1.6.7 Touch

1. mechanoreceptors

2. thermoreceptors

3. nociceptors

what are the 3 types of touch receptors?

mechanoreceptors

detect pressure and texture

thermoreceptors

detect change in temp

nociceptors

detect pain (tissue damage)

1. touch receptors

2. peripheral nervous systems

3. thalamus

4. somatosensory cortex

what is the order for processing touch?

phantom limb sensation

experience of feeling sensations (pain) in a limb that has been amputated; brain’s sensory map still includes missing limb, brain sometimes misfires

1. thalamus - sends signals to sensory cortex abt location and intensity of pain

2. limbic system - emotional response to pain

where do nociceptors send signals?

gate control theory

spinal cord contains a neurological “gate” that blocks or allows pain signals to pass to the brain; suggests chronic pain can be treated by “blank-closing” stimulation (massage, mental activity, distraction)

small nerve fibers

these nerve fibers carry pain signals

large nerve fibers

these nerve fibers carry other touch signals (ex. pressure)

1. activate large fibers

2. close gate

3. prevents signal from reaching brain

4. reduces perception of pain

what is the process for “gate-closing”?

vestibular sense

allows us to detect the movement of our head and helps us keep our balance; essential for walking, standing, balance, coordination, spatial orientation, posture

semicircular canals

3 fluid-filled tubes in inner ear with canals oriented on different planes; detect diff head movements, dizziness

vertigo

occurs when the brain receives conflicting signals from the vestibular system and other senses, leading to a spinning sensation

kinesthetic sense

body’s ability to detect the position and movement of muscles, joints, and limbs; provides sense of movement and position of our body parts relative to each other, enables us to move efficiently and accurately w/o constantly having to look at our limbs