Nervous System 5

Question 1

_____ Pathways into the CNS Enters the spinal cord via the posterior/dorsal roots

Answer 1

Afferent

Question 2

_____ are Receptors and neurons in the CNS are dedicated to carrying particular sensory information.

Answer 2

Labeled Lines:

Question 3

Which order neuron of afferent pathways always synapse in thalamus?

Answer 3

2nd order neuron

Question 4

Which afferent pathway deals with touch, pressure, propriotion, and vibration?

Answer 4

Dorsal column

Question 5

Which afferent pathway deals with pain and temp?

Answer 5

Spinothalamic

Question 6

____ receptors are activated by compression/stretch; Includes receptors in skin, muscle spindles, hearing, equilibrium, arterial pressure, etc.

Answer 6

Mechanoreceptors

Question 7

______ receptors are activated by ligands, Includes receptors for taste, smell, arterial oxygen, osmolarity, blood gas, blood glucose, etc.

Answer 7

Chemoreceptors

Question 8

____ receptors are activated by cold/warm

Answer 8

Thermoreceptors

Question 9

____ receptors are activated by damage/pain

Answer 9

Nociceptors

Question 10

The particular form of energy to which a receptor is most sensitive is called its ______ ; Receptors do respond to forms of energy, but the threshold for these nonspecific responses is much higher.

Answer 10

adequate stimulus

Question 11

Activation of any sensory receptor changes membrane potential (transduction) and produces what is called a ______ (a graded potential).

Answer 11

receptor potential

Question 12

Increases in stimulus strength will increase the _____ of receptor potentials, but this is not a direct (linear) relationship.

Answer 12

amplitude

Question 13

The intensity (or strength) of stimulus perception is determined by what 2 things?

Answer 13

Frequency of APs (temporal summation) and Total number of receptors activated (spatial summation)

Question 14

A Stronger stimulus intensity produces a ____ Receptor (Graded) Potential, ____ Actions Potentials (Temporal Summation) and causes _____ neurotransmitter release into the synapse.

Answer 14

Larger, More, More

Question 15

If a stimulus of constant strength is maintained on a sensory receptor, the frequency of the action potentials in its sensory nerve declines over time.

Answer 15

Perceptual Threshold

Question 16

_____ can occur at the receptor or in the neuron. In response to continual, high impulse sensory stimuli, the response of almost all receptors decreases, but to varying degrees.

Answer 16

Adaptation

Question 17

Decrease in amplitude of receptor potential over time in the presence of a constant stimulus; leads to corresponding decrease in frequency of APs and decreases perception of stimulus

Answer 17

Receptor adaptation

Question 18

Tonic receptors help differentiate stimulus ___

Answer 18

intensity

Question 19

Phasic receptors help differentiate stimulus ____

Answer 19

Duration

Question 20

A precise modality activates specific receptors and postsynaptic cells. This information continues on a predicted pathway such that particular kinds of information are conveyed via specific nerve fibers to specific regions of the CNS that are programmed for perception of that modality.

Answer 20

Labeled Line Principle

Question 21

______ correlates the anatomical regions of the CNS with where interpretation and awareness of sensations are perceived.

Answer 21

Homunculus

Question 22

Region where a single fiber’s afferent receptors (primarily on dendrites) are located.

Answer 22

Receptive Field:

Question 23

OVerlap of adjacent neurons _____ localization ability

Answer 23

Improves

Question 24

____ is the precision with which a stimulus is perceived

Answer 24

Acuity

Question 25

Improves discrimination ;Sensory stimulation of a single point on the skin can elicit excitation in one tract of post-synaptic cells while simultaneously inhibiting lateral neurons; occurs throughout the CNS and is advantageous since it diminishes lateral spread of an excitatory signal and increases degree of contrasts in the sensory pattern perceived in the cortex. This inhibition occurs at each synapse: (1) medulla, (2) thalamus and (3) cerebral cortex

Answer 25

Lateral inhibition

Question 26

Which sensation do you perceive first vibration or touch?

Answer 26

Vibration

Question 27

____ receptors include TACTILE and POSITION sensations that are stimulated by mechanical displacement of some tissues in the body.

