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WorksheetsPhysiology Quiz
Total questions: 35
Worksheet time: 40mins
Which of the following statements are correct regarding mechanisms of
depolarisation, repolarisation, and hyperpolarisation in a skeletal muscle action
potential?
1. Depolarisation due to influx of Na+ through voltage-gated channels
2. Depolarisation due to influx of Na through ligand-gated channels
3. Repolarisation due to efflux of K+ through a voltage-gated channel
4. Repolarisation due to efflux of K+ through a ligand-gated channel
5. Hyperpolarisation due to efflux of K+
2 and 4 are correct
1, 3, and 5 are correct
1,4, and 5 are correct
2, 4, and 5 are correct
Which of the following is not a feature of cardiac muscle?
Length-tension relationship
Plateau potential
All or none phenomenon
Tetanization
A scientist found that the latent period of muscle twitch is 10 ms and the contraction period is 40 ms. What is the tetanizing frequency (Hz)?
25
50
75
100
ATPase activity is present in
Myosin Head
Myosin Tail
Actin filaments
Desmin filaments
A sprinter would experience muscle fatigue sooner than a marathon runner due to
anaerobic metabolism in the muscles of the sprinter
anaerobic metabolism in the muscles of the marathon runner
aerobic metabolism in the muscles of the sprinter
glycolysis in the muscles of the marathon runner
Which cell type helps to repair injured muscle fibres?
ganglion cells
satellite cells
kupffer cells
microglial cells
Which of the following proteins is present in skeletal muscles, but absent in a smooth muscle?
Troponin
Tropomyosin
Actin
Myosin
The membrane conductance for potassium is maximum at which of the following
points in a nerve action potential?
1
2
4
3
Which of the following occurs during skeletal muscle contraction?
A band shorten
Both H and I band shorten
Both A and H band shorten
Both A and I band shorten
Human cardiac muscle contains
Alpha heavy chain of Myosin
Beta heavy chain of Myosin
Both alpha and beta heavy chain of myosin
None
In human skeletal muscles, calcium ions are stored in?
Transverse tubules
Sarcolemma
Terminal cistern
All are correct
In a 100-m dash, most of the energy consumed by skeletal muscles to replenish ATP is derived from
Phosphocreatine
Aerobic glycolysis
Oxidation of Fatty acids
None of the above
A motor unit is made up of
All the muscle fibers within a given muscle
All the neurons going into an muscle of the body
A fascicle and a nerve
A motor neuron and the muscle fibers it innervates
Calmodulin is mostly both structurally and functionally related to
Actin
Myosin light chain kinase
Tropomyosin
Troponin C
A sustained contraction with little expenditure of energy is made possible by a
latching mechanism in
Skeletal muscle
cardiac muscle
Smooth muscle
All of the above
Which of the following is used to calculate the equilibrium potential for diffusion of
multiple ions?
Gibbs-Donnan equation
Nernst equation
Henderson equation
Goldman equation
A cross-sectional view of a skeletal muscle fiber through the H zone would reveal the presence of
Actin and Titin
Actin and Myosin
Myosin onlv
Actin only
Which of the following is a regulatory muscle protein?
Actin
Tropomodulin
Tropomyosin
Dystrophin
Why do muscles get stiff after death?
The muscles decomposes
The muscles run out of ATP
The temperature of the body declines
The muscles run out of calcium
Muscles in hollow viscera behave as
Single unit smooth muscle
Multiunit smooth muscle
Both, depending on action
None
Which of the following would SPEED UP rigor mortis?
Cold temperatures
Sleeping right before death
Having extra body fat
Exercising right before death
-Red ( slow ) fibers are characterized by the following except
contains much blood capillaries
glycogen stores is low.
depends on anaerobic oxidation
contains high concentration of myoglobin
Muscle fatigue is likely due to the build up of
acetylcholine
lactic acid
cholinsterase
glucose
A 40-year-old diabetic man who presented with diabetic ketoacidosis is started on an intravenous insulin infusion. A repeat serum chemistry analysis shows a decrease in K+ level in blood. What is the effect on the
cellular membrane when the extracellular concentration of K+ is decreased?
Increased positivity of the
membrane
Increased negativity of RM
Decreased fluctuations in
RMP
Decreased negativity of
membrane
The botulinus toxin that causes botulism acts by
promoting the release of acetylcholine
Preventing decomposition of acetylcholine
preventing the release of acetylcholine
none of the above
How is an electrical synapse different from a chemical synapse?
No cytoplasmic continuity between presynaptic and postsynaptic membrane
Connexons are involved in electrical synapse
Direction of impulse is unidirectional
Electrical synapse has more latent period than chemical synapse
What does "optimal length" mean when describing a muscle contraction?
When the thin filaments overlap each other
When the sarcomere is at its greatest length
When the most binding sites are available to form the most crossbridges
When the sarcomere is at its shortest length
What is the structure to which actin filament are attached in skeletal muscle and smooth muscle
Z LINE , DENSE BODIES
Z LINE , MYOSIN
M LINE , INTERMEDIATE FILAMENT
M LINE , DENSE BODIES
Who discovered chemical transmission?
Henry Dale
GOLDMANN
NERNST
Ohsumi
_____ extends inward from the epimysium surrounding the fascicles.
Fascia
Perimysium
Fascicle
Epimysium
A man who is fond of exotic cuisine develops perioral numbness after
eating the Pufferfish. The given poisoning is due to which of the
following toxins?
Saxitoxin
Tetrodotoxin
Curare
Ciguatoxin
(a) is the “pacemakers” of the intestine
Enlargement of muscles is known as (a)
Muscles attach to bones by
(a)
What process is responsible for the change in membrane potential that occurs between point 1 and point 3?
Movement of Na+ into the cell
Movement of Na+ out of the cell
Movement of K+ into the cell
Movement of K+ out of the cell
