Neurophysiology Part 2: Sensory and Reflex physiology

Question 1

Organization of the Nervous System:

______:brain and spinal cord

Answer 1

Central nervous system (CNS)

Question 2

______-master control center located in the cranial cavity

Answer 2

Brain

Question 3

______-located in the vertebral cavity the spinal cord connects the brain to the
inferior regions of the body and functions as the control center for many simple reflexes

Answer 3

Spinal cord

Question 4

Organization of the Nervous System:

______-all nervous tissue outside CNS
*Nerves of PNS carry information in and out of the CNS

Answer 4

Peripheral nervous system (PNS)

Question 5

Peripheral nervous system (PNS)
_______-12 pairs of nerves carrying information in and
out of the brain.

Answer 5

Cranial Nerves (CN)

Question 6

Peripheral nervous system (PNS)
______-31 pairs of nerves carrying information in and out
of the spinal cord

Answer 6

Spiinal Nerves

Question 7

______ Receptors detects a stimulus

Answer 7

Sensation

Question 8

_______-processing of sensory stimuli by the central nervous system to produce
a meaningful interpretation.
• involves:
o recognition of the stimulus type and intensity
o localization of the receptors that detect the stimulus

Answer 8

Perception

Question 9

_______-cells that monitor internal and external conditions

Answer 9

Receptor

Question 10

Receptor:
A stimulus alters the membrane permeability of the receptor
producing graded potentials

Answer 10

Transduction

Question 11

_______-sequence of neurons that relay sensory information from sensory
receptors through nerves into the CNS leading to sensation (and potentially perception).
• Afferent fibers of PNS form synapses with interneurons of the CNS.
o Some afferent neurons also directly synapse with efferent neurons to produce
monosynaptic reflexes.

Answer 11

(Afferent) Sensory pathway

Question 12

_______-are the sensory information detected by specific receptors
and relayed through specific afferent neurons. Familiar examples taste, smell, hearing, and
vision. Somatosensation (commonly known as touch) can be subdivided into distinct modalities
detected by different receptors distributed throughout the body. The major somatosensory
modalities are light pressure, deep pressure, vibration, itch, nociception (pain), temperature, and
hair movement.

Answer 12

Modality

Question 13

Modality :
Law of 10)____________: Each modality results from
activation of distinct receptors that relay sensory information through specific afferent
(sensory) nerve pathways.

Answer 13

Law Specific Nerve Energies

Question 14

Structural Classification of Sensory Receptors is this:
________-Depolarization of bare (not encapsulated) dendrites
directly stimulates an action potential in the afferent neuron. Examples: Nociceptors causes the
sensation of pain in response to tissue damage. Thermoreceptors react to changes in
temperature.

Answer 14

Free nerve endings

Question 15

Structural Classification of Sensory Receptors is this:
________-Depolarization of dendrites enclosed in a connective
tissue capsule directly stimulates an action potential in the afferent neuron. Examples: Pacinian
corpuscles deep in the skin detect deep pressure and vibration, Meissner’s corpuscles in the
superficial papillary layer of dermis detect light touch and low frequency vibration, and Ruffini
corpuscles in reticular layer of dermis and subcutaneous layer detect deep pressure and
stretching of skin

Answer 15

Encapsulated nerve endings

Question 16

Structural Classification of Sensory Receptors is this:
________-Depolarization stimulates release of neurotransmitters that
open ligand-gated ion channels on the afferent neuron. Examples: Merkel cells of the epidermis,
photoreceptors of the retina in the eye, hair cell receptors of the inner ear, gustatory receptor
cells in taste buds.

Answer 16

Specialized receptors cells

Question 17

Functional Classification of Sensory Receptors is this:

_____-detect mechanical stimuli such as pressure, vibration, and stretching.

Answer 17

Mechanoreceptor

Question 18

Classification of Sensory Receptors is this:

_____-detect changes in temperature

Answer 18

Thermoreceptor

Question 19

Classification of Sensory Receptors is this:

_______-detect tissue damage, extreme pressure or extreme temperature

Answer 19

Nociceptors

Question 20

Classification of Sensory Receptors is this:

_______-detect light. Round in the retina of the eye.

Answer 20

Photoreceptors

Question 21

Classification of Sensory Receptors is this:

______-detect chemicals dissolved in extracellular fluid

Answer 21

Chemoreceptor

Question 22

________-region of the environment (skin surface for somatosensory
receptors of the integumentary system) where an individual receptor (or neuron in the sensory
pathway) can respond to an adequate stimulus. Receptive fields are smaller in regions with a
higher density of receptors. For example, receptive fields are smaller for somatosensory
receptors in the skin on the finger tips than in the skin of the leg.

