BioPsych Exam II :)

Sensory receptor

Specialized neuron that detects a particular category of physical events.

Sensory transduction

The process by which sensory stimuli are transducer into slow, graded receptor potentials.

Receptor potentials

A slow graded electrical potential produced by a receptor cell in response to a physical stimulus.

Hue

Determined by the wavelength of light.

Saturation

Determined by the purity of the light wave.

Brightness

Determined by the intensity of electromagnetic radiation.

Orbits

Bony pockets in the front of the skull.

Sclera

• white tissue of the eye; continuous.

Conjunctiva

Mucus membranes that line the eyelid and protect the eye.

Cornea

Transparent protective tough outer covering of the eye that admits light.

Pupil

Adjustable opening in the iris that regulates the amount of light that enters the eye.

Iris

Pigmented ring of muscles situated behind the cornea.

Lens

Consists of a series of transparent, onion-like layers; its shape can be changed by contraction of ciliary muscles.

Accommodation

Changes in the thickness of the lens, accomplished by the ciliary muscles, that focus images of near and distant objects on the retina.

Fovea

Area of retina that mediates the most acute vision; contains only sensitive cones.

Vergence movements

Cooperative movements of the eyes which ensure that the image of an object falls on identical portions of both retinas.

Saccadic movements

Rapid, jerky movements of the eyes used in scanning a visual scene.

Pursuit movements

Movements the eyes make to maintain an image of a moving object.

Retina

• neural tissue and photoreceptive cells

• located on the inner surface of the posterior portion of the eye.

• rods and cones face backwards

• converts light energy into electrical signals that our brain will receive

• has two layers

• pigmeneted layer: helps absorb light

• inner neural layer: bipolar nuerons and ganglion neurons

Rod

• Photoreceptor cells of the retina, sensitive to light of low intensity.

• detect gray scale (black and white)

• around edges of retina

• used in peripheral vision

Cone

• Photoreceptor cells of the retina maximally sensitive to one of three different wavelengths of light.

• color/ fine detail

• only focus in well lit conditions

Bipolar cell

• A bipolar neuron located in the middle layer of the retina

• conveying information from the photoreceptors to the ganglion cells

• have synapses at both ends (bridge) one with photo receptor & one with ganglionic neuron which forms optic nerve

Ganglion cell

A neuron that receives visual information from bipolar cells.

Horizontal cell

• neuron that connects nearby photoreceptors and the outer parts of bipolar cells

• Adjusts the signals before sending them to bipolar cells

• Helps control activity in photoreceptor cells

• connects photoreceptors side-to-side

• adjusts brightness & contrast

Amacrine cell

• A neuron that connects nearby ganglion cells and the inner parts of bipolar cells

• Receives signals from bipolar cells

• Helps control and coordinate activity between bipolar and ganglion cells

• connects bipolar → ganglion

• motion & changing light detection

Blue Cone

Shortwave photoreceptor sensitive to blue-violet light.

Green Cone

• Medium wavelength photoreceptor sensitive to green light.

• high frequency

• blushish colors

Red Cone

• Long wavelength photoreceptor sensitive to yellow-green light.

• low frequency

• reddish colors

Negative afterimage

The image seen after a portion of the retina is exposed to an intense visual stimulus, consists of colors complimentary to those of the psychical stimulus.

Complementary colors

Colors that make white or gray when mixed together.

Cortical blindness

Blindness caused by damage to the optic radiations or primary visual cortex.

Blindsight

The ability of a person to reach for objects located in their 'blind' field after damage to the primary visual cortex.

Agnosia

Inability to perceive or identify an object by means of a particular sensory modality.

Visual agnosia

Deficits in visual perception in the absence of blindness caused by brain damage.

apperceptive agnosia

• Failure to perceive objects by their shape, even though visual acuity is relatively normal.

• can’t build complete picture

Prosopagnosia

• Failure to recognize particular people by the sight of their faces.

• face blindness

associative agnosia

• Inability to identify objects that are perceived visually.

• can perceive, draw, and copy, but can’t link it to memory

Optic tract

• bundle of nerve fibers that carries visual information from the optic chaism to other parts of the brain.

Optic chiasm

• point where the optic nerves from both eyes meet and some of their fibers cross over, forming the optic tracts

• at this location, each retinal ganglion cell makes a decision about the route it will take into the brain -

• whether its axon will go contralaterally (cross over) or ipsilaterally (stay on the same side), depending on its position on the retina

Optic disk

• Location on retina where fibers of ganglion cells exit the eye

• responsible for the blind spot

Nerve

Outside of the central nervous system.

Tract

Inside of the central nervous system.

Nasal and Temporal Fields

Refers to the visual fields of the eye; nasal is closer to the nose, while temporal is away from the nose. Only 2 and 3 cross, while 1 and 4 remain on the same side of the brain. 

Transduction

The process through which sensory stimuli are converted into neural impulses that can be interpreted by the brain.

Sense of smell and taste

Chemical senses.

Touch comes from

Vibrations.

Sensation

• the bottom up process by which our senses like vision, hearing and smell receive and relay outside stimuli.

• stimulated receptor creates a pattern of neural messages representing the stimulus in the brain.

Perception

• the top down way our brains organize and interpret that information and put it into context

• mental process that elaborates and assigns meaning to incoming sensory patterns.

• an interpretation of sensation.

Tunnel Vision

condition where peripheral vision (side vision) is lost, leading to the perception of only a central area of vision (straight ahead)

Field Neglect

neurological condition where an individual fails to notice one side of their visual field, often as a result of damage to the right hemisphere of the brain, affecting their ability to attend to objects or stimuli on the left side.

