Muscular system
Sixth event of muscle contraction
Ca2+ binds to tropomyosin
Eleventh event of muscle contraction
Ca2+ is pumped back into the sarcoplasmic reticulum causing myosin binding sites to be covered and muscle activity to cease
Fifth event of muscle contraction
Ca2+ is released from the sarcoplasmic reticulum
Third event of muscle contraction
A muscle action potential (depolarization) is generated which moves alonf the muscle fiber surface
Second event of muscle contraction
ACh diffuses across the synaptic cleft and attaches to receptors on the sarcolemma
Ninth event of muscle contraction
ATP binds to Myosin and is converted to ADP + Pi which re-energizes the myosin heads
First event of muscle contraction
Action potential arrives at the end of the motor neuron
Tenth event of muscle contraction
Cross bridge cycling continues while Ca2+ and ATP are present
Gluteus medius
abducts and medially rotates thigh
Neurotransmitter for skeletal muscle
acetylcholine (ACh)
Adductor muscle
adducts thigh
Perimysium
around a fascle (bundle) of fibers
Endomysium
around a single muscle fiber
Tendon
attaches muscle to bone
Striations
banding pattern due to the overlapping of actin and myosin
H zone
bare zone in the middle that lacks actin filaments
Hamstring group
biceps femoris, semitendinosus, semimembranosus
Myofibril
bundles of myofilaments
Neurotransmitter
chemical released by nerve cell upon arrival of nerve impulse that travels across the synaptic cleft
Pectoralis major
chest muscle
Orbicularis oris
closes and protrudes lips
Orbicularis oculi
closes eyelids
Thin filaments
composed of actin, binding sites for myosin heads
Think filaments
composed of myosin proteins
External oblique
compresses abdomen
Internal oblique
compresses abdomen
Transversus abdominus
compresses abdomen
Buccinator
compresses cheek
Sarcomere
contractile unit of a muscle fiber between two z lines
Isometric contraction
contraction that doesn't move a load, holding something in place
Isotonic contraction
contraction that moves a load
Epimysium
covers the entire skeletal muscle and blends into a connective tissue attachment
Direct phosphorylation
creatine phosphate transfers energy to ADP to regenerate ATP
Deltoid
curve of shoulder
A band
dark band, myosin and actin
Flexion
decreases the angle of a joint
Fourth event of muscle contraction
depolarization to the T tubule
Tibialis anterior
dorsiflexes and inverts foot
Temporalis
elevates and retracts mandible
Masseter
elevates mandible
External intercostals
elevates ribs
Origin
end attached closest to the trunk or the more stationary bone
Extensor carpi radialis longus
extends and abducts wrist
Latissimus dorsi
extends and adducts humerus
Extensor carpi ulnaris
extends and adducts wrist
Extensor digitorum
extends fingers
Triceps brachii
extends forearm at elbow
Vastus lateralis
extends leg at knee
Rectus femoris
extends leg at knee and flexes thigh
Gluteus maximus
extends thigh
Biceps femoris
extends thigh and flexes leg
Semimembranosus
extends thigh and flexes leg
Semitendinosus
extends thigh and flexes leg
Extensor digitorum longus
extends toes and dorsiflexes foot
Sarco
flesh
Rectus abdominis
flexes and rotates vertebral column
Brachialis
flexes elbow
Biceps brachii
flexes forearm
Brachioradialis
flexes forearm at elbow
Sternocleidomastoid
flexes neck, rotates head
Sartorius
flexes thigh at hip
Flexor carpi radialis
flexes wrist and abducts hand
Flexor carpi ulnaris
flexes wrist and adducts hand
Recruitment
force of contraction is increased by recruiting more motor units
Synaptic cleft
gap between the end of a nerve cell and a muscle fiber
Compartment syndrome
increased pressure in a muscle compartment
Plantar fasciitis
inflammation of the thick tissue on the bottom of the foot
Transverse (T) tubules
invaginations of the sarcolemma that allow electrical signals to reach the sarcoplasmic reticulum
Vastus medialis
knee extension
Eccentric action
lengthening contraction, contributes to most cellular damage, delayed onset muscle soreness
Tropinin
lie along the tropomyosin at regular intervals, Ca2+ binds to troponin which moves tropomyosin
I band
light band, actin
Asynchronous recruitment
motor units take turns maintaining muscle tension
Myo and mys
muscle
Synergist
muscle that aids a prime mover in a movement and helps prevent rotation
Antagonist
muscle that opposes or reverses a prime mover
Prime mover
muscle with the major responsibility for a certain movement
Motor unit
neuron and muscle fibers stimulated by that neuron
Fused tetanus
no evidence of relaxation before the following contractions, sustained muscle contraction
Fascia
on the outside of the epimysium
Tetanus
one contraction is immediately followed by another, muscle does not completely return to a resting state
Fibularis longus
plantar flexes and everts foot
Gastrocnemius
plantar flexes foot
Soleus
plantar flexes foot
Sarcolemma
plasma membrane or cell membrane of a muscle cell
Anaerobic glycolysis
pyruvic acid is converted to lactic acid
Frontalis
raises eyebrows, wrinkles forehead
Quadriceps group
rectus femoris, vastus lateralis, vastus medialis
Aerobic respiration
respiration that requires oxygen
Cocentric action
shortening contraction
Twitch
single brief contraction, not a normal muscle function
Zygomaticus
smiling muscle
Sarcoplasmic reticulum
smooth ER of a muscle cell that wraps around myofibrils
Unfused tetanus
some relaxation occurs between contractions
Fixator
stabilizes the origin of a prime mover
Tropomyosin
strands wound around actin that cover the myosin binding sites
Muscle strain
tear in muscle or connective tissue
Occipitalis
tenses and retracts scalp
Platysma
tenses skin of neck
Peristalsis
the involuntary constriction and relaxation of the muscles of the intestine, movements that push the contents forward
Insertion
the more distal or more mobile attachment
Trapezius
upper back
Neuromuscular junctions
where the nerve ends meet the muscle, axon terminal
Eighth event of muscle contraction
Myosin heads bind to the binding sites on actin and the heads pull on the actin causing filaments to slide past each other
Seventh event of muscle contraction
Tropomyosin moves exposing the myosin binding sites on actin