All Cards for Exam #3 A & P

When opposite charges are arranged on opposing sides of a membrane, the membrane is said to be ______.

polarized

The plasma membrane has opposite charges arranged across the membrane and is thus said to be _______.

polarized or polar

During an action potential, repolarization is due to ________ ions leaving the cell.

potassium

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

potassium

When considering permeability to sodium and potassium, neuronal plasma membranes have a higher permeability to ______.

potassium

Muscles exhibit the property of excitability. This means that the muscle

responds to stimulation by the nervous system

A cell is not stimulated but it does contain an electrical charge difference across its membrane. This charge difference is its ______.

resting membrane potential

Contracting the right sternocleidomastoid muscle would

rotate the head toward the left.

The structure within a muscle fiber that extends from one Z disk to another Z disk is a(n) ______.

sarcomere

The tibial and common fibular nerve combine to form the ______ nerve.

sciatic

What type of potential is irreversible?

Action potential

What type of potential is non-decremental?

Action potential

Which of the following produces the greatest amount of ATP in muscle?

Aerobic respiration

Correctly pair the parts of a neuron with the correct description.

Cell Body - Enlarged portion of a neuron that contains the nucleus and other organelles Axon - Process of a neuron that transmits action potentials away from the cell body Dendrite - Process of a neuron that receives stimuli and and generates local potentials Nissl body - Rough endoplasmic reticulum of a neuron responsible for protein synthesis Collaterals - Branches of an axon

Actin and myosin fibers in _______muscle overlap to form loose bundles.

smooth

Spindle shaped muscle cells with a centrally located nucleus and visceral gap junctions are called _____ muscle cells.

smooth

The dephosphorylation of ATP by myosin-ATPase leads to:

the cocking of the myosin head

pia mater

the delicate innermost membrane enveloping the brain and spinal cord.

The type of muscle fatigue known as "psychological fatigue" is the result of

the emotional state of an individual.

Structures that contain multiunit smooth muscles include ______.

the iris of the eye arteries pulmonary airways

To which phase do these events belong? (1) An action potential triggers calcium ion release. (2) Calcium binds to troponin. (3) The myosin binding site is exposed.

Excitation-contraction coupling

Which matter of the spinal cord contains neuron cell bodies?

Gray

The biceps femoris is part of the

Hamstring muscles

Which type of muscle tissue possesses striations?

both skeletal and cardiac muscle

Spinal nerves C5 - T1 make up the _____ plexus.

brachial

The CNS consists of the ______.

brain and spinal cord

Damage to the phrenic nerve would affect one's ability to ______.

breathe

Entry of ______ ions into the synaptic knob triggers exocytosis of neurotransmitters.

calcium

Troponin binds to _____.

calcium

Synapses in which neurotransmitters are released are called ______ synapses.

chemical

Contracting the trapezius muscle would

extend and laterally flex the neck.

Action potentials are conducted more rapidly when transmission is

from node to node on a myelinated axon

A depolarizing local potential will make the neuron ______ likely to generate a nerve impulse.

more

Does aerobic respiration produce more or less ATP molecules per unit of glucose than anaerobic respiration?

more

The type of smooth muscle that has fewer gap junctions than other smooth muscle types, and its cells or groups of cells act as independent units is ______ smooth muscle.

multiunit

Smooth muscles found in the iris of the eye and arteries are classified as _____.

multiunit smooth

The brachial plexus supplies nerves that function to contract which of the following?

muscles of the arm and forearm

Action potentials (nerve messages) are able to travel faster along ______ axons.

myelinated

In excitation-contraction coupling.

myosin heads bind to exposed active sites on actin.

The nerve fiber innervates the muscle fiber at the ______.

neuromuscular junction

Synaptic vesicles within synaptic knobs contain chemicals called _________.

neurotransmitters

A multipolar neuron has ______ dendrite(s).

many

A sacromere extends from

one Z disk to an adjacent Z disk

The cross-sectional view of the spinal cord reveals white matter on the

outside, gray matter on the inside, and a ventral motor root.

The coccygeal plexus innervates _____.

the muscles of the pelvic floor

A series of local potentials causes the membrane potential to move to -80 mV. Predict the result.

the neuron is hyperpolarized

The intracellular fluid is considered to be electrically neutral because ______.

there are the same number of positively and negatively charged ions.

A single, brief contraction and relaxation cycle in a muscle fiber is called a muscle ________.

twitch

During which phase do the following occur: the release of ACh, diffusion of ACh across the cleft to the receptors and the opening of voltage gated ion receptors adjacent to the motor end plate?

