Muscle physiology Flashcards
Contraction are units in the muscle fibres
the sarcomeres
Which protein protects the sarcomeres before over-stretching?
Titin
Which protein determines the direction of actin polymerization?
Titin
Which protein forms in the sarcomere Z band?
Alpha-actinin
After the troponin- C calcium is bound…
It is activated and moves the Tropomyosinfaser into the pit of Actinfilmanents
The function of troponin T
Attaching the troponin complex to tropomysinfaser into the pit of Actinfilaments
The cross-bridge cycle is set by the following reaction in motion:
the calcium signal
If in the course of the cross-bridge cycle, ATP is completely consumed, then…
created an ongoing and inactive state of contraction (rigor mortis)
In the case of calcium deficiency
relaxes the muscle that traps for myosin heads bind to actin are covered by tropomyosin
Magnesium is important in muscle work, since the presence of magnesium requirement for
is the ATPase activity of Myosinkopfes
At the end of muscle contraction
is the myosin heads on the lowest energy level (energy rest)
Electromechanical coupling we call
the process of the formation of the muscular action potential until complete muscle contraction ( and subsequent relaxation)
During the Calcium transient
Increases in sarcoplasmic the free calcium contraction a thousand times, in parallel, the mechanisms are already well placed for transport back in gear
The conversion of the incoming electrical signal (AP) in a chemical signal (CA signal) occurs in skeletal muscle at the following location:
in the Triad
The scale of the calcium concentration of intramyoplasmatischen space at rest can be measured?
micromol/ l
Which ino channel is the voltage-dependent part of the triad?
L-type (dihydopyridine by inhibited) calcium channel
Which of the below is one of the mechanisms that climinate from the Myoplasma calcium?
Na+ / Ca2+ antiporter
During muscular work follwoing precesses require ATP:
The function of contraction units and the removal of calcium from the space intrmyoplasmatischen
ATP is required during muscle activity …
Both for muscle contraction, and for the relaxation of
The energy reserve for the short, intense muscle work is
creatine phosphate
Case of high load, the energy supply to the muscle, especially by one of the process listed below will be saved:
anaerobic glycolysis
The energy reserve for the long-lasting muscle work is
glucose
It is characteristic for the contraction of skeletal muscle:
asynchronous activities ( asynchronous ‘impulse’) of cross bridges
It is the characteristic of the red muscle fibres:
oxidative metabolism
It is characteristic of the white muscle fibres:
ATPase type: fast
What is an isotonic muscle contraction?
muscle shortening at constant tension of the muscle fibres
What is an isometric muscle contraction?
no muscle shortening with increasing voltage to the muscle fibres
What are the mixed contraction of the muscle fibres?
auxotonische contraction, support contraction, contraction stop
We speak of spatial summation, if
the increase in muscle contraction as a result of the added contractions of several muscle fibres comes about.
What is the cause of the ‘stairs’ phenomenon?
The result of the repeated stimuli to enhancing effectiveness of the ion channels
When producing the red, slow and tonic muscles the most heat?
during the active contraction
For the heat production of the fast glycolytic muscle fibres, it is characteristic:
the initial heat is much greater than the recovery of the heart
Signs of muscle fatigue
is the amplitude reduction of the shortening and extending the shortening duration
The reason for the central muscle fatigue can be:
the exhaustion of the motor unit: B
What characterises muscular atrophy?
because of extended inactivity are the catabolic processes in the myofibrils faster than the Anabolic
What causes directly caused the action potential at Myolemm in myoneural Synapse?
By the local end plate potential (EPP), which activates voltage-gated sodium channels
Characteristic effects of Kurariformen drug is:
Competitive inhibition of the ACh receptor, Na+ channels do not open, no contraction
Which of the substance listed below may inhibit the nicotinic acetylcholine receptor competitively?
Curare
Which physical porperty of the resultant in the myoneural Synapses local stream (EPP) contains information relating to the freuqancey of neuronal action potentail ?
Amplitude
How is the acetylcholine at the synapse myoneural removed from the synaptic cleft?
First by enzymatic degradation, then resumption of the resulting choline
Which of the ions below inhibits the binding of acetylcholine on Myolemm?
Mg 2+
For the small motor unit, it is characteristic:
Short muscle fibres
Innervate the Efferentien of gamma motomeurons
the intrafusal fibres
What receptors are found in the intrafusal muscle?
Kernsack - and core chain receptors
Which nerve fibres play a role in preventing the muscle over-stretching ?
The Ib fibres of the Golgi bodies
The most important role of Fusimotor system
The ‘adjustment’ of the muscle spindle, maintaining continuous low voltage, fine adjustment of muscle tone
The role of Kaldesmon in the contraction of the smooth muscles
binding of calmodulin in the presence of Ca2+ and distance from Tropomypsin from the actin binding sites
Which enzyme stimulates relaxation of the smooth muscle?
MP (myosin phosphate)
Main characteristics of the contraction of smooth muscle:
long-lasting, tonic contraction: low ATPase ctivity: slow saturation of the myosin heads
Which of the phenomena listed below is characteristic only of the smooth muscle?
myogenic response
The main source of calcium during contraction of the smooth muscles
the extracellular space
Which statement of the below is true for the ‘multi-unit’ type smooth muscles?
It contains muscarinic acetylcholine and alpha-1 receptors
It is characteristic of the myogenic response of the ‘single-unit’ muscle that
due to the muscle stretch open the cation channels in the plasma membrane and thus the depolarisation is initiated
