A &P chapter 9,10

Myotonic dystrophy

A from of muscular dystrophy that is less common than DMD; in the US it affects about 14 of 10,000 people. SYmptoms include a gradual reduction in muscle mass and of the skeletal muscles, abnormal heart rhythm, and diabetes mellitus. May appear at any time; not sex-linked.Underlying genetic defect is multiple repeats of a particular gene on chromosome 19. Because the number of repeat tends to increase from generation to generation, subsequent geenrations develop more severe symptoms. No effective treatment.

Tetanus

A state of sustained contraction of a muscle that is a normal aspect of skeletal muscle functioning. An acute infectious disease caused by the anaerobic bacterium Clostridium tetani and resulting in persistent painful spasms of some skeletal muscles. Progresses to fixed rigidity of the jaws and sapasms of the trunk and limb muscles. Usually fatal due to respiratory failure.

Spasm

A sudden, involuntary twitch in smooth and skeletal muscle ranging from merely irritating to very painful; may be due to chemical imbalances. In spasms of the eyelid and fascial muscles, called tics, psychological factors may be involved, Stretching and massaging the affected area may help end the spasm. A cramp is prolonged spasm, usually occurs at night or after exercise.

Torticollis

A twisting of the neck in which there is a chronic rotation and tilting of the head to one side, due to injury of the sternocleidomastoid muscle on one side; also called wryneck. Sometimes present at birth when the mucle fibers are torn during difficult delivery. Excercise that stretches the affected muscle is the usual treatment. May also be neurological problem that affects the nerves on one side of the head.

RICE

Acronym for rest,ice, compression, elevation. THe standard treatment pulled muscle, or excessively stretched tendons or ligamnets.

Quadriceps and hamstring strains

Also called quad and hamstring pulls, these conditions involve tearing these muscles of their tendons ; happen mainly in atheletes who do not warm up properly and then fully extend their hip or knee. Not painful at first, but pian intesifies within 3 to 6 hours. After an intial rest period, stretching is the best therapy.

Hernia

An abnormal protusion of abdominal contents through a weak point in the muscles of the abdominal wall. Most often caused by increased intra-abdominal pressure during lifting or straining. The hernia penetrates the muscle wall but not the skin and so appears as visible bulge in the body surface, Common abdominal hernias include inguinal and umbilical hernias.

Myopathy

Any disease of a muscle.

Shin splints

Common term for pai nin the anterior compartement of the leg caused by irritation of the tibialis anterior muscle as might follow extreme or unusual excercise without adequate prior conditioning. Because it is tightly wrapped by fascia, the inflammed tibialis anterior cuts off its own circulation as it swells and presses painfully on its own nerves.

Strain

Commonly called a "pulled muscle" a strain ix excessive stretching and possible tearing of a muslce due to muscle overuse or abuse. The injured muscle becomes painfully inflamed and adjacent joints are usually immobilized.

What are the characteristics of muscular dystrophy?

Muscle weakness that begins in the hips, pelvis, and legs. Difficulty standing. Trouble learning to sit independently and walk. Unsteady, waddling gait. Walking on the toes or balls of the feet. Clumsiness, falling often. Trouble climbing stairs.

Myalgia

Muslce pain resulting form any muscle disorder.

Myofascial pain syndrome

Pain caused by a tightened bad of muscle fibers, which twitch when the skin over them is touched. Mostly associated with overused or strained postural muscles.

Charley horse

Painful muscle spasm that results from musle strain or contusion, i.e, tearing of muscle followed by bleeding into the tissues (hematoma) and severe, prolonged pain. A coomon contact sports injury; football players frequently suffer a charley horse of the quadriceps muscles of the thigh.

period of relaxation

Phase of contraction; period during which more crossbridges detach than reattach to thin filaments.

period of contraction

Phase of contraction; period of force generation.

latent period

Phase of contraction; time between muscle fiber stimulation and measurement of force generation.

Hernia

Prostitution of an organ through its body cavity wall. May be cogential, but most often is caused by heavy lifting or obesity and subsequent muscle weakening.

Electromyography

Recording and interpretation of graphic records of the electrical activity of contracting muscles. Electrodes inserted into the muscles record the impulses that pass over muscle cell memebranes to stimulate contraction. The best technique for determing the functions or muscles and muscle groups.

Tennis elbow

Tenderness due to truama or overuse of the tendon of origin of the forearm extensor muscle at the laterla epicondyle of the humerus. Cause and exaggerated when the muscles contract forcefully to extend the hand and wrist--as in executin a tennis backhand or lifting a loaded snow shovel. Despite its name, tennis elbow does not involve the elbow joint; most cases caused by work activities.

Which filaments are composed of myosin?

