plasma membrane in an unstimulated cell is called?

resting membrane potential

The _________ in a muscle fiber stores calcium in between contractions

sarcoplasmic reticulum

Muscles are connected to bones by

tendons

In order for local potentials to trigger an action potential, the membrane must reach a level called the ______.

threshold

When an action potential propagates, it

travels across the plasma membrane by stimulating the production of additional action potentials

If all of the calcium within a muscle fiber was removed, which of the following could still occur? (Check all that apply)

-An action potential that was produced at the neuromuscular junction is propagated along the sarcolemma -The heads of the myosin molecules return to their resting position and the recovery stroke occurs.

During muscle contraction, ATP is involved in? (Select all)

-Cocking or energizing the myosin heads -The uptake of calcium into the sarcoplasmic reticulum at the end of a contraction -Breaking the bond between actin & myosin

List the functional properties of all muscle tissue types (select all)

-Contractility -Excitability -Elasticity -Extensibility

Fast glycolysis muscle fibers _______? (Select all)

-Fatigue more quickly -Respond rapidly to nervous stimulation

Indemnify the functions of astrocytes

-Formation of the blood-brain barrier -Support of neuron structure

Identify all of the criteria used to classify neurons

-Function -structure

Identify the components of the peripheral nervous system (select all that apply)

-Ganglia -Nerves -Sensory receptors

Describe troponin (select all that apply)

-It is a globular protein composed of 3 subunits, -it has binding sites for calcium ions -It is bound to both actin and tropomyosin

Correct order of events that occur during a single action potential beginning with the openings of the Na+ gates.

-Limited Na+ channels open and Na+ moves into the cell -Threshold is reached -More Na+ channels open and Na+ moves into the cell -Depolarization -K+ channels open and K+ leaves the cell -Repolarization

List the functions of smooth muscle (select all that apply)

-Propelling food through the GI tract -Changes in pupil size -Regulating blood vessel diameter

Both fast-twitch and slow-twitch muscle fibers can increase in _____ as a result of exercise and training. (Select all that apply)

-Size -strength -capacity

Describe the conditions in which there would be net movement of Na+ through its ion channel to the inside of a cell.

-The cytoplasm was very negative (-70 mV) while the ECF was very positive, sodium ions would flow into the cell. If the concentration of Na+ is higher in the Extracellular fluid than in the cytoplasm- sodium ions would flow into the cell.

Which of the following would be most likely if the excitability of a muscle cell INCREASED? (Choose all that apply)

-The muscle cell would contract more readily -The muscle cell would depolarize more readily

Which of the following events occurs during a relaxation phase of the muscle twitch? (Choose all that apply)

-The troponin-tropomyosin complexes move to inhibit cross-bridge formation. -Calcium ions are actively transported back into the sarcoplasmic reticulum

Identify the characteristics of action potentials (choose all that apply)

-They are all or none -The strength of the stimulus determines the frequency of the action potentials -once started they continue to the end

Name the functions of the skeletal muscle (select all that apply)

-Walking or running -Maintaining posture

The terminal cisternae (select all that are correct)

-are part of the sarcoplasmic reticulum -contain calcium ion channels that open in response to an action potential

The A band of the sarcomere (Select all)

-contains the H zone and the M line -Contains both actin and myosin filaments -extends the entire length of the myosin filaments

In order for an ion to move PASSIVELY through an ion channel in a cell membrane, there must be a(n) _______?

-gradient of some type -Difference in concentration of that ion on one side versus the other -Difference in the electrical or charge distribution between the areas

Which of the following will cross the membrane and promote depolarization. (Choose all that apply.)

-increase in Na+ permeability -increase in Ca2+ permeability

Gated ion channels respond to which of the following stimuli?

-mechanical stimulus -ligands binding to receptors -voltage changes

List all possible actions of muscle cells (select all that apply)

-movement of blood through vessels -contraction of the heart chambers -Contraction or shortening

Match the components of an action potential in the graph below with their correct label

A - Graded potential B - Depolarization C - Repolarization D - Hyperpolarization

Ganglion

A collection of neuron cell bodies located outside the central nervous system

Efferent neuron

A neuron that transmits action potentials away from the CNS towards muscles and glands

Multi-polar neuron

A neuron with many cytoplasmic extensions and one axon

Bipolar cells

A neuron with one dendrite and one axon

Perimysium

A thick connective tissue layer around each fascicle

Acetylcholine is broken down by the enzyme called _____________________?

