Test #2 Flashcards
The summing of many EPSP’s from a single presynaptic neuron over a short period of time is called
Temporal Summation
The white parts on a muscle fiber are
Fat droplets
A muscular contraction that results in a movement of body parts is called _____________
Isotonic Contraction
The most fatiguable muscle fiber type is __________
Type llx
Eccentric muscle contraction is a contraction involving
the lengthening of the muscle fibers
The thin muscle fibers located within the muscle spindle are called
intrafusal fibers
Which of the following neuron is responsible for muscle spindle contraction?
Gamma motor neuron
Nerve fibers that conduct impulses away from the CNS is are called
efferent
Receptors responsile for detection of the motion or position of the body or limb are caused by
propriceptors
True/False? During muscle contraction, the a band in a sarcomere may disappear
False
True/False? Hyperthermia is a factor causing fatigue during prolonged exercise
False
Accumulation of H+ causes
Muscle Fatigue
As we discussed in class, ___________ of a muscle fiber are observed under an electron microscope … a full course of marathon
a ruptured z line
True/False? The neurotransmitter released from the sympathetic nerve ending is norepinephrine.
True
The release of acetylcoline from the axon terminal of an alpha-motor neuron is caused by
increase in Na efflux
The release of ___________ from the axon terminal of an alpha-motor neuron is caused by increase in Na efflux
acetylcoline
During normal body movement, the skeletal muscles perform __________ contraction.
tetanus
In general, a sedentary individual can lose __% of his/her muscle mass by the age of 80
50
the right order of the simplified events in the sliding filament model
Ca binds to troponin -> myosin binds to actin -> power stroke -> ATP binds to myosin -> ….
The amount of force exerted during muscular contraction depends on
the type of motor units recruited
Fast twitch fibers contain
a relatively small number of mitochondria and high ATPase activity
What is the primary energy source in ultra short performances (less than 10sec)?
ATP-PC
True/False? Running economy becomes an increasingly important determinant of success as the duration
of the performance increases.
True
__________ refers to an inability to continue to exercise at a given intensity
Fatigue
What would be the immediate solution for central fatigue?
motivation
Reaction time and skill would be most important for
a sprinter competing in the 100-m dash
Endurance training may result in
increased number of mitochrondria
The skeletal muscle cell membrane (the membrane wrapping an individual cell) is called
sarcolemma
Slight stretching of muscle fibers will
increase cross-bridge interaction of the muscle filaments
In human, strength training can cause
muscle hypertrophy
Which of the following covers myosin binding site on actin as we discussed in class?
tropomyosin
Parasympathetic neurons are located in
brain stem and sacral spinal cord
Which part of the following is responsible for organizing complex movements?
cerebrum
The Cerebrum is responsible for organizing ___________ movements
complex
True/False? Men have more fast-twitch fibers than women do.
True
The resting membrane potential of a neuron is about ___mV
-70
Type I muscle fibers look red due to
the presence of oxygen binding to myoglobin
Muscle spindles provide sensory information relative to
the length of muscle
True/False? The “knee jerk” or stretch reflex is due to rapid stretch of the golgi tendon, which result in reflex contraction of the extensor muscles.
True
The golgi tendon organs monitor
tension produced by muscular contraction
True/False? The muscle spindles are also called “safety device”
False
Stimulation of sympathetic nervous system may cause
increase in energy utilization.
The repolarization is caused by
decrease in Na+ influx and increase in K+ efflux
A successful endurance athlete would likely have a higher percentage of __________ compared to a sedentary individual.
type I fibers
True/False? Recent evidence suggests that rigorous endurance exercise training can result in a conve… fiber type.
True
___________ is the number of muscle fibers per motor neuron AND fine movement control has low innervation ratio.
Innervation ratio
The autonomic nervous system can be divided into two functional divisions called
sympathetic and parasympathetic
True/False? The elevation of sympathetic nervous system cause increase in motility of gastrointestinal (GI) tract
False
True/False? Motor end plate is a part of the neuromuscular junction
False
The ____________ ___________ is the place for Ca2+ storage
sarcoplasmic reticulum
The sarcoplasmic reticulum is the place for ____ Storage
Ca2+
What is in the right order of the skeletal muscle components?
