CNS Class 2 - Sensory Review

Question 1

Information carried from the body’s tissues via receptors (about its internal and external environments) to the CNS.

Answer 1

Afferent/Sensory

Question 2

T/F - There are about 20 times more efferent than afferent neurons in the human body.

Answer 2

False - There are about 20 times more AFFERENT than EFFERENT neurons in the human body.

Question 3

Transmission of directive signals from the CNS to effectors in the body tissues, such as muscles or glands.

Answer 3

Efferent/Motor

Question 4

The purpose of ________ data is to inform the CNS about what is happening inside the body and external to it so that this information can be processed or evaluated.

Answer 4

Afferent Data

Question 5

The most straight forward type of response where incoming sensory information triggers an automatic efferent reaction without having to reach the brain.

Answer 5

Reflex

Question 6

Reflexes can be very simple or more complex and their neural pathway of afferent neuron to interneuron to efferent neuron is called a ______ ___.

Answer 6

Reflex Arc

Question 7

T/F - Spinal or withdrawal reflexes are able to initiate a response without input from the brain.

Answer 7

True

Question 8

Afferent information that arrives in the brain processing centres receives more complex types of analysis relating to _______ and cognition.

Answer 8

Emotion

Question 9

Data that is carried as afferent transmission along the neurons of the sensory system into the CNS for interpretation and response.

Answer 9

Sensory Input/Afferentation

Question 10

Conscious awareness of sensation.

Answer 10

Sensory Experience (aka. Sensory Perception)

Question 11

Since most afferentation does not rise to consciousness because it is filtered out or suppressed, only a percentage results in sensory __________.

Answer 11

Sensory Experience (aka. Sensory Perception)

Question 12

_________ receptors detect ambient molecules and inform the CNS. If this data is selected for experience, the perception of it is called a _____.

Answer 12

Olfactory Receptors
Scent

Question 13

___________ detect tissue stress or damage and convey this information to the CNS. At this transmission stage it is referred to as __________. Only when the person has a sensory experience of it is it called ____.

Answer 13

Nociceptors
Nociception
Pain

Question 14

T/F - The presence of afferentation from the tissues means there will be sensation.

Answer 14

False - The presence of afferentation from the tissues DOES NOT mean there will be sensation.

Question 15

All sensation is assigned by the _____.

Answer 15

Brain

Question 16

Stimuli are detected in the tissues by receptors that are specialized for specific stimulus types. These receptors are the distal ends of afferent neurons called the _______ or _____ _____ neurons.

Answer 16

Primary/First Order

Question 17

Neurons that convey the transmission to the spinal cord and their synapses occur either in the dorsal horn or farther up in the brainstem via cranial nerves.

Answer 17

Primary/First Order Neurons

Question 18

Neurons in the chain that carry the afferentation data to the thalamus.

Answer 18

Secondary/Second Order Sensory Neurons

Question 19

A reception or relay station for the brain and its crucial role in sensation is to convey data via the ________ or _____ _____ neurons.

Answer 19

Thalamus
Tertiary/Third Order Neurons

Question 20

Neurons in the chain that convey data to the somatosensory cortex, which is part of the system that consolidates sensory experience, as well as to related brain areas for memory, emotion, cognition and autonomics.

Answer 20

Tertiary/Third Order Neurons

Question 21

The anatomy can be different for the special senses and ________ sensation, compared to the pathway for somatosensation.

Answer 21

Visceral Sensation

Question 22

The typical first order neuron is attached to one or more receptors (its specific type) that are embedded in tissue. These receptors have stimulus __________, and if the stimulus is strong enough an ______ _________ is initiated.

Answer 22

Stimulus Thresholds
Action Potential

Question 23

The resulting depolarization wave from a stimulus travels along the axon of a first order neuron, which sits in the dorsal ____ ________.

Answer 23

Dorsal Root Ganglion

Question 24

The axon from the receptor to the cell body of a first order neuron located in the peripheral nerve, and then the spinal nerve, that corresponds with their supply tissue.

Answer 24

Peripheral Branch/Process

Question 25

The axon of a first order neuron that enters the spinal cord's dorsal horn in the CNS.

Answer 25

Central Process

Question 26

Each first order neuron's receptor is located in the tissue it is responsible for sensing and reporting about, meaning that it generates information about a specific stimulus type occurring in a discrete location, referred to as its _________ _____.

Answer 26

Receptive Field

Question 27

The peripheral branches of the first order neurons for a tissue area are bundled together into _________, which are then grouped together into a __________ nerve that is responsible for that tissue zone.