Answer 22

Receptive Fields

Question 23

Receptive Fields:
________-activated sensory pathways inhibit the surrounding pathways (from
adjacent receptive fields) in order to sharpen contrast facilitating the localization of
stimuli.

Answer 23

Lateral inhibition

Question 24

________- diminished response to a sustained stimulus.

Answer 24

Adaption of sensory receptor

Question 25

Adaption of sensory receptor: _______-rapidly adapting o Report changes in the environment o Burst of firing at the beginning and end of stimulus

Answer 25

phasic receptors

Question 26

Adaption of sensory receptor: ______-slowly adapting or not at all o Constant firing when continuous information about a stimulus is valuable

Answer 26

Tonic Receptors

Question 27

Somatic Receptors of the Integument | ______-widely distributed through the epidermis, dermis and subcutaneous layer

Answer 27

Free Nerve Endings

Question 28

What type of Free nerve endings is this? _______-free nerve endings associated with hair follicles, detect hair movement. o Phasic receptors

Answer 28

Root hair plexus

Question 29

What type of Free nerve endings is this? _______-detects stimuli associated with tissue damage and produces the modalities of of pain and itch. o Tonic receptors

Answer 29

Nociceptors

Question 30

What type of Free nerve endings is this? _______-react to changes in temperature. Two main types cold receptors respond to decreasing temperature and warm receptor respond to increasing temperature. Skin contains 3X more cold receptors than warm receptors. o Phasic receptors

Answer 30

Thermoceptors

Question 31

Somatic Receptors of the Integument | ________-found in dermis and subcutaneous layer

Answer 31

Encapsulated Nerve Endings

Question 32

Encapsulated Nerve Endings: _______-detect onset of light touch, found in dermal papillae. o Phasic receptors with small receptive fields

Answer 32

Meissner Corpuscles

Question 33

Encapsulated Nerve Endings: _______-deep pressure and vibration, found deep in the dermis and subcutaneous layer. o Phasic receptors with large receptive fields

Answer 33

Pacinian corpuscles

Question 34

Somatic Receptors of the Integument | _____-in stratum basale of epidermis

Answer 34

Specialized receptor cells

Question 35

Specialized receptor cells _______-detect continuous light touch and pressure. Release neurotransmitters to stimulate free nerve endings (called tactile discs or Merkel discs). o Tonic receptors with very small receptive fields.

Answer 35

Merkel Cells

Question 36

General Structure of Somatosensory Pathways Afferent neurons have a_________ o Soma of afferent neuron lies in the dorsal root ganglia. o Action potential is initiated at the peripheral end of the neuron and travels in the dorsal root of the spinal cord to reach a synapse in the CNS

Answer 36

pseudounipolar structure

Question 37

_______-a bundle of axons transmitting impulses towards the brain. Usually involves three successive neurons (three levels of processing): *Primary (1st-order) neurons *Secondary (2nd-order) *Tertiary (3rd-order)

Answer 37

Ascending Tracts

Question 38

Ascending Tracts: _______-afferent neuron running from the receptor in the periphery to form a synapse in the spinal cord or brain stem.

Answer 38

Primary (1st-order) neurons

Question 39

Ascending Tracts: ______-interneuron in spinal cord or brain stem relays information to the thalamus. The axon of this neuron usually crosses the midline to provide contralateral input to the brain.

Answer 39

Secondary (2nd-order)

Question 40

Ascending Tracts: ______-interneuron running from the thalamus to the primary somatosensory cortex in postcentral gyrus of parietal lobe.

Answer 40

Tertiary (3rd-order)

Question 41

What is the Sensory Pathway for light pressure and hair movement: ________

Answer 41

Dorsal column system

Question 42

In a Sensory Pathway for light pressure and hair movement, the Dorsal Column system, how are mechanoreceptors detected?

Answer 42

Primarily Merkel cells, Meissner’s corpuscles, and Hair root plexus.

