Sensory Physiology

Skin Receptors

Specialized nerve endings located within the skin that respond to specific types of stimuli and communicate this information to the brain, allowing to interact with the world around us and to protect ourselves from potential harm

Mechanoreceptors

Respond to mechanical stimuli such as pressure, vibration, and touch

Thermoreceptors

Detect changes in temperature and help regulate our body temperature

Nocireceptor

Pain receptors that respond to harmful or potentially damaging stimuli, such as intense pressure, extreme temperatures, or tissue injury. Play a crucial role in our body’s defense mechanism

Merkel Cells

Detect light touch and pressure

Meissner’s Corpuscles

Sensitive to changes in texture and vibration

Pacinian Corpuscles

Detect deep pressure and high-frequency vibration

Ruffini Endings

Respond to sustained pressure and skin stretching

Two-Point touch Discrimination

This test not only allows us to determine the size of receptive fields in different regions of the body, but it can also serve as an important diagnostic test

Localization of Touch

One of the reasons we have discrete receptive fields for touch is to be able to localize where on the skin the sensation was felt

Sensory Adaptation

The ability to sense change is more important than the ability to perceive constant stimuli.

Pressure Receptor Adaptation

This diminishing sensation is where the sensory receptors in your skin adjust their sensitivity to the constant pressure stimulus

Referred Pain

We often perceive those sensation as coming from regions other than where they originate. For example, brain freeze is due to cold sensation in the mouth and throat

Visual Acuity

It is estimated that more than 70& of the population has problems with the ability to see objects clearly.

Myopia

Is due to an elongated eyeball which causes near-sightedness, the inability to see far objects clearly

Snellen chart

Visual acuity is routinely measured by using?

Astigmatism

A congenital defect in the curvature of the Cornea that causes uneven focusing of light, leading to reduced visual acuity or blurred vision.

Occurs when the eye cannot focus evenly in all directions

Near point

Is how close an object can be and still remain in focus.

Hyperopia

A type of far-sightedness caused by a shortened Eyeball, where light focuses behind the retina, making near objects appear blurry.

Presbyopia

An age-related form of far-sightedness in which the Lens loses elasticity, reducing its ability to focus on near objects

Blind spot

The area where the Optic nerve exits the Retina, containing no photoreceptors and resulting in a gap in the visual field.

Stereoscopic Vision

When both eyes work together, they allow you to see objcts appear in 3D

Amblyopia

One eye does not work at all and one has no stereoscopic vision

Sensory Illusions

Are due to the physiological properties of photoreceptors

Cognitive Illusion

Are due to the way the brain processes information. The brain has to compensate for movement, the blind spot, variation in lighting, etc. how you perceive the world is not how the world actually appears

Conduction deafness

Is due to problems in the outer or middle ear resulting in a loss of vibration.

Nerve deafness

Is usually due to damage to the hair cells in the cochlia

Audiometry

Is a simple and useful hearing test to determine the thresholds for hearing at different frequencies.

Rinne Test

This test is used to distinguish between nerve deafness and conduction deafness

Weber Test

Sound should be perceived equally in both ears or in the middle of the head

Nystagmus

Is the rapid movement of the eyeball