Table of Contents
- 1 What is the purpose of optic chiasm?
- 2 What is the role of the optic chiasm in transferring visual information into the brain?
- 3 What happens if optic chiasm is severed?
- 4 What is optic chiasm quizlet?
- 5 Why is the crossing of retinal fibers significant?
- 6 Why does damage to the optic chiasm cause peripheral blindness?
- 7 What is the pathophysiology of the hemianopic lesion behind the optic chiasm?
- 8 What is the chiasma of the eye?
What is the purpose of optic chiasm?
The optic nerve connects the brain to the eye. To biologists, the optic chiasm is thought to be a turning point in evolution. 1 It is thought that the crossing and uncrossing optic nerve fibers that travel through the optic chiasm developed in such a way to aid in binocular vision and eye-hand coordination.
What is the role of the optic chiasm in transferring visual information into the brain?
The optic nerve carries visual information from the retina to the brain. At the point of the optic chiasm, information from the right visual field (which comes from both eyes) is sent to the left side of the brain, and information from the left visual field is sent to the right side of the brain.
What visual field crosses at the chiasm?
In the optic chiasm, the fibers of the nasal retina (i.e., the temporal visual field) of each eye cross, whereas the fibers of the temporal retina (i.e., the nasal visual field) of each eye proceed uncrossed.
What could be the advantage purpose of crossing over of the fibers from nasal halves?
At optic chiasm, the fibers from the nasal half cross while the fibers from the temporal half remain uncrossed. This crossing over of optic fibers is important in such a way that it allows the same hemispheric visual field to be perceived by visual cortex from both eyes.
What happens if optic chiasm is severed?
The entire left optic nerve would be cut and there would be a total loss of vision from the left eye. Damage at site #2: partial damage to the left optic nerve. Here, information from the nasal visual field of the left eye (temporal part of the left retina) is lost. Damage at site #3: the optic chiasm would be damaged.
What is optic chiasm quizlet?
Optic chiasm. Where the optic nerves meet in the 3rd ventricle of the brain. Here is where visual information from the right and left eye cross to the contralateral side of the visual systems. It is also ensheathed with the meninges and is surrounded by CSF.
What happens to visual information from the left visual field?
Optic nerve: This cranial nerve sends visual information from your retina to your brain. The left field of vision is processed by the right side (or cerebral hemisphere), and vice versa, moving along an optic tract toward the thalamus.
What happens to the optic nerve at the optic chiasm quizlet?
The information leaves the eye by way of the optic nerve, and there is a partial crossing of axons at the optic chiasm. After the chiasm, the axons are called the optic tract. The optic tract wraps around the midbrain to get to the lateral geniculate nucleus (LGN), where all the axons must synapse.
Why is the crossing of retinal fibers significant?
The partial crossing over of optic nerve fibres at the optic chiasm allows the visual cortex to receive the same hemispheric visual field from both eyes. Superimposing and processing these monocular visual signals allow the visual cortex to generate binocular and stereoscopic vision.
Why does damage to the optic chiasm cause peripheral blindness?
At a structure in the brain called the optic chiasm, each optic nerve splits, and half of its fibers cross over to the other side. Because of this anatomic arrangement, damage along the optic nerve pathway causes specific patterns of vision loss.
What does the optic chiasm look like?
The optic chiasm or optic chiasma is an X-shaped space, located in the forebrain, directly in front of the hypothalamus. Crucial to vision, the left and right optic nerves intersect at the chiasm, thus creating the hallmark X-shape.
What is the optic chiasm and what does it do?
The optic nerve connects the brain to the eye. To biologists, the optic chiasm is thought to be a turning point in evolution. 1 It is thought that the crossing and uncrossing optic nerve fibers that travel through the optic chiasm developed in such a way to aid in binocular vision and eye-hand coordination.
What is the pathophysiology of the hemianopic lesion behind the optic chiasm?
As with any lesion affecting the visual pathway behind the optic chiasm, there is a temporal hemianopic defect in the field of the contralateral eye and a nasal hemianopic defect in the field of the ipsilateral eye.
What is the chiasma of the eye?
Optic chiasma. Crucial to vision, the left and right optic nerves intersect at the chiasm, thus creating the hallmark X-shape. One-half of each nerve’s axons (their long, threadlike portions) enters the opposite tract at this location, making it a partial decussation (crossing).
What is the function of crossing and uncrossing optic fibers?
It is thought that the crossing and uncrossing optic nerve fibers that travel through the optic chiasm developed in such a way to aid in binocular vision and eye-hand coordination. At the optic chiasm, nerve fibers from half of each retina cross over to the opposite side of the brain.