Chapter 8- Muscles Flashcards
Smooth Muscle
walls of hollowed organs, vessels, respiratory passageways, tapered at each end, branching networks, non striated, involuntary
Cardiac Muscle
wall of heart, intercalated disks, involuntary
Skeletal Muscle
attached to bones, long and cylindrical, multinucleated, heavily striated, voluntary
Functions of Muscular System
Skeletal Movement
Posture Maintenance
Heat Generation
Muscle Tone
steady partial contraction of muscle
Endomysium
Single muscle fiber
Fascicle
group of fibers
Perimysium
wrapped around fascicle
Epimysium
around groups of fascicles or whole muscle
Tendons
attach muscle to bone, fascia extended out
Motor Impulses
impulses traveling away from the CNS towards the muscles
Motor Unit
a single neuron and all the muscle fibers it stimulates
Small motor units
fine movements
Large motor units
broad movements
Neuromuscular Junction (NMJ)
(Synapse) where single nerve cell meets muscle fibers
Motor neuron
Releases neurotransmitter (ACh)
Acetylcholine
diffuses across synaptic cleft, and attach to ACh receptors on motor end plate
NMJ
allows motor neuron to stimulate muscle fiber to become electrically excited
Action potential
stimulates muscle contraction, potential for movement
Excitability
ability to transmit electrical current along the plasma membrane (action potential)
Contractibility
ability to undergo shortening to change in shape becoming thicker
Sarcomere
contracting subunit, via sliding filament mechanism
Myosin
thick filaments
Actin
thin filaments
Regulatory Proteins
troponin, tropomyosin
Calcium
regulates sarcomeric contraction within the muscle cell
Muscle contraction
requires ATP
Anerobic glycolosis
build up of lactic acid and oxygen debt
Partial muscle contraction
muscle tone or tonus
Istonic
no change in tension
muscle length shortens
movement
Isometric
great increase in tension
muscle length unchanged
no movement
Aponeurosis
may attach muscle to bone or other muscles
Origin
attached to the more fixed part of the skeleton
Insertion
attached to the more moveable part
Prime mover
performs the movement
Antagonist
produces an opposite movement
Synergist
“helps” or works with prime mover
Lever
bone
Fulcrum
joint
Force
applied by muscle
Orbicularis oculi
encircles eyelid, closes eye
Levator palpebrae superioris
posterior orbit to upper eyelid, opens eye
Orbicularis oris
encircles mouth, closes lips
Buccinator
fleshy part of cheek, flattens cheek; helps in eating whistling, and blowing wind instruments (trumpeters)
Temporalis
above and near ear, closes jaw
Masseter
at angle of jaw, closes jaw
Sternocleidomastoid
along lateral neck, to mastoid process, flexes head; rotates head toward opposite side from muscle
Trapezius
posterior neck and upper back to clavicle and scapula; raises shoulder and pulls it back, superior portion extends and turns head
Latissimus dorsi
middle and lower back, to humerus; flexes and adducts arm
Pectorals major
superior, anterior chest, to humerus; flexes and adducts arm
Serratus anterior
inferior to axilla on lateral chest; moves shoulder forward; aids in raising arms, punching , or reaching forward
Deltoid
covers shoulder joint, to lateral humerus; abducts arm; flexes and extends arm
Biceps brachii
anterior arm along humerus, to radius; flexes forearm; supinates forearm and hand
Brachialis
deep to biceps brachii, inserts at anterior elbow joint; forceful flexor of forearm
Brachioradialis
lateral forearm from distal end of humerus; flexes forearm
Triceps brachii
posterior arm, to ulna; extends forearm
Flexor carpi group
anterior forearm, to hand; flexes hand
Extensor carpi group
posterior forearm, to hand; extends hand
Flexor digitorum group
anterior forearm to fingers; flexes fingers
Extensor digitorum group
posterior forearm to fingers; extends fingers
Diaphragm
dome-shaped partition between thoracic and abdominal cavities; dome descends to enlarge thoracic cavity from top to bottom
Intercostals
between ribs; elevate ribs and enlarge thoracic cavity
Internal oblique, external oblique, transversus abdominus, rectus abdominus
anterolateral abdominal wall; compress abdominal cavity and expel substances from the body, flex spinal column
Levator ani
pelvic floor; aids defecation
Erector spinae
group of deep vertical muscles between sacrum and skull, extends vertebral column to produces erect posture
Gluteus maximus
superficial buttock, to femur; extends thigh
Gluteus medius
deep buttock, to femur; abducts thigh
Iliopsoas
crosses anterior hip joint, to femur; flexes thigh
Adductor group
medial thigh, to femur; adducts thigh
Sartorius
crosses anterior thigh from ilium to medial tibia; flexes thigh and leg (to sit cross-legged)
Gracilis
pubic bone to medial surface of tibia; adducts thigh at hip; flexes
Quadriceps femoris
anterior thigh, to tibia; extends leg
Hamstring group
posterior thigh, ischium and femur to tibia and fibula; flexes leg ad knee, extends and rotates thigh at hip
Gastrocenemius
posterior leg, to calcaneus, inserting by achilles tendon; plantar flexes foot
Soleus
posterior leg deep to gastrocenemius; plantar flexes foot
Tibialis anterior
anterior and lateral leg, to foot; dorsiflexes and inverts foot
Fibularis longus
lateral leg, to foot; everts foot
Flexor digitorum group
posterior leg and foot to interior surface of phalanges; flexes toes
Extensor digitorum group
anterior surface of leg bones to superior surface of phalanges; extends toes
Spasm
sudden and involuntary contraction
Colic
spasm of visceral muscle
Seizure or Convulsion
spasms in series
Cramps
strong, painful contractions
Atrophy
wasting or decreasing in size
Strains
overuse or over-stretching (charley horse)
Sprains
tearing of ligaments around joint
DOMS
delayed onset muscle soreness
Rhabdomyolysis
life threatening due to serious over training
Muscular dystrophy
deterioration of muscles with intact nerve functions
Myasthenia Gravis
chronic muscle fatigue brought on by slightest exertion, defect in transmission at NMJ
Myalgia
muscle pain
Myositis
inflammation of muscle tissue
Fibrositis
inflammation of connective tissues associated with muscles and joints
Tendinitis
inflammation of tendon
Plantar fasciitis
bottom of foot
Tenosynovitis
synovial sheath enclosing tendon
Shinsplints
tendinitis of tibialis anterior muscle
