Referred pain

Sensory adaptation

*Smell - Chemoreceptors

          Pheromones

          Olfactory cell

*Taste - Chemoreceptors

          Taste buds

                    Umami - MSG

*Temperature - Thermoreceptors

          Warm receptors

          Cold receptors

*Vision - Photoreceptors

          Cornea

          Iris and Pupil

          Lens

          Retina

Vitreous humor

Optic nerve

          Rods - Coarse vision

          Cones - Sharp color vision

                   Fovea

*Ears - Mechanoreceptors

          Hair cell

*Balance - Mechanoreceptors

          Vestibular apparatus

                    3 Semicircular canals

*Hearing - Mechanoreceptors

          Pinna

          Ear Canal

          Tympanum (Ear drum)

          Middle ear

                    Ossicles (H A S)

          Inner ear

                    Cochlea

Vision:

Cornea --> Pupil --> Lens --> Retina --> Optic nerve --> Brain (occipital lobe)

Hearing:

Pinna --> Ear Canal --> Tympanum --> Ossicles --> Cochlea

In 1 square centimeter (size of a Dime) of skin there are:

200 Nerve endings                                         3 Blood vessels

10 Hairs and muscles                                  12 Heat-sensing organs

100 Sweat glands                                           2 Cold-sensing organs

15 Oil glands                                                  25 Pressure-sensing organs