Question 43

``` In a Sensory Pathway for light pressure and hair movement, Dorsal Column system, the afferent fiber enters the dorsal root then travels up the dorsal white column (ascending tract) of the spinal cord to form a synapse in the medulla oblongata what order of neurons is this? ```

Answer 43

Primary (1st-order) neurons

Question 44

In a Sensory Pathway for light pressure and hair movement, Dorsal Column system, interneuron with its soma in the medulla oblongata extends its axon across the midline then up to form a synapse in a nucleus of the thalamus what order of neurons is this?

Answer 44

Secondary (2nd-order)

Question 45

Sensory Pathway for nociception and temperature is called?

Answer 45

Spinalthalamic tract

Question 46

Sensory Pathway for nociception and temperature called "Spinalthalamic tract" the afferent fiber extends from the receptor and enters the dorsal root to form a synapse with an interneuron in the dorsal horn of the spinal cord, what order of neurons is this?

Answer 46

Primary (1st-order) neurons

Question 47

Sensory Pathway for nociception and temperature called "Spinalthalamic tract" the interneuron with its soma in the dorsal horn of the spinal cord extends its axon across the midline then up through the lateral white column of the spinal cord to form a synapse in a nucleus of the thalamus what order of neurons is this?

Answer 47

Secondary (2nd-order)

Question 48

______-radid predictable response to a stimulus

Answer 48

Reflex

Question 49

What Component of reflex arc is this? | _______-cell that transduces the stimulus into a neural signal

Answer 49

Receptor

Question 50

What Component of reflex arc is this? ______-sensory (afferent) neurons relay the information from the receptor into the integrating center.

Answer 50

Afferent pathway

Question 51

What Component of reflex arc is this? ______-structure that processes sensory information and sends out motor commands. Usually found in the central nervous system.

Answer 51

Integration center

Question 52

What Component of reflex arc is this? ______-motor (efferent) neurons relay information from the integrating center to the effector cells/organs.

Answer 52

Afferent pathway

Question 53

What Component of reflex arc is this? _____-cells or organs (typically muscles or glands) that produce the response.

Answer 53

Effector

Question 54

______-reflexes may be classified according to: | • Location of the integrating center, and Type of Effector Tissue Responding

Answer 54

Classification of Reflexes

Question 55

Classification of Reflexes: Location of the integrating center: ______-have an integrating center in the spinal cord

Answer 55

Spinal Reflexes

Question 56

Classification of Reflexes: Location of the integrating center: ______-have an integrating center in the brain

Answer 56

Cranial reflexes

Question 57

Classification of Reflexes: Type of Effector Tissue Responding ______-have skeletal muscles as the effector organs. § The efferent neurons for the somatic reflexes are called somatic neurons

Answer 57

Somatic reflexes

Question 58

Classification of Reflexes: Type of Effector Tissue Responding ______-have visceral organs, smooth muscles, or glands as the effector organs. § The efferent neurons for autonomic reflexes are called autonomic neurons.

Answer 58

autonomic reflexes

Question 59

Classification of Reflexes: Circuitry of the Integrating Center: ______-Reflexes involving an integrating center with only one synapse. Ex: bicep, Tricep, patellar, plantar reflex.

Answer 59

Monosynaptic reflexes

Question 60

Classification of Reflexes: Circuitry of the Integrating Center: ______-Reflexes involving integrating centers with multiple synapses. Ex: Cranial reflexes, pupilary reflexes

Answer 60

Polysynaptic reflexes

Question 61

Classification of Reflexes: Circuitry of the Integrating Center: ______-reflexes involving afferent and efferent neurons both on the same (left or right) side of the body Ex: carotid artery

Answer 61

Ipsilateral reflexes

Question 62

Classification of Reflexes: Circuitry of the Integrating Center: _______-reflexes involving afferent neurons on one side of body (left or right) and efferent neurons on opposite side. Ex: eye light shine both pupils are going to constrict.

Answer 62

Contralateral

Question 63

Classification of Sensory Modalities: | _______-receptors are distributed throughout the body.

Answer 63

general senses

Question 64

Classification of Sensory Modalities: ________-receptors are concentrated in special sense organs (olfactory epithelium, eyes, ears, and tongue).

Answer 64

Special Senses

Question 65

Special Senses: ______-travel in cranial nerves from retina (CNII), inner ears (CNVIII), taste buds (CNs VII, IX, & X), and olfactory epithelium (CNI).

Answer 65

Special sense afferent fibers

Question 66

Special Senses: Afferent impulses are sent to a special sense cortex: Primary visual cortex is in the 47) ______________ lobe.

Answer 66

Occipital Lobe

Question 67

Special Senses: Afferent impulses are sent to a special sense cortex: Primary auditory cortex is in the lateral 48) ______________ lobe.

Answer 67

temporal lobe

Question 68

Special Senses: Afferent impulses are sent to a special sense cortex: Primary gustatory cortex is in the 49) ______________ lobe

Answer 68

Insular Lobe

Question 69

Special Senses: Afferent impulses are sent to a special sense cortex: Primary olfactory cortex is in the medial 50) ____________ lobe

Answer 69

Temporal Lobe