6.5 Post cell/muscle/nerve physio Flashcards by Jewel Jace

A bundle of muscle fiber in the skeletal muscles is called:
a. Fasciculus
b. Myofilaments
c. Myofibrils
d. Sarcomere

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Type Ia afferents in the muscle spindle is/are also known as:
a. Annulospiral nerve endings
b. Flowerspray nerve endings
c. Alpha motor neuron
d. Gamma motor neuron
e. A beta nerve fibers

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The following statement describes the principle of all or none law, EXCEPT:
a. Physiologic mechanism exist for fine gradation of the force of muscle contraction
b. The law applies only to individual motor units
c. All muscle fibers in a given motor unit contract or relax simultaneously
d. Activated muscle fibers contract maximally if the nerve activates the motor fibers of a motor unit sufficiently
e. In the same motor unit, it is possible for some muscle fiber to contract while others are relaxed

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True about the myelin sheath:
a. Increases conduction velocity in large A beta and C fibers
b. Absent at the nodes of Ranvier thereby facilitating saltatory conduction
c. The Myelin sheath acts as a conductor of electricity
d. A and B
e. All of these are correct

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Glial cell responsible for myelin production in the PNS
a. Oligodendrocytes
b. Ependydymal
c. Schwann cells
d. Microglia
e. Astrocytes

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Generation of end plate potential in the sarcolemma of skeletal muscle is linked with
a. Voltage-gated channels
b. Ligand-gated channels
c. Mechanical-gated channels
d. Thermal-gated channels

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The connective tissue that covers individual muscle bundle:
a. Epimysium
b. Perineurium
c. Perimysium
d. Subcutaneous fascia
e. Endomysium

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The portion between two Z-discs is called:
a. H zone d. Y band
b. I band e. Sarcomere
c. A band

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The plasma membrane of a skeletal muscle fiber is called:
a. Sarcoplasm
b. Sarcolemma
c. Sarcomere
d. Sarcoplasmic Reticulum
e. Neurolemma

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Type of nerve fiber that has the fastest conduction:
a. Large myelinated axons
b. small myelinated axons
c. Small unmyelinated axon
d. large unmyelinated axon

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The main neurotransmitter of the neuromuscular junction:
a. Calcium
b. Acetylcholine
c. Serotonin
d. Norepinephrine
e. Epinephrine

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This thin filament has a high affinity for calcium:
a. Troponin I
b. Troponin C
c. Troponin T
d. Actin
e. Tropomyosin

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Which among the following is the correct sequence for muscle contraction?
I. Action potentials arrive at the presynaptic terminal
II. Troponin C of the actin filament binds with Calcium
III. Acetylcholine is released in the synaptic cleft
IV. Power stroke occurs
V. ATP attaches to the myosin head
a. I II III IV V
b. I III II V IV
c. I II IV III V
d. I III II IV V

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Location of the “triad” in skeletal muscles i
a. At A-H junction
b. Along the Z line
c. At A-I junction
d. Along the M line

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Which of the following does NOT properly describe a sarcomere?
a. The M line divides the A band
b. I band contains thin filaments
c. The H zone contains thin and thick filaments
d. Width of I band changes during contraction, A band does not
e. Actin filaments slide toward each other during contraction

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True of thin filaments:
a. Actin is the only thin filament
b. Consists of two heads: one is a binding site for ATP, the other is for the formation of cross bridges
c. Its backbone is a double stranded filamentous G actin, made of individual globular molecules called F actin
d. Tropomyosin spiral around the binding sites and attached intermittently are troponin molecules altogether forming a troponin- tropomyosin complex
e. None of these

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In comparing electron micrographs of a relaxed skeletal muscle fiber and a fully contracted muscle fiber which would be seen only in the relaxed fiber?
a. Z lines d. A bands
b. Triads e. H zones
c. Myosin

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Which of the following generates the lowest tension?
a. Fast concentric
b. Slow concentric
c. Fast eccentric
d. Slow eccentric
e. Isometric

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Skeletal muscle contraction stops when:
a. ATP is released from myosin
b. Decreased concentration of intracellular calcium ions
c. Ionization of cell
d. Sodium pump reversal
e. Depolarization of the cell

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Which of the following muscle is involuntary non- striated?
a. Cardiac and smooth muscles
b. Cardiac muscles
c. Skeletal and cardiac muscles
d. Smooth muscles

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“Cell Drinking mechanism”
a. Osmosis
b. Diffusion
c. Phagocytosis
d. Pinocytosis
e. Active transport

The physiologic property unique to muscle cells is due to the presence of which of the following?
a. Ligand-gated channels
b. Terminal endings
c. Myofilaments
d. Sarcolemma

Source of calcium in skeletal muscle contraction?
a. Exocytosis from the vesicle to synaptic cleft
b. Release from sarcoplasmic reticulum to sarcoplasm
c. Efflux from cisterns of sarcoplasmic reticulum to extracellular area
d. Sarcolemma after exocytosis from the sarcoplasm

