Sensory Pathways

Question 1

Sensory receptors monitor what?

Answer 1

Monitor internal and external environment

Question 2

Visceral sensory

Answer 2

Goes to brain stem and diencephalon

Question 3

Somatic sensory

Answer 3

Goes to post central gyrus or appropriate cerebral hemisphere

Question 4

Post central gyrus

Answer 4

Receives general senses

Temp, pain, touch, pressure, vibration, and body position

Question 5

Sensation

Answer 5

Is when action potential arrives

The arrival of information

Question 6

Perception

Answer 6

Is conscious awareness

Question 7

Receptive fields

Answer 7

Monitored by receptor cell
Larger field- poorer ability to localize stimuli
Smaller field- more precise localization

Question 8

Two types of receptors

Answer 8

Tonic receptors

Phasic receptors

Question 9

Tonic receptors

Answer 9

Always active, show little peripheral adaptation, and are slow adapting
Ex. Pain

Question 10

Phasic receptors

Answer 10

Not active, fast adapting

Ex. Smell

Question 11

Adaptation

Answer 11

Receptor becomes numb to stimuli

Question 12

Sensory receptor classification

Answer 12

Exteroceptors
Proprioceptors
Interoceptors

Question 13

General sensory receptors

Answer 13

Nociceptors-pain
Thermoreceptors- temp
Mechanoreceptors- physical distortion
Chemoreceptors- chemical concentration

Question 14

Nociceptors

Answer 14

Have free nerve endings and large receptive fields

Sensitive to temp, chemicals, and mechanical damage.

Question 15

Type A fibers

Answer 15

Carry painful sensation Myelinated, fast pain, and conscious

Question 16

Type C fibers

Answer 16

Carry painful sensations, slow pain, you are aware but only have general idea of location

Question 17

Thermoreptors

Location

Answer 17

Free nerve endings

Located in dermis, skeletal muscle, liver, and hypothalamus

Question 18

Mechanoreceptors

Answer 18

Sensitive to distortion of plasma membrane

Question 19

3 types of mechanoreceptors

Answer 19

Tactile- sensation for touch, pressure, vibration
Barorecptors- detect pressure in Blood vessels
Proprioceptors- monitor position of joints, tension in tendons and ligaments, muscle contraction.

Question 20

First order neuron

Answer 20

Delivers sensation to CNS

Located in dorsal root ganglion

Question 21

Second order neuron

Answer 21

Interneuron located in brain stem or spinal cord

Question 22

Third order neuron

Answer 22

Located in thalamus

Only synapses if sensation reaches our awareness

Question 23

Somatic sensory pathways

Answer 23

Spinothalamic pathway
Posterior column pathway
Spinocerebellar pathway

Question 24

Spinothalamic pathway

Answer 24

Provides conscious sensation poorly localized (crude) touch pressure pain and temp
Ascending

Question 25

Posterior column pathway

Answer 25

Carriers sensations of highly localized (fine) touch, pressure, vibration, and proprioception

Question 26

Spinocerebellar pathway

Answer 26

Sends info to cerebellum | Proprioceptive- positions of skeletal muscles, tendons, and joints

Question 27

2 spinal tracts of | Posterior Column pathway

Answer 27

Fasciculus gracilis— inferior part of body | Fasciculus cuneatus—superior part of the body

Question 28

Nerves that carry visceral sensory info

Answer 28

Cranial nerves 5,7,9,10 | Delivered to solitary nucleus

Question 29

Somatic motor pathways always involve 2 motor neurons

Answer 29

Upper motor neuron—pre central gyrus | Lower motor neuron—anterior horn opposite side in brain stem or spinal cord

Question 30

Chemoreceptors

Answer 30

Located in carotid bodies and aortic bodies | Monitor ph of CO2, hydrogen ions, and oxygen

Question 31

Corticospinal pathway

Answer 31

Begins at pyramidal cells in pre central gyrus and descends down spinal cord Conscious

Question 32

Corticobular

Answer 32

Synapse on motor neuron in cranial nerves 3,4,5,6,7,9,11,12 Move eye, jaw, face, neck, pharynx Cross at brain stem and end on opposite side

Question 33

3 types of medial pathway

Answer 33

Vestibulospinal Tectospinal Reticulospinal

Question 34

Lateral pathway

Answer 34

Control muscle tone and precise movement in distal limbs Midbrain cross then descend to cervical spinal cord Ex rubrospinal tract