Ossicles

• three tiny bones in the middle ear (malleus, incus, stapes)

• transmit sound vibrations from the tympanic membrane to the inner ear.

Malleus

The ‘hammer’, the first of the three ossicles attached to the tympanic membrane.

Incus

The ‘anvil’ located between the malleus and the stapes.

Stapes

The ‘stirrup’, the third ossicle attached to the oval window of the cochlea.

Pitch

• perceptual dimension of sound that corresponds to the fundamental frequency of the stimulus.

• frequency = high pitch = hue

• amplitude = high volume = brightness

Hertz

Cycles per second.

Loudness

A perceptual dimension of sound that corresponds to the intensity of the stimulus.

Timbre

A perceptual dimension of sound that corresponds to the complexity of the stimulus.

Pinna

 the external ear that we can see, collects sound from movement 

Tympanic membrane

the eardrum, vibrates when stimulated by sound waves 

Cochlea

• snail shaped, fluid filled, bony structure of the inner ear

• contains the basilar membrane/auditory receptor hair cells

• contains scale of vestibuli, media, typmani

Oval window

• opening in the bone of the cohlea

• reveals a membrane agaisnt which the baseplate of the stapes presses

• transmits sound vibrations into the fluid-filled cochlea.

Utricle

Receptor for horizontal movements.

Saccule

Receptor for vertical movements.

Deiter cell

A supporting cell found in the organ of Corti, sustains auditory hairs

Basilar membrane

membrane in the cochlea of the inner ear; contains the organ of Corti 

Tectorial membrane

membrane located above the basilar membrane. serves as the shelf against which the cilia of the auditory hair cells move 

Cilium

• hair-like appendage of a cell involved in movement of traducing sensory information

• found on the receptors in the auditory and vestibular system

Cochlear nerve

• branch of eight cranial nerve

• the branch of auditory nerve that transmits auditory information from the cochlea to the brain 

Cochlear nucleus

one of group of nuclei in the medulla that recieve auditory information

Superior olivary complex

a group of nuclei in the medulla; involved with auditory functions, including localization of the sound source

Lateral lemniscus

a band of fibers running rostrally through the medulla and pons, carries fibers of the auditory system

Tonotopic representation

A topographical organized mapping of different frequencies of sound represented in a region of the brain.

Belt region

The first level of auditory association cortex surrounding the primary auditory cortex.

Parabelt region

The second level of auditory association cortex surrounding the belt region.

Cochlear implant

An electrical device surgically implanted in the inner ear to enable hearing for a deaf person 

Kinesthetic System

• sensory system that provides info about body position and movement,

•  known as proprioception

• some receptors report changes in muscle length to the brain, providing our sense of this. 

Blind Spot

• area in the visual field where there are no photoreceptors because this is where the optic nerve exits the eye

• it has no visual information.

Eustachian Tube

connects the middle ear to the nasopharynx

helping to equalize air pressure in the ear (cartilage and bone) 

Homunculus

• the somatic map of the human brain

• little man

• Big hands & lips

• tiny torso & legs

Pacinian Corpuscles

• a specialized somatosensory nerve ending

• detects vibrations

• encapsulated - little protective covering.

• It detects mechanical sensations, like pressure or vibrations.

• it sends that information to your brain so you can feel and respond

Merkel’s Disks

• touch sensitive end organs

• in the skin that sit at the bottom layer of the epidermis

• detect light

• steady pressure and texture

• help you feel fine details

• ex: shapes and textures

Ruffini Endings

• vibration sensitive organs located in hairy skin

• “stretch”

• they notice skin stretching and slow pressure

• not quick vibrations

Gustation (eating)

• first chemical sense

• modality helps us to determine the nature of things we put in our mouths 

Saltiness

this receptor appears to be a simple sodium channel

Sourness

• this receptor appears to respond to hydrogen ions in acidic solutions

Bitterness

typical stimulus for this receptor is a plant alkaloid such as quinine.

Sweetness

• typical stimulus for this receptor is a sugar

• glucose or fructose.

Gustducin

• A G-protein

• transduction of sweetness and bitterness.

• messenger that carries test signals

Olfaction (Smell)

• most enigmatic of the modalities

• odor detection

Olfactory epithelium

• tissue of the nasal sinus that covers the cribiform plate

• the spot in your nose where smells are picked up before going to the brain

Olfactory bulb

• protrusion at the end of the olfactory tract that receives information from olfactory receptors

• processes the smell

Dermatome

• area of skin that is controlled by one spinal nerve.

• It sends sensory information to the central nervous system.

Organ of Corti

• the main hearing organ inside the cochlea of the inner ear.

• turns sound vibrations into electrical signals that the brain understands as sound

• translation of the movement of basilar membrane into electrical impulses

Hierarchical Organization

• association cortex at the highest level

• muscles at the lowest

• parallel structure signals flow between levels over multiple path

• Top (brain) plans → Middle (spinal cord) sends → Bottom (muscles) move.

Mirror Neurons

• active when performing an action or watching another perform the same action.

• study in monkeys

• thought to play a role in empathy and learning through imitation.

Hans Selye

• the “father” of stress.

• a misnomer really. stress vs. strain

• distinguished between stress, which refers to the external pressures and demands placed on an individual

• strain, which is the physiological and psychological response to those stresses. 

Motor Unit

• motor neuron and all the muscle fibers it controls

• when the neuron fires, all its fibers contract.

• Fewer fibers per neuron allow finer control

Acetylcholine

• neurotransmitter released by motor neurons at the neuromuscular junction

• activates muscles

• tells your muscles, “Time to move!”

Adrenaline (Epinephrine)

• A hormone and neurotransmitter involved in the fight-or-flight response

• increasing heart rate

• muscle strength

• blood pressure

• sugar metabolism during stress situations.