Spinal cord and sensory part of nervous system

Descrição

Based on PUM physiology presentations and own notes
Soheila Amri
Quiz por Soheila Amri, atualizado more than 1 year ago
Soheila Amri
Criado por Soheila Amri mais de 2 anos atrás
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Resumo de Recurso

Questão 1

Questão
Functions of sensory systems; choose WRONG
Responda
  • Monitor the internal and external environment
  • Transmits signals from CNS to periphery
  • Control of movement
  • Transmits peripheral signal to CNS for processing
  • Regulation of internal organs

Questão 2

Questão
Which of these are sensory input under general (somatic) sensation?
Responda
  • Touch
  • Pain
  • Vision
  • Hearing

Questão 3

Questão
Which of these are sensory input under general (somatic) sensation?
Responda
  • Smell
  • Thermal sensation
  • Proprioception
  • Taste

Questão 4

Questão
Which of these are NOT sensory input under special sensation?
Responda
  • Vision
  • Hearing
  • Taste
  • Pain
  • Smell

Questão 5

Questão
What is true about the senses?
Responda
  • General senses have receptors distributed over a large part of the body
  • General senses have receptors within specific organs
  • General senses located in skin, muscle and joints are somatic (touch, pain, temp, etc..)
  • General senses located in internal organs are visceral (pain and pressure)
  • Balance is not a special sense

Questão 6

Questão
Stages of sensation; choose proper order
Responda
  • Stimulation, Perception, Transduction, Transmission
  • Stimulation, Transmission, Perception, Transduction
  • Stimulation, Transduction, Transmission, Perception
  • Stimulation, Transmission, Transduction, Perception

Questão 7

Questão
Receptor types choose correct
Responda
  • Somatic and olfactory senses reception is through secondary sensory neurons
  • General secondary receptors release neurotransmitter that bind to a neuron that transmits info to brain
  • Special secondary receptors release neurotransmitter that bind to a neuron that transmits info to brain
  • In taste, hearing, sight and balance it is through specialized epithelial receptor cells - secondary receptor.

Questão 8

Questão
Choose correct match of location and receptor
Responda
  • Exteroreceptors - associated with skin
  • Proprioceptors - associated with joints, tendons, muscle, vestibular system
  • Visceroreceptors - associated with organs
  • Exteroreceptors - associated with organs

Questão 9

Questão
Choose correct receptor with the type of activation.
Responda
  • Nociceptors - respond to changes in temperature
  • Thermoreceptors - extreme mechanical, chemical, or thermal stimuli. Pain sensation
  • Mechanoreceptors: compression, bending, stretching of cells. Touch, pressure, proprioception, hearing, and balance sensation
  • Chemoreceptors - chemicals become attached to receptors on their membranes. Smell and taste sensation
  • Photoreceptors - respond to light. Vision

Questão 10

Questão
Division of sensation; choose WRONG
Responda
  • PROPRIOCEPTION – profound
  • EKSTEROCEPTION – superficial
  • INTEROCEPTION – special
  • TELECEPTION – visceral

Questão 11

Questão
Which of these are not an attribute of stimulus
Responda
  • Modality (type of sensation; touch, pain)
  • Location
  • Intensity
  • Timing - When stimuli starts
  • Reflex

Questão 12

Questão
Division of sensations; according to the head
Responda
  • EPICRITIC SENSATION – identification, localisation, characteristic, strength of stimulus possible
  • PROTOPATHIC SENSATION – identification, localisation, characteristic, strength of stimulus possible
  • PROTOPATHIC SENSATION – impossible precise identification of stimulus; often connected with impairing factors - crude touch, pain, extreme temperature
  • EPICRITIC SENSATION – impossible precise identification of stimulus; often connected with impairing factors - crude touch, pain, extreme temperature

Questão 13

Questão
Modalities of stimulus;
Responda
  • Modality is encoded by a single pathway.
  • Each pathway encodes one specific sense
  • Each type of sensation (touch, sound, light, etc.) is called modality of sensation
  • Different modality of sensation is transmitted by a specific nerve fiber and determined by where the nerve fiber terminates in the brain

