Quiz 6: Reflexes

Question 1

Reflexes

Answer 1

The basic unit for sensory-motor integration

Sensory neuron connecting to motor neuron for response

Question 2

Basic components of a reflex pattern

Answer 2

Sensory receptor/afferent neuron

Lower motor neuron (alpha motor neuron) and muscle fibers it activates

Question 3

Basic reflex patterns

Answer 3

Monosynaptic stretch reflex

Polysynaptic reflex arc

Gamma loop

Question 4

Monosynaptic stretch reflex

Answer 4

Most direct reflex response

1. Proprioceptive input (muscle spindle) to dorsal root ganglion into spinal/cranial dorsal horn
2. Afferent input directly to lower (alpha) motor neuron in spinal/cranial ventral horn
3. LMN sends efferent to muscle fibers
4. Muscle moves in quick, unsustained, and physic pattern

Question 5

Polysynaptic reflex pattern

Answer 5

Second most direct reflex

1. Cutaneous input to dorsal root ganglion
2. Afferent connects with interneuron between spinal/cranial dorsal and ventral horns
3. Interneuron connects with LMN in spinal/cranial ventral horn
4. LMN efferent to muscle fibers
5. Muscle moves in quick, unsustained, and phasic pattern

Question 6

Gamma loop

Answer 6

Indirect reflex

1. Cutaneous input into dorsal root ganglion and into spinal/cranial dorsal horn
2. Afferent axon connects with gamma motor neuron in spinal/cranial ventral horn
3. GMN sends efferent to muscle spindle telling it to stretch
4. Muscle spindle stretches
5. Stretch causes spindle to send afferent to dorsal root ganglion and into spinal/cranial dorsal horn
6. Spindle afferent connects with LMN in spinal/cranial ventral horn
7. LMN sends efferent stimulation to muscle fibers
8. Muscle moves in relatively sustained pattern

Question 7

Lower motor neuron

Answer 7

Also alpha motor neuron and final common pathway for response from nervous system

In ventral horn of brain stem and spinal cord

Question 8

Nervous system function

Answer 8

Sensory afferent (input) to motor efferent (output)

Sensory info from outside body travels into nervous system by sensory neurons and contacts central nervous system through dorsal horn (in spinal cord and brain stem)

Question 9

Motor/efferent travel information

Answer 9

Leaves nervous system by lower motor neuron located in ventral horn (in spinal cord and brain stem)