The Other Senses

Smell

Taste

Kinesthetic and Vestibular

Sensations of Motion

Skin Senses

Pain

Smell Parts of the nose are

directly connected to the amygdala and hippocampus

Smell often plays a large part in determining our likes and dislikes Anyone remember the

facial expression associated with disgust?

Animals with the best sense of smell walk on all fours Their heads are close

to the ground!

Yuck! Another smelly

diaper…

Detecting Common Odors Odorant binding

protein (OBP) Produced in nasal

gland Activates sense of

smell Olfactory epithelium

Patch of tissue in each nasal cavity where receptors are located

OBP is sprayed through a duct at tip of nose that binds with airborne molecules

Olfactory bulb Recodes information

from the axons in the epithelium

SMELL CENTER OF THE BRAIN

From here information travels along the olfactory tract to the temporal lobe and brain core

How does your sense of smell adapt?

Human Olfactory System

Molecules from flower reach

receptor cells high in nasal cavity

Axons from receptors carry

nerve impulse to olfactory bulb

Olfactory bulb transmits impulses

to the brain

Communicating with Pheromones VNO activates

hypothalamus and amygdala Involved with

reproduction and defensive behavior

Pheromones can help us distinguish another animal’s identity and level of stress Hamsters use

pheromones to avoid aggressive and sexial contact with family!

Pheromones Chemical molecule

that communicates information to other members of a species and influences behavior

Stimulate receptors in the vomeronasal organ (VNO)

VNO then sends messages to another olfactory bulb

Taste

Humans are omnivores - we eat anything Girls, I’m not just

talking about guys

Taste vs. flavor Taste can be detected

with just the tongue Flavor involves not

only the tongue, but also our nose

Taste buds Each taste bud

contains a cluster of receptor cells

These cells die and are replaced every 7 days!

Locate in the tongue’s papillae (those small bumps on your tongue)

Can you explain grow your sense of taste adapts?

Kinesthetic and Vestibular Vestibular senses -

sense of equilibrium and body position (orientation) Originate in the

semicircular canals - fluid provides messages about speed and direction of body rotation

Movement of fluid in the vestibular sacs provides information about movement forward, backward, up, and down

Kinesthetic senses - relay information about muscle movement, posture, and strain on muscles and joints Stretch receptors -

specialized nerve endings attached to muscle

Golgi tendon organs - receptors attached to tendons (connect muscle to bone)

Information is constantly relayed to the parietal lobes through the spinal cord

Sensations of Motion

Awareness of vestibular senses Can you think of a time when you

notice your vestibular senses? Motion sickness - our senses send

contradictory information to our brain

The Skin Senses Our skin is our

largest sense organ Numerous nerve

receptors Input travels to the

parietal lobe and reticular formation by way of the medulla and thalamus

Skin senses can be influenced be expectations Is there a

difference between tickling yourself and being tickled by a friend?

Like your other sensory organs, skin adapts As you sit in a hot

bath it begins to feel tolerable

The larger the area being stimulated, the longer adaptation takes

Pain Pain is a warning signal

Individual differences in pain threshold Gate control theory - a “neurological gate” in

the spinal cord controls the transmission of pain messages to the brain Individual difference due to numbers of small vs.

large fibers in spinal cord Biopsychological theory - interaction of

biological, psychological, and cultural factors influence the intensity and duration of pain Individual differences depend on past experiences,

our beliefs, and personality Pain management - acupuncture and

hypnosis Placebo effect