The document discusses four mechanical senses: vestibular, touch, pain, and itch. It describes the vestibular system in the inner ear which detects head position and movement through three semicircular canals and helps with balance and eye movement. It also notes different types of touch receptors for light touch, pressure, temperature, and different pain receptors for sharp and dull pain. The itch sensation is described as the inverse of pain.

1. Today’s Topic
Mechanical Senses

4. Vestibular
Touch
Pain
Itch
Four

5. INNER EAR

6. position of head
INNER EAR

7. orthogonal structure
3-D

8. lateral (horizontal) = pirouette
superior (anterior) = head-heel
inferior (posterior) = cartwheel

9. linear acceleration

10. linear acceleration
utricle = eye movement
saccular = posture

11. Vestibular System ProblemsVETIGO

12. Vestibular System ProblemsVETIGO
Peripheral
motion sickness, flu, etc.
Central
MS, Parkinson’s, etc.

13. TOUCH

14. TOUCH

15. TOUCH
Cold
Measured against skin temp
Warm
No “hot” receptors

16. TOUCH
Light
Meissner’s = onset-offset
Merkel’s = sustained pressure

17. TOUCH
Deep
Pacinian = onset-offset
Ruffini = sustained pressure

18. PAIN

19. TOUCH
Sharp
Good pain = put down skillet
Dull
Bad pain = chronic pain

20. ITCH

21. TOUCH
Inverse to pain
Opiates: pain down, itch increases

22. TOUCH
Pain-itch cycle
Scratch to stop itch
Scratch damages skin, itch starts

23. Dr. Ken Tangen
www.BiologicalPsych.com