Post on 15-Jan-2016
Brain and Senses
http://db.bbc.co.uk/science/humanbody/mind/articles/disorders/causesofocd.shtml
http://www.city.ac.uk/optometry/Biolabs/Brainlab/Brainlab.htm
AUDITORY
VISIONVISION
SPEECH
Working Memory “Your Minds Blackboard”
SENSORY
MOVEMENT &
BALANCE
http://www.city.ac.uk/optometry/Biolabs/Brainlab/Brainlab.htm
AUDITORY
VISIONVISION
MOVEMENT &
BALANCE
SPEECH
Working Memory “Your Minds Blackboard”
SENSORY
Sense of Sight
Picture From: http://www.newporteyecare.com/graphics/eye_diagram_300x350.jpg
How You See:• Light waves enter the eye through the
cornea• Pass through the pupil• Pass through the crystalline lens• Light waves are bent by the cornea
and crystalline lens as they pass through
• They converge on a nodal point immediately behind the lens
• At the nodal point the image becomes reversed and inverted
Information and Picture from: http://library.thinkquest.org/05aug/00386/vision/fun/experiment/index.htm
How You See:• Light waves continue through the vitreous humor to a clear focus on the retina• The small central portion of the retina is called the macula – it provides the best
vision of any location in the retina
Pictures from: http://library.thinkquest.org/05aug/00386/vision/fun/experiment/index.htm and http://www.ghi.com/yourhealth/encyclopedia/articles/color_blindness_basics.html
How You See:• Rod cells
– more sensitive– responsible for night vision
• Cone cells – responsible for color vision– work best in bright light
Picture from: http://www.colorado.edu/intphys/Class/IPHY3430-200/image/10-35.jpg
How You See:• Light waves are then changed into
electrical signals• These signals travel through the
optic nerve to the occipital cortex of the brain
• This is where the brain interprets the signals as an image
• Seeing is a collaboration between the eyes and the brain
Picture From: http://www.msstrength.com/wp-content/themes/zen/images/optic_nerve.jpg
Fun Vision Facts• The eye of a human can distinguish 500 shades of the gray.• The cornea is the only living tissue in the human body that does not
contain any blood vessels.• All babies are color blind when they are born.• A newborn baby sees the world upside down because it takes some
time for the baby's brain to learn to turn the picture right-side up.• Pirates wore earrings because they believed it improved their
eyesight.
Information From: http://www.funshun.com/amazing-facts/eye-human-body-facts.html andhttp://www.drgoldstone2020.com/custom/15/Fun_Eye_Facts.html
Optical illusions happen when your brain misinterprets signals from your eyes
Picture From: http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/
Optical illusions happen when your brain misinterprets signals from your eyes
Picture From: http://www.eyetricks.com/0102.htm
Sense of Smell
Picture From: http://www.worsleyschool.net/science/files/nose/page.html
How You Smell:• Tiny particles from
objects vaporize and enter the nose
• In the nose they are trapped by and dissolve in mucous
• Special cells in the nasal cavity sense these particles
Picture From: http://www.scienceclarified.com/Ro-Sp/Smell.html
How You Smell:• Olfactory receptor neurons transform
the odor to a chemical message that is sent to the olfactory bulb
• The principle neurons in the olfactory bulb are called mitral cells
• There are about 50,000 of these cells in the olfactory bulb of a human
• From the olfactory bulb, the information is sent to the olfactory cortex
• The information is sent to the amygdala (fear/emotion) and hippocampus (memory)
Picture From: http://bionoid.net/index.php?c=blog&f=itemview&i=3
Fun Smell Facts• Everyone has a unique smell, except for identical twins.• Recall can be enhanced if learning is done in the presence of an
odor and that same odor is present at the time of the recollection.• No two people smell the same odor the same way.• People recall smells with 65% accuracy after a year, while the visual
recall of photos sinks to about 50% after only three months.The average human being is able to recognize approximately 10,000 different odors.