Excitation phase

Which phase of contraction links the action potential in the sarcolemma to the activation of the myofilament?

Excitation-contraction coupling

During a contraction, which areas of the sarcomere are most likely to either disappear or decrease?

I band H zone

Neuroglial cells that aid in the production of cerebrospinal fluid are the ________ cells.

ependymal

Neuroglial cells that produce cerebrospinal fluid are ______.

ependymal cells

Sodium is more concentrated in the _____ fluid than in the _____ fluid.

extracellular, intracellular

The speed of an action potential along myelinated axons is ______ the speed of an action potential along an unmyelinated axon.

faster than

A decrease in the capacity to do work and the reduced efficiency of performance that normally follows a period of activity is called ______.

fatigue

The decreased capacity of a muscle to do work is known as ______.

fatigue

Skeletal muscle is described as striated. What does that mean?

The tissue exhibits alternating dark and light bands.

Axons contain

The trigger zone

What is the effect when calcium binds to troponin?

The troponin-tropomyosin complex changes shape and exposes the myosin binding sites.

The plasma membrane of a neuron is more permeable to K+ because

There are more leak ion channels for K+ than for Na+

True or false: ATP is needed for both muscle contraction and muscle relaxation.

True

True or false: The gluteal nerve is a nerve of the lumbosacral plexus.

True

True or false: There is a significant difference in concentration between the intracellular concentration of sodium and the extracellular concentration of sodium.

True

True or false: Three factors that generate the resting membrane potential include diffusion of ions across a membrane, a selectively permeable membrane, and the electrical attraction of oppositely charged ions.

True

The 6th cranial nerve that is responsible for lateral eye movement.....

abducens

A period of time when a cell cannot respond again to an electrical stimulus is the __ refractory period.

absolute

After a nerve cell responds to a stimulus, the period of time when the cell cannot respond again except to an unusually strong stimulus is called the ______________ refractory period.

absolute

Synaptic vesicles in the neuromuscular junction contain

acetylcholine

During contraction of the sarcomere, the Z disk helps hold the ______ in place.

actin myofilament

The energized or cocked myosin heads bind to _____ forming a _______.

actin, cross-bridge

The nervous system transfers information from one part of the body to another by using _____.

action potentials

Traveling waves of excitation moving down an axon are referred to as ______.

action potentials

The power stroke occurs because the myosin heads go from a high energy position to a low energy position once ______ is released.

adenine diphosphate (ADP)

Anaerobic respiration allows the cell to make a small amount of ______ in the absence of oxygen, but also produces ______.

adenosine triphosphate (ATP), lactic acid

The mechanism of ATP production that requires oxygen is __________ respiration.

aerobic

ATP, carbon dioxide, and water are the major end products of ______.

aerobic respiration

Resting muscles or muscles involved in long-term exercise primarily use ______ for ATP production.

aerobic respiration

The energy required to produce ATP comes from ______.

aerobic respiration creatine phosphate anaerobic respiration

Acetylcholine released into the synaptic cleft is rapidly broken down to acetic acid and choline by ______.

an enzyme acetylcholinesterase

Cells produce a small amount of ATP and lactic acid in the absence of oxygen through the process of ________ respiration.

anaerobic

Cells produce a small amount of ATP and lactic acid in the absence of oxygen through the process of __________ respiration.

anaerobic

The energy required to produce ATP comes from ______. Select all that apply.

anaerobic respiration creatine phosphate aerobic respiration

Fibers that connect areas of the cerebral cortex within the same hemisphere are.....

association fibers

The function of acetylcholinesterase is to

breakdown acetylcholine in the synapse.

Large, negatively charged proteins inside the cell _____ readily diffuse across the neuron membrane.

cannot

The brain and spinal cord are the two components of the ______.

central nervous system

The brain and the spinal cord make up the ____.

central nervous system

The cerebellum communicates with other regions of the CNS through

cerebellar peduncles

Neurotransmitter receptors at the postsynaptic membrane act as ______________ -regulated ion gates.

chemical or ligand

The "cocking" of the myosin heads, hydrolysis of ATP, and the power stroke occur during the ______ phase of skeletal muscle contraction.

contraction

During a single contraction, each myosin molecule undergoes the cycle of cross-bridge formation, movement, release, and return to its original position many times. This process is called _______.

cross-bridge cycling

A protein channel that opens or closes in response to a stimulus would be classified as a ______ channel.

gated

Some protein channels in a cellular membrane are able to open or close in response to stimuli; because of this characteristic, these channels are called ______ channels.

