Module 3 Flashcards
A fibrous joint that is a peg-in-socket is called a ________ joint.
gomphosis
A joint united by dense fibrocartilaginous tissue that usually permits a slight degree of movement is a ________.
symphysis
A movement of the forearm in which the palm of the hand is turned from posterior to anterior is supination.
True
A neuron that has as its primary function the job of connecting other neurons is called a(n) ________.
association neuron
A person who has been diagnosed with a sprained ankle has an injury to the ligaments that attach to that joint.
True
A person who has been diagnosed with rheumatoid arthritis would be suffering loss of the synovial fluids.
False
A postsynaptic potential is a graded potential that is the result of a neurotransmitter released into the synapse between two neurons.
true
A resting potential is caused by a difference in the concentration of certain ions inside and outside the cell.
true
A stimulus traveling toward a synapse appears to open calcium ion channels at the presynaptic end, which in turn promotes fusion of synaptic vesicles to the axonal membrane.
true
After nervous stimulation stops, what prevents ACh in the synaptic cleft from continuing to stimulate contraction?
acetylcholinesterase destroying the ACh
All joints permit some degree of movement, even if very slight.
False
Also called a nerve impulse transmitted by axons.
Action potential
Although there are no sarcomeres, smooth muscle still possesses thick and thin filaments.
true
An anaerobic metabolic pathway that results in the production of two net ATPs per glucose plus two pyruvic acid molecules is ________.
glycolysis
An example of an interosseus fibrous joint is ________.
the radius and ulna along its length
An exceptionally strong stimulus can trigger a response.
Relative refractory period
An impulse from one nerve cell is communicated to another nerve cell via the ________.
synapse
An inhibitory postsynaptic potential (IPSP) is associated with ________.
hyperpolarization
An insufficient stimulus.
Subthreshold stimulus
Any stimulus below this intensity will result in no response in a neuron.
Threshold stimulus
Articular cartilage found at the ends of the long bones serves to ________.
provide a smooth surface at the ends of synovial joints
Articulations permitting only slight degrees of movement are ________.
amphiarthroses
Bending of the tip of the finger exhibits flexion.
True
Bending your head back until it hurts is an example of ________.
hyperextension
Bipolar neurons are commonly ________.
found in the retina of the eye
Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system.
true
Collections of nerve cell bodies outside the central nervous system are called ________.
ganglia
Compared to the shoulder, displacements of the hip joints are ________.
rare because of the ligament reinforcement
Connective tissue sacs lined with synovial membranes that act as cushions in places where friction develops are called ________.
bursae
Contractures are a result of a total lack of ATP.
true
Cruciate ligaments are important ligaments that stabilize all ball-and-socket joints.
False
Destroys ACh.
Acetylcholinesterase
Different types of sensory input can have the same ultimate effect.
Converging circuit
During depolarization, the inside of the neuron’s membrane becomes less negative.
true
During vigorous exercise, there may be insufficient oxygen available to completely break down pyruvic acid for energy. As a result, the pyruvic acid is converted to ________.
lactic acid
Eccentric contractions are more forceful than concentric contractions.
true
Efferent nerve fibers may be described as motor nerve fibers.
true
Enkephalins and endorphins are peptides that act like morphine.
true
Ependymal cells ________.
help to circulate the cerebrospinal fluid
Excitation-contraction coupling requires which of the following substances?
Ca2+ and ATP
Extracapsular ligaments stabilizing the knee include ________.
lateral and medial collateral ligaments preventing lateral or medial angular movements
Fatigued muscle cells that recover rapidly are the products of ________.
intense exercise of short duration
“Feel-good” neurotransmitter.
Norepinephrine
Football players often sustain lateral blows to the extended knee. Which of the ligaments is (are) damaged as a result?
medial collateral, medial meniscus, and anterior cruciate
If bacteria invaded the CNS tissue, microglia would migrate to the area to engulf and destroy them.
true
Immediately after an action potential has peaked, which cellular gates open?
potassium
In an isotonic contraction, the muscle ________.
changes in length and moves the “load”
In myelinated axons the voltage-regulated sodium channels are concentrated at the nodes of Ranvier.
true
In symphysis joints the articular surfaces of the bones are covered with ________.
hyaline cartilage
In the classification of joints, which of the following is true?
