SKIN

Question 1

SENSORY MODALITY

Answer 1

property by which one sensation is distinguished from another

Question 2

FREE NERVE ENDINGS

Answer 2

• bare dendrites

- pain, temperature, tickle, itch + light touch

Question 3

ENCAPSULATED NERVE ENDINGS

Answer 3

• dendrites enclosed in connective tissue capsule

- pressure, vibration + deep touch

Question 4

MECHANORECEPTORS

Answer 4

• detect pressure or stretch

- touch, pressure, vibration, hearing, proprioception, equilibrium + blood pressure

Question 5

THERMORECEPTORS

Answer 5

detect changes in temperature

Question 6

NOCICEPTORS

Answer 6

detect damage to tissues

Question 7

GENERATOR POTENTIAL

Answer 7

free/ encapsulated nerve endings + olfactory reflects produce generator potentials

when large enough - generates a nerve impulse in a first order neuron

Question 8

RECEPTOR POTENTIAL

Answer 8

receptor cells release neurotransmitter molecules on first-order neurons producing post-synaptic potentials

PSP may trigger a nerve impulse

Question 9

EXTEROCEPTORS

Answer 9

near surface of body

receives external stimuli

convey visual, smell, taste, touch, pressure, vibration, thermal + pain sensations

Question 10

INTEROCEPTORS

Answer 10

monitor internal environment (BV or viscera)

not conscious except for pain or pressure

Question 11

PROPRIOCEPTORS

Answer 11

muscle, tendon, joint + internal ear

senses body position, movement + equilibrium

Question 12

MEISSNER’S CORPUSCLE

Answer 12

in dermal papillae of hairless skin

responsible for sensitivity to light touch

rapidly adapting

Question 13

CRUDE TOUCH

Answer 13

sensory modality that allows someone to know something has touched the skin without knowing where it has touched the skin

Question 14

DISCRIMINATIVE TOUCH

Answer 14

provides specific info about a touch sensation such as the location, size, shape + texture of source of stimulation

Question 15

MERKEL’S DISC

Answer 15

type I cutaneous mechanoreceptors

flattened dendrites touching cells of stratum basale

used in discriminative touch (25% of receptors in hands)

Question 16

RUFFINI CORPUSCLE

Answer 16

type II cutaneous mechanoreceptor

found in deep dermis skin

ligaments + tendons

detects heavy + continuous touch + pressure

Question 17

PACINIAN (LAMELLATED) CORPUSCLE

Answer 17

onion-like connective tissue capsule enclosing a dendrite

found in subcutaneous tissues + certain viscera

sensations of pressure or high-frequency vibration

Question 18

HAIR ROOT PLEXUS

Answer 18

free nerve endings found around follicles

detects movement of hair

Question 19

ITCHING

Answer 19

chemical stimulation of free nerve endings

produced by histamine

Question 20

WHAT TEMPERATURES DO COLD RECEPTORS RESPOND TO?

Answer 20

10-40.5 degrees in stratum basale

Question 21

WHAT TEMPERATURE DO WARM RECEPTORS IN DERMIS RESPOND TO?

Answer 21

32.2 to 47.8 degrees

Question 22

WHAT TEMPERATURE IS PAIN PRODUCED?

Answer 22

below 10 + above 40.5 degrees

Question 23

PROPRIOCEPTIVE OR KINESTHETIC SENSE

Answer 23

awareness of body position + movement

estimate weight of objects + walking/typing without looking

Question 24

HOW DOES BRAIN REGULATE MUSCLE TONE?

Answer 24

by controlling gamma fibres

Question 25

SPINDLE SENSORY FIBRES MONITOR CHANGES IN WHAT?

Answer 25

muscle length

Question 26

GOLGI TENDON ORGANS

Answer 26

found at junction of tendon + muscle

consists of encapsulated bundle of collagen fibres laced with sensory fibres

when tendon is overly stretched, sensory signals head for CNS resulting in muscle relaxation

Question 27

SOMATIC SENSORY PATHWAY NEURONS

Answer 27

first-order neurons conduct impulses to CNS by spinal or cranial nerves

second-order neurons conduct impulses from brain stem/ spinal cord to thalamus by crossing over to opposite side of body

third-order neurons conduct impulses from thalamus to primary somatosensory cortex