gated

The cells that are general support cells for neurone in the brain and spinal cord are ______ cells.

glial

Cells of the nervous system that support and protect the neurons are called ______.

glial cells

Which of the following is part of a thin myofilament?

globular (G) actin

Myosin heads bind to ______.

globular actin

An axon hillock transitions into the ______ segment of an axon.

initial

The beginning of the axon is called the ______ segment.

initial

The beginning of the axon is called the _______ segment.

initial

axillary nerve

innervates deltoid and teres minor

common fibular nerve

innervates lateral leg and anterior leg

A negative membrane potential indicates that the area with a more negative charge is on the ______ of the membrane.

inside

Potassium ions and negatively charged proteins are more concentrated ______ the cell.

inside

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

multipolar

The type of smooth muscle that contracts as many independent units is smooth muscle.

multiunit

Each _____ is a threadlike structure, approximately 1-3 micrometers in diameter, that extends from one end of the muscle fiber to the other.

myofibril

During the recovery stroke, ATP binds to the _____ to recock it, beginning the cycle again.

myosin head

The energized _____ attach to the exposed myosin binding site on G-actin forming a cross-bridge.

myosin heads

While muscle is relaxed, energy stored in the _______ is held in reserve until the next contraction.

myosin heads

If the area just inside the membrane of a cell is more negative than the outside, the resting membrane potential will have a ______ value.

negative

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

neuroglia, glia, or glial

The general class of cells in the nervous system that protect nerve cells and help in their functioning are called _________ cells.

neuroglial, glia, glial, or neuroglia

The intracellular fluid has essentially the same number of positive and negative charges and is therefore electrically __________.

neutral or balanced

An action potential

occurs when the local potential reaches threshold level

Glial cells that form myelin sheaths within the CNS are the ________.

oligodendrocytes

The glial cells that form myelin sheaths in the brain and spinal cord are ______.

oligodendrocytes

The diaphragm is innervated specifically by the ________ nerve(s).

phrenic

The deepest meningeal layer that is tightly attached to the spinal cord is called the mater.

pia

The ion that is in a higher concentration in the intracellular fluid compared to the extracellular fluid is _______.

potassium, K, or K+

The plasma membrane is more permeable to _____ and chloride and much less permeable to _____.

potassium, sodium

Upon the release of ADP, the myosin head pulls the thin filament past the myosin myofilaments; this is referred to as the ______.

power stroke

When the myosin head flexes into a bend, pulling the actin filament along with it, this is called the

power stroke

The purpose of the absolute refractory period is to _____.

prevent action potentials from being generated in reverse direction

Aerobic respiration ______. Select all that apply.

produces more ATP per unit of glucose than anaerobic respiration produces ATP molecules at a slower rate than anaerobic respiration

Major branches of a spinal nerve are called _____.

rami

The role of the Na+-K+ pump in membrane potential regulation is that it ______.

reestablishes correct ion distribution, compensating for ion leakage

A period of time after a nerve cell has responded to a stimulus in which it cannot be re-excited by a threshold stimulus is called a(n) ______ period.

refractory

A nerve cell can only respond to an unusually strong stimulus during the ______ refractory period.

relative

When the voltage of a plasma membrane shifts from +35mV towards 0 mV, the cell is __________.

repolarizing

The basic structural and functional unit of a skeletal muscle fiber is called the_____________ ; it is the smallest unit of skeletal muscle that is capable of contracting.

sarcomere or sarcomeres

The ___________ reticulum is a modified form of smooth endoplasmic reticulum located in muscle cells.

sarcoplasmic

In a muscle cell, the highly specialized, smooth endoplasmic reticulum is called the _________.

sarcoplasmic reticulum

Dorsal (posterior) roots consist of only ______ fibers (axons).

sensory

epidural space

separates dura mater from periosteum

Which type of muscle tissue has spindle-shaped cells?

smooth muscle

During an EPSP, an influx of ______ occurs.

sodium

The ion ______ is more concentrated in the extracellular fluid.

sodium

The cell body of a neuron is also known as the ______.

soma, neurosoma, or perikaryon

The cell body of a neuron is also known as the ________.

soma, neurosoma, or perikaryon

When examined in a longitudinal section, skeletal muscle has alternating light and dark bands producing a(n) ______ appearance.

striated

During a spinal tap, cerebrospinal fluid is obtained from which of the following locations?

subarachnoid space

The space related to the meninges that contains cerebrospinal fluid is the _____.

subarachnoid space

The grooves of the surface of the cerebrum are called the ...

