test 2 Flashcards
The ____________ nervous system is made up of the brain and spinal cord
Central nervous system
When a neuron is at its resting potential, opening a Na+ ion channel results in net
movement of Na+
into the cell by facilitated diffusion
The channels which are most important in determining the resting potential are:
open channels for sodium
=
=
no
no
A neuron in a lower limb transmitting a signal from within a nerve to the central
nervous system is best classified as a(n)
sensory or afferent neuron
The channels which either open or close in response to a neurotransmitter are called
ligand or chemically-gated channels
A C.N.S. neuroglia cell having little feet and can help support endothelial cells
making up the blood-brain barrier are called
astrocytes
at the peak of an action potential
sodium -gated channels close potasium voltage-gated channels open
Which of the following structures house voltage-gated protein channels necessary
for carrying an action potential along the entire length of an axon:
nodes of Ranvier
A neuron which is unipolar has _______ process(es) extending from its
cell body (soma) surface and functions as a ___________ neuron
1, sensory
in order for the brain to send an impulse to the biceps muscle the action potential
must normally pass through
cell bodies and axons of afferent (sensory) axons
Which of the following types of neurons has its cell body located in a ganglion?
afferent (sensory) neuron
nerve fiber is unresponsive to a stimulus of normal strength, however it responds
when the strength of the stimulus is increased. The membrane is in the
relative refractory period.
What is the role of calcium in muscle contraction?
It binds to troponin to expose a myosin binding site.
You have been selected by your peers to explain about how the molecules found
within the I-band of a sarcomere work. Which protein should you speak about?
actin
Tropomyosin and troponin
help to regulate the contractile cycle.
p
k
. Which of the following units of muscle is larger than a myofibril, but smaller than
a muscle fascicle?
myofiber
suppose that a muscle fiber was stimulated to the point that Ca2+ ions were in high
concentration within the sarcoplasm, but there is no ATP circulating from inside the
cell. What state would the muscle fiber be in?
. rigor
Detachment of the cross-bridges connecting the myosin heads to actin is
dependent upon:
ATP
hich of the following structures is NOT associated with individual sarcomeres:
motor end plate
Myasthenia Gravis is an autoimmune disorder causing antibodies to target and
destroy acetylcholine receptors located on the motor end plates of skeletal muscle.
One of main problems associated with this condition is that
Na+ ions will not be able to gain entry to the muscle cell through chemical gates
Which of the following molecules can myosin attach to?
Not atp adp or actin
Which of the following terms is correctly paired with its connective tissue covering?
muscle cell-endomysium
u read an article about venomous snakes. You learn about a rare snake producing
a poison that blocks calcium pumps in the sarcoplasmic reticulum of skeletal
muscle cells. As a result, Ca2+ ions accumulate in the sarcoplasm and cannot be
pumped back into the sarcoplasmic reticulum for proper storage. For anybody who
is exposed to the venom, which one of the following processes will most likely be
affected
The ability of muscle fibers to stretch and relax
When acetylcholine is released by a somatic motor neuron at the neuromuscular
junction, it stimulates a skeletal muscle fiber to depolarize. Which type of channel
does acetylcholine stimulate to open
chemical-gated Na+ ion channels
Starting with the heart muscle proper, or myocardium, arrange the layers within the
heart wall in the correct order from deepest to most superficial in position
myocardium, epicardium, parietal pericardium, fibrous pericardium
