chapter 15

Question 1

what is the component of the efferent division of the nervous system

Answer 1

Somatic motor portion

Carries out somatic motor commands that control peripheral effectors

Commands travel from motor centers in brain along somatic motor pathways

Question 2

what does somatic system mean

Answer 2

Controls contractions of skeletal muscles

Question 3

defn what is transduction

Answer 3

Conversion of an arriving stimulus into an action potential by a sensory receptor

Question 4

what is general sense

Answer 4

-Temperature
-Pain
-Touch
-Pressure
-Vibration
-Proprioception (body position)

Question 5

what is special sense

Answer 5

-Olfaction (smell)
-Gustation (taste)
-Vision (sight)
-Equilibrium (balance)
-Hearing

Question 6

what is receptor specificity

Answer 6

Each receptor has a characteristic sensitivity

Question 7

Receptive field what is being monitored by and what makes it difficult to localize it

Answer 7

Area monitored by a single receptor cell

The larger the receptive field, the more difficult it is to localize a stimulus

Question 8

what is the function of labeled line

Answer 8

Each labeled line carries information about one modality, or type of stimulus (e.g., touch or light)

Question 9

adaption what does it do when constant stimulus and what does it adapt to

Answer 9

Reduction of receptor sensitivity in the presence of a constant stimulus

Nervous system quickly adapts to painless, constant stimuli

Question 10

defn Phasic receptors

Answer 10

Provide information about intensity and rate of change of a stimulus, normally inactive

Question 11

defn Slow-adapting receptors

Answer 11

Show little peripheral adaptation

Question 12

what are the 4 main types of General sensory receptors

Answer 12

-Nociceptors (pain)
-Thermoreceptors (temperature)
-Mechanoreceptors (physical distortion)
-Chemoreceptors (chemical concentration)

Question 13

what are Nociceptors, where are they most common in, and what are they sensitive to

Answer 13

pain receptors)
Free nerve endings with large receptive fields,

Are common
In superficial portions of skin
In joint capsules and within periostea of bones
Around walls of blood vessels

May be sensitive to
Temperature extremes
Mechanical damage
Dissolved chemicals (as released by injured cells)

Question 14

what types of fibers and where do they relay info to what cortex of the Nociceptors

Answer 14

Myelinated Type A fibers, Carry sensations of fast pain (prickling pain) such as that caused by injection or deep cut

Unmyelinated Type C fibers Carry sensations of slow pain (burning and aching pain)

Relayed to primary somatosensory cortex and thus receive conscious attention

Question 15

what is the thermoreceptors, where are the nerve endings, and in what pathway is it going?

Answer 15

temperature receptors

Free nerve endings located in
-Dermis
-Skeletal muscles
-Liver
-Hypothalamus

Sensations are conducted along same pathways that carry pain sensations

Question 16

the function of mechanoreceptors, what are they sensitive to, and the 3 classes of it

Answer 16

Sensitive to physical stimuli that distort their plasma membranes

sensitive to
-Stretching
-Compression
-Twisting
-Other distortions of the membrane

the 3 classes of mechanoreceptors
- tactile receptors
-barorecptors
-proprioceptors

Question 17

Tactile receptors

Answer 17

provide sensations of
Touch (shape or texture)
Pressure (degree of mechanical distortion)
Vibration (pulsing pressure)

Question 18

Baroreceptors

Answer 18

Detect pressure changes in blood vessels and in digestive, respiratory, and urinary tracts

Question 19

Proprioceptors

Answer 19

Monitor positions of joints and skeletal muscles

Question 20

the chemoreceptors what do they respond to and what do they monitor

Answer 20

Respond to water- and lipid-soluble substances that are dissolved in body fluids

Monitor pH, carbon dioxide, and oxygen levels in arterial blood at

Question 21

what does the Golgi do during muscles contraction and where

Answer 21

At junction between skeletal muscle and its tendon

Monitor tension during muscle contraction

Question 22

the first oder of neuron deliver what

Answer 22

Sensory neuron that delivers sensations to CNS

Question 23

the second order of neuron receives from which neuron and what does it crosses

Answer 23

interneuron in spinal cord or brainstem that receives information from first-order neuron

Crosses to opposite side of CNS (decussation)

Question 24

the third oder of neuron what does it receives and what sensation does it reach

Answer 24

Neuron in thalamus that must receive information from second-order neuron

For the sensation to reach our awareness

Question 25

the sensory homunculus which column pathway is, which cortex, and to what is density to?

Answer 25

posterior column pathway

Functional map of primary somatosensory cortex

Area devoted to a particular body region is
Proportional to density of sensory neurons
Not proportional to region’s size

Question 26

spinothalamic pathway what does it carry

Answer 26

Carries sensations of crude touch, pressure, pain, and temperature

Question 27

what does the posterior column pathway

Answer 27

Carries sensations of fine touch, vibration, pressure, and proprioception

Question 28

Anterior spinothalamic tract

Answer 28

Crude touch and pressure

Question 29

Lateral spinothalamic tract

Answer 29

Pain and temperature

Question 30

the somatic sensory pathway are the two

Answer 30

Always involve at least two motor neurons
Upper motor neuron
Lower motor neuron

Question 31

upper motor neuron where does It lies in, what are the activity

Answer 31

Cell body lies in a CNS processing center

Synapses on lower motor neuron

Activity may facilitate or inhibit lower motor neuron

Question 32

the lower motor neuron were does it lies, what does innervate, what does it trigger

Answer 32

Cell body lies in a nucleus of brainstem or spinal cord
Only the axon extends outside CNS

innervates a single motor unit in a skeletal muscle

Activation triggers a contraction in innervated muscle

Damage eliminates voluntary and reflex control over innervated motor unit

Question 33

Cerebellum monitors

Answer 33

Proprioceptive (position) sensations

Visual information from eyes

Vestibular (balance) sensations from internal ear