Answer 27

Fascicles Peripheral Nerve

Question 28

A tissue zone and its associated peripheral nerve give rise to an identified pattern of sensation responsibility that is called the nerve's "______ _______."

Answer 28

Supply Tissues

Question 29

In relation to nerve supply tissues, there are smaller areas for which the nerve exclusively carries the ________ neurons, and larger zones where the nerve is the primary but not _________ supplier.

Answer 29

Afferent Neurons Exclusive Supplier

Question 30

First order neurons are in a different configuration once their __________ branches enter a ______ nerve.

Answer 30

Peripheral Branches Spinal Nerve

Question 31

Each ascending dorsal root axon, before reaching the spinal cord, __________ into ascending and descending branches entering several segments _____ and _____ their own segment.

Answer 31

Bifurcates Below Above

Question 32

T/F - Peripheral nerves each carry a group of neurons that do not sense the same tissue zone, but report to the same spinal cord segment.

Answer 32

False - Peripheral nerves each carry a group of neurons that DO sense the same tissue zone, but DO NOT report to the same spinal cord segment.

Question 33

The nerve that contains all the neurons whose functions correspond to one spinal cord level.

Answer 33

Spinal Nerve

Question 34

The supply zone pattern is different for the same body tissues, depending on whether the ______ nerve or the __________ nerve pattern is what is clinically relevant in a case.

Answer 34

Spinal Nerve Peripheral Nerve

Question 35

A spinal nerve's pattern of skin responsibility.

Answer 35

Dermatome

Question 36

A spinal nerve's pattern of responsibility relating to deeper structures such as bone, periosteum and joints.

Answer 36

Sclerotome

Question 37

A term meaning "of the root."

Answer 37

Radicular

Question 38

The spinal nerve is the combination of the nerve _____ from that spinal segment.

Answer 38

Nerve Roots

Question 39

The idea that humans have 5 senses has been around since Aristotle, but in fact there are at least __ identified sensory modalities.

Answer 39

17

Question 40

Sometimes sensory modalities are viewed by the experts as ________ senses (e.g. itch), while other believe in _________ senses that integrate several sub-modalities (e.g. itch is a sub-category of pain).

Answer 40

Separate Senses Principal Senses

Question 41

The term used when a sense has receptors distributed throughout the body in various tissue types.

Answer 41

General Sense

Question 42

T/F - Pain, temperature and motion are all examples of special senses.

Answer 42

False - Pain, temperature and motion are all examples of GENERAL senses.

Question 43

These senses have receptors located in one part of the body and have a special sense organ dedicated to them. They often have specific dedicated interpretation areas in the brain as well.

Answer 43

Special Sense

Question 44

T/F - Vision, smell, hearing and tase are all examples of special senses.

Answer 44

True

Question 45

Experts often disagree about how to categorize senses such as _____ and equilibrium because they are clearly principal sensory categories, but they don't have distinct _________.

Answer 45

Touch Receptors

Question 46

A sense that integrates data from several receptor types, including temperature, light/deep pressure, vibration, stretch, hair movement and nociception.

Answer 46

Touch (aka. Somatosensation)

Question 47

A sense that integrates data from several receptor types, including body position, effects of movement and balance/centre of gravity forces.

Answer 47

Equilibrium

Question 48

T/F - Whether a general, specific or integrated sense, all are premised on information collected by receptors located in the body's tissues.

Answer 48

True

Question 49

Receptors in the body's tissues are in contact with and impacted by _______.

Answer 49

Stimuli

Question 50

_________ are the sensory end-organ that registers stimuli, and they have the capacity to _________ the energy of the stimulus.

Answer 50

Receptors Transduce

Question 51

A process in which stimulus energy is transformed into an action potential that travels along the first order neuron towards the CNS.

Answer 51

Sensory Transduction

Question 52

Each receptor has sensitivity to a particular stimulus type called its ________ stimulus.

Answer 52

Adequate Stimulus

Question 53

Receptors can be __________ in a number of ways, including: - Adequate stimulus - Morphology - Rate of adaptation - Firing threshold

Answer 53

Classified

Question 54

Receptor type associated with mechanical forces as applied to tissue (e.g. pressure, stretch/distortion, tension).

Answer 54

Mechanoreceptors

Question 55

Receptor type associated with temperature relative to tissue temperature (e.g. heat, cold).

