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 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

Mechanosensory Directionally sensitive Fabulously sensitive –

Can respond tosub-nanometer displacement!

synapticvesicles

Proprioceptors

Body position, motion

Muscle contraction

Tendon stretch

Ligament movement

What type of receptor?

This receptor detects what kind of energy transfer?

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 receptorsIntense pressure or heat – imminent or actual tissue damage

Thermoreceptors Heat

MechanoreceptorsPressure, vibration, Body position

Receptor type Senses Using Them

Pain Receptors Touch

Thermoreceptor Touch

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.