Prepare for NEET Biology Locomotion And Movement with MCQs & PYQs on NEET.GUIDE. Access free practice, previous year questions, and expert explanations of muscles and skeleton.
The specialized synapse between a motor neuron and a skeletal muscle fiber is called the:
Synaptic cleft
Myoneural junction
Neuromuscular junction
Motor end plate
In a research experiment, a muscle fiber is exposed to a drug that inhibits the activity of acetylcholinesterase. Which of the following is the MOST likely direct effect on muscle contraction?
Inhibition of action potential generation in the muscle fiber
Prevention of calcium release from the sarcoplasmic reticulum
Prolonged muscle contraction due to continuous stimulation at the neuromuscular junction
Increased rate of ATP hydrolysis
A patient presents with muscle weakness and fatigue, particularly affecting the eyelids and extraocular muscles. Repetitive nerve stimulation studies show a decrement in muscle response. Which receptor is MOST directly affected in this condition?
Muscarinic acetylcholine receptor
Beta-adrenergic receptor
Nicotinic acetylcholine receptor
Alpha-adrenergic receptor
Statements about the mechanism of muscle contraction are given below.
I. Acetylcholine is released when the neural signal reaches the motor end plate.
II. Muscle contraction is initiated by a signal sent by CNS via a sensory neuron.
III. During muscle contraction isotropic band gets elongated.
IV. Repeated activation of the muscles can lead to lactic acid accumulation.
Identify the correct statement.
I and II
II and III
I and IV
II and IV
Neuromuscular junction is a junction between
Two neurons and muscles
Sensory neurons and muscles
Motor neurons and sarcolemma of muscles
Sensory neurons and sarcolemma of muscles
Identify the correct statements
I. Acetylcholine is released when the neural signal reaches to the motor end plate
II. Muscle contraction is initiated by signals sent by CNS via a sensory neuron
III. During muscle contraction, isotropic bands get elongated
IV. Repeated activation of the muscles can lead to lactic acid accumulation in them
The option with correct choices is
I and III
I and IV
II and III
I and II
Arrange the following steps of muscle contraction in the sequence of events occurring first I. Receptor sites on sarcolemma II. Nerve impulse III. Release of IV. Acetylcholine release V. Shortening of sarcomere VI. Synaptic cleft VII. Spread of impulse over sarcolemma on T-tubule The correct option is
II → IV → VI → I → VII → III → V
II → IV → I → VI → VII → III → V
II → IV → I → VI → VII → V → III
IV → II → I → VI → VII → V → III
At motor-end plate the following transmitters is released
acetylcholine
bradykinin
serotonin
histamine
Statements about the mechanism of muscle contraction are given below. I. Acetylcholine is released when the neural signal reaches the motor end plate.
II. Muscle contraction is initiated by a signal sent by CNS via a sensory neuron. III. During muscle contraction isotropic band gets elongated. IV. Repeated activation of the muscles can lead to lactic acid accumulation. Identify the correct statement.
I and IV are correct
I and III are correct
II and III are correct
I, II, and III are correct
