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Membrane Potential Quiz
Membrane Potential - Muscles
44
Anatomy
04/16/2008

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Term
The resting potential of a cell is?
Definition
-70mv
Term
If the millivolt becomes more positive, it is said to be ______________?
Definition
depolarizing
Term
Durring depolarization the cell becomes more permiable to?
Definition
Na+ (sodium)
Term
The charge on the outside the cell is _________________ compared to the inside of the cell.
Definition
Positive
Term
The difference in charge at resting potential is mostly due to _______________ located ___________________ the cell.
Definition
Negative Protiens, inside
Term
The absolute refractory period begins at -55 mv and ends at +30 mv. (true or False).
Definition
False
Term
List three differences between the action potential and the local potential?
Definition
Durration of the event, The part of the membrane effected, Action potential is -55mv or higher and local potential is -56 or lower, Action potential-the cell membrane is more permeability to Na+ then local potential
Term
The potassium channels open at _____mv and close at _____mv?
Definition
+30, -90
Term
Some _____ is always leaking out of the cell at resting potential and some ____ is always leaking in.
Definition
K+, Na+
Term
At the end of hyperpolarization, what brings the cell back to the resting potential?
Definition
Sodium/Potassium pump
Term
A fasicle is held together or wrapped by the _____________.
Definition
Perimysium
Term
Many fasicles are held together by the _________________.
Definition
Epimysium
Term
To form whole muscle, inside a fascicle are many?
Definition
Muscle fibers
Term
The bounderies of sarcomeres are from the ________ to _______.
Definition
Z LIne to Z Line
Term
What are the components of the actin myofiliment?
Definition
Troponin complex, tropomyosin, Two strings of G-Actin called F-Actin
Term
Which component of the Actin myofiliment has an affinity for calcium?
Definition
One of the molecules of the troponin
Term
What are the 2 special components of the myosin head?
Definition
ATPase, An part with an affinity for the active site of G-Actin
Term
The T-Tubules are connect the ____________ to the __________________.
Definition
Sarcolemma, Sarcoplasmic Reticulum
Term
Where is calcium stored within the muscle cell?
Definition
Terminal Cisterna
Term
Define Threshold:
Definition
-55mv action potential
Term
Define Strong Stimulus:
Definition
A stimulus that produces an action potential (greater than -55mv)
Term
Define Relative refractory period:
Definition
When the cell is in hyperpolarization and a stronger stimulus can cause an action potential
Term
Define Sarcolemma:
Definition
Muscle cell membrane
Term
List the parts of the neuromuscular junction:
Definition
Axon Terminal, pre synaptic terminal, post synaptic terminal, synaptic cleft, sarcolema
Term
What is the neurotransmitter used in skeletal muscle neuromuscular junctions?
Definition
Acetytocholine
Term
In which step of muscle contraction is the energy of ATP or ADP used?
Definition
When the myosin pulls the actin filament toward the center of the sarcomere. 
Term
In which step of muscle contraction is the presence of ATP required but not used?
Definition
When the myosin head dettaches from the actin
Term
The reaction of the terminal cisterna to an action potential is to?
Definition
they release Ca+(calcium)
Term
Muscle relaxation begins by doing what?
Definition
When Ca+ (calcium)is sucked up by the sarcoplasmic reticulum and the tropomyosin blocks the active sites of the actin again.
Term
The ion with the largest concentration inside the cell is?
Definition
Potassium (K+)
Term
The ion with the largest concentration outside the cell is?
Definition
Sodium (Na+)
Term
True or False: Whe the cell is at resting membrane potential potassium does not leak out of the cell.
Definition
False
Term
Sodium and potssium are actively pumped in and out of the cell by what method?
Definition
Counter-Transport
Term
doing something that makes the charge MORE negative than the resting potential is called?
Definition
Hyperpolarizing
Term
Weak stimuli will cause depolarization only to _____ mv.
Definition
-56mv
Term
-55mv depolarization is called the ___________________ and is a "magical millivolgate at which action potential begins.
Definition

threshold

Term

Which represents a cell at the end of hyperpolarization?

[image]

Definition

The one with Na+ inside and K+ outside

Term
What is the functional unit of muscle contraction?
Definition

Sarcomere

Term
Where is the protien staple that holds down the myosin?
Definition
M-Line
Term
What covers the active sites on the G-Actin?
Definition
Tropomyosin
Term
What do the three glovular molecules of Troponin have an affinity for?
Definition
G-Actin, tropomyacin, and Calcium
Term
What is needed for a myosin head to detach from the g-Actin?
Definition
an ATP
Term
What zone is gone at full contraction?
Definition
H zone
Term

Identify #1 - #4 and the two types of bands

[image]

Definition

1 - Z line, 2 - A Band, 3 - H Zone, 4 I band

thick filament - Myosin

thin filament  Actin