Exam #3
there are fewer motor neurons than skeletal muscle fibers
Due to the pattern of innervation of skeletal muscles, one would expect that
most superficial and thickest meninix
Dura mater
is insensitive to further stimulation
During the asbolute refractory period, the cell
the production of an action potential in the sacrolemma
Excitation coupling begins with
temporal summation
If five action potentials arrive at the same synapse in very close succession, which of the following would occur?
myosin heads bind to exposed active sites on actin
In excitation coupling,
K+ tend to diffuse out of the cell
In hyperpolarization,
threshold
In order for local potentials to trigger an action potential, the membrane must reach a level called the ______
muscles of the arm and forearm
The brachial plexus supplies nerves that function to contract which of the following?
destroyed by cholinesterane
after contraction has occured, the Ca2+ are
median nerve
an injury to the wrist that results in edema in the carpal tunnel would compress the
the deltoid and teres minor muscles
axillary nerves innervates
the trigger zone
axon contains
hamstring muscles
biceps femoris is part of the
nodes of ranvier
gaps or interruptions in the mylein sheath are called
responds to stimulation by the nervous system
muscles exhibit the property of excitbility. this. means that the muscle
thick myofilament
myosin is known as the
lumbar
spinal nerve exiting the spinal cord from the level of L4 to S4 from the ______ plexus
exposure of the active sites on G actin
substance A is to be found to be a competitor with ACH. Which step of muscle contraction physiology would be directyl effected by this substance?
form the medial and lateral plantar nerves
tibial nerve branches to
from node to node on a mylenated fibers
Action potentials are conducted more rapidly when transmission is
yeilds as many as 36 ATP per glucose metabolized produces ATP molecules faster than anerobic respiration
Aerobic respiration
occurs when the local potential reaches threshold level.
An action potential
the ability of a muscle to maintain a contraction against an outside force
A proper definiton of muscle tone is
the nuueron is hyperpolarized
A series of local potentials causes the membrane potential to move to -80 mV. Predict the result
Have straitions
Cardiac muscle cells are like skeletal muscle cells in that they both
difficulty breathing
Damage to the phrenic nerve would result in
Anaroeib
Most important chemical process you need to rely on while running a 50 m dash
is a condition in which cross-bridges cannot release
Phsyiological contracture
the meninix bound tightly to brain and spinal cord
Pia mater
ACH
Synaptic vessicles in the neuromusclar junction contain
an excitory postsynaptic potential will result
When a neurotransmitter binds to its receptor and increases the permeability of the postsynaptic membrane to sodium ions,
As NA+ enter, the inside of the plasma membrane becomes more negative
Which of the following events is NOT a characteristic of action potential?
Depolarization causes voltage-gated Na+ channels to open
Which of the following situations occurs in electrically excitable cells?
Aerobic
Which skeletal muscle is producing CO2 and water while making ATP, which chemical process could be active at this time?
local
a change in resting membrane potential confined to a small area is called a/an ______ potential
innervates the anterior and lateral muscles of the leg
common fibular nerve
rotate the head toward the left
contracting the right sternocledomastoid would
extend and laterally flex the neck
contracting the trapezius muscle would
phrenic nerve
damage to which of these nerves would be most life threatening?
movement
if the ventral root of a spinal nerve were cut, the regions innervated by that spinal nerve would experience a complete loss of
contractility
the capacity of a muscle cell to shorten forcefully is known as
outside, gray matter on the inside, a ventral motor root
the cross-sectional view of the spinal cord reveals white matter on the
ventral
the motor root of a spinal nerve is also referred to as the ______ root
stores ca2+
the sarcoplasmic reticulum
tibial and common fibular nerves
the sciatic nerve is composed of
dorsal
the sensory root of a spinal nerve is also referred as _____root
dura matter
the thickest of the meninges is the
8
there are __________ cervicle spinal nerve
the movement of myosin head while attached to actin myofilament
what is a cross bridge?
repolarizing
when the voltage of a plasma membrane shifts form +35mv towards 0 mv, the neuron is ____
skeletal and cardiac
which type of muscles contain strations?