What is similar about the structure of the retina and the lateral geniculate nucleus?

Asked By: Deniz Piarali | Last Updated: 4th April, 2020
Category: medical health brain and nervous system disorders
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Like the retina, the lateral geniculate nucleus is a laminated structure, in this case, with six principal layers of cells (Figure 15.3B). Thin layers of the smallest cells (i.e., the koniocellular neurons) are interposed between these principal layers.

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Simply so, what is the function of the lateral geniculate nucleus?

Anatomical terms of neuroanatomy The lateral geniculate nucleus (LGN; also called the lateral geniculate body or lateral geniculate complex) is a relay center in the thalamus for the visual pathway. It receives a major sensory input from the retina.

Also Know, where is the lateral geniculate nucleus located? They wrap around the midbrain and cross the medial surface of the temporal lobe, and 80% of them then terminate in a synaptic relay called the lateral geniculate nucleus (LGN), located in the dorsal part of the thalamus. The LGN is thus the major target for each optic tract.

Regarding this, what happens if the lateral geniculate nucleus is damaged?

Damage at site #4 and #5: damage to the optic tract (#4) or the fiber tract from the lateral geniculate to the cortex (#5) can cause identical visual loss. In this case, loss of vision of the right side. Partial damage to these fiber tracts can cause other predictable visual problems.

What is the pathway for vision?

Visual Pathway. The visual pathway consists of the series of cells and synapses that carry visual information from the environment to the brain for processing. It includes the retina, optic nerve, optic chiasm, optic tract, lateral geniculate nucleus (LGN), optic radiations, and striate cortex (Figure 13-1).

35 Related Question Answers Found

How many lateral geniculate nucleus are there?

…which extend to the two lateral geniculate nuclei (LGN) in the thalamus. The LGN act as way stations on the pathway to the primary visual cortex, in the occipital (rear) area of the cerebral cortex.

Why is lateral inhibition important?

Lateral inhibition increases the contrast and sharpness in visual response. This phenomenon already occurs in the mammalian retina. This mechanism also creates the Mach band visual effect. Visual lateral inhibition is the process in which photoreceptor cells aid the brain in perceiving contrast within an image.

What is Retinotopic organization?

In lower visual areas (e.g., V1 through V5) the neurons are organized in an orderly fashion called topograpphic or retinotopic mapping, in the sense that they form a 2D representation of the visual image formed on the retina in such a way that neighboring regions of the image are represented by neighboring regions of

Where is the Pretectum located?

Location and structure. The pretectum is a bilateral group of highly interconnected nuclei located near the junction of the midbrain and forebrain.

What is a receptive field?

The receptive field is a portion of sensory space that can elicit neuronal responses when stimulated. A sensory space can also map into a particular region on an animal's body. For example, it could be a hair in the cochlea or a piece of skin, retina, or tongue or other part of an animal's body.

How many thalamus do we have?

The thalamus is the main integrator and relay of sensory information to the cortex and has over 50 individual nuclei, each with its own specific function.

What does Magnocellular mean?

Medical Definition of magnocellular
: being or containing neurons with large cell bodies motion and depth perception processed by the magnocellular visual pathway — compare parvocellular.

What do Koniocellular cells do?

Koniocellular layers are located ventral to each parvocellular and magnocellular layer of the LGN. Koniocellular cells are a heterogeneous population differing in many aspects, such as response properties and connectivity.

What happens when the visual cortex is damaged?

Destruction of the primary visual cortex leads to blindness in the part of the visual field that corresponds to the damaged cortical representation. The area of blindness – known as a scotoma – is in the visual field opposite the damaged hemisphere and can vary from a small area up to the entire hemifield.

What happens if the auditory cortex is damaged?

Lesions to the auditory cortex could present no cognitive deficits, deficits which can be repaired, impair seemingly 'unrelated' functions like motor, vestibular, or visual processing, can induce permanent deafness, chronic auditory hallucination etc. It is absolutely a case-to-case basis kind of thing.

What would happen if the cerebral cortex was damaged?

As each of the lobes (and the cortexes located in each lobe) hold different functions, damage to the cerebral cortex can cause many different problems, depending on which part of the cerebral cortex was injured. Damage to the Parietal Lobe can cause one to experience abnormalities in body image and spatial relations.

How does the visual system function?

The visual system is the part of the central nervous system which gives organisms the ability to process visual detail as sight, as well as enabling the formation of several non-image photo response functions.

How do you know if your optic nerve is damaged?

Symptoms might include:
  1. Pain. Most people who develop optic neuritis have eye pain that's worsened by eye movement.
  2. Vision loss in one eye. Most people have at least some temporary reduction in vision, but the extent of loss varies.
  3. Visual field loss.
  4. Loss of color vision.
  5. Flashing lights.

What part of the brain controls visual processing?

Visual cortex. The visual cortex of the brain is that part of the cerebral cortex which processes visual information. It is located in the occipital lobe. Visual nerves run straight from the eye to the primary visual cortex to the visual association cortex.

What does the visual system consist of?

This system is comprised of the eye, optic nerve, optic chiasm, optic tract, lateral geniculate nucleus (LGN), optic radiation, visual cortex and visual association cortex.

What is the purpose of optic chiasm?

Optic chiasm provides a site for the crossing over or desiccation of optic nerve fibers so that contralateral half of the visual field is perceived and processed by the visual cortex. Optic chiasm is surrounded by the circle of Willis and derives its blood from the vessels forming this circle.

Can a severed optic nerve be repaired?

Severed optical nerves can be made to grow again. It is being hailed as one of the most significant advances in nerve regeneration in a decade. They first anaesthetised rats and severed their optic nerves. Then they sutured the two cut ends back together to repair the connective tissue sheath surrounding the nerve.