Animal Physiology Ch. 7 Vocab

Front 1

Rhodopsins

Back 1

A purplish-red, light-sensitive pigment with 11-cis retinal as its prosthetic group; found in the rods and cones of the vertebrate retina and in the eyes of many other phyla; bleaches to ‘visual yellow’ (all-trans-retinal) when it absorbs incident light

Front 2

Fovea (area centralis)

Back 2

The portion of the mammalian retina that has the highest visual resolution due to the small divergence and convergence in the pathways linking photoreceptors to retinal ganglion cells; in primates, contains closely packed cone cells

Front 3

Endolymph

Back 3

The aqueous solution surrounding many hair-cell sensory receptors, including cochlear hair cells; it has a high K+ concentration and a low Na+ concentration

Front 4

Hair cells

Back 4

A mechanosensory epithelial cell bearing stereocilia and in some cases a kinocilium

Front 5

Stereocilia

Back 5

Nonmotile filament-filled projections of hair cells, lacking the internal structure of motile “9 + 2” cilia

Front 6

Kinocilium

Back 6

A true “9 + 2” or “9 + 0” cilium present in sensory hair cells.

Front 7

Labeled line coding

Back 7

A pattern of info processing in the nervous system in which each neuron encodes only one particular type of info (eg sour stimuli in the taste system), and all of the axons that carry that type of info project to the same location or locations

Front 8

Quality

Back 8

A property that distinguishes sensory stimuli within a sensory modality (eg color is a quality of visual stimuli)

Front 9

Stretch receptors

Back 9

A sensory receptor that responds to stretch, typically associated with lungs, blood vessels, or muscle tissue

Front 10

Pupil

Back 10

The opening at the center of the iris through which light passes into the eye

Front 11

Interoceptive (internal) receptors

Back 11

Sensory receptors that respond to changes inside the body

Front 12

Proprioceptors

Back 12

Sensory receptors situated primarily in muscles and tendons that relay information about the position and relative motion of parts of the body

Front 13

Transduction

Back 13

The transformation of one kind of energy or signals into another kind of energy or signal

Front 14

Threshold of detection

Back 14

In sensory transduction, the minimum stimulus energy that will produce a response in a receptor 50% of the time

Front 15

Receptor potential

Back 15

A change in membrane potential elicited in sensory receptor cells by sensory stimulation, which changes the flow of ionic current across the plasma membrane

Front 16

Phasic receptor

Back 16

A sensory receptor that produces action potentials during only part of a sustained stimulus, typically at the onset or offset of the stimulus, or in some cases both.

Front 17

Tonic receptors

Back 17

Sensory receptors that continue to fire action potentials throughout the duration of a stimulus and can thus directly convey info about how long the stimulus lasts

Front 18

Generator potential

Back 18

A change in transmembrane potential within the receptive portion of a sensory neuron whose amplitude is graded with stimulus intensity and is sufficiently large at the spike-initiating zone to produce action potentials

Front 19

Dynamic range of receptor cell

Back 19

The range of energy over which a sensory system is responsive and can encode info about stimulus intensity

Front 20

Sensory adaptation

Back 20

The process by which a sensory system becomes less sensitive to stimuli during prolonged or repeated stimulation

Front 21

Range fractionation

Back 21

The arrangement by which receptors within a sensory modality are turned to receive info within relatively narrow, but not identical, intensity ranges, so the entire dynamic range of the modality is divided among different classes of receptors.

Front 22

Autoinhibition

Back 22

Self-inhibition

Front 23

Lateral inhibition

Back 23

Reciprocal suppression of excitation by neighboring neurons in a sensory network; produces enhanced contrast at boundaries and an increase in dynamic range

Front 24

Olfactory receptors

Back 24

Respond to airborne molecules

Front 25

Chemoreceptors

Back 25

A sensory receptor that is specifically sensitive to certain molecules

Front 26

Gustatory receptors

Back 26

Receptor molecules involved in taste

Front 27

Cochlea

Back 27

A portion of the inner ear of many vertebrates; a tapered tube wound in mammals into a spiral like the shell of a snail, containing hair-cell receptors for detecting sound

Front 28

Organ of Corti

Back 28

The part of the cochlea that contains the hair cells

Front 29

Thermoreceptors

Back 29

Sensory nerve ending specifically responsive to temperature changes

Front 30

Photoreceptors

Back 30

Sensory neuron that is tuned to receive light energy

Front 31

Retinal

Back 31

The aldehyde of retinal obtained from the enzymatic oxidative cleavage of carotene; in the 11-cis form, it unites with opsins in the retina to form the visual pigments

Front 32

Ommatidium (ommatadia)

Back 32

The functional unit of the invertebrate compound eye, consisting of an elongated structure with a corneal lens, a focusing cone, and several photoreceptors

Front 33

Rhabdomere

Back 33

The light absorbing part of a retinular cell that faces the central axis of an ommatidium; the photopigment-bearing plasma membrane is expanded intro closely packed microvilli, increasing the amount of photosensitve membrane

Front 34

Rhabdome

Back 34

The aggregate structure consisting of a longitudinal rosette of rhabdomeres arranged axially in the ommatidium

Front 35

Cornea

Back 35

The clear surface of the eye through which light passes as it enters the eye

Front 36

Corneal lens

Back 36

The clear structure at the outside surface of an ommatidium; it admits and focuses light entering the ommatidium.

Front 37

Retina

Back 37

The photosensitive inner surface of the vertebrate eye

Front 38

Vomeronasal organ

Back 38

Mediates chemical communication among animals of the same species. Detects pheremones

Front 39

Mechanoreceptors

Back 39

A sensory receptor turned to respond to mechanical distortion or pressure