sulk

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

threshold

The sciatic nerve is composed of the

tibial nerve and common fibular nerve

The role of the transverse tubules is to ______.

transmit the signal to contract deep into the muscle fiber

The action potential moves from the sarcolemma surface deep into the myofiber via the ______.

transverse or T Tubules

Tube-like invaginations of the sarcolemma that conduct action potentials toward the center of the muscle fiber are called _____.

transverse tubules

Once stimulated, a single action potential ______.

travels only a short distance before stimulating another action potential

The molecule that inhibits the binding of myosin to actin by blocking the binding site is _____.

tropomyosin

During skeletal muscle contraction, calcium binds to _____.

troponin

Within a myofibril, calcium-binding sites are found on ______.

troponin

When a person hits their "funny bone," they cause temporary damage to the _____ nerve.

ulnar

Motor axons are found in ______ roots.

ventral

The _____ rami of spinal nerves innervate the ribs, the intercostal muscles and the skin of the thorax.

ventral

The ______ rami form nerve plexuses.

ventral

The motor root of a spinal nerve is also referred to as the

ventral root

The cranial nerve responsible for hearing and equilibrium is ...

vestibulocochlear (VIII) nerve

multiunit smooth muscle is located in the

wall of blood vessels

List the end products of aerobic respiration. Select all that apply.

water ATP carbon dioxide

After a nerve cell responds to a stimulus, the period of time when the cell cannot respond again, regardless of the strength of stimulus, is called the _________ refractory period.

Absolute

When skeletal muscle is producing CO2 and water while making ATP, which chemical process could be active at this time?

Aerobic respiration

Treppe

All of these are correct

Hannah has damaged her left deltoid muscle. Which of the following actions would least likely be affected by the damage?

All the choices are correct (moving her arm medially, rotating her arm at the shoulder, moving her arm laterally)

When a neurotransmitter binds to its receptor and increases the permeability of the postsynaptic membrane to Na+,

An excitatory Postsynaptic potential will result

In the sliding filament theory, ATP is involved in ______.

1. breaking the bond between actin and myosin 2. cocking or energizing the myosin heads 3the uptake of calcium into the sarcoplasmic reticulum at the end of contraction

How many ATP molecules does aerobic respiration produce per glucose molecule?

36

Select all that apply List the functions of the spinal cord. Select all that apply.

It serves as the link between the brain and the PNS. It produces responses through reflex mechanisms. It integrates incoming information.

The sodium-potassium pump is responsible for what portion of the resting membrane potential?

Less than 15mV

In regards to ATP production, __________respiration is more efficient than _________ respiration.

Blank 1: aerobic Blank 2: anaerobic

The hollow space in the center of the gray commissure of the spinal cord that helps to circulate CSF is called the _______, ________ .

Blank 1: central Blank 2: canal

The muscles of the hyoid, skin of the neck, the posterior portion of the head and the diaphragm are innervated by the ________ plexus.

Blank 1: cervical

The spinal cord is divided into 4 segments; they are the _____, _____, _____, and the sacral.

Blank 1: cervical Blank 2: thoracic Blank 3: lumbar

When considering spinal nerves, there are 8 pairs of ________ nerves, 12 pairs of _____ nerves, 5 pairs of ______ nerves, 5 pairs of sacral nerves and 1 pair of ________ nerves.

Blank 1: cervical Blank 2: thoracic Blank 3: lumbar Blank 4: coccygeal

Which color structure represents the Z disks?

Blue

Select all that apply Identify the three layers of meninges.

Dura mater Arachnoid mater Pia mater

Click and drag on elements in order Indicate the correct order of meninges from superficial at the top to deep at the bottom.

Dura mater, Arachnoid mater, Pia mater

When does the sarcoplasmic reticulum release calcium?

Calcium is released when the muscle fiber is depolarized or excited.

Describe what must occur before tropomyosin can move away from the myosin binding sites.

Calcium must bind to troponin

Predict the effects on membrane potential if the membrane's permeability to Cl- increases.

Cl- would diffuse into the cell, causing a hyperpolarization.

Which of the following is not a source of energy for the production of ATP in muscle?

Creatine

List the actions that occur during the process known as cross-bridge cycling.

Cross-bridge release Recovery stroke Power stroke Cross-bridge formation

What is the pia mater?

Deepest meninx that is attached directly to the surface of the spinal cord

When is ATP required by muscle cells?

During both relaxation & contraction

Match the connective tissue component of a nerve with the correct description.

