The Senses!

I. The Sensory Organs Allow for the body to receive information from the outside world Have specialized receptors for specific stimuli Transmit the information to the brain (via nervous system) Are 5 sensory organs Skin (for touch), Tongue (for taste), Eye (for sight), Nose (for smell), Ear (for hearing)

II. The Skin Largest organ of the body Main functions are to protect the body and allow for the sensation of touch Is composed of three layers The epidermis (“epi” meaning over); outer layers The dermis; where sensory receptors are found The hypodermis (“hypo” meaning low); contains fat cells (for energy and heat)

Types of sensory receptors in the dermis Pain receptors Touch and pressure receptors Temperature receptors (hot and cold) Certain areas of the body will have more sensory receptors than others

Anatomy of the skin Hair Epidermis Blood vessels Dermis Hypodermis Sensory receptors Fat cells Nerve

Sensory Receptors in Skin

Touch and pressure receptors in skin

“Homunculus”

II. The Tongue Is a muscle (not an organ!) Main functions are to allow for food to be swallowed, sense taste and create sounds (to talk) The taste buds sense taste. Humans detect 5 tastes Sweet (i.e. bubblegum) Sour (i.e. lemons) Salty (i.e. salt) Bitter (i.e. citric fruit skin) Umami (new; associated with aged meat taste)

Anatomy of the tongue Papillae Taste bud