MIDTERM 1 Flashcards
Beta-adrenergic receptors stimulate the production of cAMP.
True/False
True
During the absolute refractory period, a supramaximal stimulus can bring the cell to threshold.
True/False
False
Once threshold is reached on the postsynaptic membrane, an action potential is generated and propagated over the muscle cell membrane.
True/False
True
In a contracting muscle the Z lines come closer together.
True/False
True
Smooth muscle and skeletal muscle fibers both have their contractions triggered by calcium ions.
True/False
True
Lower motor neurons are found in the lower part of the brain.
True/False
False
The epimysium surrounds the individual muscle cells.
True/False
False
An EPSP is conducted decrementally to the axon hillock, where voltage-gated Na+ and K+ channels are opened to created an action potential in the first segment of the axon.
True/False
True
Adrenergic receptors are found on the surface of postganglionic sympathetic neurons.
True/False
False
Receptors that bind the neurotransmitter at the post-synaptic cell membrane are voltage-gated.
True/False
False
The axons that extend from the autonomic ganglion to the effector organs are called
__________
postganglionic
The ________
tract terminates at the cerebellum.
spinocerebellar
The endocrine and nervous systems are considered
_________
homeostatic regulatory mechanisms.
extrinsic
Contraction of
__________
muscle can be consciously controlled.
skeletal
Rigor mortis in skeletal muscle occurs due to a lack of _________
ATP
The blood-brain barrier results mostly from the action of
________, a type of glial cell.
astrocytes
The paravertebral and collateral ganglia are associated with the
_________ division of the autonomic nervous system.
sympathetic
Multipolar neurons are the most common type and they have several
________ and one axon ending from the cell body.
dendrites
The ________ complex contains three proteins designated as the I, T, and C types.
troponin
The ________ is composed of high concentrations of cell bodies and dendrites which lack myelin sheaths.
grey matter
Which of the following is true of autonomic innervation of effectors?
- ANS stimulation can be excitatory or inhibitory.
- Smooth and cardiac muscle cannot contract without ANS stimulation.
- Ganglia may or may not be present along ANS pathways.
- There are specialized motor end plates at ANS effectors the same as PNS effectors.
ANS stimulation can be excitatory or inhibitory.
The gap of exposed axon in the myelin sheath is the
- neurilemma.
- node of Ranvier.
- sheath of Schwann.
- white matter.
node of Ranvier
Which of the following adrenergic effects is correct?
- heart rate increases
- GI tract motility increase
- GI tract motility increase
- constriction of bronchioles
heart rate increases
The bond between the actin and myosin head is broken when…
- an ATP molecule binds to the myosin head.
- ADP and phosphate bind to the myosin head.
- an ATP molecule breaks down on the myosin head.
- n ATP molecule breaks down on the actin molecule.
an ATP molecule binds to the myosin head
Cells supporting neuron cell bodies in ganglia are termed
- astrocytes.
- ependymal cells.
- satellite cells.
- Schwann cells.
satellite cells
Which of the following organs is dually innervated?
- adrenal medulla
- arrector pili muscles in the skin
- urinary bladder
- most blood vessels
-urinary bladder
What is the role of ATP in muscle contraction and relaxation?
- It is hydrolyzed from the myosin head to attach to actin.
- It causes myosin head to detach from actin.
- It powers the Ca2+ pumps to return Ca2+ to the SR.
- All apply.
All apply
The sodium-potassium pump functions to pump _____.
- sodium ions out of the cell and potassium ions into the cell.
- sodium ions into the cell and potassium ions out of the cell.
- sodium and potassium ions into the cell.
- sodium and potassium ions out of the cell.
sodium ions out of the cell and potassium ions into the cell
What enzyme is needed to start the cross bridging process?
- creatine phosphatase
- kinase
- myosin ATPase
- Ca2+ATPase
myosin ATPase
Which type of cell lines the ventricles of the brain and help produce cerebrospinal fluid?
- microglia
- satellite cells
- ependymal cells
- oligodendrocytes
ependymal cells
What muscle structural and functional unit runs from Z disc to Z disc?
- A band
- I band
- sarcomere
- myofibril
sarcomere
What is the function of acetylcholinesterase?
- binds to nicotinic receptors
- catalyzes resynthesis of ACh
- blocks muscarinic receptors
- catalyzes hydrolysis of ACh to remove it from the synaptic cleft
catalyzes hydrolysis of ACh to remove it from the synaptic cleft
Which of the following is true of axons?