Thick Filaments

fascicle

a bundle of structures, such as nerve or muscle fibers or conducting vessels in plants

myoglobin

a red protein containing heme that carries and stores oxygen in muscle cells. It is structurally similar to a subunit of hemoglobin

epimysium

a sheath of fibrous elastic tissue surrounding a muscle.

What is a sarcomere?

a structural unit of a myofibril in striated muscle, consisting of a dark band and the nearer half of each adjacent pale band.

deltoid

abducts, flexes, extends arm

glutues medius

abducts, medially rotates thigh

gracilis

adducts thigh; flexes and medially rotates leg

fibromyalgia

also known as fibromyositis; a group of conditions involving chronic inflammation of a muscle, its connective tissue coverings and tendons, and capsules of nearby joints. Symptoms are nonspecific trigger points, as well as fatigue and frequent awakening from sleep.

Orbicularis oculi

closes eyelid

masseter

closes jaw

Orbicularis Oris

closes lip (kissingamd whistling muscle)

external oblique

compresses abdomen; rotates trunk

internal oblique

compresses abdomen; rotates trunk

rectus abdominis

compresses abdomen; rotates trunk

transversus abdominis

compresses abdomen; rotates trunk

genioglossus

depresses and protrudes tongue

sternohyoid

depresses hyoid bone and larynx

tibialis anterior

dorsiflexes and inverts foot

external and internal

draws ribs together; aid in inspiration

extensor digitorum

extends and abducts fingers

extensor carpi radialis longus

extends and abducts wrist

extensor carpi ulnaris

extends and abducts wrist

vastus lateralis

extends and stabilizes knee

extensor hallucis longus

extends great toe; dorsiflexes foot

glutues maximus

extends laterally, rotates andabducts

vastus medialis

extends leg at knee

rectus femoris

extends leg at knee; flexes thigh at hip

semitendinous

extends thigh at hip; flexes knee; medially rotates leg

biceps femoris

extends thigh at hip; flexes leg at the knee

semimembranosus

extends thigh;flexes knee; medially rotates leg

pollicis

extends thumb

extensor digitorium longus

extends toe

latissimus dorsi

extends, adducts, rotates arm medially

triceps brachii

extends,adducts forearm

teres major

extends,rotates, adducts humerus

brachioradialis

flexes arm

biceps brachii

flexes elbow joint; supinates forearm

brachialis

flexes forearm

palmaris longus

flexes wrist

flexor digitorum superficials

flexes wrist and middle phalanges of fingers

flexor carpi radialis

flexes wrist;abducts hand

flexor carpi ulnaris

flexes wrist;abducts hand

pectinues

flexes, adducts, medially roates thigh

pectoralis major

flexes, adducts, rotates arm

sartorius

flexes,abducts, and laterally rotates thigh; flexes knee

T-tubules

is a deep invagination of the sarcolemma, which is the plasma membrane of skeletal muscle and cardiac muscle cells.

sarcolemma

is the cell membrane of a striated muscle fiber cell.

endomysium

meaning within the muscle, is a wispy layer of areolar connective tissue that ensheaths each individual myocyte (muscle fiber, or muscle cell).

serratus anterior

moves scapula forward

isotonic contraction

muscular contraction against resistance in which the length of the muscle changes.

isometric contraction

muscular contraction against resistance in which the length of the muscle remains the same

fibularis longus

plantar flexes and everts foot

flexor hallucis longus

plantar flexes and inverts foot

soleus

plantar flexes foot

gastrocnemius

plantar flexes foot and leg

diaphragm

prime mover of inspiration

pronator teres

pronates forearm

occipitalis

pulls scalp posteriorly

Frontalis

raises eyebrows; wrinkles forehead skin

Zygomaticus

raises lateral corners of mouth upward(smiling muscle)

temporalis

raises mandible; closes jaw

trapezius

raises,retracts, and rotates scapula

What is the major function of the sarcoplasmic reticulum in muscle contraction?

regulate intracelleular calcium concentration

styloglossus

retracts and elevates tongue

sternocleidomastoid

rotates head

infraspinatus

rotates humerus

What creates the striations in skeletal muscle cells?

sarcomeres

Platysma

sheet muscle; facial expressions; depresses mandible; wrinkles skin

What type of muscle cells have the greatest ability to regenerate?

smooth muscle cells

What affects the strength or force of skeletal muscle contraction?

the degree of muscle stretch

Ruptured calacneal tendon

the largest and strongest tendon in the body, its rupture is suprisingly common, particularly in older people as a result of stumbling and young sprinters when the tendon is traumatized durong takeoff. The rupture is followed by abrupt pain; a gap is seen just above the heel,and the calg bulges as the triceps surae are realeased from their insertion. Plantar flexion is weak or impossible, but dorsiflexion is exaggerated. Usually repaired surgically.

perimysium

the sheath of connective tissue surrounding a bundle of muscle fibers.