Final Exam Review: Block XC Module X7 Flashcards
(28 cards)
skeletal muscle is responsible for
voluntary movements
Skeletal muscles are innervated by what?
Motor neurons
The term myofiber is synonymous with what?
Muscle Fiber and Muscle cell
Muscle striation is do to the presence of what muscle cell compartment?
Sarcomeres
when looking at a skeletal muscle with a microscope, the presence of X accounts for muscle striation
Sarcomeres
Sarcomeres allow muscle cells to X and X, and are composed of Myofilaments X and X.
Shorten, Contract, Myosin. Actin
I am a stabilizing protein inside the sarcomere, I help with stability and elasticity! who am I?
Titin
what are three major fundamental properties of Skeletal muscle
Excitability, Electrical conductivity, and contractility.
Steps of skeletal muscle Excitability:
Four steps
ACh diffuses across synaptic cleft > Binds to nicotinic ion channels on motor end plate> Ions channels open - Influx of Na+> end plate potential generated.
i.e. membrane potential
Draw the nicotinic receptore channel when ACh binds
In the motor end plate
Skeletal Muscle slides p.14
Are End plate potentials (EPPs) graded or action potentials?
Graded potentials
Steps for electrical conductivity
Three steps
Influx of Na+ by EPP > voltage gated Na+ channels open > action potential propagated along length of the myofiber.
Steps of Ca+ Release from the Sarcoplasmic reticulum.
Three steps
AP in T-Tubules triggers conf. change of DHPR > Triggers conf change of RyR > Ca+ efflux from Sr to sarcoplasm following its consentration gradient.
RyR blocks movement of Ca+ into the sarcoplasm from. the SR
X controles the movement of Tropomysin
troponin
I bind to x protien that moves x protien so that actin and myosin can interact.
Name the binding compound and both protiens
Ca+, troponin, Tropomyosin.
The interaction between actin and myosin when there is an influx of Ca+ is called what?
Crassbridge cycling
Describe the actin and myosin interaction at rest.
Hint: Three componants
Rest: when there is no Ca+ around
Tropomyosin blocking binding site on actin; ADP+Pi bound to Myosin head; Troponin = unocupied.
Describe the actin and myosin reaction during contraction.
Hint: Three components
Contraction: when Ca+ is present
Troponin binds with Ca+ triggering conf. change > mouves Tropomyosin out of the way. ; Myosin head bind with actin; phosphate realese from myosin head allows powerstroke; actin is pulled towards the centre of the sarcomere and sarcomere shortens.
How does myosin unbind from actin?
ATP binds to the myosin head
This repositions the myosin head so the cycle can continue.
how does contraction stop?
i.e: How does Relaxation Start?
Ca+ is pumped back into the SR via Ca2+ ATPases
when AP occur repedatly sometimes before the end of the prvious this is called.
Temporal summation
As I increase, so does muscle tention.
What am I?
Action potential frequency
Your leg muscles start to exaust towards the end of your morning sprint.
This is an exemple of what phisiological process?
Fused Tetanus
highest AP frequency > max tension within the myofiber causing fatigue.
Spatial summation in regard to muscle phisiology referes to what.
The motor unit network controling the tension of mucles fibers within one or many muscles.
