Other Senses

TOUCH

Touch is the most pleasurable of all the senses

1. Critical for healthy development1. Children that are deprived of touch can

develop Psychosocial dwarfism – a condition where by their physical development is stunted

2. Greatest sensitivity to touch is where you need it the most.1. Face2. Tongue3. Hands

We use our SKIN for our sense of touch. Every bit of skin all over our bodies, including our nails, is used for touching.

Our sense of touch shows us the shape, size and

"feel" of our world.

The Sense of Touch is called Tactile

Types of Touch

PressureWarmthColdPain

Common ReceptorsThe body has about twenty different

types of nerve endings that all send messages to your brain. However, the most common receptors are heat, cold, pain, and pressure or touch receptors. Pain receptors are probably the most important for your safety because they can protect you by warning your brain that your body is hurt!

Fun Facts 1. What type of nerve endings to

you have the most of?1. Pain

2. Where is the least sensitive part of your body?

1. Middle of your back3. How many touch receptors are

in each fingertip?1. 100

4. When your body shivers what is trying to do?

1. To get warm

KinesthesisThe system for

sensing the position and movement of individual body parts.

Allows you, even with your eyes closed, to know where your limbs are located.

Vestibular SenseThe sense of body

movement and position, including the sense of balance.

This tells you which way is up, how your body is oriented in relation to up, and how your body is moving in space.

How Vestibular Sense Works with the Semicircular Canals

In the semicircular canals, the motion of the fluid as you spin causes gelatinous lumps called cupulas to bend one way or the other, which in turn causes the hair cells to bend. 

The vestibular sense is connected to parts of the brain that tell you when it is time to vomit.  This is the cause of motion sickness.

If you spin hard enough and then suddenly stop, the tiny current keeps going for a little bit, and gives you the sensation that you are still spinning, but in the opposite direction.  Your brain may try to compensate for this, and cause you to fall or at very least feel dizzy.

PAIN

PAINPain is a perception,

and like any perception, it is rooted in sensation, and on the biological level, in the stimulation of receptor neurons.  Also like other forms of perception, pain is sometimes experienced when there is no corresponding biological basis!

Pain’s PurposePain is a body sense that warns us of

potential harm and helps us cope with sickness and injury.

In the fight to survive, it’s one of our best defenses.

Understanding Pain - Biological

NociceptorsSpecial sensory neurons translate certain stimuli into

action potentials that are then transmitted to the brain.

There are FOUR different nociceptors:1. Thermal nociceptors are sensitive to high or

low temperatures.

2. Mechanical nociceptors respond to strong pressure to the skin that comes with cuts and blows.  These receptors respond quickly, and often trigger protective reflexes!

3. Chemical nociceptors respond to a variety of chemicals released with tissue damage, as well as to external chemicals such as capsaicin (the chemical that makes hot peppers "hot") and spider venom.

4. Silent (or sleeping) nociceptors stay quiet - hence the name - but become more sensitive to stimulation when they are surrounded by inflammation.

Understanding Pain - BiologicalThe nerves carry messages from the nociceptors up the spinal cord can follow several different tracts.  Most go to the thalamus, where they are distributed to various higher centers. 

Some also go to the reticular formation (which, among other things, governs alertness)

Others go to the amygdala (a part of the limbic system involved in emotion).

Understanding Pain - Biological

Gate-Control Theory 1. States pain is the

balance between the information traveling into the spinal cord through large nerve fibers and information traveling into the spinal cord through small nerve fibers.

2. Large nerve fibers carry non-nociceptive information & small nerve fibers carry nociceptive information.

3. If the amount of activity is greater in large nerve fibers, then little or no pain. 4. However, if there is more activity in small nerve fibers, then there will be pain.

I = "Inhibitory Interneuron"; P = "Projection Neuron"- = inhibition (blocking); + = excitation (activation)

Understanding Pain - Biological

Phantom Pain – The pain amputees

sometimes feel in the very limb they are missing - is due to the fact that, when nociceptors are damaged or missing, the neurons in the spinal cord that transmit pain messages sometimes become hyperactive.  So the brain gets messages of pain where there isn’t even any tissue left!

