Ch 15 special senses PLTL

​Special Senses: Vision

​VISION:

vision is the most dominant sense  

• Almost half of the cerebral cortex is involved in vision  

• The eye itself is surrounded by bone and fat  

Multiple Choice

What sense is the most dominant one?

• vision

• taste

• smell

• balance

​Some of the accesory structure of the eye include:  

• Eyebrows 

• ´Eyelids (palpebrae) 

• ´Conjunctiva 

• ´Lacrimal apparatus 

• Extrinsic eye muscles 

Open Ended

Name one of the accesory structures of the eye

Sclera-  

1. (White of the eye) 

• Protects and shapes eyeball 

• Anchors extrinsic eye muscles 

 

Cornea-  

• Transparent anterior 1/6 of fibrous layer 

• Bends light as it enters the eye 

• Numerous pain receptors contribute to blinking and tearing reflexes  

 

Some text here about the topic of discussion

Open Ended

What is the anatomical term for the white of the eye?

​vascular layer of the eye-  

• Vascular supply  

• Middle pigmented layer 

• Three regions: choroid, ciliary body, and iris 

1. Choroid region 

• Posterior portion of the uvea 

• Supplies blood to all layers of the eyeball 

• Brown pigment absorbs light to prevent visual confusion 

 

 

choroid region-  

• Posterior portion of the uvea 

• Supplies blood to all layers of the eyeball 

Brown pigment absorbs light to prevent visual confusion, prevents against messed up light signals  

 

Open Ended

What are the 3 regions that are part of the vascular layer of the eye?

​ciliary muscle-  

Smooth muscle bundles that control the lens shape  

 

Iris- 

• The colored part of the eye 

• Pupil—central opening that regulates the amount of light entering the eye 

• Close vision and bright light—sphincter papillae (circular muscles) contract; pupils constrict 

• Distant vision and dim light—dilator papillae (radial muscles) contract; pupils dilate 

• Changes in emotional state—pupils dilate when the subject matter is appealing or requires problem-solving skills 

 

Pupil-  

central opening that regulates the amount of light entering the eye 

Multiple Choice

what is the colored part of the eye called?

• iris

• uvea centralis

• fovea centralis

• sclera

Open Ended

parasympathetic response on the pupil will show as

​Cones- Color  

 

fovea centralis-  

Highest visual activity, WHERE YOU ARE ABLE TO GET THE BEST IMAGE  

 

ganglion cells- 

Part of the neural layer first from superficial to deep  

 

bipolar cells-  

Part of the neural layer second from superficial to deep  

 

Receptors- 

Part of the neural layer, third from superficial to deep  

 

 

​vitreous humor-  

• Clear gel (Posterior chamber, BEHIND the lense) 

• Transmits light 

• Supports lens 

• Holds neural retina against pigmented layer 

• Contributes to intraocular pressure 

• Lasts for a life time 

 

Cataract-  Clouding of the lens 

 

Emmetropic- Normal vision  

Convergence- fixing on a close object woth BOTH eyes

Myopia- short vision, near-shighteness

Hyperopia- long vision, or far-sightedness

Astigamtism- unequal curvature of the lens

 

Multiple Choice

Myopia refers to

• near sightness

• far-sighteness

Open Ended

What is the term used to describe normal vision?