- contain receptive areas
- very thin and short
- originates at the axon hillock on the cell body
- transmits graded electrochemical impulses
originates at the axon hillock on the cell body
An action potential arriving at the presynaptic terminal causes
- sodium ions to diffuse into the cell.
- sodium ions to diffuse out of the cell.
- calcium ions to diffuse into the cell.
- acetylcholine to diffuse into the cell.
calcium ions to diffuse into the cell
Each somatic motor neuron with all the muscle fibers it innervates is a
- fascicle.
- varicosity.
- motor unit.
- sarcolemma.
motor unit
What process is needed to return a membrane to its resting membrane potential with all ions in the correct locations?
- after-hyperpolarization
- all-or-none-law
- Na+/K+ pump
- refractory period
Na+/K+ pump
A ligand is _________________________.
- a small molecule that binds to the alpha subunit of the G-protein.
- a small molecule that binds to a membrane-bound receptor.
- a large molecule that binds to the alpha subunit of the G-protein.
- a large molecule that binds to a membrane-bound receptor.
a small molecule that binds to a membrane-bound receptor.
What is present at the axon hillock that allows the production of action potentials?
- voltage-gated channels
- ligand-gated channels
- muscarinic receptors
- chemical-gated channels
voltage-gated channels
In the neuromuscular junction, acetylcholine
- diffuses across the synaptic cleft and binds to acetylcholine receptors on the postsynaptic muscle fiber.
- is actively transported across the synaptic cleft and binds to acetylcholine receptors on the postsynaptic muscle fiber.
- diffuses across the synaptic cleft and causes calcium ions to diffuse into the postsynaptic muscle fiber.
- diffuses across the synaptic cleft and causes sodium ions to diffuse out of the postsynaptic muscle fiber.
diffuses across the synaptic cleft and binds to acetylcholine receptors on the postsynaptic muscle fiber.
Which molecule blocks the myosin head from binding to actin in a relaxed muscle?
- tropomysin
- troponin
- calcium
- titin
tropomysin
The two major categories of motor neurons include:
- autonomic and skeletal
- skeletal and somatic
- visceral and skeletal
- somatic and autonomic
somatic and autonomic
What type of neuron is found entirely in the CNS?
- sensory neuron
- interneuron
- association neuron
- Interneuron and association neuron are correct.
Interneuron and association neuron are correct
An integrating center sends information to a(n)
- sensor.
- effector.
- brain region.
- neuron.
effector
When a neurotransmitter binds to a nicotinic receptor, the ion channel opens and
- only Na+ diffuses into the cell.
- only K+ diffuses into the cell.
- Na+ diffuses into and K+ diffuses out of the cell simultaneously.
- both Na+ and K+ diffuse into the cell.
Na+ diffuses into and K+ diffuses out of the cell
The pumps that actively transport calcium back into the _______ are called Ca2+ -ATPase pumps.
- transverse tubules
- sarcoplasmic reticulum
- neuromuscular junction
- none apply.
sarcoplasmic reticulum
Which of the following molecules is NOT part of the thin filament?
- actin
- titin
- troponin
- tropomysin
titin
Spatial summation
- occurs when a single neuron releases neurotransmitter rapidly.
- only involves excitatory postsynaptic potentials.
- occurs because of the convergence of many neurons on a single postsynaptic cell.
- only involves inhibitory postsynaptic potentials.
occurs because of the convergence of many neurons on a single postsynaptic cell.
The Na+/K+ pump
- is an example of primary active transport.
- generates a positive membrane potential.
- actively transports 2 potassium ions out of the cell.
- actively transports 3 sodium ions into the cell.
is an example of primary active transport
The prime mover of any skeletal movement is called the
- flexor.
- agonist.
- abductor.
- antagonist.
agonist.
Depolarization occurs because
- potassium ions continue to diffuse out of the cell after the inactivation gates of the voltage-gated sodium ion channels begin to close.
- the extra efflux of potassium ions causes the membrane potential to become slightly more positive than the resting value.
- the increased potassium ion permeability lasts slightly longer than the time required to bring the membrane potential back to its resting level.
- more sodium ions diffuse into the cell than potassium ions diffuse out of it.
more sodium ions diffuse into the cell than potassium ions diffuse out of it.