WK 1 part 1 phototransduction, eye anatomy

What did Young's experiments in the 19th century demonstrate about light?

Light can show interference patterns, indicating it acts as a wave.

What theory did Maxwell propose in the context of light?

He proposed that light is an electromagnetic wave.

What phenomenon suggests that light acts both as a wave and a particle?

Wave-particle duality.

What are the discrete energy packets that light is composed of, according to the photoelectric effect?

Photons or quanta.

How did Einstein reconcile the wave and particle nature of light?

He proposed that light acts as both a wave and a particle depending on the situation.

What is refraction in the context of light?

The bending of light due to a change in speed when entering a different material.

What is the frequency range of visible light?

It ranges from approximately 4 to 7 times 10 to the 14th hertz.

What color of light has the highest energy?

Blue light.

What does amplitude in a wave refer to?

The maximum displacement from the midline of the wave.

What is the definition of wavelength?

The distance between two identical points on consecutive waves.

What happens to an electron in a photoreceptor when it absorbs light?

It gets excited and moves to a higher energy state.

What do OFF bipolar cells do in response to light?

They hyperpolarize and turn off due to decreased glutamate levels.

What do ON bipolar cells do when light hits photoreceptors?

They depolarize and turn on as inhibition is lifted.

What structure in the eye absorbs most colors except for the one we see?

The colored object absorbs all other colors, allowing only its own to be reflected.

How is the intensity of light related to amplitude?

Higher amplitude means higher intensity of the light wave.

What is diffraction in the context of light?

The spreading out of light waves around obstacles.

What health issue can arise from the degradation of macular cells?

Macular degeneration.

What is the significance of the cornea in terms of light?

The cornea significantly bends light before it reaches the lens.

What occurs to rods and cones when exposed to light?

They convert light into electrical signals for processing.

What are the rods primarily responsible for in vision?

They are responsible for vision in low light conditions.

What do cones allow for in vision?

They allow for color vision and vision in bright light conditions.

What happens to the release of neurotransmitter glutamate in light?

The release decreases when light hits photoreceptors.

What is the term for the structure where light signals are processed in the eye?

The retina.

How does the eye respond to different wavelengths of light?

It absorbs and processes them differently based on their frequency.

What causes hyperpolarization in photoreceptor cells?

Closure of sodium channels in response to light.

What is the refractive index?

A measure of the amount light bends when passing through a material.

What happens to light rays when they enter a denser medium?

They bend towards the normal line.

How is vision corrected using lenses?

Lenses bend light to focus images correctly on the retina.

What is the 'dark current' in photoreceptors?

The steady inward flow of positive ions in darkness.

Why can we see colors like green?

Because green objects reflect green light and absorb other colors.

How does the eye's response to red light differ from blue light?

Red light requires more energy to achieve the same response.

What role do ciliary muscles play in the eye?

They adjust the shape of the lens for focusing.

What important anatomical structure processes signals before they reach the brain?

The retina.

What phenomenon is explained by the fact that light travels in straight lines?

Reflection.

What do we call the process of converting light signals to electrical signals in photoreceptors?

Phototransduction.

What is unique about the fovea compared to the rest of the retina?

It has the highest concentration of photoreceptors for sharp color vision.

How does aging affect the vitreous humor in the eye?

It tends to shrink and absorb, affecting eye shape.

What is the function of the optic nerve in the eye?

It carries processed visual information to the brain.

Which color of light has the lowest energy?

Red light.

How does light affect bipolar cells?

Light decreases glutamate release, thus affecting their depolarization.

What type of waves are light waves considered to be?

Transverse waves.

Which cells in the retina are primarily responsible for color vision?

Cone cells.

What is hyperpolarization in the context of phototransduction?

The decrease in membrane potential when light is absorbed.

What are the main components of a laser?

Excited electrons releasing energy as photons through stimulated emission.

What causes the bending of light and is key to visual clarity?

Refraction caused by the density of materials.

What is the function of the iris in the eye?

The iris controls the size of the pupil, regulating the amount of light entering the eye.

What is the pupil?

The pupil is the opening in the center of the iris that allows light to enter the eye.

What is the sclera?

The sclera is the white outer layer of the eyeball, providing protection and structure.

What is the choroid?

The choroid is a vascular layer between the retina and the sclera, providing nourishment to the outer retina.

What is the aqueous humor?

The aqueous humor is a transparent fluid filling the front part of the eye, between the cornea and the lens, providing nourishment and maintaining pressure.

What are suspensory ligaments?

Suspensory ligaments connect the ciliary body to the lens, holding the lens in place and helping to change its shape for focusing.

What is the outermost layer of the eye that protects the inner structures?

The sclera.