Answer 27

Mechanoreceptors

Question 28

_____ mechanoreceptors Touch sensations from stimulation of tactile receptors in the skin or tissues beneath the skin; Pressure sensations from deformation of deeper tissues; Vibration sensations from rapidly repetitive sensory signals.

Answer 28

Tactile

Question 29

_____ mechanoreceptors Static position sense is conscious perception of orientation of different parts of the body with respect to one another; Rate of movement sense is also called kinesthesia or dynamic proprioception.

Answer 29

Position

Question 30

_____ receptors are sensitive to pressure, touch, and vibration so mechanical stimuli are responsible for their activation.

Answer 30

Mechanoreceptors

Question 31

Detect touch & pressure (temp. & pain)b.In skin, cornea, dental pulp, GI tract; Slow adaptation/ Tonic

Answer 31

Free Nerve Endings

Question 32

Which mechanoreceptors Detect deep pressure, vibrationb.In subcutaneous tissue, viscera, jointsc.Rapid adaptation/Phasic

Answer 32

Pacinian Corpuscles

Question 33

Higher frequency vibration is sensed by which mechanoreceptors?

Answer 33

Pacinian Corpuscles

Question 34

Lower frequency vibration is sensed by which mechanoreceptors?

Answer 34

Meissner's Corpuscles

Question 35

Which ascending spinal pathway detects vibration?

Answer 35

Dorsal column

Question 36

Which mechanoreceptors Detect light touch, pressure, vibration; Localization; Found on glabrous skin; Rapid adaptation/Phasic

Answer 36

Meissner's Corpuscles

Question 37

Which mechanoreceptors Localize continuous pressure and sensing an object’s texture; All skin; Slow adaptation/Tonic

Answer 37

Merkel's Disks

Question 38

Which mechanoreceptors are Sensitive to stretch or indentation; proprioceptionb.Deep layers of skin, joints, surrounding tooth roots; Slow adaptation/Tonic

Answer 38

Ruffini’s Endings

Question 39

Which mechanoreceptors Hair Movement b.Base of hair follicle c.Rapid Adaptation/Phasic

Answer 39

Hair End-Organ

Question 40

The _____ is an ascending bundle of heavily myelinated axons that cross over in the medulla. in the dorsal pathway

Answer 40

medial lemniscus

Question 41

The The second order neuron crosses over in the _____ and synapses w/ 3rd order in _______

Answer 41

medulla oblongata; thalamus

Question 42

What size nerve fibers are associated w dorsal column pathway?

Answer 42

A beta fibers

Question 43

The ___ pathway deals with touch, pressure, and vibration

Answer 43

Dorsal column pathway

Question 44

The ____ pathways senses Pain, Thermoreceptors, Crude Tactile, Tickle, Itch and Sexual Sensations

Answer 44

Spinothalamic

Question 45

What size nerve fibers are involved in the spinothalamic pathways?

Answer 45

A delta and C fibers

Question 46

Where does the 2nd order neuron decussate in spinothalamic pathway?

Answer 46

Spinal cord

Question 47

With a UNILATERAL lesion of the spinal cord, one would expect to lose _____ lateral touch/pressure & _____ lateral pain/temperature sensations below the injury level.

Answer 47

Ipsilateral; contralateral

Question 48

Receptors for ____ include photoreceptors, touch and pressure receptors in skin, joints, and ligaments, skeletal muscle receptors (muscle spindles and golgi tendon organs), and vestibular receptors; used for awareness of body's position in space

Answer 48

Proprioception

Question 49

______ mechanoreceptors areMostly complex Ruffini-like receptors; also free nerve endings. Axons are large & myelinated. 3.Adaptation is both slow and fast Location of receptors allow them to respond to any forces applied to the crown of the teeth (when biting and chewing)

Answer 49

Periodontal

Question 50

Brisk tap on tooth ____ jaw closing muscles (ex. jaw opens to prevent damage)

Answer 50

inhibits

Question 51

Weak tap on tooth ____ jaw closing muscles (ex. to hold onto food and adjust chewing force)

Answer 51

activates