Hap special ssenses

Chemoreceptor

Receptors stimulated by changes in concentrations of certain chemicals

Pain Receptors

Receptors stimulated by tissue damage

Thermoreceptors

receptors stimulated by change in temperature

Mechanoreceptors

receptors stimulated by changes in pressure or movement

Photoreceptors

receptors stimulated by changes in light

When does a sensation occur

When a sensory receptor reaches the threshold leading to an action potential

When does perception occur

when a brain interprets sensory impulses (realization)

Projection

A process by which the cerebral cortex makes the sensation felt come from the stimulated receptors (helps perceive region of stimulation)

How are resulting sensations and regions of the brain correlated

the region of the brain receiving the impulse will interpret it as a certain sensation (sound, touch, etc…)

Sensory adaptation

the ability of the nervous system to become less responsive or ignore maintained stimulus

Free nerve endings

Receptors common in epithelial tissue with branches extending between them, responsible for itching sensation

Tactile (Meissner’s) corpuscles

Abundant in hairless areas of skin, responding to the motion of objects barely contacting the skin interpreting it as light touches. In and are connective tissues with 2+ sensory nerve fibers branching into one.

Lamellated (Pacinian) Corpuscles

Composed of CT fibers and cells, one sensory nerve fiber extends into each. Found in deeper dermal and subcutaneous tissues + muscle tendons and joint ligaments. Respond to heavy pressure and associated with the sensation of deep pressure.

Warm receptors

receptors responding to warmer temperatures, most sensitive above 77℉ unresponsive above 113℉ (above 113 = pain receptors burning sensation)

Cold receptors

receptors responding to colder temperatures most sensitive at temperatures between 50℉ and 68℉ (Below 50 = pain receptors freezing sensation)

How do thermoreceptors adapt

they adapt to temperature change rapidly making sensation of warmth or cold fade quickly

Where are pain receptors located

throughout the skin and internal tissues

What lacks pain receptors

The brain

How do pain receptors adapt

they adapt very little even by a single stimulus causing persisting pain

Referred pain

a phenomenon that makes visceral pain be felt from another place in the body other than the place where it’s stimulated

Main types of axons conducting impulses away from pain receptors

Acute pain fibers and Chronic Pain fibers

Acute pain fibers feature

Myelinated, conduct impulses rapidly, create the sensation of sharp pains, stops quickly after stimulus stops, from sin usually

Chronic Pain fibers feature

Unmyelinated, conduct impulses slowly, create a sensation of dull aching that’s difficult to pinpoint, impulse continues after stimulus stops

How does the cerebral cortex and thalamus work together for pain

Awareness of pain occurs when it reaches the thalamus, the cerebral cortex determines intensity, source, and response

Enkephalins

a type of inhibiting substance that naturally suppresses acute and chronic pain, released in response in extreme pain + natural pain control

Endorphins

Has pain suppressing properties and are released with other natural pain suppressors in the body