Answer 55

Thermoreceptors

Question 56

Receptor type associated with potential or actual tissue damage, as well as potential damage from beyond threshold stimuli (e.g. extremes of cold/hot, excess pressure/mechanical deformation, range of chemicals)

Answer 56

Nociceptors

Question 57

Receptor type associated with sense of position (e.g. placement, stretch, effects of movement).

Answer 57

Proprioceptors

Question 58

Receptor type associated with sense of movement.

Answer 58

Kinaesthetic Receptors

Question 59

Receptor type associated with humidity.

Answer 59

Hydroreceptors

Question 60

Receptor type associated with fluid osmolality (e.g. solute concentration, water-electrolyte balance).

Answer 60

Osmoreceptor

Question 61

Receptor type associated with pressure in blood vessel walls (e.g. increased/decreased wall deformation).

Answer 61

Baroreceptors

Question 62

Receptor type associated with range of chemicals, ions and macromolecules (e.g. taste/odour, noxious).

Answer 62

Chemoreceptors

Question 63

Receptor type associated with electrical fields.

Answer 63

Electroreceptors

Question 64

Receptor type associated with electromagnetic fields (e.g. light, infrared, ultraviolet).

Answer 64

Electromagnetic Receptors

Question 65

Receptor type associated with magnetic fields.

Answer 65

Magnetoreceptors

Question 66

Receptor type associated with chemoreceptors and mechanoreceptors in organs (e.g. report information about visceral structures via ANS reflexes or directly to hypothalamus).

Answer 66

Visceroreceptors

Question 67

T/F - Sensory experience of viscera usually only occurs when there is something functioning properly, never the result of nociception.

Answer 67

False - Sensory experience of viscera usually only occurs when there is something WRONG , USUALLY the result of nociception.

Question 68

Sensory receptors fall in 3 main groupings based on their __________: 1) Free Nerve Endings 2) Encapsulated Receptors 3) Specialized Cells

Answer 68

Morphology

Question 69

These receptors are very common and are found extensively in the skin, as well as most other structures. They are used to sense nociception, temperature and hair follicle movement. They typically have several sensing ends per neuron that are embedded directly in their tissues.

Answer 69

Free Nerve Endings (aka. Bare, Naked, Unmyelinated)

Question 70

These receptors have "bare" endings, but they are encapsulated in a structure that acts to attune them to specific stimuli. This helps lower their firing threshold for it (e.g. detecting the vibration caused by light touch, sensitivity to ranges of deformation, pressure & stretch).

Answer 70

Encapsulated Receptors (aka. Protected, Bulbous, Lamellar/Lamellated, Tactile)

Question 71

These receptors are complex distinct cells that synapses with first order neurons and are used for special senses (e.g. vision, taste).

Answer 71

Specialized Cells

Question 72

A term referring to the priority of the sensory system to keep track of new or worrisome stimuli (e.g. an identified benign stimulus typically loses signal intensity quickly).

Answer 72

Adaptation

Question 73

This receptor adapts slowly to a stimulus and continues to produce action potentials for the duration of the stimulus (e.g. nociception, joint capsule stretch, baroreception). Monitor parameters that must be continually evaluated.

Answer 73

Tonic Receptor

Question 74

T/F - Some tonic receptors are permanently active to convey a background level of firing, such as the 1a sensory neuron in muscle spindles.

Answer 74

True

Question 75

This receptor adapts rapidly to a stimulus by communicating it, then the response diminishes quickly and often stops. It will fire again to signal significant changes in speed/intensity of the stimulus and often fires again when the stimulus stops (e.g. tissue indentation, vibration).

Answer 75

Phasic Receptor

Question 76

T/F - Tonic receptors allow the body to ignore constant unimportant information.

Answer 76

False - PHASIC receptors allow the body to ignore constant unimportant information.

Question 77

T/F - Most exteroreceptors are phasic.

Answer 77

True

Question 78

A term referring to how sensitive a receptor is to it's adequate stimulus.

Answer 78

Firing Thershold

Question 79

These sensitive receptors are immediately activated by their adequate stimulus. They are generally sensing innocuous, everyday types of stimuli and convey all kinds of afferent information that represent routine sensory functions.

Answer 79

Low Threshold Receptors

Question 80

These receptors have a higher activation threshold and are used to detect harm or potential for harm in their tissues. They are sensitive to a variety of chemicals and to extremes of temperature and mechanical stress.

Answer 80

High Threshold Receptors

Question 81

The size or ________ of first order neuron axons and whether or not they are __________ determines the speed at which they conduct their information to the spinal cord.

