Term
| What are the 2 types of cells in the nervous system? |
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Definition
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Definition
| Generate and transmit action potentials along an axon to the synapse with another cell |
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Definition
| A bundle of axons from different neurons |
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Definition
| Produce Myelin and insulate axons in the central nervous system |
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Definition
| Produce Myelin and insulate axons in the peripheral nervous system |
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Definition
| contribute to the blood brain barrier which protects the brain from toxic chemicals in the blood |
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Definition
| Provide the central nervous system with immune defenses |
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Definition
| Neural network: Carry sensory information into the nervous system |
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Definition
Neural network: carry commands to Physiological and behavioral effectors
-muscles & glands |
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Definition
integrate and store information and
communicate between the afferent and efferent neurons |
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Definition
| Neural network: clusters of neurons with similar characteristics or functions |
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Term
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Definition
| Neural network: the centralized integrative center of the nervous system |
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Definition
| Neural network: site where many nerve cells are found in vertebrates (along with the brain) |
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Definition
| The brain and spinal cord |
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Term
| Peripheral Nervous System (PNS) |
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Definition
| Nerve cells that are not in the brain or spinal cord |
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Term
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Definition
| A specialized type of junction where a neuron meets its target cell and passes information along |
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Term
| Target cells can be either |
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Definition
a preysynaptic neuron
a postsynaptic neuron |
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Term
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Definition
| They generate and transmit signals called action potentials |
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Term
| what is the membrane potential? |
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Definition
| Difference in charge across the plasma membrane of a cell |
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Term
| What alters the membrane potential? |
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Definition
1)pumping ions against a concentration gradient
2)ion channels let ions back into the cell |
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Term
| what can generate an action potential? |
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Definition
| sudden changes in sodium and potassium channels |
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Term
| What is resting potential? |
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Definition
| the membrane potential of a living cell at rest. The interior is negative with respect to the exterior |
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Term
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Definition
| A change in the resting potential of a cell in which the interior becomes less negative(or even positive) compared to the exterior |
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Term
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Definition
| a change in the resting potential of a cell in which the interior becomes more negative compared to the exterior |
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Term
| What does the threshold do? |
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Definition
| it ensures there is an all or nothing response to nerve stimuli which ensures the max. value is always reached |
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Term
| what is a self regenerating action potential? |
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Definition
| local currents flow to adjacent regions of the plasma membrane, bringing those areas to threshold as well |
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Term
| How do action potentials move? |
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Definition
| They are directional, they travel down the entire length of the the axon |
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Term
| What do Myelinated neurons do? |
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Definition
have gaps called nodes of Ranvier that can speed action potentials along an axon
ex:Saltatory conduction |
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Term
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Definition
| axon releases neurotransmiters directly into the synapse when the action potential reaches it, and the post synaptic membrane responds |
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Term
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Definition
the action potential spreads
directly from a presynaptic cell to a postsynaptic cell |
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Term
| Even though electrical synapses are fast, why don't they integrate information well? |
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Definition
1)they contain numerous gap junctions through which the action potential travels
2)Signal is not unidirectional
3)very few are in vertebrate nervous system |
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Term
| Why is turning off a neurotransmitter just as important as turning it on? |
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Definition
1)enzymes may destroy the neurotransmitter soon after its release into the synapse
2)alternatively, neurotransmitter may diffuse away from the synapse, or be taken up by nearby cells |
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Term
| What do sensory receptors do? |
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Definition
| converts physical and chemical stimuli into neural signals |
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Term
| How do sensory receptors convert chemical & physical stimuli into neural signals? |
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Definition
1)Sensory receptor proteins receive a signal
2)Receptor protein opens or closes ion channels in the cell
- releases neurotransmitter or creates
an action potential |
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Term
| What does sensation depend on? |
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Definition
| which neurons receive action potentials from sensory cells. Cell receptors vary among cells, and only those with proper receptors will recognize the signal |
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Term
| How do sensory cells adapt? |
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Definition
| give gradually diminishing responses to repeated stimulation |
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Term
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Definition
| receptor proteins that bind to various molecules |
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Definition
| chemical signals used to communicate with other individuals |
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Definition
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Term
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Definition
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Term
| What does olfaction depend on? |
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Definition
chemoreceptors on cells in the epithelial
tissue at the top of the nasal cavity |
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Term
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Definition
a molecule that activates an olfactory
receptor protein (usually very specific) |
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Term
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Definition
bulbs formed from clusters of axons
from neurons expressing the same receptor
proteins |
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Term
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Definition
| clusters of chemoreceptors |
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Term
| Where are taste buds located in most terrestrial vertebrates? |
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Definition
in the mouth
-humans have aprox. 10,000 |
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Term
| Where do aquatic vertebrates have their taste buds? |
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Definition
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Term
| what are the 5 main tastes humans can recieve |
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Definition
| bitter, salty, sweet, sour, umami |
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Term
| How does one taste subtle flavors in food? |
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Definition
| using a combination of olfaction and gustation |
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Definition
sensory receptors that respond to mechanical forces.