Endoneurium - Delicate layer of connective tissue surrounding a single axon and its Schwann cell sheath Perineurium - Layer of connective tissue surrounding a nerve fascicle Epineurium - A layer of dense connective tissue surrounding a nerve

What causes the cocking of the myosin head into a high energy (cocked) position?

Energy released by hydrolysis of ATP

Hydrocephalus is a condition whereby cerebrospinal fluid accumulates around the brain. Which supportive cells continue CSF production despite it backing up in the subarachnoid space?

Ependymal cells

List the layers of connective tissue surrounding nervous tissue starting with the most superficial layer and ending with innermost layer surrounding an individual Schwann cell sheath.

Epineurium, Perineurium, Endoneurium

True or false: Aerobic respiration does not require oxygen in order to produce ATP.

False

True or false: During the absolute refractory period a neuron will be re-stimulated if it reaches threshold.

False

True or false: In order to initiate contraction, myosin heads must bind a molecule of acetylcholine (ACh).

False

True or false: Once achieved, a single action potential can travel the distance of the entire axon of the neuron.

False

True or false: The spinal cord contains two enlargements. One of these enlargements is found in the cervical area and the other is in the thoracic region.

False (There are two enlargements associated with the spinal cord; the cervical and lumbar enlargements of the spinal cord accommodate extra sensory and motor components for the extremities. There is not an enlargement in the thoracic region.)

What type of reflex prevents contracting muscles from applying excessive tension on tendons by inhibiting muscle contraction?

Golgi tendon reflex

List the steps in contraction of skeletal muscle fibers.

Hydrolysis of ATP Binding of ATP to the myosin head Release of ADP from the myosin head

Where do you find acetycholine?

In synaptic vesicles

List actions of nerves from the brachial plexus. Select all that apply.

Innervate the skin of the medial arm and forearm Supply muscles acting on the scapula and arm

What is the neuromuscular junction?

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

In hyperpolarization

K+ tend to diffuse out of the cell

Predict the effect of increasing a membrane's permeability to K+ on membrane potential.

K+ will diffuse out of the cell, causing a hyperpolarization.

Which of the labeled structures (A -D) represents myofilaments?

Label A

Which of the labeled structures (A -D) represents the transverse (T) tubules?

Label A

Tropomyosin is indicated by which of the labeled structures (A-D)?

Label B

Frank has a microbial infection attacking his brain. Which cell type would you expect to proliferate and be the most active during this time?

Microglia

Ventral roots consist of only _____ fibers (axons).

Motor

If the ventral root of a spinal nerve were cut, The regions innervated by that spinal nerve would experience complete loss of _______

Movement

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

Na+ diffuses into the cell.

Gaps or interruptions in the myelin sheath are called

Nodes of Ranvier

What is the name of the gaps found between segments of myelin along an axon?

Nodes of Ranvier

Sodium is more abundant in which fluid compartment?

Outside the plasma membrane

A patient is having difficulty breathing. Name a nerve could be responsible for this difficulty.

Phrenic nerve

Damage to which of these nerves would be most life-threatening?

Phrenic nerves

Select all that apply Identify the functions of astrocytes. Select all that apply.

Regulation of synaptic activity Promotion of the formation of synapses Synthesis of neurotransmitters

After contraction has occurred, the Ca2+ are

Released from troponin

Spinal nerves exiting the spinal cord from the level of L4 to S4 form the ____ plexus

Sacral

At the onset of exercise when the small ATP reserve in muscle fibers is quickly depleted, _____ occurs next.

direct phosphorylation of ADP

Identify characteristics of smooth muscle. Select all that apply.

Single, centrally located nucleus Gap junctions between visceral cells

Select all that apply Identify the structures innervated by the cervical plexus. Select all that apply.

Skin of the neck Muscles of the hyoid Diaphragm Posterior portion of the head

Name the reflex where muscles contract in response to stretching within the muscle.

Stretch

Select all that apply List actions of nerves from the brachial plexus. Select all that apply.

Supply muscles acting on the scapula and arm Innervate the skin of the medial arm and forearm

What ensures the one-way propagation of action potentials along an axon?

The absolute refractory period

Explain why the propagation of action potentials occurs in one direction.

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

What returns the myosin heads to the "energized" configuration required for another cross-bridge formation?

The binding and hydrolysis of ATP

Select the item that best defines the soma of a neuron.

The cell body of neuron

Due to the pattern of innervation of skeletal muscle, one would except that

The number of muscle fibers and mortar neurons is equal

Select all that apply Identify the regions of the spinal cord. Select all that apply.

Thoracic Cervical Sacral Lumbar

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

Threshold

Select all that apply Identify the nerves that combine to form the sciatic nerve.

