HAP Ch 8: Muscular System Review Cards
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126 terms
Terms | Definitions |
|---|---|
 sarcoplasmic reticulum | network of channels that surround each myofibril and runs parallel to it |
| synaptic vesicles | tiny vesicles that stores neurotransmitters |
| flexor carpi radialis | flexes and abducts wrist |
| peristalsis | wave-like motion caused by transmission of impulses from cell to cell and rhythmicity |
| gluteus medius & gluteus minimus | abducts and rotates thigh medially |
| pronator quadratus | rotates forearm medially |
| orbicularis oris | closes and protrudes lips |
| gluteus maximus | extends thigh |
| flexor carpi ulnaris | flexes and abduct wrist |
| extensor carpi ulnaris | extends and adducts wrists |
| biceps brachii | flexes forearm at elbow rotates hand laterally |
| buccinator | compresses cheeks inward |
| myosin | two twisted protein strands with cross-bridges projecting outward along their lengths |
| I bands | light bands, made of actin that attach to Z lines |
| Duchenne muscular dystrophy | -most severe affecting only boys -dystrophin is often missing |
| summation | when twitches combine because a muscle fiber is exposed to a series of stimuli of increasing frequency and becomes unable to completely relax before the next stimulus |
| actin | -a globular structure with a binding site where myosin cross-bridges can attach -proteins: troponin and tropomyosin |
| sarcomere | a segment of a myofibril that goes from one Z line to the next Z line |
| latent period | delay between the time the stimulus was applied and the time the muscle responded |
| A band | dark bands, made of myosin overlapping with actin |
| muscle tone | -partial but sustained contraction -a response to nerve impulses that originate repeatedly from the spinal cord and stimulate a few muscle fibers |
| tetanic contraction | when forceful, sustained contraction lacks even partial relaxation |
| muscle hypertrophy (weightlifting) | -fast fibers, fatigable -fibers produce new filaments -muscle fiber diameter increases |
| motor end plate | specialized area of the muscle fiber by the neuromuscular junction that has numerous nuclei and mitochondria and has an extensively folded cell membrane |
| oxygen debt | equals the amount of oxygen liver cells require to convert lactic acid into glucose and the amount muscle cells require to restore ATP and creatine phosphate to original conditions |
| Charcot-Marie-Tooth Disease | -slowly progressing weakness in the muscles of the ands and feet and decrease in tendon reflexes -extra gene impairs the insulating sheath around affected nerve cells |
| muscles of facial expression | epicranius obicularis oculi obicularis oris buccinator zygomaticus platysma |
| recruitment | when intensity of contractions are increased causing more motor units to become stimulated until all possible motor units in the muscle are activated and the muscle contracts with maximal tension |
| motor neuron | nerve cell that extends outward from the brain or spinal cord and stimulates a muscle to contract |
| closes jaw | massester temporalis |
| all-or-none response | if a skeletal contracts at all, it contracts completely, even though in some cases it many not shorten completely |
| two major types of smooth muscle | -multiunit smooth muscle -visceral smooth muscle |
| muscle fatigue | -a muscle loses its ability to contract -caused by: interruption in muscle's blood supply lack of acetylcholine build-up of lactic acid |
| sustained contraction | produced by both summation and recruitment |
| rhythmicity | a pattern of repeated contractions due to self-exciting fibers |
| threshold stimulus | minimal strength required to cause a contraction |
| myofibrils | contains two kinds of protein filaments: myosin and actin |
| heat production | over half the energy released in cellular respiration is lost as heat |
| atrophy | -decrease in size and strength -capillary networks shrink -mitochondria numbers drop -number of actin and myosin filaments decrease -muscle becomes smaller |
| acetylcholine | -neurotransmitter that stimulates skeletal muscle fibers -causes cisternae to become permeable and Ca2+ diffuse into the sarcoplasm causing troponin and tropomyosin to interact and expose binding sites on actin |
| triceps brachii | extends forearm at elbow |
| Becker muscular dystrophy | -symptoms begin in early adulthood -dystrophin is under produced |
| Limb-girdle muscular dystrophy | -cause weakness in upper limbs -usually noticed in thirties -result of a missing or abnormal DAG |
| acetylcholinesterase | -enzyme that decomposes acetylcholine -prevents a single nerve impulse from continuously stimulating the muscle fiber |
| epicranius | raises eyebrow |
| multiunit smooth muscle | -muscle fibers are separate -found in the irises of the eyes and in the walls of blood vessels -contracts only in response to stimulation by motor nerve impulses or certain hormones |
| twitch | -a single contraction that lasts only a fraction of a second -happens when a muscle is exposed to a single stimulus of enough strength to activate some of its motor units |
| hereditary idiopathic dilated cardiomyopathy | -inherited form of heart failure that begins in your forties -caused by a genetic error |
| endomysium | thin covering that surrounds each muscle fiber |
| perimysium | layer of tissue that extends inward and separate the muscle tissue into small compartments called fascicles |
| ATPase | -globular portion on myosin -enzyme that speeds up the breakdown of ATP to ADP and phosphate releasing energy -puts cross-bridge in a "cocked" position |
| transverse tubules | membranous channels that extend inward from the fiber's membrane to the outside of the muscle fiber and contains extracellular fluid |
| quadriceps femoris group | -extends leg at knee rectus femoris vastus lateralis vastus medialis vastus intermedius |
| tenses abdominal wall and compresses abdominal contents | external oblique internal oblique transversus abdominis rectus abdominis (also flexes vertebral column) |
| levator scapulae | elevates scapula |
