Slides 60-68

What does touch involve?

Sensations involving:

• Modality: What kind of sensation is it? For example, pressure, vibration, or light touch.

• Intensity: How strong is the sensation? Is someone touching you lightly or pressing firmly?

• Location: Where on your body are you being touched?

• Duration: How long does the sensation last?

how your body detects things that contact your skin

Where are touch receptors located?

In the skin

• Meissner corpuscles

• Pacinian corpuscles

• Merkel disks

• Ruffini endings

What is proprioception?

Awareness of the position and location of the body and its parts

• your body's ability to sense where your body parts are and how they are positioned, without needing to look at them.

What does proprioception depend on?

• Impulses from the inner ear

• receptors in joints

• ligaments

What is proprioception necessary for?

• Balance

• Coordinated movement

• Grading of muscular contraction

What Proprioceptive Dysfunction do we need to know?

• Vestibular nystagmus

• Vertigo

• Ménière disease

• Peripheral neuropathies

What is vestibular nystagmus?

Constant involuntary eyeball movement caused by ear disturbances and overstimulation of the semicircular canal system

What is vertigo?

A sensation of spinning associated with inflammation of the ear semicircular canals

What is Ménière disease?

An idiopathic episodic vestibular disorder caused by abnormalities of endolymph in the middle ear

What else is listed as a proprioceptive dysfunction?

Peripheral neuropathies

What vision conditions and diseases do we need to know?

• Blepharitis

• Hordeolum (stye)

• Chalazion

• Entropion

• Conjunctivitis

• Keratitis

What is blepharitis?

Inflammation of the eyelids

• The edges of the eyelids become inflamed, often causing redness, irritation, or crusting near the eyelashes.

What is a hordeolum or stye?

Infection of sebaceous glands of the eyelids

• A painful, red bump forms on the eyelid due to an infection involving an eyelid gland.

What is a chalazion?

A noninfectious lipogranuloma of the meibomian oil-secreting gland

• An oil-producing meibomian gland becomes blocked, leading to inflammation and a lump. Unlike a stye, it is usually not caused by an active infection.

What is entropion?

A common eyelid malposition in which the lid margin turns inward against the eyeball

• The eyelid margin turns toward the eyeball, so the eyelashes may rub against the eye and irritate it.

What is conjunctivitis?

Inflammation of the conjunctiva

What is acute bacterial conjunctivitis?

Highly contagious pinkeye with mucopurulent drainage and redness

What other types of conjunctivitis are listed?

• Acute bacterial

• viral

• allergic

• chronic

• trachoma

What is trachoma?

Chlamydial conjunctivitis that is a leading cause of preventable blindness in the world

What is keratitis?

Inflammation of the cornea

• The cornea is the clear front surface of the eye. Inflammation can cause pain, redness, light sensitivity, and blurred vision.

What part of the eye is affected with aging?

The lens

What conditions can affect the eye in aging?

Chronic disease, dementia, and diabetes also affect the eye, especially visual acuity (How sharply you can see details) and extraocular motor function (How well the muscles move your eyes)

What does it mean by visual dysfunction?

Something is interfering with that process, causing a problem with how you see or how your eyes move.

What alterations in ocular movement that lead to dysfunction do we need to know?

• Strabismus

• Nystagmus

• Paralysis of individual ocular 

What can cause alterations in ocular movements?

Oculomotor, trochlear. Abducens cranial nerve dysfunction

What is strabismus?

Deviation of one eye from the other

• causes diplopia

What is diplopia?

Double vision

What is nystagmus

Involuntary unilateral or bilateral rhythmic movement of the eyes

• Pendular and jerk nystagmus

What can paralysis of individual ocular motor muscles cause?

• Limited abduction

• abnormal eyelid closure

• ptosis

• diplopia

What are alterations in visual acuity we need to know?

• Amblyopia or lazy eye

• Scotoma

• Cataracts

• Dark adaptation

• Glaucoma

• retinal detachment

• Age-related macular degeneration (AMD)

What is visual acuity?

The ability to see objects in sharp detail

What is amblyopia or lazy eye?

Reduction or dimness of vision for unknown reasons

What is a scotoma?

A circumscribed defect of the central field of vision

• a localized area of missing or reduced vision

What are cataracts?

Cloudy or opaque areas in the ocular lens that lead to visual loss

What is dark adaptation?

Impaired visual acuity caused by low illumination

What is Glaucoma?

A group of conditions that damage the optic nerve, often associated with elevated intraocular pressure.

• Vision loss can occur, commonly affecting peripheral vision early on.

What is glaucoma associated with?

Intraocular pressures above the normal pressure of 12 to 20 mmHg

What is retinal detachment?

Separation involving the retina

What type of retinal detachment is most common

Rhegmatogenous retinal detachment

What causes rhegmatogenous retinal detachment?

Retinal breaks caused by vitreoretinal traction

What is age-related macular degeneration?

A condition involving accumulation of drusen or retinal waste products in the deep retinal layers

Which type of AMD is most severe?

Wet AMD

• more rapidly damaging, involving abnormal blood vessel growth and leakage.

Which type of AMD is most common?

Dry AMD

• associated with changes including drusen, which are deposits beneath the retina.

What is accommodation?

The process by which the thickness of the lens changes

• the process of changing the lens's shape to focus on objects at different distances.

What can affect accommodation?

• Oculomotor nerve changes

• decreased lens flexibility

What are clinical manifestations of altered accommodation

• Diplopia

• blurred vision

• headache

What is presbyopia?

Loss of accommodation in older adults