Picture From: http://www.everythingsmells.com/smellyfacts.html http://www.pu-smells.com/educators/funfacts3.html and http://www.senseofsmell.org/funfacts_main.php
Smell is also plays an important role in taste
Picture From: http://www.tcho.com/chocolate/how-to-taste-chocolate
Sense of Touch
Somatosensory(versus Viscerosensory)
•Receptors in skin (over 20 different kinds of nerve endings that send messages to the brain)•Use unipolar neurons (cell bodies in dorsal root ganglia)•Second cell body in spinal cord•Axons cross spinal cord and go to thalamus (relays senses)•In some cases, thalamus sends information to parietal lobe of brain (receives sensory information)
Brain
Picture from: http://www.coheadquarters.com/coInnerBrain1.htm
Picture from: http://www.braininjury.com/symptoms.html
Touch Receptors
Picture and information from: www.thinkquest.org
•Some areas of your skin are more sensitive than others because they have more receptors•Most sensitive areas of your body are your hands, lips, face, neck, tongue, fingertips and feet•There are about 100 touch receptors in each of your fingertips•More pain nerve endings than any other type•Fun Fact: Rattlesnakes use their skin to feel the body heat of other animals
Touch
Picture from: http://www.rci.rutgers.edu/~uzwiak/NBSpring11/NBSpringLect3.html
Touch Experiment/Vocabulary
• Pain receptors most common but you also have receptors that allow you to recognize objects, numbers, letters, etc. by touch
• Inability to recognize objects by touch: asterognosia
• Inability to recognize drawn numbers or letters: agraphesthesia
• Loss of touch/sensation: anesthesia• Loss of pain: analgesia
Sense of Taste
Gustatory System•Sensation of taste:
•Salty•Sweet•Bitter•Sour•Umami—detection of natural amino acids and found in meats, cheeses, and broth
•Traditionally, taste was a survival mechanism as many harmful substances taste bitter•Much of the perception of taste is actually mediated by your sense of smell (olfactory neurons)•Must have saliva to taste
Taste
Picture from: www.wikipedia.org
•Approximately 10,000 taste buds in our mouth (even some on roof of mouth)•Each taste bud had 50-150 receptors•Each receptor responds best to one type of taste•Taste bud receptors are replaced approximately every 7 days•Receptors send information through cranial nerves to part of the brain stem called the nucleus of the solitary tract•Information is then sent to the thalamus and then the cerebral cortex (parietal lobe)•Like smell, taste information also goes to the limbic system (hypothalamus and amygdala)•Also touch receptors on tongue
Information from: http://faculty.washington.edu/chudler/tasty.html and http://library.thinkquest.org/3750/taste/taste.html
Brain
Picture from: http://northofneutral.wordpress.com/2009/11/12/beware-of-amygdala-hijacks/
Picture from: http://www.braininjury.com/symptoms.html
Fun Taste Facts
• Insects have the most highly developed sense of taste—they have taste organs on their feet, antennae, and mouthparts
• Fish can taste with their fins and tail as well as their mouth
• In general, girls have more taste buds than boys
• Taste is the weakest of the five senses• Inability to taste is called ageusia
Information from: http://library.thinkquest.org/3750/taste/taste.html
Taste Experiment
• Dry your tongue with a paper towel• Put a saltine cracker on your dry tongue and
see if you can taste it!
Picture from: http://www.thegeminiweb.com/babyboomer/?p=898
Auditory System•Sound waves funnel into ear through the external ear canal•In the middle ear, the sound waves will cause your eardrum/tympanic membrane to vibrate•Eardrum causes the three smallest bones in your body: the malleus, the incus, and the stapes to vibrate•Vibrations then pass to a coiled tube in the inner ear called the cochlea•The cochlea is fluid filled and contains hair-like nerve endings called cilia•Cilia vibrations are sent to the brain through the auditory nerve to the temporal lobe
Picture and information from: www.thinkquest.org
•The auditory nerve carries information from approximately 25,000 receptors in your ear!
Brain
Picture from: http://northofneutral.wordpress.com/2009/11/12/beware-of-amygdala-hijacks/
Picture from: http://www.braininjury.com/symptoms.html
Your Ears and Balance• Near the top of the cochlea are three
loops called the semi-circular canals full of liquid
• When you move your head, the liquid moves and pushes against the hair-like nerve endings
• From these messages, your brain can tell how your body is moving
• If you have ever felt dizzy after having spun around, it was probably because the liquid inside the semicircular canals swirled around inside your ears causing the hair-like projections to move in all different directions sending mixed messages to your brain
Picture from: http://medical-dictionary.thefreedictionary.com/cochlear+canal
Hearing
Noise Decibels
Whisper 20
Normal Talking 50-60
Car Traffic 70
Alarm Clock 80
Lawn Mower 95
Rock Concert 100
Jackhammer 115
Jet Engine 130
Gun Shot 140
Loudness is measured in decibels
Long-term exposure can cause hearing loss
Pain begins
Short-term exposure can cause hearing loss
Information from: www.thinkquest.org and http://www.gcaudio.com/resources/howtos/loudness.html
Fun Hearing Facts
• When you go up to high elevations, the change in pressure causes your ears to pop
• Children have more sensitive ears than adults• Dolphins have the best sense of hearing
among animals (14X better than humans)• An earache is caused by too much fluid
putting pressure on your eardrum—often from an infection, allergies or a virus
Information from: www.thinkquest.org
Hearing Experiment
• Demonstration of how hearing works!
Picture from: http://www.freedomscope.com/wireless_stethoscope_for_the_hearing_impaired.htm