Chemoreception Taste, Smell, Touch

Sensory receptors Rely on the transfer of matter and energy Molecular transfer Chemical receptors Energy transfer Conduction – The transfer of heat (kinetic energy) by physical contact between molecules. Includes mechanical waves and pressure waves Convection – The transfer of kinetic energy by moving groups of molecules from one area to another Radiation- The transfer of energy via electromagnetic waves. These include visible light, x-rays, UV- light.

Sensory: taste Chemoreception Taste receptors Bitter Sweet Salty Sour Umami? (meaty)

Each taste bud contains more than 100 taste receptor cells.

Sensory: taste Convection – movement of molecules by bulk flow Energy transfer? Convection – movement of molecules by bulk flow

Sensory: smell Smell Receptor Types: Ethereal Floral Camphoraceous Peppermint Putrid (rotten) Musk (Animal or sweat) Pungent

Diffusion : surface area Turbinals; increased surface area for diffusion

Sensory: mechanoreceptors What type of energy transfer do these types of receptors detect?

Hair Cells synaptic vesicles Mechanosensory Directionally sensitive Fabulously sensitive – Can respond to sub-nanometer displacement! synaptic vesicles

Proprioceptors What type of receptor? This receptor detects what kind of energy transfer? Body position, motion Muscle contraction Tendon stretch Ligament movement Proprioceptors are located within muscles, tendons, and joints.

Pain receptors

TOUCH AND RELATED SENSES 1. All Regions of our bodies are sensitive to TOUCH. 2. YOUR LARGEST SENSE ORGAN IS YOUR SKIN. 3. MECHANORECEPTORS located throughout the Skin make it possible to sense touch, pressure, and tension. 4. In humans, the receptors for touch are concentrated in the face, tongue, and fingertips. 5. Body hair also plays an important role in the ability to sense touch.  Large numbers of Mechanoreceptors are found in the skin at the base of hair follicles. 6.  Our Skin has several different types of Sensory Receptors that are just below the surface of the Skin. 7.  Two Types respond to Heat or Cold - THERMORECEPTORS; Two others respond to TOUCH - MECHANORECEPTORS; one Type responds to TISSUE DAMAGE WHICH CAUSES PAIN - PAIN RECEPTORS. 8. Sensory receptors for Hot or Cold are scattered directly below the surface of the skin. There are THREE to FOUR WARM Receptors for every COLD Receptor. 9. Sensory Receptor can be more concentrated in different places of our bodies. 10. The MOST TOUCH-Sensitive areas are the FINGERS, TOES, AND LIPS. 11.  Pain Receptors are located throughout the skin.  The Sensation of Pain can be experienced as either Prickling Pain (FAST PAIN) or Burning and Aching Pain (SLOW PAIN). Pain receptors are Stimulated by mechanical, thermal, electrical, or chemical Energy.

Sense Energetic transfer used Sight Radiation -- electromagnetic waves Hearing Conduction – mechanical (sound) waves Taste Convection – movement of molecules via bulk flow Smell Convection – movement of molecules via diffusion and bulk flow Touch/heat All Three!

Touch Receptor types Touch receptor type What it senses Pain receptors Intense pressure or heat – imminent or actual tissue damage Thermoreceptors Heat Mechanoreceptors Pressure, vibration, Body position

Receptor type Senses Using Them Pain Receptors Touch Thermoreceptor Mechanoreceptors Touch, Hearing Chemoreceptors Taste, Smell Electromagnetic receptors Sight

What you should be able to do: Identify which energetic process is responsible for transmitting information to each sense organ. Explain how the property of sensation derives from a pattern of responses from cells that sense different stimuli (Colors from 3 types of cones, taste from 4-5 types of receptors, etc.). Explain how receptor specificity for chemoreception works. Explain the importance of sensory information to survival. Identify the location of sensory cells for each sense (Taste bud, nasal passages, skin). Identify which senses detect energy patterns and which detect patterns in matter.