All synovial joints are freely movable.
Increases acid secretion in the stomach; blocked by cimetidine.
Histamine
Involved in activating fibers of a skeletal muscle such as the biceps muscle.
Diverging circuit
Involved in control of rhythmic activities such as breathing.
Reverberating circuit
Large-diameter nerve fibers conduct impulses much faster than small-diameter fibers.
true
May be involved in complex, exacting types of mental processing.
Parallel after-discharge circuit
Mediates pain.
Substance P
Most skeletal muscles contain ________.
a mixture of fiber types
Movement at the hip joint does not have as wide a range of motion as at the shoulder joint.
True
Muscle contraction will always promote movement of body parts regardless of how they are attached,
false
Muscle tissue has all of the following properties except ________.
secretion
Muscle tone is the small amount of tautness or tension in the muscle due to weak, involuntary contractions of its motor units.
true
Myelination of the nerve fibers in the central nervous system is the job of the oligodendrocytes.
true
Natural opiates that inhibit pain; effect mimicked by morphine.
Endorphins
Neuroglia that control the chemical environment around neurons by buffering potassium and recapturing neurotransmitters are ________.
astrocytes
Neurons in the CNS are organized into functional groups.
true
Numerous nerve impulses arriving at a synapse at closely timed intervals exert a cumulative effect.
Temporal summation
Once a motor neuron has fired, all the muscle fibers in a muscle contract.
false
One incoming fiber triggers responses in ever-increasing numbers farther and farther along the circuit.
Diverging circuit
Pointing the toes is an example of ________.
plantar flexion
Principal inhibitory neurotransmitter of the spinal cord.
Glycine
Reflexes are rapid, automatic responses to stimuli.
true
Saltatory conduction is made possible by ________.
the myelin sheath
Schwann cells are functionally similar to ________.
oligodendrocytes
Select the correct statement regarding synapses.
The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another.
Smooth muscle is characterized by all of the following except ________.
there are more thick filaments than thin filaments
Stimulation of a postsynaptic neuron by many terminals at the same time.
Spatial summation
Strong stimuli cause the amplitude of action potentials generated to increase.
false
Synarthrotic joints ________.
permit essentially no movement
Synovial fluid contains phagocytic cells that protect the cavity from invasion by microbes or other debris.
True
Synovial fluid is a viscous material that is derived by filtration from blood.
True
Synovial fluid is present in joint cavities of freely movable joints. Which of the following statements is true about this fluid?
It contains hyaluronic acid.
Tendon sheaths ________.
act as friction-reducing structures
The all-or-none phenomenon as applied to nerve conduction states that the whole nerve cell must be stimulated for conduction to take place.
false
The articular surfaces of synovial joints play a minimal role in joint stability.
True
The contractile units of skeletal muscles are ________.
myofibrils
The cruciate ligaments of the knee ________.
prevent hyperextension of the knee
The effect of a neurotransmitter on the muscle cell membrane is to modify its ion permeability properties temporarily.
true
The force of muscle contraction is controlled by multiple motor unit summation or recruitment.
true
The interior of the cell becomes less negative due to an influx of sodium ions.
Depolarization
The ligaments that protect the alignment of the femoral and tibial condyles and limit the movement of the femur anteriorly and posteriorly are called ________.
cruciate ligaments
The main effect of the warm-up period of athletes, as the muscle contractions increase in strength, is to ________.
enhance the availability of calcium and the efficiency of enzyme systems
The neuron cannot respond to a second stimulus, no matter how strong.
Absolute refractory period
The major role of ligaments at synovial joints is to help direct movement and restrict undesirable movement.
True
The muscle cell membrane is called the ________.
sarcolemma
The nodes of Ranvier are found only on myelinated, peripheral neuron processes.
false
The oligodendrocytes can myelinate several axons.
true
The only movement allowed between the first two cervical vertebrae is flexion.