-Often involve neurons that are associated with hairs. Movement of the hair stimulates the neuron |
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Term
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Definition
| mechanoreceptor in the skin: adapt slowly, and provide continuous information about things touching the skin |
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Term
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Definition
| Mechanoreceptor in the skin: adapt rapidly, and provide information about changes in things touching the skin |
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Term
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Definition
| Mechanoreceptor in the skin: adapt slowly, and provide information about low frequency vibrations |
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Term
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Definition
| Mechanoreceptor in the skin: adapt rapidly, and provide information about high frequency vibrations |
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Definition
| modified muscle cells embedded in connective tissue in muscle and innervated by sensory neurons |
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Definition
| found in tendons and ligaments and provides information about the force generated by a contracting muscle |
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Term
| How do mechanreceptors in auditory systems work? |
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Definition
use hair cells to convert pressure waves into receptor potentials.
-Auditory systems gather sound waves, direct them toward the sensory organ, and amplify their effect on the mechanoreceptors |
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Term
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Definition
| Air filled cavity between the tympanum and the inner ear |
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Term
| what is the middle ear connected to? |
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Definition
| the throat via Eustachian tubes |
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Term
| What does the middle ear do? |
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Definition
Equilibrates pressure in the middle ear with the pressure outside.
-Ossicles transmit vibrations of the tympanic membrane to the oval window of the inner ear (malleus, incus, and stapes) |
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Definition
| inner ear canal that is responsible for maintaining balance |
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Definition
a tapered and coiled, fluid filled chamber
composed of three parallel canals that is
responsible for hearing (located in the inner ear) |
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Term
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Definition
In the inner ear: separates the vestibular
canal and middle canal |
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Term
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Definition
| located in the inner ear: separates middle canal from the tympanic canal |
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Term
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Definition
| located in the inner ear: is positioned on the basilar membrane and contains hair cells with cilia that convert pressure waves into action potentials |
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Term
| What 2 categories does hearing loss fall into? |
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Definition
Conduction defenses
Nerve defenses |
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Term
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Definition
| caused by the loss of function of the tympanic membrane or ossicles in the middle ear |
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Term
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Definition
caused by damage to the inner ear or auditory pathways
-often occurs from repeated exposure to loud sounds |
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Term
| Why are hair cells sensitive to being bent? |
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Definition
bending in one direction causes depolarization
bending in the other direction causes hyperpolarization.
Can detect gravity and momentum.
Are evolutionarily conserved (e.g.,lateral line) |
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Term
| What do light sensory systems rely on? |
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Definition
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Term
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Definition
| pigment molecules that absorb light photons and transduce neural signals |
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Term
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Definition
light sensitive cells in the retina that are
responsible for black and white vision |
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Term
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Definition
photoreceptor cells in the retina that are
responsible for color vision.