Questão 14

Questão
Location of stimulus; choose correct
Responda
  • Receptors fires action potential only when stimulus impinges on the receptive field.
  • Fine resolution requires large receptive fields
  • Coarse resolution requires fewer receptive fields to cover the same body surface area
  • Receptive field in skin differ in size and response to touch

Questão 15

Questão
Location of stimulus; coarse and fine resolution. Choose correct.
Responda
  • Coarse resolution; Certain regions of the body, such as arms & legs, have such very large receptive fields.
  • Coarse resolution; Two stimuli separated by as much as 40 mm will be perceived as a single point
  • Coarse resolution; Sensitive regions of the body with small secondary receptive fields include the fingertips.
  • Coarse resolution; Two stimuli separated by as little as 2 mm will activate separate pathways and will be perceived as distinct stimuli
  • Meissner occupy small receptive fields
  • Paccini occupy large receptive fields

Questão 16

Questão
Location of stimulus; choose correct
Responda
  • Primary neuron response is improper to stimulus strength
  • lateral inhibition - adjacent relay cells are inhibited from firing by the excited relay cell
  • feed forward inhibition - primary sensory cell inhibits directly adjacent relay cells.
  • Lateral inhibition increases stimulus contrast

Questão 17

Questão
Intensity of stimulus;
Responda
  • Population code - more sensory receptors are activated as stimulus gets greater
  • Intensity is encoded through the firing rate of receptors
  • Duration of action potential code for underlie perception of stimulus strength
  • Frequency of the stimulus is encoded by the time course of firing

Questão 18

Questão
Timing of stimulus
Responda
  • Duration of the stimulus is encoded by the time course of firing
  • Phasic receptors - long-lasting stimulus will produce a prolonged repetitive discharge in the primary afferent neurons. (pain)
  • Phasic reseptors - long-lasting stimulus will produce a short-lived response in the primary afferent neurons.
  • Tonic receptors are fast-adapting

Questão 19

Questão
Which of these are NOT tonic receptors?
Responda
  • Baroreceptors
  • Paccinian corpuscles
  • Nociceptors
  • Poprioceptors

Questão 20

Questão
Choose correct match of somatic sensory receptors to its stimuli.
Responda
  • Tactile receptors (mechanoreceptors) - receptors detect position and movement
  • Thermal receptors - stimuli: heat and cold
  • Nociceptors - stimuli: painful touch, cut, extreme temperatures
  • Proprioceptive - stimuli: touch, pressure, vibration
  • Static proprioceptors - tonic discharge
  • Static proprioceptors - phasic discharge

Questão 21

Questão
Pacini's corpuscle;
Responda
  • Stimulus: deep cutaneous pressure; vibration
  • Located in epidermis
  • Lamellated corpuscles, single dendrite to layers of corpuscles arranged like
  • Pacini's corpuscle is a skin, sensory nerve ending
  • Slow adapting

Questão 22

Questão
Meissner's (tactile) corpuscle
Responda
  • Has a two-point discrimination. Ability to detect simultaneous stimulations at two points on the skin.
  • Rapidly adapting
  • Numerous and close together on thigh and chest
  • Used to determined temp of objects.

Questão 23

Questão
Merkel (tactile) disks; Choose WRONG
Responda
  • Axonal branches end as flattened expansions associated with epithelial cells
  • Responsible for steady-state signals (continuous touch)
  • Slowly adapting
  • Basal layers of hypodermis
  • Light touch and superficial pressure

Questão 24

Questão
Ruffini's end organ
Responda
  • Primarily in dermis of fingers
  • Rapidly adapting
  • Respond to continuous touch or pressure
  • Slowly adapting

Questão 25

Questão
Hair follicle receptors
Responda
  • Does not respond to bending of hair as occurs in light touch
  • Hair end organs
  • End organ receptor fields overlap; sensation not very localized, yet very sensitive
  • Respond to bending of hair as occurs in light touch

