MSKS Physiology Lecture 2_Muscle Phys Part 1 Flashcards
What is a common sign of Duchenne’s muscular dystrophy
pseudohypertrophy of the calf muscles which is due to an inflammatory response generated by the damaged muscle cells and the replacement of damaged muscle cells with scar tissue. This results in muscles that are relativly weak
Describe the Neuromuscular junction
Neuromuscular junction is a chemical synapse formed by the contact between a motor neuron and a muscle fiber. It is at the neuromuscular junction that a motor neuron is able to transmit a signal to the muscle fiber, causing muscle contraction
How are longitudinal muscle forces transmitted to the tendon?
By the myotendinous junction
What is Troponin C
Troponin C binds Ca2+ and is found only in striated muscle.
What is a triad junction?
T-tubule membrane and its two neighboring cisternae (butons of the SR)
What is Troponin T
Troponin T binds the complex to tropomyosin.
What are the eight steps of How a signal is transferred to the muscle to contract?
How are lateral muscle forces transmitted?
Through Costameres which include the dystrophin–glycoprotein complex (dystrophin attaches periferal thin filiments to the sarcolemma) and the integrin–vinculin–talin complex (this includes desmine which attaches the z line to integrins)
What are Muscle spindles?
They are afferent sensory receptors that are located in muscle. Their function is to detect changes in muscle length and the speed of change in muscle length.
What is Troponin I
Troponin I inhibits the binding of myosin to actin.
How is the Ca gradient between the cytosol and SR reduced?
The consentration of free Ca within the SR is reduced by Ca binding to calreticulin and calsequestrin
Describe the 5 steps of the myosin actin cross bridge cycle
Define the following parameters for glycolitic fast twitch, oxidative fast twitch, and oxidative slow twitch muscles.