-three types absorb different wavelengths of light |
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Term
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Definition
| concentrated photoreceptor cells |
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Term
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Definition
| eyes that consist of many optical units called ommatidia |
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Term
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Definition
| eyes that can form images of the visual world |
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Term
| How did convergent evolution occur? |
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Definition
| with image forming eyes evolving separately in vertebrates and mollusks |
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Term
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Definition
| muscle involved in many voluntary and involuntary movements |
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Term
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Definition
| responsible for contractions of the heart |
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Term
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Definition
involuntary muscles responsible
for movement of many hollow internal organs |
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Term
| What do muscle fibers consist of? |
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Definition
contractile proteins:
1)Actin:thin filaments
2)Myosin:thick filaments
Actin and myosin filaments slide past each other in a ratcheting motion when muscles contract |
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Term
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Definition
bundles of actin and myosin filaments
arranged in an orderly fashion |
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Term
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Definition
repeating units of a myofibril that have
distinct banding patterns |
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Term
| How does smooth muscle contract? |
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Definition
| All cells contract simultaneously |
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Term
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Definition
simultaneous contraction of smooth
muscle to force food through the digestive tract (smooth muscle) |
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Term
| what plays a important role in smooth muscle contraction? |
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Definition
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Term
| How are muscle twitches measured? |
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Definition
by the tension or force generated when a
muscle contracts |
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Term
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Definition
| one motor neuron innervates only one or a few muscle fibers |
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Term
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Definition
| one motor neuron innervates an entire bundle of muscle fibers |
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Term
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Definition
continuous activation of the contractile
machinery |
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Term
| what are slow twitch fibers controlled by? |
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Definition
Red muscle: Cells contain the protein myoglobin, many mitochondria, and are surrounded by many blood vessels, resulting in high levels of oxygen metabolism.
-Maximum tension is low, so they are resistant to fatigue and good for long term aerobic work |
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Term
| what controls fast twitch fibers? |
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Definition
White muscles: Cells contain few mitochondria, have little myoglobin, and are surrounded by few blood vessels. Maximum tension is high, but these fibers fatigue easily.
-Contraction can only be maintained for short bursts because these fibers cannot generate ATP as readily as slow twitch fibers |
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Term
| A muscle has an optimal length for achieving what? |
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Definition
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Term
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Definition
no overlap between actin and
myosin filaments means no cross bridges form and no force is generated |
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Term
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Definition
| z-lines overlap so no force is generated because the muscle cannot get any shorter |
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Term
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Definition
| Increases muscle strength and endurance |
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Term
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Definition
maximum force a muscle exerts
-strength training |
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Term
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Definition
work capacity or length of time a given workload can be sustained
-Aerobic exercise |
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Term
| What is muscle performance limited by? |
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Definition
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Term
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Definition
| uses preformed ATP and creatine phosphate |
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Term
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Definition
| metabolizes carbohydrates to lactate and pyruvate (i.e., fermentation) |
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Term
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Definition
| metabolizes carbohydrates or fats all the way to H2O and CO2 |
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Term
| what is the skeletal system? |
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Definition
| rigid support structure that muscles can contract against |
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Term
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Definition
| volume of fluid enclosed in a body cavity surrounded by muscle |
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Term
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Definition
| a hardened outer surface to which muscles can attach |
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Term
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Definition
| an internal skeleton to which muscles can attach and pull against |
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Term
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Definition
| stiff yet flexible connective tissue |
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Term
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Definition
rigid component of vertebrate skeletal
systems that contains an extracellular matrix of insoluble calcium phosphate crystals and collagen |
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Term
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Definition
| forms on a scaffold of connective tissue membrane |
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Term
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Definition
forms first as a cartilagenous structure
resembling the mature bone, then ossifies to become bone |
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Term
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Definition
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Term
| Cancellous bone structure |
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Definition
| rigid, but pores give it a spongy appearance |
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Term
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Definition
a cell that lays down the protein matrix
of bone: formation |
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Term
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Definition
an osteoblast that has been enclosed in
lacunae (cavities) within the bone it has built: metabolism, nutrient/waste exchange |
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Term
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Definition
a cell that dissolves bone: resorption &
degradation of existing bone |
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Term
| when do bones and muscles work together? |
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Definition
around joints where two (or more) bones come together.
-Different joints allow motion in different directions |
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Term
| How do muscles move joints? |
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Definition
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Term
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Definition
| the muscle that bends the joint |
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Term
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Definition
| the muscle that extends the joint |
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Term
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Definition
| flexible bands of connective tissue that hold bones together at the joint |
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Term
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Definition
| straps of connective tissue that attach muscles to bones |
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Term
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Definition
as levers that have an effort arm and a load arm working together around a fulcrum.Force depends on the ratio between effort and load arms.
-A high effort to load arm ratio yields great force
-A low effort to load arm ratio results in low force |
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