Questão 26

Questão
Free nerve endings; Choose WRONG
Responda
  • Simplest, most common sensory receptor
  • Scattered through most of body; visceroceptors are of this type.
  • Picks up warm 10-15 times more numerous than cold
  • Pain: respons to freezing cold and burning hot, cut of skin, painful touch

Questão 27

Questão
Thermal sensation - choose correct
Responda
  • Rapidly adapting
  • Large receptive area
  • Warm receptors: up to 30C, max excitability at 44-46C;
  • Thermal signals are transmitted in pathways same to those for pain signals
  • Cold receptors: max excitability at 24-28oC;

Questão 28

Questão
Thermal sensation - choose correct
Responda
  • Warm sensation - Transmission by C fibers
  • For each 10C change metabolic rates (temp) alters intracellular chemical reactions more than 2-fold.
  • Cold sensation - Transmission by C fibers
  • Cold sensation - Transmission by Aδ

Questão 29

Questão
Muscle spindle;
Responda
  • Provide information about tension of muscles
  • 3-10 specialized intrafusal skeletal muscle cells
  • Provide information about length of muscles
  • Involved in stretch reflex

Questão 30

Questão
Golgi tendon organ - Choose wrong
Responda
  • Proprioceptors associated with tendons
  • Respond to increased tension on tendon
  • Involved in invers stretch reflex
  • Provide information about length of muscles

Questão 31

Questão
Stimulus encoding - Choose correct
Responda
  • Lateral inhibition - Key attributes of the stimulus must be represented in the signals of the primary SN
  • Stimulus transduction - Stimulus energy is converted into electrochemical energy
  • The stimulus information must be encoded into an electrical signal of some sort. These will result in information about intensity, duration, and location.
  • Neural encoding - sensory information must be fine tuned to achieve maximal discriminative capacity

Questão 32

Questão
Which of these are NOT an organisation of the sensory system?
Responda
  • Parallel pathways
  • Relay nuclei and Interneurons
  • Hierarchical organisation - different levels (highest at the head)
  • Spinal cord and fiber types
  • Neural maps - Parts of brain for different sensations

Questão 33

Questão
Somatosensory transmission - Choose correct
Responda
  • Transmission has specificity and follows topographical organisation
  • Cross-over to decussate through 2 major pathways; Dorsal column and anterolateral pathway.
  • Starts in the neurons of dorsal root ganglia
  • Ends in thalamus nuclei

Questão 34

Questão
Classification of sensory nerve fibers - Choose correct match
Responda
  • Ia = Annulo-spiral ending of muscle spindle - A-alpha Fiber
  • Ia = Golgi tendon organ - A-alpha Fiber
  • II = Flower-spray ending of muscle spindle - A-beta Fiber
  • III = Pain, temp and other receptors - Cdr Fiber

Questão 35

Questão
Dermatomes; Choose correct
Responda
  • Sensory supply to skin
  • All impulses from the receptors first enter the peripheral afferent nerve fiber.
  • After entering the Dorsal Roots it enters spinal ganglion
  • Terminates in spinal cord
  • Each dermatome is innervated by 2 segments of the spinal cord.

Questão 36

Questão
Somatosensory transmission - Which is NOT a pathway?
Responda
  • Ventral columns
  • Dorsal columns
  • Lateral and Anterior spinothalamic tract
  • Anterior and posterior spinocerebellar tracts
  • Spino-olivary cerebellar tract and Trigeminothalamic tract

Questão 37

Questão
Dorsal columns- Choose correct
Responda
  • Primary neurons have cell bodies in dorsal root ganglion.
  • Fasciculus gracilis: sensations from inferior to midthoracic level.
  • Fasciculus gracilis : impulses from above midthorax.
  • Carries sensations of two-point discrimination, proprioception, pressure, vibration to cerebrum, and cerebellum
  • Axons enter spinal cord and ascend to the medulla oblongata by decussating where they synapse with secondary neurons.