Tibial nerve Common fibular nerve

What type of smooth muscle tissue is found within the digestive, reproductive and urinary tracts.

Visceral smooth muscle

Identify why the membrane becomes hyperpolarized following the repolarization phase of an action potential.

Voltage-gated K+ channels remain open for a short period of time after reaching RMP; allowing K+ to diffuse out of the cell.

Which of the following locations have single-unit (unitary) smooth muscle tissue? Select all that apply.

Walls of the esophagus Urinary and reproductive tract

Physiological contracture

is a condition in which cross-bridges cannot release.

During the absolute refractory period, the cell

is insensitive to further stimulation

A synapse is a ______.

junction between two cells

The sarcoplasmic reticulum

stores calcium ca2+

Match the cranial nerves that are only sensory or only Motar Only Sensory Cranial Nerves ______________ Only Motar Cranial Nerves ______________

1, 2, 8 3, 4, 6, 11, 12

Click and drag on elements in order Identify the layers of meninges and the related spaces from most superficial to deepest.

1. Epidural Space 2. Dura mater 3. Subdural Space 4. Arachnoid mater 5. Sub arachnoid mater 6.Pia mater

During a muscle fiber contraction, which decrease in size?

1. H zone 2. entire sarcomere 3. I band

Describe troponin.

1. It is a globular protein composed of three subunits. 2. It is bound to both actin and tropomyosin. 3. It has a binding site for calcium ions.

Click and drag on elements in order Indicate the correct order of events that occur during a single action potential.

1. Local potential decreases membrane potential 2. Threshold is reached 3. Depolarization spike occurs 4. Repolarization occurs 5. Afterpotential occurs 6. Resting membrane potential is reestablished

Click and drag on elements in order Place the steps of muscle relaxation in order.

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

The synaptic vesicles of the presynaptic neuron of the neuromuscular junction ______.

1. contain neurotransmitters 2. contain acetylcholine 3. contain ACh

Myofibrils ______.

1. extend from one end of the muscle fiber to the other and 2. are bundles of protein filaments

Energy from the breakdown of ATP is used to ______.

1. release the cross-bridges 2. move calcium ions into the sarcoplasmic reticulum 3. move the myosin heads during contraction

In order for myosin to initiate contraction ______ must bind to the myosin head.

ATP

In comparing anaerobic respiration with aerobic respiration, which statement is true?

Anaerobic respiration is less efficient than aerobic respiration.

Which type of neuroglia helps promote and regulate synapse formation?

Astrocyte

Explain why Na+ has little effect on establishing the resting membrane potential?

At rest, the membrane is relatively impermeable to Na+ because there are few Na+ leak channels.

Identify the nerve that innervates the deltoid and teres minor and the skin of the shoulder.

Axillary nerve

Match each branch of the brachial plexus with the structure that it innervates.

Axillary nerve - Deltoid, teres minor and skin of the shoulder Radial nerve - Extensor muscles of the arm and forearm and skin of the posterior surface of the arm, forearm and hand Musculocutaneous nerve Anterior arm muscles and the skin of the lateral surface of the forearm Ulnar nerve - Intrinsic muscles of the hand muscles and the skin on the medial side of the hand Median nerve - Pronator and most of the flexor muscles of the forearm, most of the thenar muscles, and the skin of the lateral side of the palm of the hand

Match each nerve of the brachial plexus with the correct region that it innervates.

Axillary nerve - Inferior lateral shoulder Radial nerve - Posterior surface of arm, forearm and lateral two-thirds of dorsum of hand Musculocutaneous nerve - Anterior portion of arm Ulnar nerve - Medial one-third of hand, little finger and middle half of ring finger Median nerve - Lateral two-thirds of palm, anterior thumb, index, and middle fingers, dorsal tips of thumb, index, middle, and ring fingers

Correctly pair each nerve of the brachial plexus with the correct region that it innervates.

Axillary nerve - Part of the shoulder Radial nerve - Posterior portion of arm, forearm and hand Musculocutaneous nerve - Anterior portion of arm Ulnar nerve - Anterior portion of forearm and hand Median nerve - Similar to the ulnar nerve

Match the parts of a neuron with the appropriate description.

Axon ----- Process of a neuron that transmits action potentials away from the cell body Dendrite ----- Process of a neuron that transmits action potentials towards the cell body Collaterals ----- Branches of an axon Presynaptic terminal ------ Enlarged end of axon containing vesicles filled with neurotransmitters Axon hillock ---- Site where the axon originates

The _____ rami of spinal nerves innervate most of the deep muscles of the back and muscles of the trunk responsible for moving the vertebral column.