Acetylcholinesterase

Electrical signals that are propagated along axons in a non-decremental fashion of called _____ potentials.

Action

Electrical signal, called ______ potentials travel from the brain or spinal cord along the axons to muscle fibers and call them to contract.

Action potential

Incomplete tetanus:

Allows the muscle fiber to partially relax between the contractions.

Efferent division

Also referred to as the motor division of the PNS

Afferent Division

Also referred to as the sensory division in the PNS

Smooth muscle is classified as involuntary but sometimes it is capable of contracting without nervous stimulation. What is this called?

Autorhythmicity

Tropomysin is indicated by which of the labeled structures?

B (rope like structure around the cells)

Entry of _______into the synaptic knob triggers exocytosis of neurotransmitters.

Calcium

Which of the following is responsible for active transport of Ca2+ out of the sarcoplasm at the end of the contraction cycle?

Calcium ion pumps

During the relaxation phase of the muscle twitch, which ions are actively transported back into the SR? (Sarcoplasmic reticulum)

Calcium ions

List the types of muscle tissue (Check all that apply)

Cardiac,, Smooth, skeletal

The division in the nervous system that is responsible for processing, integrating, storing and responding to information

Central nervous system

Motor neuron

Conducts impulses away from the CNS

interneuron

Conducts impulses from one neuron to another neuron within the CNS.

Sensory neuron

Conducts impulses towards the central nervous system (CNS)

Peripheral Nervous System (PNS)

Consists of sensory receptors,nerves, and ganglia

autonomic nervous system (ANS)

Consists of the sympathetic nervous & parasympathetic divisions

The sarcomere is called the basic functional unit of a muscle fiber because it is the smallest part of the fiber that is capable of ___________?

Contracting

True or False: When a neurotransmitter binds to a receptor on a postsynaptic membrane, a depolarization will occur

False

Cardiac muscle cell characteristics

Cylindrical, branched cells with a single, centrally located nucleus.

The highly branched cytoplasmic extensions of the neurons cell body that are specialized to receive input and conduct signals towards the cell body are called ________?

Dendrites

Identify the phases of an action potential (select all)

Depolarization, Hyperpolarization, Repolarization

Somatic Nervous System (SNS)

Division of the efferent division that is mostly under voluntary control

True or False: The myelin sheath consists of connective tissue wrapped around the cell body and axon of a neuron.

False

Sodium is more abundant in which fluid compartment when the cell is at rest?

ECF (Extracellular fluid)

Identify the difference between EPSPs and IPSPs

EPSPs promote a depolarization and IPSPs promote a hyperpolarization.

The ability of muscle to recoil to its original resting length after it has been stretched is called ________?

Elasticity

Which type of neuroglial cell is responsible for assisting in the movement of cerebral spinal fluid (CSF)

Ependymal

In a resting cell Na+ concentration is higher in the _______ fluid

Extracellular

In a resting cell, Na+ concentration is higher in the ____________ fluid.

Extracellular

True or False: During contraction, actin and myosin filaments change length causing the sarcomeres to shorten?

False

True or False: Neurons consist of a single cell body, a single dendrite and multiple axons

False

The first stage of fermentation and aerobic respiration is?

Glycolysis

Nerve tissue consisting primarily of cell bodies and unmyelinated neurons is often referred to as _______________ matter

Gray

Slow Oxidative fiber

High aerobic capacity and highest resistance to fatigue

Fast oxidative Glycolytic fiber

High myoglobin and glycogen concentration with both aerobic and anaerobic capacity

The neuroglial cells that phagocytize dead tissue and foreig substances within the CNS are the ______?

Microglia

When the membrane potential increases compared to the resting membrane potential, the inside of the membrane becomes ______ negative. This is known as ______.

More negative, hyperpolarization

Skeletal muscle general description

Most abundant muscle type, multinucleated and striated.

A neuron with one axon and multiple dendrites is called a ________neuron.

