REFLEX ARC
What is the function of an afferent neuron in a reflex arc?
Carries sensory information toward the CNS
Which motor neurons maintain muscle spindle sensitivity during contraction?
Gamma motor neurons
What is the main response of the stretch reflex when a muscle is suddenly stretched?
The muscle contracts
Where are Golgi Tendon Organs located relative to muscle fibers?
In series with muscle fibers in the tendon
How many lobes does the right lung have?
Three
What are the five basic components of a reflex arc?
Receptor, afferent neuron, integration center, efferent neuron, effector.
Which two types of intrafusal muscle fibers are found in the muscle spindle?
Nuclear bag and nuclear chain fibers
What receptor initiates the stretch reflex?
Muscle spindle
What does the Golgi tendon organ primarily detect?
Muscle tension
In Grey’s Anatomy, what is Dr. McDreamy’s real name?
Derek Shepherd
Where does the integration of most spinal reflexes occur?
In the spinal cord.
What specific change in the muscle does the muscle spindle detect?
Muscle length and changes in length
Which sensory afferent fiber is primarily responsible for the rapid stretch reflex?
Group la
What type of sensory fiber carries information from the Golgi tendon organ to the spinal cord?
Type lb
Which cranial nerve is known as the vagus nerve?
Cranial Nerve X
Why is the stretch reflex considered monosynaptic?
Because the Ia afferent makes a direct synapse with the alpha motor neuron.
What happens during mechanotransduction in the muscle spindle?
Stretch opens mechanically gated ion channels, causing depolarization
What happens to the antagonist muscle during the stretch reflex?
It is inhibited through an inhibitory interneuron
What is the main effect of the Golgi tendon reflex on the same muscle?
Decreased alpha motor neuron activity and reduced contraction
Which bone does not directly articulate with any other bone?
The hyoid bone
Put the following in the correct order:
α motor neuron — receptor — spinal cord — effector — afferent neuron
Receptor → afferent neuron → spinal cord → α motor neuron → effector
What happens at the sensory ending when the muscle spindle is stretched?
Mechanical deformation → mechanically gated ion channels open → cation influx → depolarization → receptor potential → action potentials in the sensory afferent.
A muscle is suddenly stretched. Which sequence correctly describes the stretch reflex?
Muscle spindle → Ia afferent → spinal cord → α motor neuron → muscle contraction
A person is holding a very heavy object and muscle tension increases. Explain the GTO reflex pathway.
Increased muscle tension → GTO → Ib afferent → spinal cord → inhibitory interneuron → ↓ α motor neuron activity → reduced muscle contraction.
What is Dr. B’s full name?
ARTURO YONATAN BOJORQUEZ GONZALEZ