Blank 1: dorsal

On myelinated axons, small gaps exist between adjacent Schwann cells; these gaps are known as __________ of ____________.

Blank 1: nodes Blank 2: Ranvier

The difference in electrical charge across the plasma membrane in an unstimulated cell is called the __________ ____________ potential.

Blank 1: resting Blank 2: membrane

Dorsal roots consist of only _____ fibers (axons).

Blank 1: sensory or afferent

The reflex where muscles contract in response to stretching within the muscle is called a _____ reflex.

Blank 1: stretch

A nerve plexus is formed when the __________ rami of different spinal nerves intermingle.

Blank 1: ventral

The _________ matter of the spinal cord consists of myelinated axons, and the _________ matter consists of neuron cell bodies.

Blank 1: white Blank 2: gray or grey

Name the plexus which supplies innervation to the muscles acting on the scapula and innervates the skin of the medial arm and forearm.

Brachial plexus

Select the components of the central nervous system.

Brain and spinal cord

tibial nerve

Branches to form the medial and lateral plantar nerves

Which of the following situation occurs in electrically excitable cells?

Depolarization causes voltage gated sodium channels to open

smooth muscle

Depolarizers when both na+ and Ca2+ diffuse into the cell

Select all that apply Which factors contribute to the generation of the resting membrane potential? Select all that apply.

Diffusion of ions down their concentration gradients through the membrane The electrical attraction of cations and anions to each other Selective permeability of the membrane, allowing some ions to pass more easily than others

What are the functions of the axillary nerve? Select all that apply.

It innervates the deltoid and teres minor muscles. It provides sensory innervation to the shoulder joint and to the skin over part of the shoulder.

What term is used to describe a single, brief contraction and relaxation cycle in a muscle fiber?

Muscle twitch

What structure(s) are indicated by the letter A in this illustration of skeletal muscle?

Myofilaments

Which of the following is not a step in the excitation phase of muscle contraction?

Myosin kinase cleaves ATP.

Which of the following is associated with the relaxation phase?

Myosin releases thin filaments. Muscle tension declines. Calcium levels in the cytoplasm fall.

Which statement below best describes why Na+ is highly concentrated outside of neurons and K+ is concentrated within neurons?

Na+ and K+ are actively pumped across the membrane in opposite directions by Na+/K+ pumps utilizing ATP.

Explain why Na+ ions diffuse into the neuron when the Na+ channels open.

Na+ is more concentrated outside the cell than inside; hence, the concentration gradient causes diffusion into the cell.

Predict the effect of increasing a membrane's permeability to Na+ on membrane potential.

Na+ will diffuse into the cell, causing a depolarization.

What is responsible for concentrating K+ inside and Na+ outside of neurons?

Na+-K+ pumps

Identify the function of Golgi tendon reflexes.

Protect muscles and tendons from damages caused by excessive tension

Which is a nerve of the lumbosacral plexus?

Pudendal nerve

During which phase of muscle contraction is calcium transported back into the cisternae and tropomyosin moves back to block the actin active sites?

Relaxation

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

Relaxation

Identify the function of withdrawal reflexes.

Removes a body part from a painful stimulus

The sodium-potassium pump moves the ions in which direction?

Sodium out of the cell and potassium into the cell

Correctly match the parts of a neuron with the correct description.

Soma ---- Also known as the cell body Nissl body ---- Rough endoplasmic reticulum of a neuron responsible for protein synthesis Collaterals ---- Branches of an axon Presynaptic terminal -----Enlarged end of axon containing vesicles filled with neurotransmitters Axoplasm ---- Cytoplasm of an axon

Name the structure that serves as the link between the brain and the PNS.

Spinal cord

Explain how spinal nerves are named.

Spinal nerves are named for the region of the vertebral column from which they emerge.

Which term best describes the concentration gradients for sodium and potassium on an excitable cell?

Steep

What triggers the release of calcium ions from the sarcoplasmic reticulum?

The depolarization of the adjacent transverse tubule

Define acetylcholinesterase.

The enzyme that breaks down the neurotransmitter in the neuromuscular junction

Select all that apply Identify the statements that are true regarding the nature of the large proteins found within neurons. Select all that apply.

They are synthesized inside the cell. They do not readily diffuse through the membrane. They are negatively charged.

What are the transverse (T) tubules?

They are tube-like invaginations of the sarcolemma that extend inward throughout the muscle cell.

