Anatomy of the Eye and Retina Lecture Slides Quiz

Eye Structure and Function

• The cornea performs 2/3 of the bending of light as it enters the eye.
• The iris muscle controls the diameter of the pupil to regulate the amount of light entering the eye.
• The involuntary reflexive response that occurs when the cornea is stimulated is the blink reflex.
• The ciliary muscle changes shape to focus the lens at different distances.
• The lens performs 1/3 of the bending of light as it enters the eye.
• The trigeminal nerve is responsible for detecting the corneal reflex.
• The posterior chamber is filled with vitreous humor.
• Phototransduction occurs in the photoreceptors (rods and cones) of the retina.
• The photoreceptors form the innermost layer of the retina.
• The posterior chamber is the space between the iris and the lens.
• Ganglion cell axons are located in the optic nerve of the retina.
• Rods contain the type of opsin called rhodopsin.
• Photoreceptors release glutamate onto bipolar and horizontal cells in the retina.
• The retina has a layered (laminated) structure approximately 250 µm thick.

Vestibular System

• The main function of the vestibular system is to maintain balance and equilibrium.
• The otolith organs are located in the vestibule of the inner ear.
• The semicircular canals of the vestibular system are filled with endolymph.
• The function of the cupula in the ampulla of the semicircular canals is to detect rotational movements.
• When you turn your head, the endolymph lags behind, stimulating the hair cells.
• The vestibular system plays a crucial role in reflexive eye movements.
• When the head is turned, the hair cells in the left horizontal semicircular canal are stimulated.
• The otolith organs detect linear acceleration and deceleration.
• Calcium carbonate crystals are embedded in the otolithic membrane of the otolith organs.
• Hair cells in the utricle and saccule respond to linear acceleration by bending their cilia.
• The vestibular nuclei are located in the brainstem.
• When the head is turned, the hair cells in the right horizontal semicircular canal are inhibited.
• The otolithic membrane divides the utricle and saccule into two regions of opposite hair cell orientation.
• The mechanical force of the moving endolymph is responsible for pulling on the cilia of the hair cells in response to linear acceleration.
• Hair cells in otolith organs primarily face away from the center of the utricle and saccule.
• Hair cells in the utricle primarily face downwards.

Visual Perception and Brain Function

• The area of the brain heavily involved in the perception of color is V4.
• The clinical syndrome characterized by the inability to perceive color is called achromatopsia.
• Patients with damage to ventral stream association cortices have difficulty recognizing objects.
• A highly intelligent patient described a flower as a "thing with a shape and a certain smell" when asked to identify it.
• The scientific term for the condition characterized by the inability to perceive color is achromatopsia.
• The article "Visual Routes toLexical Access" by Ungerleider and Mishkin introduced the concept of distributed hierarchical processing in the primate cerebral cortex.
• The main characteristic of visual apperceptive agnosia is the inability to recognize objects despite normal visual acuity.
• The primary cause of prosopagnosia (face blindness) is damage to the fusiform gyrus.
• Visual associative agnosia typically results from damage to the lateral occipital complex.
• The characteristic feature of dorsal stream association cortices disorders is difficulty with guiding actions towards objects.
• Optic ataxia is distinguished from other visual impairments by the inability to guide movements towards objects.
• A defining characteristic of simultanagnosia is the inability to see multiple objects at once.
• The primary cause of akinetopsia is damage to area V5/MT.
• A defining characteristic of contralateral neglect syndrome (hemi-neglect) is the inability to attend to one side of the visual field.
• The primary function of area MT/V5 is to detect motion.
• The brain area primarily responsible for controlling reflexive eye movements is the frontal eye fields.