External Intercostals
The Muscles responsible for elevating the ribs during inspiration
Gluteus Medius
The hip muscle commonly used as a site for injections
Cholinesterase
Enzyme that breaks down acetylcholine
Synaptic Cleft
The Space between the presynaptic terminal and postsynaptic membrane
Sarcomere
The basic structural and functional unit of a muscle
Fascia
Connective tissue that separates muscles and surrounds the epiysium
Creatine Phosphate
High energy molecule that can be quickly used to produce ATP
Recruitment of Motor Units
The characteristic that allows muscles to have slow,smooth, sustained contractions.
Slow Twitch Muscle Fibers
Fatigue resistant muscle fibers
Fast Twitch Muscle Fibers
Fatigable muscle fibers
Contractibility
Ability to shorten with a force
Excitability
The capacity to respond to a stimulus
Extensibility
Ability to be stretched
Elasticity
Ability o recoil to original resting length after being stretched.
Epimysium
Connective tissue sheath that surrounds each skeletal muscle
Muscle Fasciculus
Muscle Bundle
Perimysium
Connective tissue that surrounds the muscle fasciculi
Muscle Fiber
Single muscle cell; makes up muscle fasciculi
Endomysium
Connective tissue that surrounds a muscle fiber
Muscle Twitch
Contraction of an entire muscle in response to a stimulus that causes an action potential in one or more muscle fibers
All-or-None response
Below a threshold stimulus a muscle fiber does not contract; a threshold or stronger stimulus causes the muscle fiber to contract maximally
Lag Phase
Time between application of stimulus and the beginning of contraction
Contraction Phase
Time during which a muscle shortens
tetanus
Condition where a muscle remains contracted without relaxing; results from rapid simulation of the muscle
Recruitment
The number of motor units being activated increases
ATP
Molecule used to provide energy for muscle contraction
Aerobic respiration
a type of respiration that requires oxygen and that produces most ATP molecules for each glucose molecule used.
Anaerobic Respiration
Type of respiration that produces lactic acid. Used during short period of intense exercise.
Oxygen Debt
Amount of oxygen needed to convert lactic acid to glucose
Muscle Fatigue
Results when ATP is used during muscle contraction faster than it can be produced in muscle cells, and lactic acid builds up faster than it can be removed.
Insertion
General term for the attachment of a muscle to a bone
Aponeurosis
A broad, sheetlike tendon
Origin
The most stationary end of a muscle; the head.
Tendon
End of the muscle attached to the bone undergoing the greatest movement
Belly
Part of the muscle between the origin and insertion
Synergists
Muscles that work together to accomplish movement
Antagonist
Muscle working in opposition to another muscle
Prime Mover
Muscle that plays the major role in accomplishing a particular movement
Fixator
Muscle that holds a bone in place
Occipitofrontales
Raises the eyebrow
Orbicularious oculi
Closes the eye
Oribcularis Oris
Only purses the mouth
Buccinator
Flattens the cheek
Zygomaticus
responsible for smiling
Levator Labii superioris
Accomplishes sneering
Depressor anguli oris
responsible for frowning