In an action potential, what happens to potassium ions during repolarization?

They leave the cell.

In this view of skeletal muscle, what structure is the arrow indicating?

Transverse (T) tubules

Name the blue linear structure in the figure.

Tropomyosin

Which of the following molecules covers the active sites on the G-Actin molecule when the muscle fiber is relaxed?

Tropomyosin

Which of the following events occur during the excitation-contraction coupling phase?

Troponin-tropomyosin changes conformation Calcium binds to troponin Action potential reaches T-tubules

What type of reflex functions to remove a body part from a painful stimulus?

Withdrawal reflex

The filamentous protein network that serves as the attachment site for actin myofilaments is called the _____.

Z disk

The boundaries of the sarcomere are defined by the _____.

Z disks

The central canal of the spinal cord is ______.

a hollow space

The ventral and dorsal rami are branches of _____.

a spinal nerve

A proper definition of muscle tone is

constant tension produced by muscles for long periods of time.

The capacity of a muscle cell to shorten forcefully is known as

contractility

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

Branched cytoplasmic extensions of the neuron that receive input and transmit signals toward the cell body are ______

dendrites

The highly branched cytoplasmic extensions of a neuron cell body that are specialized to receive input and conduct signals toward the cell body are called ______.

dendrites

An increase in a membrane's permeability to Na+ will result in ______________of the membrane.

depolarization or depolarisation

When the resting membrane potential shifts to a more positive value, this is referred to as ________ .

depolarization or depolarisation

During an action potential, an increase in membrane permeability to Na+ leads to a(n) _______ followed by an increase in permeability to K+ that leads to a(n) ______ of the membrane and a slight afterhyperpolarization.

depolarization, repolarization

When the neuron membrane becomes less negative 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

The phrenic nerve innervates the ______.

diaphragm

Damage to the phrenic nerve would result in

difficulty breathing

The sensory root of a spinal nerve is also referred to as ______ root.

dorsal root

The most superficial of the meninges is a thick, tough membrane called the

dura mater

The thickest of the meninges is the

dura mater

The most superficial layer of the meninges is the _____ mater and the deepest layer of the meninges is the _____ mater.

dura; pia

There are ________ cervical spinal nerves.

eight

Synapses in which gap junctions allow ions to diffuse quickly from cell to cell are called ______ synapses.

electrical

Synapses in which gap junctions allow ions to diffuse quickly from cell to cell are called ________ synapses.

electrical

Two areas of the spinal cord are thicker than the rest. These areas give rise to the nerves leading to the limbs. These areas are called the cervical and lumbar ______.

enlargements

An increase in a membrane's permeability to K+ will result in ______ of the membrane.

hyperpolarization

The slow closing of voltage-gated potassium channels is the cause of ______.

hyperpolarization

The part of the diencephalon directly connected to the pituitary gland is the ...

hypothalamus

At rest, the neuron plasma membrane is relatively ______ to Na+; therefore, Na+ does not influence the resting membrane potential very much.

impermeable

Energy released from the hydrolysis of ATP is stored _____.

in the heads of the myosin molecules

When the membrane potential decreases, the inside of the membrane becomes _____ negative. This is called ______.

less, depolarization

The actin and myosin fibers in smooth muscle are arranged in ______.

loose bundles

The concentration of sodium ions is ____________ in the cytosol of the cell at rest than it is in the surrounding extracellular fluid.

lower, smaller, less, lesser, or low

Rapid removal or destruction of neurotransmitter in the synaptic cleft

may affect the ability of the postsynaptic membrane to generate action potentials.

An injury to the wrist that results in Edema in the carpal tunnel would compress the

median nerve

Important centers for heart rate, blood pressure, respiration, swallowing, coughing, and vomiting are located in the

medulla oblongata

The sodium-potassium pump plays a _____ role in maintaining resting membrane potential.

minor

function of pineal gland is to ....

modulate sleep-wake cycle

A junction between a neuron and another cell is called a(n) ________.

synapse

The junction between two neurons is a

synapse

The small, membrane-bound organelles that are found in the presynaptic terminals and which contain neurotransmitters are called _____.

synaptic vesicles

If five action potential's arrive at the same synapse in very close succession, which of the following would occur?

temporal summation occurs

Excitation-contraction coupling refers to ______.

the actions that link the action potential of the sarcolemma to the activation of the myofilament contraction

In order for an action potential to occur, a minimum membrane potential called the _________ must be reached.

threshold

Myosin is also known as the

thick myofilament

dura mater

thick, outermost layer of the meninges surrounding and protecting the brain and spinal cord