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
