Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
the muscular system
| Question | Answer |
|---|---|
| the ability of skeletal muscle to shorten with force | contractility |
| the capability of skeletal muscle to respond to a stimulus | excitability |
| the ability to be stretched | extensibility |
| ability to recoil to their original resting length after they have been stretched | elasticity |
| help to produce heat essential for maintenance of normal body temperature | muscles |
| each skeletal muscle is surrounded by a connective tissue sheath called the | perimysium |
| another connective tissue located outside the epimysium | fascia |
| surrounds and separates muscles | fascia |
| a muscle is composed of numerous visible bundles called | muscle fasciculi (fascicle) |
| muscle fasciculi are surrounded by loose connective tissue called the | perimysium |
| the fasciculi are composed of single muscle cells called | fibers |
| each fiber is a | single cylindrical cell containing several nuclei |
| each fiber is surrounded by a connective sheath called the | endomysium |
| the cytoplasm of each fiber is filled with | myofibrils |
| a thread like structure that extends from one end of the fiber to the other | myofibrils |
| what two kinds of protein fibers do myofibrils consist of | actin myofilaments and myosin myofilaments |
| thin myofilaments | actin |
| thick myofilaments | myosin |
| actin and myosin myofilaments form highly ordered units called | sarcomeres |
| sarcomeres are joined end to end to form the | myofibril |
| the ________ is the basic structural and functional unit of the muscle | sarcomere |
| each sarcomere extends from | one z line to another z line |
| the arrangement of actin and myosin give a | banded appearance |
| the i band is ______ and contains _______ | light and actin |
| the a band extends the length of the | myosin |
| the a band is | darker |
| in the center of each sarcomere is a light area called | the H zone |
| the H zone consists of only | myosin |
| the myosin myofilaments are anchored in the center of the sarcomere at a dark staining band called | the M line |
| the outside of most cell membranes is | positively charged |
| the inside of cell membranes is | negatively charged |
| the charge difference across the membrane is called the | resting membrane potential |
| the brief reversal back of the charge is called | action potential |
| nerve cells that carry action potentials to skeletal muscle fibers | motor neurons |
| each branch that connects to the muscle forms a ______ near the center of the cell | neuromuscular junction or synapse |
| a single muscle neuron and all the skeletal muscle fibers it innervates are called | a motor unit |
| __________ is formed by an enlarged nerve terminal resting in an indentation of the muscle cell membrane | a neuromuscular junction |
| the enlarged nerve terminal is the | presynaptic terminal |
| the space between the presynaptic terminal and the muscle cell is the | synaptic cleft |
| the muscle fiber is the | postsynaptic terminal |
| each presynaptic terminal contains __________ that secrete a neurotransmitter | synaptic vesicles |
| synaptic vesicles secrete a neurotransmitter called | acetylcholine |
| muscle cell is rapidly broken down by an enzymes called | acetylcholinesterase |
| occurs as actin and myosin myofilaments slide past one another causing sarcomere s to shorten | muscle contraction |
| the sliding of actin myofilaments past myosin myofilaments during contraction is called | sliding filament mechanism |
| a contraction of an entire muscle in response to a stimulus that causes the action potential in one or more muscle fibers | muscle twitch |
| a muscle fiber will not respond to stimulus until that stimulus reaches a level called _________ at which point the muscle fiber will contract maximally. | threshold |
| muscle fibers maximally contracted | all-or-none response |
| the time between application of a stimulus to a motor neuron and the beginning of a contraction is the | lag phase |
| time of contraction | contraction phase |
| time during which muscles relax | relaxation phase |
| where the muscle remains contracted without relaxing | tetany |
| the increase in number of motor units being activated is called | recruitment |
| __________ is needed for energy for muscle contraction | ATP (adenosine triphosphate) |
| ATP is 1) 2) | 1) produced in the mitochondria 2) short lived and unstable |
| it is necessary for muscle cells to constantly produce | ATP |
| when at rest they cant stockpile ATP but they can store another high-energy molecule, called | creatine phosphate |
| without oxygen | anaerobic respiration |
| with oxygen | aerobic respiration |
| the ____________ is the amount of oxygen needed in chemical reactions to convert lactic acid to glucose and to replenish the depleted stores of creatine phosphate stores in muscle cells. | oxygen debt |
| results when ATP is used during muscle contraction faster than it can be produced in the muscle cells | muscle fatigue |
| the length of the muscle does not change, but the amount of tension increases during the contraction process | isometric |
| the amount of tension produced by the muscle is constant during contraction, but the length of the muscle changes | isotonic |
| costant tension produced by the muscles of the body for long periods of time | muscle tone |
| contract quickly and fatigue quickly and fatigue quickly | fast-twitch fibers |
| contract more slowly and are more resistant to fatigue | slow-twitch fibers |
| the points of attachment of each muscle are its | origin and insertion |
| the ________ is the most stationary end of the muscle | origin |
| the __________ is the end of the muscle undergoing the greatest movement | insertion |
| the portion of the muscle between the origin and the insertion is the | belly |
| muscles that work together to accomplish specific movements are called | synergists |
| muscles that work in opposition to one another are called | antagonists |
| among a group of synergists, if one muscle plays the major role in accomplishing the desired movement, it is the | prime mover |
| muscles are named according to their | location, size, orientation of fibers, shape, origin, insertion, and function |
| raises eyebrows | occipitofrontalis |
| closes the eyelids and causes " crows feet" wrinkles in the skin at the lateral corners of the eye | orbicularis oculi |
| puckers the lips | orbicularis oris |
| flattens the cheeks trumpeter's muscle | buccinator |
| kissing muscles | orbicularis and buccinator |
| smiling muscle | zygomatius |
| sneering | levator labii superioris |
| frowning | depressor anguli oris |
Created by:
kailiebellomy