Ascending sensory pathways

Question 1

sensation

Answer 1

detection of sensory stimuli

Question 2

sensory stimulus

Answer 2

a change in the internal or external environments. this includes sight, sound, smell, touch, pressure, taste, temperature, etc.

Question 3

perception

Answer 3

the interpretation of the meanings of sensory stimuli

Question 4

special senses

Answer 4

taste, smell, vision, hearing and balance

Question 5

Where is the taste sensory cortex

Answer 5

the lower end of the postcentral gyrus

Question 6

where is the smell sensory cortex

Answer 6

medial temporal (uncus) and orbitofrontal lobes

Question 7

where is the vision sensory cortex

Answer 7

occipital lobe

Question 8

where is the hearing sensory cortex

Answer 8

superior temporal lobe

Question 9

where is the balance sensory cortex

Answer 9

cerebellum

Question 10

mechanoreceptors

Answer 10

sensitive to a mechanical force

Question 11

thermoreceptors

Answer 11

sensitive to temperature changes

Question 12

photoreceptors

Answer 12

respond to light energy

Question 13

chemoreceptors

Answer 13

responds to chemicals in solution

Question 14

nociceptors

Answer 14

respond to potentially damaging stimuli that result in pain

Question 15

exteroceptors

Answer 15

are sensitive to stimuli arising outside the body. these are located near or at the body surface.
includes: touch, pressure, pain and temp receptors, as well as receptors of special senses

Question 16

interoceptors or interoceptors

Answer 16

are sensitive to stimuli within the body. they are located in the visceral organs or blood vessels. they monitor a variety of stimuli

Question 17

proprioceptors

Answer 17

are sensitive to internal stimuli. they are located in skeletal muscles, tendons, joints, ligaments and in connective tissue. balance receptors of the inner ear may be included

Question 18

complex receptors

Answer 18

located in the special sense organs

Question 19

simple receptors

Answer 19

detect tactile sensation, temperature, pain, muscle senses

Question 20

types of nerve endings for simple receptors

Answer 20

free nerve endings

encapsulated nerve endings

Question 21

free nerve endings

Answer 21

detects pain and temperature. they are located in epithelial tissue

Question 22

encapsulated nerve endings

Answer 22

tactile corpuscles - fine touch

lamellate corpuscles - pressure

Question 23

General organisation of the somatosensory system

Answer 23

sensory receptors at the receptor level
ascending pathways at the circuit level
cerebral neural circuits at the perceptual level

Question 24

processing at the receptor level

Answer 24

involves receptors detecting stimuli, transduction of the stimuli into membrane potentials and propagation of nerve impulses to be send to the brain

Question 25

processing at the circuit level

Answer 25

impulses are delivered to the appropriate regions of the cerebellar cortex for stimulus localisation and perception, or to the cerebellum

Question 26

dorsal column pathway (function)

Answer 26

is for discriminative sensation. this pathway is for fine touch/vibration, conscious proprioception and precise localisation.

Question 27

the medial lemniscus pathway

Answer 27

transmits sensory impulses from general sensory receptors of skin and proprioceptors to opposite somatosensory cortex. it has two tracts - the graciel and cuneate tract

Question 28

the graciel tract

Answer 28

carrier impulses from the lower limbs and inferior body trunk

Question 29

the cuneate tract

Answer 29

transmits afferent impulses from the upper limbs, trunk and neck

Question 30

the spinothalamic pathways (function)

Answer 30

is it non-discriminative sensation. these pathways detect pain and temperature, crude touch and pressure.

Question 31

the dorsal column pathway

Answer 31

sensory neurons are connected to the first-order neuron, which has its cell body in the dorsal root ganglion. the first-order neuron sends the signal through the dorsal column and synapses onto the second-order neuron, which has its cell body in the medulla. decussation occurs. the second-order neuron synapses onto the third-order neuron, which is located in the thalamus. this neuron sends the information up to the post-central gyrus through the medial lemniscus pathway.

Question 32

the spinothalamic pathway

Answer 32

the first order neuron is connected to the sensory receptor. it has its body in the dorsal root ganglion. the first-order neuron synapses with the second-order neuron at the dorsal horn neuron. this is where decussation occurs. the second-order neuron sends information up through the lateral column of the spinal cord, and synapses with the third-order neuron at the thalamus. the third-order neuron sends the information to the post central gyrus.

Question 33

the lateral spinothalamic pathway

Answer 33

transmits impulses concerned with pain and temperature to the opposite somatosensory cortex

Question 34

the anterior spinothalamic pathway

Answer 34

transmits impulses concerned with cruse touch and pressure to opposite somatosensory cortex

Question 35

the spinocerebellar pathway (function)

Answer 35

do not contribute to conscious sensation. they transmit information about muscle or tendon stretch to the cerebellum, which uses this information to coordinate skeletal muscle activity. it is responsible for unconscious proprioception

Question 36

the spinocerebellar pathway

Answer 36

the receptor is a proprioceptor, which connects with the first-order neuron in the dorsal root ganglion. it synapses with the second-order neuron in the dorsal horn neuron. the second-order neurons send information up to the cerebellum.

Question 37

processing at the perceptual level

Answer 37

involves interpretation of sensory input. it depends on the locations of the target neurons in the sensory cortex. each sensory axon tells the brain the action and its location.

Question 38

dorsal column injury

Answer 38

results in loss of fine touch and conscious proprioception on the same side below the site of injury.

Question 39

injury on the left anterolateral side of the spinal cord

Answer 39

results in loss of pain and temperature on the right side

Question 40

injury on the right posterolateral side on the spinal cord

Answer 40

results in loss of conscious proprioception to the cerebellum on the right side of the body