Chapter 3: Senses and Perception

Odorants

Odorants

________ are detected by sensory neurons in a small patch of mucus membrane on the roof of the nose.

Iris

The muscled ring around the eye that controls the size of the pupil.

Emotional

________ and sensory components constitute a mosaic of activity leading to pain.

Macula

The area in the retina around the fovea critical for reading and driving.

optic nerve

Signals are sent via the _____ _____ to parts of the brain that process images and allow us to see.

Taste

________ is focused on distinguishing chemicals that have sweet, salty, sour, bitter, or umami (savory) ________.

Olfactory bulb

A rounded structure that contains neurons receiving information about odors detected by sensory neurons on the roof of the nose.

Cones

Photoreceptors that need a bright enough light but give acute details and convey color.

Rods

Photoreceptors that are extremely sensitive to light & allow us to see in dim light but do not convey color.

relative size

Perception of movement, depth, perspective, ________ and movement, shading, and gradations in texture primarily depend on contrasts in light intensity rather than color.

left auditory cortex

The ________ is specialized for speech.

communication

Hearing allows for ________ and information for survival.

Ossicles

The three bones in the middle ear (malleus, incus, stapes) that amplifies the vibrations produced by the eardrum.

Touch

The sense by which we determine the characteristics of objects (size, shape, texture)

spinal cord

They suppress pain by inhibiting the transmission of pain signals from the dorsal horn of the ________ to higher brain areas.

two-point threshold

Neurologists measure sensitivity by determining the _________ _________.

Prostaglandins

Chemicals that enhance the sensitivity of receptors to tissue damage and induces more pain.

Tympanic membrane/Eardrum

The thin tissue that produces and sends sound vibrations to the middle ear.

sensory cells

When stimulated, ________ send impulses along the cranial nerves to taste regions in brain to the thalamus.

Visual signals

________ pass from the optic nerve to the optic chiasm.

Taste buds

________ are found on the tongue, the back of the mouth, and on the palate.

Superior temporal gyrus/Auditory cortex

The part of the brain that analyzes auditory information.

Impulses

________ relayed to several brain structures including the thalamus and cerebral cortex.

Allodynia

Triggering of the pain response from stimuli which doesn't usually provoke pain.

30

Vision involves around __ % of the human brain.

eardrum

The ________ makes the ossicles vibrate and amplify its vibration.

Visual processing

________ starts by comparing the amount of light striking any tiny region of the retina with the amount of surrounding light.

Nociceptors

Sensory fibers that respond to tissue-damaging stimuli and cause pain.

Thalamus

________ and cerebral cortex involved in making the pain /itch message into a conscious experience.

Hair cells

________ convert mechanical vibration to electrical signals and excite the auditory nerve.

Tissue injury

________ releases many different chemicals at the site of damage or inflammation.

Cochlea

The snail-shaped organ in the inner ear that converts mechanical vibrations from the eardrum and ossicles to electrical signals to be sent to the brain.

Topographic

A term referring to the fact that the body is represented in an orderly fashion based on sensory requirements at different levels of the nervous system.

Fovea

The area of the retina where the light is focused.

optic nerve

The third layer of retina is made of ganglia that make up the ________.

Photoreceptors

Neurons that are specialized to turn light into electrical signals.

External ear

The collective name for the visible portion of the ear (pinna) and the auditory canal.

Two-point threshold

The distance between 2 points of skin in order for the person to distinguish 2 stimuli from one.

Signals

________ are fed into at least 3 processing systems.

Odorants

________ can act on more than 1 receptor but to varying degrees.

Cones

________ work in combination to convey information about all visible colors.

Tastants

________ are detected by taste buds.

thalamus

The ________ sends it to a specific area of cerebral cortex which makes us conscious of taste.

spinal cord

The ________ passes information about touch to the thalamus and to the sensory cortex.

Hair cells

________ are topped with stereocilia that are deflected by the overlying tectorial membrane.

Odorants

________ stimulate receptors and initiate a neural response.

Taste buds

________ are embedded in papillae.

Retina

A sheet of photoreceptors in the back of the eye.

Pupil

A hole in the eye that allows light to enter.

Binocular vision

Vision that utilizes two eyes

Optic Chiasm

The X-shaped structure formed at the point below the brain where the two optic nerves cross over each other

2 major types

rods and cones

3 colors of cones

Red, green, and blue

1st layer of retina is made of

Rods and cones

2nd layer of retina is made of

interneurons that relay information

3rd layer of retina is made of

Ganglia that make up the optic nerve

Receptive Field

The region of visual space providing an input to the neuron

Strabismus

A condition where the eyes are not properly aligned

basilar membrane

The membrane containing cells called hair cells that react to different frequencies or pitches

auditory nerve

One of the 12 cranial nerves that is responsible for carrying auditory information from the cochlea to the brain

Tastants

The chemicals present in foods that give them flavor

Taste buds

The sensory organs responsible for obtaining information about taste

E.g

the cornea is several hundreds of times more sensitive to painful stimuli than the soles of feet

Some systems use natural chemicals

endogenous opioids or endorphins