Questão 38

Questão
Lateral spinothalamic tract - Choose correct
Responda
  • Picks up pain and temperature
  • Follows a 3 neuron system, where the primary neuron starts in dorsal root ganglia
  • Secondary neuron - thalamus VPL nucleus
  • Tertiary neuron - posterior horn neuron

Questão 39

Questão
Anterior spinothalamic tract picks up which 4 sensations?
Responda
  • Heat
  • Tickle
  • Itch
  • Crude touch
  • Pressure

Questão 40

Questão
Trigemino-thalamic tract - Choose wrong
Responda
  • Fibers join the spinothalamic tract in the brainstem
  • Involves Cranial nerve VI
  • In thalamus synapses on VPL nucleus
  • Carries similar information to that of the spinothalamic and dorsal-column/medial- lemniscal system
  • Carries info from face, Nasal cavity and Oral cavity

Questão 41

Questão
Spino-olivary cerebellar tract - Choose correct
Responda
  • Spino-reticular tract to superior olivary nuclei
  • Spinal dorsal columns to nuclei of the medulla
  • Starts as climbing fibers on Purkinje cells
  • Spino-olivary - contribute to coordination of movement associated with balance
  • Both impulses from Spino-reticular tract and Spinal dorsal columns go to cerebellum

Questão 42

Questão
Anterior and posterior spino-cerebellar tracts - choose correct
Responda
  • Anterior - sensation = Proprioception of muscle, tendon, Joints receptors . Large tactile skin sensation
  • Anterior - sensation = Efferent copy of the anterior horn motor drive
  • Posterior - termination = The same side as its origin. Mossy fibers on cerebellar cortex granular cells
  • Posterior - termination = Both side of cerebellum. Mossy fibers on cerebellar cortex granular cells

Questão 43

Questão
Sensory tracts - choose correct
Responda
  • Cerebellum may reduce the conscious perception of sensations
  • Cortex may reduce the conscious perception of sensations
  • Spinotectal - involved in reflexes that turn the eyes and the head toward point of cutaneous stimulation
  • Corticospinal tracts send branches to ascending tracts and release neuromodulators such as endorphins
  • Corticospinal tracts send branches to descending tracts and release neuromodulators such as endorphins

Questão 44

Questão
Somatic sensory area 1 - Choose correct
Responda
  • Includes areas 3a, 3b, 1, and 2 in postcentral gyrus of the cortex
  • Topographic (somatotopic) projection = the feet - near the midline of the brain,
  • Topographic (somatotopic) projection = the feet - laterally, near the lateral fissure.
  • The cells of the S1 cortex are organized in columns specific to a particular modality.
  • The receptive fields of neurons contain only excitatory zones.

Questão 45

Questão
Somatic sensory area 1 (homunculus) - Choose correct
Responda
  • Regions needing low resolution are represented in the brain in fine detail
  • Regions of the body most richly supplied with sensory receptors have the largest number of neurons in the related areas of the neocortex.
  • High resolution is achieved by having many small receptive fields on the body surface
  • A larger representation in the cortex occurs when less neurons are dedicated to a region of the body.

Questão 46

Questão
Sensory area 1 - Modality of stimulus - Choose correct
Responda
  • Areas 3b, 1- respond to slowly adapting cutaneous receptors
  • Area 1- Deep skin receptors
  • Area 2 - deep skin receptors
  • Area 3a - muscle spindle, tendon and joint receptors

Questão 47

Questão
Somatic sensory area 1 (homunculus - S1) = destruction to S1 causes inability to ...
Responda
  • ...to localize sensations discretely and judge pressure and weight
  • ...to judge shapes and forms and to recognize the position of parts of the body.
  • ...to judge taste and smell
  • ...to judge texture of material and fine gradations in temperature

Questão 48

Questão
Somatic sensory area 2 - choose correct sentence
Responda
  • Impulses come from the ventral column system
  • Impulses come from the spinothalamic system and S1 area
  • Located in postcentral gyrus - posterior and inferior part (area 40 of the cerebral cortex).
  • Localization in this area is good.

