Muscle Physiology Flashcards
type of striated muscle attached to the skeleton used to facilitate movment, by applying force to bones and joints by contractions
Skeletal Muscle
type of involuntary mononucliated or uninucleated, striated muscle found exclusively within the heart.
Cardiac muscle
type of non-striated muscle, found with the “walls” of hollow organs such as the bladder, uterus and gastro tract . lines the lumen of the body such as blood vessels
smooth muscle
tiny blood vessels throuhgout the body that connect arteries and veins. form intricate network around body tissues in order to distribute oxygen and nutrients to the cells and to remove waste substances.
capillaries
tubular network that surrounds each individual myofibril and acts as a storage site for calcium within the skeletal muscle
sarcoplasmic reticulum
passes in a transverse manner from the sarcolemma across a myofibril of striated muscle, allowing depolarization of the membrane to quickly penetrate to the interior cell
T-tubules
thin polarized membrane enclosing a striated muscle fiber
sarcolemma
fine connective tissue sheath surrounding a muscle fiber
endomysium
wave-like change in the electrical properties of a cell membrane, resulting from the difference, in electrical charge between the inside and outside of the membrane, causing the muscle cell to contract
action potential
site at which nerve impulses are transmitted to muscles
neuromuscular junction
smallest functional unit of a muscle fiber, composed of contractile myofilaments
sarcomere
a protein complex found in both skeletal muscle and cardiac muscle that relays calcium sensitivity to muscle cells
troponin
group of muscle protein that bind to molecules of actin and troponin to regulate the interaction of actin and myosin
tropomyosin
motor neuron and all of the corresponding muscle fibers it innervates
motor unit
serves as the major energy source within a cell to drive a number of biological processes such as muscle contractions and the synthesis of proteins
adenosine triphosphate (ATP)
myosin head that projects from the surface of thick filaments that bind to the surface of a thin filament (actin) in the presence of calcium ions
cross bridge
sustained skeletal muscle contraction due to repeated stimulation at a frequency which prevents relaxation
complete tetanus
unconscious nerve impulses that maintain the muscles in a partially contracted state
muscle tone
specialized muscle structure innervated by both sensory and motor neuron axons, functioning to send proprioceptive information about the muscle to the central nervous system in response to muscle stretching
muscle spindles
kinesthetic receptors situated near the junction of muscle fibers and tendons which act as muscle-tension regulators
golgi tendon organs
a type of muscle contraction in which the muscles apply enough force to overcome the resistive force so that it shortens as it contracts
concentric contraction
type of muscle contraction in which the resistive force is greater than the force applied by the muscle so that the muscle lengthens as it contracts
eccentric contraction
contraction in which the muscle tension is increased but the joint angle is not changed because the resistance cannot be overcome. also known as static contraction
isometric contraction
largest diameter muscle fiber, characterized by anerobic metabolism and the greatest maximum tension
type 2b fibers
large diameter muscle fiber, characterized by aerobic and anaerobic metabolism. high maximum tension
type 2a fibers
smaller diameter muscle fiber characterized by aerobic metabolism and lower maximum tension
type 1 fibers
oxygen-transporting protein of muscle, resembling blood hemoglobin in function
myoglobin
Used to produce energy
Mitochondria
N/a
Sliding filament Theory
N/a
All or none principle
Causes of short term fatigue (5)
Exhaustion of ATP/CP Decreased muscle pH Insufficient oxygen Reduced enzyme activity Tubular system disturbance
Causes of long-term fatigue (3)
Depleted glycogen and blood glucose levels
Damage to sarcoplasmic reticulum
Depletion of electrolyte ions
Inability to produce force, due to intense exercise - occurring in CNS and PNS
Fatigue
Period between repeated actions in an exercise; energy system specific, based on physical condition
Rest interval/rest period
Period between exercise bouts (visits). Muscle fibers: replenish energy reserves, repair damage from force, return to pre-exertion levels
Recovery period