Understanding Pain - Biological

EndorphinsStress and Pain are the two most common

factors leading to the release of endorphins. Endorphins interact with the opiate receptors in the brain to reduce our perception of pain and act similarly to drugs such as morphine and codeine. In contrast to the opiate drugs, however, activation of the opiate receptors by the body's endorphins does not lead to addictions or dependence.

Endorphin release varies among individuals. This means that two people suffer the same degree of pain will not necessarily produce similar levels of endorphins.

Understanding Pain – Social-Cultural

InfluenceOur perception of pain varies with our

social situation and cultural traditions. We tend perceive more pain when others

are also experiencing pain. Men vs. Women

Understanding Pain - Psychological

Pain is often “all in your head.”

The way we experience pain, communicate about pain to others and how we respond to pain-relieving treatment may have more to do our psychological state than with the actual intensity of the pain.

Things that magnify your emotions can

increase your experience with pain

Biopsychosocial Approach to Pain

Controlling Pain Physical Methods

Drugs, Surgery, Acupuncture, Electrical Stimulation, massage, and exercise

Psychological MethodsHypnosis, Relations training and Thought

Distractions

Placebo EffectSome people who participate in research

studies and take inactive medication see health improvements, such as reduced pain.

Researchers not sure why, but could help with mind-body relationship if it could be figured out.

Congenital Insensitivity to PainPeople who are born WITHOUT the sense of

pain.Their nervous systems are not equipped to

detect painful information. You may think this is a good thing....it is

NOT. Without the ability to detect painful events,

you would continue to cause injury to yourself.

Brain tissue is not sensitive to pain! The brain itself does not have any receptors for pain. In fact, most brain surgery is performed using a local anesthetic only

TASTE

How We Taste or Gustation

Molecules from the food we eat get mixed with saliva and find their way into the little pits and onto the surfaces of the neurons.  Like a key fitting into a lock, these molecules open up tiny pores on the cell membranes and begin the process of firing the neuron very much the same way as the neurotransmitters do between neurons.

How We TasteThere are about 10,000

taste buds on the tongue, clustered in papillae (those bumps all over your tongue).  The taste buds are clusters of neuron bodies that line tiny pits in the papillae, and look sort of like a microscopic bunch of bananas.

There are FIVE Basic

Tastes

Five Basic TastesSWEET

Like a Piece of CakeEnergy Source

Five Basic TastesSour

Like a LemonPotentially a Toxic Acid

Five Basic TastesSalty

Like, well, salt!Sodium Essential to Psychological Processes

Five Basic TastesBitter

Like a cup of bad coffeePotential Poisons

Five Basic TastesUmami

Like in tomato or aged cheeseSavoriness involves a sensitivity to

glutamate Proteins to grow and repair tissue

Sensory InteractionNO two senses work together better than

smell and taste. The taste of something is enhanced by the

aroma we intake by our nose. Smell can change our perception of taste. –

Think what it is like to eat when you have a cold.

Flavor is made up by adding Smell to Taste to Texture.

Smell

How Our Sense of Smell Works

Moist air being drawn over a piece of specialized mucous membrane about the size of a dime at the top of your nasal cavity.

In olfactory epithelium is where the chemical molecules that entered the nose is dissolved Hair cells are the receptors in the olfactory

epithelium that respond to particular chemicals

The electrical activity produced in these hair cells is transmitted to the olfactory bulb. The information is then passed on to mitral cells in the olfactory bulb.

The olfactory tract transmits the signals to the brain to areas such as the olfactory cortex, hippocampus, amygdala, and hypothalamus

Sense of Smell - OlfactionThese are the seven smells suggested by the researcher

Floral Pepperminty Musky Pungent (like spices) Camphoraceous (like mothballs or muscle liniments) Ethereal (like dry-cleaning fluid) Putrid (like rotten eggs)

Smell Age and Gender

Smell Age and Gender