Ch 11 Flashcards
Bilateral action of erector spinae muscles
Maintain posture
Extend the vertebral column
Muscles in rotator cuff
Supraspinatus
Teres minor
Subscapularis
Muscles in quadriceps
Rectus femoris
Bastia intermedius
Vastus lateralis
Muscles in hamstrings
Biceps femoris
Semimembranous
Action of gluteus maximus
Extension of thigh
Diaphragm
Internally placed, some-shaped muscle that forms a partition between the thoracic and abdominal cavities
Antagonist
Triceps brachii is stretched as you flex your forearm at the elbow
Agonist
Triceps brachii contracts to extend the forearm
Synergist
Biceps brachii and brachioradialis contract to flex your forearm at the elbow
Masseter
Most powerful muscle of mastication
Elevates and protracts the mandible
Small motor units
Greater control
Fine motor skills
Larger motor units
Less control
Muscle fiber parts
Synaptic knob (end of axon)
Motor end plate
Synaptic cleft
Acetylcholine (ACh)
Neurotransmitter
Sends signal to nerve
Motor end plate
Specialized region of the sarcolemma of muscle fiber
Chemically gated, channels open when ACh binds
Synaptic cleft
Narrow space separating the synaptic knob and motor end
Legs muscles in anterior compartment
Dorsiflexors and toe extensors
Leg muscles in lateral compartment
Evertors and weak plantar flexors
Muscles in posterior compartment
Plantar flexors and flexors of leg and toes
Myoglobin
Protein that binds oxygen when the muscle is at rest and release oxygen during contraction
Short term supply
Glucose available from glycogen
50-60 sec
Long term supply
Aerobic cellular respiration
5-6 min
Fast twitch
Strong contraction
quick and powerful
Short duration
Slow twitch
Weak contraction
Slow and weak
Long duration
Slow oxidative
Slow, fatigue resistant
Maintains POSTURE
Fast glycolytic
Fast twitch
Easily fatigue
Short duration
Sprinting or weightlifting
