Neuroscience Chapter 13 Study Guide

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Questions and Answers

What is the key difference between tonic and phasic receptors?

Phasic receptors adapt, whereas tonic receptors exhibit little or no adaptation.

How does the cortex tell the difference between hot and cold?

Hot and cold are conveyed by different sensory receptors that are parts of separate 'labeled lines.'

Which cells were important in Will's recovery after his femoral nerve was crushed?

Schwann cells, macrophages, and the neurons themselves.

How are dorsal roots and dorsal rami different?

Dorsal roots are purely sensory, whereas dorsal rami carry both motor and sensory fibers. Signup and view all the answers

What is the response called when Juan's big toe pointed up and his other toes fanned out?

Babinski's sign. Signup and view all the answers

Dorsal root ganglia contain:

Cell bodies of sensory neurons Signup and view all the answers

Which reflex causes reciprocal activation of the antagonist muscle?

Tendon Signup and view all the answers

Why is damage to peripheral nerve fibers often reversible?

Damaged fibers can be replaced or repaired by physical and chemical processes directed by macrophages and Schwann cells. Signup and view all the answers

What clinical information can be gained by conducting somatic reflex tests?

Reflex tests assess the condition of the nervous system. Signup and view all the answers

Which cranial nerve is NOT involved with the eye?

Trigeminal Signup and view all the answers

Which cranial nerve is purely sensory?

Optic Signup and view all the answers

Which cranial nerve's name means 'the wanderer'?

Vagus Signup and view all the answers

Which reflex tests the integrity of L4 to S2?

Downward curling of the toes as a blunt object is drawn downward along the lateral aspect of the foot Signup and view all the answers

Collections of neuron cell bodies in the peripheral nervous system are known as?

Ganglia. Signup and view all the answers

In a reflex arc, the muscle fiber or gland that responds to the efferent impulses is known as the?

Effector. Signup and view all the answers

Which cranial nerve controls chewing food?

Trigeminal nerve Signup and view all the answers

The two-point discrimination test assesses the patient's for?

Spatial discrimination Signup and view all the answers

Wallerian degeneration is the?

Degeneration of the axon and myelin sheath distal to the injury site caused by the lack of nutrients Signup and view all the answers

Hilton's law states that?

Any nerve serving a muscle that produces a movement at a joint innervates the joint, but it does not innervate the skin over the joint Signup and view all the answers

Which of the following structures is NOT a part of the peripheral nervous system?

Brain Signup and view all the answers

Proprioceptors advise the brain of?

Body movements Signup and view all the answers

Fast-adapting receptors are called?

Phasic receptors Signup and view all the answers

Most nerves are able to transmit impulses both to and from the central nervous system.

True Signup and view all the answers

Most central nervous system axons are able to regenerate following injury.

False Signup and view all the answers

A nerve that carries autonomic signals away from the central nervous system is classified as a?

Visceral efferent Signup and view all the answers

All spinal nerves are mixed nerves.

True Signup and view all the answers

If the phrenic nerve were severed, what would be the most immediate effect?

Breathing would stop. Signup and view all the answers

In a reflex arc, the __________ transmits afferent impulses to the central nervous system.

Sensory neuron Signup and view all the answers

Does a reflex arc include five neurons?

No. Signup and view all the answers

What does it mean for a reflex to be 'somatic'?

A somatic reflex activates muscles over which you normally have voluntary control. Signup and view all the answers

Classify each reflex studied in lab as somatic or visceral and as spinal or cranial:

Patellar tendon = Somatic, Spinal Babinski = Somatic, Spinal Corneal = Somatic, Cranial Salivary = Visceral, Cranial Pupillary = Visceral, Cranial Signup and view all the answers

Which nerve plexus roughly covers the anterior thigh?

Lumbar Signup and view all the answers

Explain how sensory adaptation affects sensory neurons.

Sensory neurons fire fewer action potentials in response to a constant stimulus. Signup and view all the answers

Briefly explain what referred pain is.