Answer 81

Diameter Myelinated

Question 82

Match the following fibre types with the corresponding axon size. 1) A-Delta Fibres 2) C-Fibres 3) A-Beta Fibres A) Smallest size axon B) Medium size axon C) Largest size axon

Answer 82

1) A-Delta Fibres = B) Medium size axon 2) C-Fibres = A) Smallest size axon 3) A-Beta Fibres = C) Largest size axon

Question 83

Match the following fibre types with the corresponding level of myelination. 1) A-Delta Fibres 2) C-Fibres 3) A-Beta Fibres A) Heavily myelinated B) Lightly myelinated C) Unmyelinated

Answer 83

1) A-Delta Fibres = B) Lightly myelinated 2) C-Fibres = C) Unmyelinated 3) A-Beta Fibres = A) Heavily myelinated

Question 84

T/F - The smaller the diameter and the more heavily myelinated an axon, the faster it conducts.

Answer 84

False - The LARGER the diameter and the more heavily myelinated an axon, the faster it conducts.

Question 85

______________ are the largest, most thickly myelinated first order neurons, followed by cutaneous A-Beta fibres, which are majority of the tactile/touch ______________ neurons.

Answer 85

Proprioceptors Discrimination

Question 86

A-Delta fibres are mostly ___________, but some are cold-sensing neurons and others communicate ____ movements.

Answer 86

Nociceptors Hair

Question 87

C-Fibres are either nociceptors or conveyors of the type of _____ best described as diffuse, gentle and pleasant.

Answer 87

Touch

Question 88

T/F - The more a first order neuron's information is needed for functional reflex responses and/or fine motor control, the faster it will conduct back to the CNS.

Answer 88

True

Question 89

First order afferent neurons synapse with ______ order neurons in the spinal cord, and these neurons are responsible for conveying the data into the brain, mostly to the ________.

Answer 89

Second Thalamus

Question 90

______ order neurons are organized into ______, in which neurons of the same sensation types travel together.

Answer 90

Second Tracts

Question 91

A much larger number of _____ order neurons converges on a much smaller number of ______ order neurons in the spinal cord. This means that the incoming signals are ____________/summarized before they travel to the brain.

Answer 91

First Second Consolidated

Question 92

Each sensory situation results in the ______ of a cluster of first order neurons that communicates a specific "_______," based on a number of factors (e.g. proportion of slow/fast adaptors, mix of thresholds & transmission speeds).

Answer 92

Firing "Picture"

Question 93

The process in which second order neurons carry afferent information contralaterally where it is interpreted in the somatosensory cortex areas on the opposite side of the brain.

Answer 93

Decussation

Question 94

Most afferent information enters the spinal cord and travels up it _____________, meeting its second order neurons in the medulla oblongata in the _________. They then _________ and carry it to the contralateral third order neurons in the thalamus.

Answer 94

Ipsilaterally Brainstem Decussate

Question 95

Data about nociception, temperature and _____ touch meets it second order neurons right away upon entering the ______ ____, and they immediately cross and transmit up the _____________ side.

Answer 95

Crude Spinal Cord Contralateral

Question 96

As information enters the ______ horn, it is organized into modality-specific tracts and is also subdivided within them into the ____ areas from which it is coming.

Answer 96

Dorsal Body

Question 97

T/F - The dorsal horn itself is divided into four layers, which are referred to as laminae.

Answer 97

False - The dorsal horn itself is divided into SIX layers, which are referred to as laminae.

Question 98

Incoming first order neurons enter in different _______ based on their type and most of these layers also contain ____________ that have the capacity to boost or inhibit second order neuron transmission.

Answer 98

Laminae Interneurons

Question 99

The ____________ are situated between incoming first order neurons and the cell bodies of the second order neurons, ready to carry data to the brain.

Answer 99

Interneurons

Question 100

T/F - All second order neuron transmission heads to the brain to undergo analysis and response processes.

Answer 100

False - NOT all second order neuron transmission heads to the brain to undergo analysis and response processes.

Question 101

Some afferent information goes directly to the cerebellum in the _______________ tracts, and this data is never experienced as sensation.

Answer 101

Spinocerebellar

Question 102

The central receiving area is the ________ and its involvement/relationship with the _____________ cortex along with other brain association areas is crucial to sensory perception.

Answer 102

Thalamus Somatosensory

Question 103

T/F - Third order neurons are the thalamus' communication channels.

Answer 103

True