Muscle -> fascicle -> muscle fiber -> myofibril -> filament
The smallest contractile unit in skeletal muscle is a ___________
sarcomere
The change in muscle fiber type would most likely occur as a result of endurance training is
type IIx -> type IIa
The Motor neuron and all the muscle fibers it innervates is called a
motor unit
The two prinicipal contractile protein filaments found in skeletal muscle are
actin and myosin
True/False? At any given velocity of movement, the peak force is greater in muscles that contain a high percentage of fast twitch fibers when compared to muscles that possess predominantly slow twitch fibers
True
Fast-Twitch fibers contain a relatively
small number of mitochondria and high ATPase activity
The trigger to initiate the contractile process in skeletal muscles is
calcium binding to troponin
During the initial period of disuse (i.e., 2 days), muscle atrophy is predominantly due to
decreased protein synthesis
The site where the motor neuron and muscle cell meet is called the
motor unit
True/False? In sprinting type activities, ONLY fast twitch muscle fibers are recruited
True
Calcium is stored in muscle within the
sarcoplasmic reticulum
Type IIx fibers have __________.
high specific tension
The motor neuron and all the muscle fibers it innervates is called a
Motor Unit
The part of the nervous system that controls the Brain and spinal cord is the ____
CNS
The two divisions of the Peripheral nervous system (PNS) are
Sensory and Motor
____________ conduct impulses toward cell body
Dendrites
The ________ carries electrical impulse away from cell body toward another neuron or effector organ.
Axon
____________ __________ formed by Schwann cells; the insulating envelope surrounding the core of an axon and facilitating the transmission of nerve impulses
Myelin sheath
_____________ fibers of the autonomic nervous system are non-myelinated
Postganglionic
Neurons are an “_________ __________”
excitable tissue
____________ ability to respond to a stimulus and convert it to a neural impulse
Irritability
____________ transmission of the impulse along the axon
Conductivity
________ ________ Occurs when a stimulus of sufficient strength depolarizes the cell. Inside becomes more positive (from about -70 to +30mv)
Action Potential
______________ once a nerve impulse is initiated, it will travel the length of the neuron
All or None law
EPSP- Summing from several different presynaptic neurons
Spatial summation
_____ Causes inhibitory postsynaptic potential (hyperpolarization)
Inhibitory postsynaptic potentials (IPSP)
Example: gamma-aminobutyric acid (GABA) opens Cl channels
Inhibitory postsynaptic potentials (IPSP)
IPSP stands for
Inhibitory postsynaptic potentials
At rest, neurons are __________ charged in the interior with respect to the electrical charge outside the cell.
negatively
Neurons communicate with other neurons at junctions called ___________.
synapses
Synaptic transmission occurs when sufficient amounts of a specific neurotransmitter are released from the _________ neuron.
presynaptic
Upon release, the neurotransmitter binds to a receptor on the ___________ membrane.
postsynaptic
____________ - receptors that provide CNS with information about body position. Chiefly located in muscles, tendons, joints, and the inner ear
Proprioceptors
The nickname of muscles spindles are
the length detector
_________________ - Located in tendons.
Monitors tension developed in muscle. Stimulation results in reflex relaxation of muscle.
Golgi Tendon Organ (GTO)
_______________ - Sensitive to changes in the chemical environment surrounding a muscle. Provide CNS about metabolic rate of muscular activity
Muscle Chemoreceptors
_________________ - Located in the inner ear
Responsible for maintaining general equilibrium and balance. Sensitive to changes in linear and angular acceleration
Vestibular Apparatus
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_- is responsible for maintaining postural tone, eye movement & muscle tone, Cardiorespiratory control (contain major autonomic regulatory center (respiratory and cardiovascular system)
Brain stem