What type of transport process is involved when sodium is transported into the cell in exchange for calcium?
a. Vesicular transport
b. Primary active transport
c. Passive transport
d. Secondary active transport

Rate of diffusion is fasted in/for: a. Gases like O2 and CO2 b. A solid medium c. A membrane that is 1 micrometer thick d. 2 solutions having equal solute concentration

The potassium leak channels are: a. Markedly affected by electrical gradient or electrostatic forces when a cell is polarized b. Transporting ions without control or regulation c. Capable of promoting potassium influx d. Not active during the repolarization of the action potential

Osmosis is movement of water through a semipermeable membrane from an area of: a. High solute concentration to an area of low solute concentration b. Low water concentration to an area of high water concentration c. Low solute concentration to an area of high solute concentration d. Low water concentration to an area of high solute concentration

Which statement is CORRECT regarding impulse transmission in a myelinated nerve? a. The generated action potential skips the area covered by myelin b. Action potentials are mostly generated on the myelin (sheath) covering c. It is slower than what is observed in type C nerve fibers d. Lesser action potentials are developed at the nodes of Ranvier

The most abundant cation intracellularly is: a. Sodium b. Potassium c. Proteins d. Bicarbonate e. Chloride

Efferent fibers of the muscle spindle come from the: a. All of these b. alpha motor neuron c. Gamma motor neuron d. extrafusal muscle

how does extracellular fluid (ECF) differ from intracellular fluid (ICF)? a. Plasma is part of the ECF, which contains more large proteins like albumin b. ECF is 40% of the body weight while ICF is 20% of the body weight c. Potassium content in the ECF is the major determinant of plasma osmolality d. There is greater sodium concentration in ICF

Vesicles storing the NTAs are normally present in the a. Dendrites b. Axon terminal c. “trigger zone” d. Cell body

In a neuron, action potentials are initially generated at the region of the: a. Axon hillock b. Dendrites c. Perikaryon d. Telodendria

A stack of flattened sacs which modify and package the proteins sent by the endoplasmic reticulum: a. Smooth ER b. Mitochondria c. Peroxisomes d. Golgi Tendon Organ e. None of these

E, golgi apparatus

In an action potential, voltage gated Na+ channels are initially closed by their gates during a. After-depolarization b. Middle period of repolarization c. Peak of depolarization d. After-hyperpolarization

Diffusion occurs faster if: a. Temperature is lower b. Molecular size is bigger c. Higher partition coefficient d. All of these e. None of these

In this phase of Mitosis, the centrioles are at the opposite ends of the cell poles and the chromosomes are lined up at an imaginary line equidistant between the two poles. This sequence belongs to what phase? a. Prophase c. Anaphase b. Metaphase d. Telophase c. Anaphase II

In which phase of Mitosis does the cleavage furrow appear? a. Prophase b. Telophase c. Anaphase d. Metaphase e. NOTA

“Somatic cell” division is termed: a. Meiosis d. ptosis b. Mitosis e. Phagocytosis c. Miosis

Mitosis ends with “Diploid” daughter cells which have how many pairs of chromosomes each? a. 2 d. 46 b. 4 e. 92 c. 23

The Na K ATPase pump: a. Pumps 2 Na ions out, 3 K ions in b. Pumps 3 Na ions in, 2 K ions out c. Pumps 3 Na ions out, 2 K ions in d. Pumps 2 Na ions in, 3 K ions out e. Pumps 3 Na ions out, 2 K ions out

In contrast to axons, dendrites are typically: a. Thinner b. Receive more synaptic contacts c. Product one or more synaptic end feet d. Longer

phagocytosis by macrophages is what type of vesicular transport? a. Endocytosis, non-specific fluid and small particle intake b. Transcytosis c. Endocytosis, larger particle intake d. Exocytosis

Resting membrane potential of the skeletal muscle? a. 70 mV d. -90 mV b. -70 mV e. -60 mV c. 90 mV

Depolarization is initiated when this enters the neuron: a. Potassium b. Magnesium c. Chloride d. Sodium e. Permanganate

A decrease in resting membrane potential, making it more positive is: a. Depolarization b. Membrane denervation c. Hyperpolarization d. Action potential degradation e. Variable conductance

The nerve fiber that transmits sharp, acute, pricking pain: a. Small myelinated nerve fiber b. Small unmyelinated nerve fiber c. Medium myelinated nerve fiber d. Large myelinated nerve fiber

A state in which a stronger than the threshold stimulus is required to trigger another action potential a. Relative refractory period b. Absolute refractory period c. Hypopolarized state d. Depolarization

This type of summation occurs when many presynaptic terminals are stimulated at the same time a. Spatial Summation b. Renshaw Inhibition c. Temporal Summation d. Subliminal Fringe e. Presynaptic Facilitation

As action potential travels over the muscle fiber membrane, large quantities of calcium ions are released which activate the forces between filaments to initiate contraction. This causes the . a. Myosin filaments to slide outward among the actin filaments b. Actin filament to slide outward among the myosin filaments c. Myosin filaments to slide inward among the actin filament d. Actin filaments to slide inward among the myosin filaments