Blank - Conscious awareness of stimuli received by sensory neurons

Blank - Sensory nerve endings that respond to stimuli by developing action

potentials

Receptors over large part of body that sense touch, pressure, pain, temperature, and

itch

Somatic senses provide information about body and environment

Visceral senses provide information about internal organs

Blank over large part of body that sense touch, pressure, pain, temperature, and

itch

Blank senses provide information about body and environment

Blank senses provide information about internal organs

Smell, taste, sight, hearing, and balance

Types of Receptors:

• Detect movement

• Example, touch, pressure, vibration

Types of Receptors:

• Detect chemicals

• Examples, odors and taste

Types of Receptors:

• Detect light

Types of Receptors:

• Detect temperature changes

Types of Receptors:

• Detect pain

Types of Touch receptors

• Detect light touch and pressure

Types of Touch receptors

• Detect light touch

Types of Touch receptors

• Deep in epidermis

• Localizing tactile sensations

Types of Touch receptors

• Deepest receptors

• Associated with tendons and joints

• Detect deep pressure, vibration, position

Types of Touch receptors

• Deep tactile receptors

• Detects continuous pressure in skin

Pain is an unpleasant perceptual and emotional experience

Pain can be localized or diffuse

Blank - Sharp, pricking, cutting pain

• Rapid action potential

Blank - Burning, aching pain

• Slower action potentials

Pain control

• Action potentials suppressed from pain

• Receptors in local areas

• Chemicals are injected near sensory nerv

Pain control

• Loss of consciousness

• Chemicals affect reticular formation

Blank - Sense of smell

• Occurs in response to odorants

• Receptors are located in superior portion of the nasal cavity

• We can detect 10,000 different smells

Blank contains a thin film of mucous where odors become dissolved.

Blank neurons are located in the mucous. Dendrites of olfactory neurons are

enlarged and contain cilia.

Dendrites pick up odor, depolarize, and carry odor to axons in _ (cranial

nerve I)

Blank and blank lobes process odor

Blank - Sensory structures that detect taste

• Located on papillae on tongue, hard palate, throat

• Inside each taste bud are 40 taste cells

• Each taste cell has taste hairs that extend into taste pores

Taste buds contain about how many taste cells.

Taste cells send taste stimuli to _

_ contain hairlike processes, called taste hairs, that extend through a taste pore

to the surface of the taste bud.

Dissolved molecules or ions bind to receptors on the taste hairs and initiate action

potentials. Sensory neurons carry signals to the insula of the cerebellum

Types of tastes

Vision

Accessory Structures

• Protects from sweat

• Shade from sun

ision

Accessory Structures

• Protects from foreign objects

• Lubricates by blinking

The eye and accessory structure

• Thin membrane that covers inner surface of eyelid

The eye and accessory structure

• Produces tears

The eye and accessory structure

• Help move eyeball

Outermost Tunic

1. Sclera:

• Firm, white outer part

• Helps maintain eye shape, provides attachment sites for muscles, protects internal

structures

2. Cornea:

• Transparent structure that covers iris and pupil

• Allows light to enter and focuses light

Blank - Firm, white outer part

• Helps maintain eye shape, provides attachment sites for muscles, protects internal

structures

Blank - Transparent structure that covers iris and pupil

• Allows light to enter and focuses light

It is made up of the middle Tunic, Choroid, Cilliary body, Cilliary muscle, Suspensory ligaments, Lens, Iris, and Pupil

• Contains blood supply

• Black part (melanin)

• Delivers O2 and nutrients to retina

• Helps hold lens in place

• Controls shape of lens via suspensory ligaments

• Attaches the ciliary body that helps hold lens in place

• Flexible disk

• Focuses light onto retina

• Colored part of eye

• Surrounds and regulates pupil

• Regulates amount of light entering

• Lots of light = constricted

• Little light = dilated

It is composed of the retina, pigmented retina, sensory retina, rods, and cones

Innermost Tunic

• Covers posterior 5/6 of eye

• Contains 2 layers

• Outer layer

• Keeps light from reflecting back in eye

• Contains photoreceptors (rods and cones)

• Contains interneurons

• Photoreceptor sensitive to light

• 20 times more _ than cones

• Can function in dim light

• Photoreceptor provide color vision

• 3 types blue, green, red

Rods and cones synapse with bipolar cells of sensory retina

Vertical cells of retina modify output of rods and cones

Bipolar and horizontal cells synapse with ganglion cells

Blank cell's axons converge to form optic nerve

• Small spot near center of retina

• Center of macula

• Where light is focused when looking directly at an object

• Only cones

• Ability to discriminate fine images

• White spot medial to macula

• Blood vessels enter eye and spread over retina

• Axons exit as optic nerve

• No photoreceptors

• Called “blind spot”

