Physiological Psychology Module 3

sclera, choroid, and retina

3 layers of the eye

sclera

which maintains, protects, and supports the shape of the eye and includes the cornea

choroid

which provides oxygen and nourishment to the eye and consists of the pupil, iris, and lens

retina

allows us to piece images together and includes cones and rods

optic chiasm

complicated crossover of optic nerve fibers behind the eyes at the bottom of the brain, allowing the right eye to "wire" to the left neural hemisphere and the left eye to "wire" to the right hemisphere

retina

Visual stimulus transduction happens in the

phototransduction

the ability to convert light into electrical signals.

rods and cones

two types of photoreceptor cells

rods

responsible for scotopic vision (night vision)

cones

which are responsible for photopic vision (daytime vision)

brightness

based on luminance and reflectivity

saturation

based on the amount of white present

hue

based on color combinations

inner ear

contains the receptor cells necessary for hearing and equilibrium maintenance

sound localization

Humans can also uniquely estimate where sounds originate

ear

It performs the first processing of sound and houses all the sensory receptors required for hearing

outer ear

main task is gathering sound energy and amplifying sound pressure

pinna

the fold of cartilage that surrounds the ear canal, reflects and attenuates sound waves, which helps the brain determine the location of the sound.

ear canal

amplifies the sound into the eardrum

tympanic membrane.

Sound enters the middle ear once the wave has vibrated the ________

middle ear

an air-filled tympanic (drum-like) cavity that transmits acoustic energy from the ear canal to the cochlea in the inner ear; acts as a gatekeeper to the inner ear, protecting it from damage by loud sounds.

malleus

is connected to the mobile portion of the eardrum. It senses sound vibrations and transfers them onto the incus

incus

bridges the malleus and the stapes

stapes

transfer the vibrations from the incus to the oval window, the portion of the inner ear to which it is connected.

inner ear

filled with fluid

cochlea

to transform mechanical sound waves into electrical or neural signals for use in the brain.

the tympanic canal, the vestibular canal, and the middle canal

three fluid-filled spaces

Corti

Fluid movement within these canals stimulates hair cells of the organ of _, a ribbon of sensory cells along the cochlea.

spiral ganglion

transmits the electrical signals along the auditory nerve and eventually onto the brain system

taste buds

Specialized cells in the gustatory system located on the tongue; send the information from the tastants to the brain, where a molecule is processed as a taste

fungiform papillae

which are mushroom-shaped and located at the tip of the tongue

foliate papillae

which are ridges and grooves toward the back of the tongue

circumvallate papillae

are circular shaped and situated in a row just before the tongue's end.

Gustatory cells

are short-lived and are continuously regenerating. They each contain a taste pore at the tongue's surface, which is the site of sensory transduction.

bitter, sweet, umami

involves in G protein-coupled receptor or GPCR

salty

simplest of all the receptors in the mouth

natural sweeteners

such as saccharides, activate the GPCRs to release gustducin

synthetic sweeteners

activate a separate set of GPCRs

olfactory epithelium

where odorant reception occurs

olfactory mucous membrane

where olfactory receptor cells are located

olfactory transduction

series of events in which olfactory receptors detect odor molecules

odotope

group of odorants that shares some chemical feature and causes similar patterns of neural firing

cilia

tiny hair-like projections that contain olfactory receptor proteins

phermones

airborne, often odorless molecules crucial to many animal's behavior

touch

first sense body develops

somatosensory system

uses specialized receptor cells in the skin and body to detect environmental changes

cutaneous receptors

The receptors in the skin, also called___, tell the body about the three main subdivisions mentioned above: pressure and surface texture (mechanoreceptors), temperature (thermoreceptors), and pain (nociceptors).

Mechanoreceptors

the skin give us a sense of pressure and texture.

speed

refers to how quickly the receptor will react to stimulus and how long that reaction will be sustained after the stimulus is removed

rapid adapting cells

allow us to adjust grip and force appropriately

slowly adapting cells

enable us to perceive form and texture

receptive field size

refers to the amount of skin area that responds to the stimulus

Thermoreceptors

detect changes in temperature through their free nerve endings

Nociceptors

use free nerve endings to detect pain.

first pain or cutaneous pricking pain

easy to locate and generally easy to tolerate

second pain or burning pain

most difficult to locate and not as easy to tolerate

deep pain

challenging to locate, and often, it is intolerable and chronic

Proprioceptors

the receptor cells found in the body's muscles and joints. They detect joint position and movement, as well as the direction and velocity of the movement.

somatic system disorder

psychological disorder related to the somatosensory system

Conversion disorder

A somatic symptom disorder involving an actual loss of bodily function such as blindness, paralysis, or numbness due to excessive anxiety

Illness anxiety disorder

A somatic symptom disorder involving persistent and excessive worry about developing a severe illness.

Body dysmorphic disorder

The afflicted individual is concerned with body image and is excessively concerned about and preoccupied with a perceived defect in their physical appearance.

Pain disorder

Chronic pain experienced by a patient in one or more areas thought to be caused by psychological stress. The pain is often so severe that it prevents proper body function. The duration may be as short as a few days or many years.

Undifferentiated somatic symptom disorder

requires only one unexplained symptom for at least six months

vestibular system

sensory system that contributes to balance and the sense of spatial orientation

semicircular canal system and otoliths

vestibulum has two primary components

components

semicircular canal system

indicates rotational movements,

otoliths

indicate linear accelerations

vestibulo-ocular reflex

control eye movements and provide us with clear vision

Proprioception

involves positioning limbs and awareness of body parts concerning one another