| rigor mortis | -partial contraction of muscles that fixes the joints several hours after death -results from an increase in permeability to calcium ions and a decrease in ATP |
| neuromuscular junction | connection between the motor neuron and muscle fiber |
| myoglobin | pigment in skeletal muscle tissue that can combine and store oxygen temporarily |
| visceral smooth muscle | -composed of sheets of spindle-shaped cells in close contact with one another -found in walls of hollow organs -fibers can stimulate each other |
| sliding filament theory | -head of a myosin cross-bridge can attach to an actin binding site and bend pulling actin with it -head can release, straighten and combine with another binding site |
| myopathy | any muscular disease |
| skeletal muscle fiber | -a single cell that contracts and relaxes in response to stimuli -a thin, elongated cylinder with rounded ends -contain large number of nuclei and mitochondria |
| creatine phosphate | stores excess energy released from mitochondria |
| creatine phosphokinase | -enzyme in mitochondria that stores ATP in its phosphate bonds when there is excess -promotes the making of creatine phosphate |
| deltoid | abducts arm, extends or flexes humerus |
| myogram | the recorded movement of a muscle that is stimulated electrically to contract |
| cramp | -painful condition where a muscle undergoes a sustained involuntary contraction -occurs when changes in extracellular fluid trigger uncontrolled stimulation of the muscle |
| hamstring group | -flexes leg and extends thigh biceps femoris semitendinosus semimembranosus |
| supinator | rotates forearm laterally |
| levator ani | supports pelvic viscera and provides sphincter-like action in anal canal and vagina |
| myotonic dystrophy | -causes delayed muscle relaxation -caused by an "expanding gene" so it grows and becomes worse with each generation |
| skeletal muscle fiber | a single cell that contracts and relaxes in response to stimuli |
| skeletal muscle | organ of the muscular system made of skeletal muscle tissue, nervous tissue, blood, and connective tissue |
| smooth muscle | -cells are elongated with tapering ends -lack striations -sarcoplasmic reticulum is not well developed |
| ischiocavernosus | assists function of bulbospongiosus |
| dystrophin | a protein that holds skeletal muscle cells together by linking actin in the cell to glycoproteins called dystrophin-associated glycoproteins or DAGs |
| motor neuron | neuron that transmits impulses from the central nervous system to an effector |
| pectoralis major | pulls arm anteriorly and across chest, rotates humerus, or adducts arm |
| pectoralis minor | -pulls scapula anteriorly and downward -raises ribs |
| tensor fasciae latae | abducts, flexes, and rotates thigh medially |
| extensor digitorum longus | dorsiflexion and eversion of foot and extension of toes |
| pronator teres | rotates forearm medially |
| subscapularis | rotates arm medially |
| extensor carpi radialis brevis | extends wrists and abducts hand |
| serratus anterior | pulls scapula anteriorly and downward |
| gracilis | adducts thigh, flexes, and rotates lower limb medially |
| latissimus dorsi | extends and adducts arm and rotates humerus inwardly or pulls shoulder downward and posteriorly |
| teres major | extends humerus, or adducts and rotates arm medially |
| bulbospongiosus | -male: assists emptying of urethra -female: constricts vagina |
| platysma | draws angle of mouth downward |
| orbicularis oculi | closes eye |
| sartorius | flexes leg and thigh, abducts thigh, rotates thigh laterally, and rotates leg medially |
| tibialis anterior | dorsiflexion and inversion of foot |
| rhomboideus major | raises and adduct scapula |
| adductor longus | adducts, flexes, and rotates thigh laterally |
| coracobrachialis | flexes and adducts arm |
| extensor digitorum | extends fingers |
| peroneus longus | plantar flexion and eversion of foot supports arch |
| superficial transversus perinei | supports pelvic viscera |
| semispinalis capitis | extends head, bends head to one side, or rotates head |
| flexor digitorum longus | plantar flexion and inversion of foot and flexion of the four lateral toes |
| tibialis posterior | plantar flexion and inversion of foot |
| trapezius | rotates scapula and raises arm raises scapula pulls scapula medially pulls scapula and shoulder downward |
| teres minor | rotates arm laterally |
| extensor carpi radialis longus | extends wrist and abducts hand |
| flexor digitorum profundus | flexes distal joints of fingers |
| adductor magnus | adducts, extends, and rotates thigh laterally |
| splenius capitis | rotates head, bends head to one side or brings head into upright position |
| gastrocnemius | plantar flexion of foot and flexion of leg at knee |
| brachioradialis | flexes forearm at elbow |
| supraspinatus | abducts arm |
| peroneus tertius | dorsiflexion and eversion of foot |
| infraspinatus | rotates arm laterally |
| palmaris longus | flexes wrist |
| smooth verse skeletal muscle | (1) acetycholine and norepinephrin can stimulate or inhibit contractions (2) several hormones can stimulate contraction or alter the degree of response (3) slower to contract and relax (4) can maintain forceful contractions longer (5) can change length without changing tautness |
| zygomaticus | raises corner of mouth |
| brachialis | flexes forearm at elbow |
| soleus | plantar flexion of foot |
| as ATP decomposes | energy from creatine phosphate can be transferred to ADP, changing them back into ATP |
| sarcolemma | cell membrane |
| cardiac muscle | -found only in the heart -intercalated disks -self-exciting and rhythmic -transverse tubules are larger -composed of striated cells joined end to end forming fibers that interconnect in branching, 3-D networks -each cell contains actin and myosin |
| epimysium | layer of tissue that surrounds the skeletal muscle |
| sarcoplasm | cytoplasm |
| sternocleidomastoid | pulls head to one side, pulls head toward chest, or raises sternum |
| muscle hypertrophy (swimming & running) | -slow fibers, fatigue-resistant -more mitochondria -more extensive capillary networks |
| flexes thigh | psoas major iliacus |
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