Chambers of the Eye

• Located between cornea and lens

• Filled with aqueous humor (watery)

• Aqueous humor helps maintain pressure, refracts light, and provide nutrients to inner

surface of eye

• Located behind anterior chamber

• Contains aqueous humor

• Located in retina region

• Filled with vitreous humor: jelly-like substance

• Vitreous humor helps maintain pressure, holds lens and retina in place, refracts light

The eye functions much like a camera.

The iris allows light into the eye through the pupil, which is focused by the cornea, lens,

and humors onto the retina.

The light striking the iris produces action potentials that are relayed to the brain.

Light refraction and image focusing are two important processes in establishing vision.

• Bending of light

• Point where light rays converge

• Occurs anterior to retina

• Object is inverted

• Changes in shape of the lens so image can be focused on retina

• Enables eye to focus on images closer than 20 feet

Action Potential Generation at the Retina

• Photosensitive pigment in rod cells

Action Potential Generation at the Retina

• Colorless protein in rhodopsin

Action Potential Generation at the Retina

• Yellow pigment in rhodopsin

• Requires vitamin A

Effects of light on Rhodopsin

1. Light strikes rod cell

2. Retinal changes shape

3. Opsin changes shape

4. Retinal dissociates from opsin

5. Change in rhodopsin shape stimulates response in rod cell which results in vision

6. Retinal detaches from opsin

7. ATP required to reattach retinal to opsin and return rhodopsin to original shape

• Leaves eye and exits orbit through optic foramen to enter cranial cavity

• Where 2 optic nerves connect

• Route of ganglion axons

• The absence of perception of one or more colors

• The loss may involve perception of all three colors or of one or two colors.

• Most forms of _ occur more frequently in males and are X-linked genetic

traits

The organs of hearing and balance are located in the _

Each ear is divided into three areas:

Extends from outside of head to eardrum

• Fleshy part on the outside of the ear

• Canal that leads to eardrum

• Eardrum

• Thin membrane that separates external and

• Middle ear

Air filled chamber with ossicles

• bone attached to tympanic membrane

• bone that connects malleus to stapes

• bone located at base of oval window

• separates middle and inner ear

• opens into pharynx

• equalizes air pressure between outside air and middle ear

Set of fluid filled chambers

• Tunnels filled with fluid

• 3 regions: cochlea, vestibule, semicircular canals

• Inside bony labyrinth

• Filled with endolymph

• Clear fluid in membranous labyrinth

• Fluid between membranous and bony labyrinth

• Snail-shell shaped structure

• Where hearing takes place

• In cochlea

• Filled with perilymph

• below cochlear duct

• Filled with perilymph

• In cochlea

• Filled with endolymph

• In cochlear duct

• Contains hair cells

• In cochlea

• Vibrates against hair cells

• Attached to sensory neurons that when bent produce an action potential

• Wall of membranous labyrinth that lines scala vestibuli

• Wall of membranous labyrinth that lines scala tympani

Hearing Process

• Sound travels in waves through air and is funneled into ear by auricle.

• Sound travels through external auditory meatus to tympanic membrane.

• Tympanic membrane vibrates and sound is amplified by malleus, incus, stapes which transmit

sound to oval window.

• Oval window produces waves in perilymph of cochlea.

• Vibrations of perilymph cause vestibular membrane and endolymph to vibrate.

• Endolymph vibrations cause displacement of basilar membrane.

• Movement of basilar membrane is detected by hair hairs in spiral organ.

• Hair cells become bent and cause action potentials to be created

• Associated with vestibule

• Evaluates position of head relative to gravity

• Associated with semicircular canals

• Evaluates changes in direction and rate of head movement

• Inner ear

• Contains utricle and saccule

• Specialized patches of epithelium in utricle and saccule surround by endolymph

• Contain hair cells

• Particles of protein and calcium carbonate embedded in a gelatinous substance that

moves in response to gravity

• Microvilli of hair cells are embedded in the gelatinous substance and initiate action

potentials when bent

• Dynamic equilibrium

• Sense head movement in any direction

• Swelling at base of semicircular canal

• In ampulla

• Gelatinous mass

• Contains microvilli of hair cells

• Float that is displaced by endolymph movement