Questão 49

Questão
Somatic association area - Choose wrong
Responda
  • Lesion to this area cause inability to recognize own body on same side as the lesion
  • Located behind the S1 area - areas 5 and 7
  • Lesion to this area cause inability to recognize own body opposite to the lesion
  • Lesion of this area lead to inability to recognize the complex forms (feeling for the shape of one's own body is lost).

Questão 50

Questão
Sensory are of the cerebral cortex - choose correct pairing
Responda
  • Visual cortex: occipital lobe
  • Olfactory cortex: superior surface of prefrontal lobe
  • Primary auditory cortex: inferior part of temporal lobe
  • Taste area: lower tip of postcentral gyrus

Questão 51

Questão
Division of neurons; choose what doesn't belong below.
Responda
  • Sensory neuron
  • Dorsal root ganglion
  • Efferent neuron
  • Interneurons of CNS - most reflexes go through these

Questão 52

Questão
Interneurons - characteristics; choose correct
Responda
  • Have both inhibitory and excitatory function
  • Slow neuron
  • Produce action potential
  • Hard neuron to excite

Questão 53

Questão
Salitatory conduction
Responda
  • Fast conduction (120m/s)
  • From one node of ranvier to another
  • Slow conduction (3m/s)
  • Unmyelinated conduction

Questão 54

Questão
Bell-Magendie Law; choose correct
Responda
  • In spinal cord conduction goes uni-aterally between anterior and porsterior root, in one direction only.
  • Anterior spinal nerve roots contain only motor fibers
  • Posterior spinal nerve roots contain only sensory fibers
  • In spinal cord conduction goes bi-laterally between anterior and porsterior root

Questão 55

Questão
Reflexes; choose wrong
Responda
  • Somatic motor reflex - goes to viscera
  • Somatic motor reflex - goes to muscle and skin
  • Autonomic motor reflex - goes to viscera
  • Autonomic motor reflex - goes to muscle and skin

Questão 56

Questão
Monosynaptic reflex (knee-jerk)- Choose correct
Responda
  • Large reflex arc
  • One synaps between sensory and motor neuron
  • Starts in Ia afferent fibers from muscle spindle
  • Complicated reflex
  • Duration of the knee jerk 19-24 ms.

Questão 57

Questão
Spinal regulation; choose correct
Responda
  • Each muscle spindle consists of 10 muscle fibers enclosed in a connective tissue capsule
  • Nuclear bag fibers - thicker, 2 per spindle
  • Nuclear chain fibers - thicker, 2 per spindle
  • Primary - annulospiral endings – rapidly conducting Ia (A-alpha) afferents
  • Secondary - annulospiral endings – rapidly conducting Ia (A-alpha) afferents

Questão 58

Questão
Spinal regulation; choose correct
Responda
  • Static (tonic) response of the nuclear bag region (rapid discharge after fast stretch, less rapid during sustained stretch)
  • Dynamic (phasic) response of the nuclear chain region (discharge at an increased rate throughout the period when the muscle is stretched).
  • Intrafusal muscle fibers - have gamma-motor neurons (S, D)
  • Extrafusal muscle fibers - have alpha-motor neurons

Questão 59

Questão
Spinal regulation - muscle spindle; choose correct
Responda
  • Only the ends of the muscle spindle contract, due to lack of actin and myosin in the centre
  • The mid-portion of the muscle spindle can stretch
  • Gamma motor neurons contract extrafusal muscle fibers and plates, contracting outer part of muscle spindle
  • Ia fibers only gives nuclear chain fiber

Questão 60

Questão
Reflex patterns; choose correct
Responda
  • Dynamic response –increase spindle sensitivity to steady stretch
  • Gamma motoneurons cause contraction of spindle- stretch of nuclear bag portion – activation of Ia – reflex
  • Gamma discharge increases with alpha discharge
  • Static response - increase spindle sensitivity to rate of stretch