Referred pain is when pain from one area of the body is perceived as coming from another area. Signup and view all the answers

Which reflex is completed faster: patellar or salivary?

The patellar tendon reflex is faster. Signup and view all the answers

In which area can you more easily make subtle adjustments to your muscles?

Your face. Signup and view all the answers

If given a pin prick on the sole of your foot that feels painful but does not lead to withdrawal, where might the problem be?

In the interneuron, motor neuron, or effector. Signup and view all the answers

If given trouble moving your tongue, which cranial nerve is likely involved?

Cranial nerve XII (hypoglossal). Signup and view all the answers

The sensory receptors that sense touch, pressure, or tension have ion channels that are?

Mechanically gated Signup and view all the answers

Which cells are most helpful in repairing axons of injured neurons?

Schwann cells Signup and view all the answers

In general, the effector of a reflex arc could be?

All of the above Signup and view all the answers

Which cranial nerves concern the tongue?

IX and XII Signup and view all the answers

What is the 'modality' of the oculomotor cranial nerve?

Efferent Signup and view all the answers

Study Notes

Receptors and Sensory Pathways

Tonic receptors do not adapt; they continuously send signals, reminding us of potential harm (e.g., pain).
Phasic receptors adapt quickly to stimuli, ceasing to fire during constant stimulation.
Different sensory receptors in labeled lines differentiate between hot and cold, with specific receptors for each temperature range.

Nerve Function and Recovery

Schwann cells, macrophages, and neurons assist in the recovery process of damaged peripheral nerves.
Dorsal roots (medial, sensory only) and dorsal rami (lateral, mixed motor and sensory) differ in location and fiber composition.
The Babinski's sign indicates corticospinal tract damage when toes fan out upon foot stimulation.

Reflex Arcs and Neurological Assessments

Reflex arcs consist of five components: receptor, sensory neuron, integration center, motor neuron, and effector; may not require five neurons.
Different reflexes can be classified as somatic (voluntary) or visceral (involuntary) and can be either spinal or cranial.
Testing spinal reflexes can reveal nervous system integrity, with exaggerated or absent reflexes indicating pathology.

Cranial Nerves and Peripheral Nervous System

Trigeminal nerve controls chewing; optic nerve is purely sensory.
Vagus nerve extends to thoracic and abdominal regions; cranial nerves IX (glossopharyngeal) and XII (hypoglossal) are involved with the tongue.

Sensory and Motor Pathways

Congestion nerve signals can indicate the integrity of the nervous system or specific spinal cord segments.
Reflex centers utilize mechanisms like sensory adaptation to regulate the body's response to stimuli, leading to reduced action potential firing from persistent stimuli.

Peripheral vs. Central Nervous System

Peripheral nerves can regenerate due to the support of Schwann cells, unlike CNS fibers which are inhibited by oligodendrocytes.
All spinal nerves are classified as mixed nerves, transmitting both afferent (to CNS) and efferent (from CNS) impulses.

Special Cases and Considerations

The phrenic nerve is essential for breathing; its damage causes immediate respiratory failure.
Wallerian degeneration refers to distal damage and loss of nerve components after injury due to nutrient deprivation.
Hilton's law states that nerves serving muscles at joints also innervate the overlying skin but do not innervate the joint itself.

Additional Key Concepts

Fast-adapting receptors are called phasic receptors; proprioceptors provide information about body movements.
Two-point discrimination tests measure spatial discrimination abilities of sensory perception.
Types of axons impacted by injury differ significantly between the PNS (regenerative) and CNS (typically non-regenerative).

Study of Reflexes and Symptoms

Reflexes like the patellar tendon reflex are quicker due to fewer involved neurons, emphasizing their role in immediate responses.
For sensory pathways, issues can arise in specific reflex arc components, indicating the likely site of dysfunction.
Understanding which cranial nerves impact specific functions is crucial for diagnosing neurological conditions.

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Description

This quiz covers key concepts from Chapter 13 of Neuroscience. Focus is on sensory receptors, including tonic and phasic receptors, and how the cortex interprets different sensations. Prepare to test your understanding of these fundamental topics!