Characteristics of Electromagnetic Radiation and Vertebrate Vision

A set of flashcards to review key concepts related to electromagnetic radiation, the anatomy of the vertebrate eye, and the phototransduction process.

Electromagnetic Radiation

Energy that propagates through space with speed in a vacuum of 300,000 km/s.

Frequency

The number of cycles of energy fluctuation per second.

Wavelength

The distance covered by one cycle of electromagnetic radiation.

Photoreceptor Cells

Cells in the human retina that can only detect wavelengths between 400 and 700 nm.

Pupil

The part of the eye that controls the amount of light entering.

Lens

The transparent structure in the eye that focuses light onto the retina.

Retina

The back layer of the eye containing neurons that process visual information.

Macula

A region of concentrated light-sensitive cells around the fovea.

Fovea

The most concentrated part of the macula, populated almost entirely by cones.

Optic Nerve

The nerve that transmits visual information from the retina to the brain.

Photoreceptors

The primary light detectors in the retina, which include rods and cones.

Hyperpolarization

The change in membrane potential of photoreceptors in response to light.

Rhodopsin

A light-sensitive receptor protein in rod cells, essential for detecting light.

Cyclic GMP (cGMP)

The soluble second messenger involved in transducing the signal from photoreceptors.

Guanylate Cyclase

An enzyme that converts GTP to cGMP; highly active in the dark.

Phosphodiesterase (PDE)

An enzyme that breaks down cGMP, playing a critical role in the phototransduction cascade.

Calcium Channels

Channels that allow calcium ions to enter cells, influencing neurotransmitter release.

Color Vision

The ability to perceive differences in color, enabled by different types of photoreceptors.

Trichromatic Vision

Vision based on the use of three types of cones sensitive to different wavelengths.

Opsins

Light-sensitive proteins that are part of the photoreceptor cells, including rhodopsin and cone opsins.

Color Blindness

A genetic condition affecting the perception of color due to faulty opsins.