Questão 61

Questão
Reflex patterns; choose correct
Responda
  • Gamma discharge with muscle stretch – increase of discharge in Ia
  • Dynamic response – decrease spindle sensitivity to rate of stretch
  • Control – descending tracts from CNS – postural control
  • Gamma discharge decreases with alpha discharge

Questão 62

Questão
Inverse stretch reflex; choose correct
Responda
  • Sensory innervation: Ib - EPSP on motor neurons via interneurons
  • Activation: passive stretch, active contraction of muscle
  • Receptors: in muscle spindle (nerve endings among fascicles of tendon)
  • Very high muscle tension produces – cessation of contraction (autogenic inhibition)
  • Regulate muscle force

Questão 63

Questão
Withdrawal reflex; choose correct
Responda
  • Receptor: in muscle
  • Stimuli - nociceptive, noxious, painful
  • Response - flexor muscle- contraction (limb is moved away from the range of the irritating stimulus), extensor – inhibition
  • Effectors - recruitment of motor units – after discharge
  • Center - inhibition of stimulus in spinal cord

Questão 64

Questão
Functions of spinal cord; choose correct
Responda
  • Regulation of the sensory function, contains motor centers and efferent pathways.
  • Regulation of the motor function, contains sensory centers and efferent pathways
  • Spinal modulation of impulses performed by sensory, motor, and interneurons in particular spinal segment
  • Spinal modulation of impulses performed by sensory, motor, and interneurons among various spinal segments

Questão 65

Questão
Function of spinal cord - spinal centers; choose correct
Responda
  • Grey matter – neural centers for somatic-motor & sensory, and autonomic-motor & sensory
  • White matter – neural centers for somatic-motor & sensory, and autonomic-motor & sensory
  • Grey matter – neural pathways afferent and efferent
  • White matter – neural pathways afferent and efferent

Questão 66

Questão
Which does not belong as a division of the functions of the spinal cord?
Responda
  • Convergence and divergence
  • After-effect
  • Contraction and relaxation
  • Summation and facilitation
  • Inhibition

Questão 67

Questão
Spinal cord; choose correct
Responda
  • alpha-motor neuron is a final common pathway, it connects impulses
  • Central inhibition - presynaptic is only EPSP
  • Central inhibition - Postsynaptic and autoinhibition are EPSP
  • Central inhibition - Autoinhibition is IPSP and mediated by renshaw cells

Questão 68

Questão
Inhibitory interneurons; choose correct
Responda
  • Inhibitory interneurons modulating alpha-motoneurons through (IPSP) renshaw cells
  • Inhibitory interneurons in stretch reflex.
  • Inhibitory interneurons in inverse-stretch reflex.
  • Inhibitory interneurons in withdrawal reflex.
  • Use glycine in its synapses

Questão 69

Questão
Afferent pathways to cerebral cortex - Spino reticular tract
Responda
  • Crosses midline and ascends to brain stem reticular formation
  • Projects bi-laterally through intralaminar nuclei of the thalamus to regions of the cerebral cortex
  • Plays major role in general alertness and arousal in response to tactile (painful) stimuli
  • Does not cross midline before ascending to brain stem reticular formation

Questão 70

Questão
Afferent pathways to cerebral cortex - spinotectal (spinomesencephalic) tract; choose wrong
Responda
  • Does not cross midline
  • Crosses midline
  • Projects to and synapses with anterior colliculi, play major role in orientating eyes and head towards visual stimuli
  • The tract send fibers to grey matter with axons to post. horn of the spinal cord, can suppress incoming pain signal

Questão 71

Questão
Spinal cord tests; choose correct
Responda
  • Turck exam - Examines withdrawal reflex in spinal frog
  • Brondgest - facilitation and inhibition of the reflex
  • Sechenov - Component of the reflex arc
  • Turck exam - Relation between strength of the stimulus and response

Questão 72

Questão
Neurological examinations; choose correct
Responda
  • Always consider left side symmetry
  • Consider central vs. peripheral deficits
  • Organize your thinking into seven categories
  • Organize your thinking into five categories

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