False
The oxygen-binding protein found in muscle cells is ________.
myoglobin
The part of a neuron that conducts impulses away from its cell body is called a(n) ________.
axon
The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________.
absolute refractory period
The phenomenon in which the contraction strength of a muscle increases, due to increased Ca2+availability and enzyme efficiency during the warm-up.
Treppe
The sliding filament model of contraction involves ________.
actin and myosin sliding past each other and partially overlapping
The specific period during which potassium ions diffuse out of the neuron due to a change in membrane permeability.
Repolarization
The stimulus above which no stronger contraction can be elicited, because all motor units are firing in the muscle.
Maximal stimulus
The strongest muscle contractions are normally achieved by ________.
increasing the stimulation up to the maximal stimulus
The structural classification of joints is based on the composition of the binding material and the presence or absence of a joint cavity.
True
The substance released at axon terminals to propagate a nervous impulse is called a(n) ________.
neurotransmitter
The term aponeurosis refers to ________.
a sheetlike indirect attachment to a skeletal element
The term central nervous system refers to the ________.
brain and spinal cord
The terms inversion and eversion pertain only to the ________.
feet
The thin filaments (actin) contain a polypeptide subunit G actin that bears active sites for myosin attachment.
true
The warm-up period required of athletes in order to bring their muscles to peak performance is called ________.
treppe
Three discrete types of muscle fibers are identified on the basis of their size, speed, and endurance. Which of the following athletic endeavors best represents the use of red fibers?
a long, relaxing swim
What are ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid called?
ependymal cells
What are menisci?
semilunar cartilage pads
What can cause gouty arthritis?
excessive blood levels of uric acid deposited as crystals in the soft tissue joints
What is moving a limb away from the median plane of the body along the frontal plane called?
abduction
What is the functional role of the T tubules?
enhance cellular communication during muscle contraction
What is the functional unit of a skeletal muscle called?
a sarcomere
What is the role of acetylcholinesterase?
destroy ACh a brief period after its release by the axon endings
What is the role of calcium ions in muscle contraction?
bind to regulatory sites on troponin to remove contraction inhibition
What is the role of tropomyosin in skeletal muscles?
Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules.
What structure in skeletal muscle cells functions in calcium storage?
sarcoplasmic reticulum
When a muscle fiber contracts, the I bands diminish in size, the H zones disappear, and the A bands move closer together but do not diminish in length.
true
When a muscle is unable to respond to stimuli temporarily, it is in which of the following periods?
refractory period
Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials?
voltage-gated channel
Which ligament of the knee initiates the knee-jerk reflex when tapped?
the patellar ligament
Which muscle cells have the greatest ability to regenerate?
smooth
Which of the choices below describes the ANS?
motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands
Which of the following conditions is generally considered a noninflammatory type of arthritis?
osteoarthritis
Which of the following describes the nervous system integrative function?
analyzes sensory information, stores information, makes decisions
Which of the following is a factor that affects the velocity and duration of muscle contraction?
load on the fiber
Which of the following is a true statement regarding gliding movements?
Gliding movements occur at the intercarpal and intertarsal joints.
Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle?
acetylcholine
Which of the following is not a chemical class of neurotransmitters?
nucleic acid
Which of the following is not a function of astrocytes?
provide the defense for the CNS
Which of the following is not a function of the autonomic nervous system?
innervation of skeletal muscle
Which of the following is not a part of the synovial joint?
tendon sheath
Which of the following is not a role of ionic calcium in muscle contraction?
activates epinephrine released from adrenal gland
Which of the following is not a special characteristic of neurons?
They are mitotic.
Which of the following is not a usual result of resistance exercise?
increase in the number of muscle cells
Which of the following is not a way muscle contractions can be graded?
changing the type of muscle fibers involved in the contraction
Which of the following is the correct sequence of events for muscle contractions?
motor neuron action potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments
Which of the following statements defines synchondroses?
cartilaginous joints where hyaline cartilage unites the ends of bones
Which of the following statements is false or incorrect?
Cardiac muscle fibers depend mostly on anaerobic cellular respiration to generate ATP.
Which of the following statements is true?
Striated muscle cells are long and cylindrical with many nuclei.
Which of the following would be recruited later in muscle stimulation when contractile strength increases?
motor units with larger, less excitable neurons