Multipolar

A single, brief contraction and relaxation cycle in a muscle fiber is called a muscle ____?

Muscle twitch

The protein found in muscle cells that stores and then releases oxygen when needed is called ___________?

Myoglobin

When Na+ channels open, what happens to the Na+ ions?

Na+ diffuses into the cell

If the area just inside the membrane of a call is more negative than the outside, the resting membrane will have a __________ value?

Negative

The voltage of a repolarizing neuron or muscle fiber is becoming more ________ with respect to the Extracellular fluid around it?

Negative

When a voltmeter measures a potential difference of -85 mV, the inside of the membrane is more ________ with respect to the outside of the membrane?

Negative

A bundle of axons wrapped in fibrous connective tissue in the peripheral nervous system in called a _____?

Nerve

oligodendrocyte

Neuroglia cell that forms the myelin sheaths around neurons of the CNS.

ependymal cells

Neuroglia that line the ventricles of the brain and the central canal of the spinal cord.

Afferent neuron

Neuron that transmits action potentials towards the CNS

microglia

Phagocytic neuroglia of the CNS

Select all of the cell types that are components of the nervous system (select all that apply)

Neurons, Neuroglia

Identify the primary site of protein synthesis within the neuron

Nissl bodies

Each fascicle is surrounded by a connective tissue layer called the ____?

Perimysium

The plasma membrane has opposite charges across the membrane and causes the membrane to be ______?

Polarized

Inside excitable cells at rest, you'll find high concentrations of ______ ions and negatively charged proteins.

Potassium

When considering permeability to sodium and potassium, neuron plasma membranes have a higher permeability t0 ____________?

Potassium

When considering permeability to sodium and potassium, neuron plasma membranes have a higher permeability to ___?

Potassium

______ is the electrolyte that has the greatest influence on resting membrane potential due to the greater permeability of the plasma membrane to this electrolyte

Potassium

During depolarization, _____channels open more slowly than _____channels.

Potassium; sodium

Tropomysin moves back to cover the active sites on actin during the __________ phase of the muscle twitch?

Relaxation

The charge difference across the plasma membrane in a cell at rest is called the __________ potential?

Resting membrane

The structure within a muscle fiber that extends from one Z line to another Z line?

Sarcomere

The cytoplasm of a muscle cell is called the __________?

Sarcoplasm

Explain why the propagation of action potentials is in one direction

The absolute refractory period prevents the generation of an action potential in the reverse direction

True or False: Inhibitory postsynaptic potentials (IPSPs) cause hyperpolarization of the plasma membrane.

True

Which of the following ionic movements causes the phase of the action potential?

The movement of a large number of potassium ions out of the cell

The optimal length of a muscle is the length at which:

The sarcomeres are in the ideal position to generate the greatest tension

The ____ filament is composed of actin

Thin

The minimum membrane potential needed to be achieved before the voltage-gated ion channels open, and an action potential begins is called the ________?

Threshold

The protein that blocks the active sites in a resting muscle is ______?

Tropomyosin

During contraction, the sarcomeres shorten because:

actin is pulled past myosin towards the M line of the sarcomere

The method of ATP production that can produce up to 36 ATP molecules for each glucose molecule is _____ respiration.

aerobic

The plasma membrane of the axon is the?

axolemma

The division of the motor nervous system that is under involuntary control and innervates glands, smooth muscle, and cardiac muscle is the _________ division?

autonomic

The cytoplasm of the axon is called the

axoplasm

Select the components of the central nervous system

brain and spinal cord

The function of acetylcholinesterase is to _____?

break down the neurotransmitter acetylcholine

When a neuron or muscle cell is at rest, the voltage-gated ion channels in its membrane are ________

closed

two types of isotonic contractions

concentric and eccentric

Central Nervous System (CNS)

consists of the brain and spinal cord

The type of action potential conduction in an unmyelinated axon is ____ conduction.

continuous

Myoglobin would be most abundant in what type of muscle fiber?

slow oxidative

The motor division of the peripheral nervous system is further divided into the _________ and ____________ subdivisions?

somatic and autonomic

Summation that results from EPSPs occurring at multiple synapses is called _________ summation.

spatial

When the effect of one graded potential is added to the effect of another, this is referred to as _________.

summation