Transcript Brain Awareness Day - Lakehead Science Education (Matt Roy)

5 SENSES
The Nervous System!
• Body’s control center
• 3 main parts:
– Brain
– Spinal Cord
– Neurons
• Your brain uses
information it receives
from your nerves to
coordinate all of your
actions and reactions!
NERVES (or NEURONS)
DENDRITES
AXON
CELL BODY
• Different from normal cells? Why?
– Neurons carry electrical signals from one part
of your body to another
– DENDRITES receive signals from other
neurons
– AXONS pass signals away to other neurons
The BRAIN
• The brain is made up of ~100 billion nerve
cells
• Controls EVERYTHING that makes you
who you are (likes, dislikes, skills)
• Even controls things you don’t need to
think about (heartbeat, breathing, blood
pressure)
Cerebral LOBES
•
•
•
•
FRONTAL: Planning, Problem solving, Speech, Smell
PARIETAL: Touch, Movements in response to environment
TEMPORAL: Memory, Hearing, Emotion, Language
OCCIPITAL: Vision
VISION
VISION
• When light hits an object, it
bounces off and is reflected
into our eyes.
• The LENS and CORNEA
collect the light and focus it
through the PUPIL
• The IRIS opens and closes
depending on how much
light is available
• The light is then projected
onto a special layer of cells
called the RETINA .
RETINA: PHOTORECEPTORS
• The retina is made up of specialized
NEURONS known as
PHOTORECEPTORS
• 2 types:
– RODS: VERY light sensitive
• Black and white
• 120 million
– CONES: not so light sensitive
• Colour vision
• 6-7 million
Yellow Green Violet
Cone Cone Cone
Different Photoreceptors = Different Vision
ANIMAL VISION
• Prairie dogs and squirrels are red/green color
blind
• Sharks are almost completely color blind
To the brain!
• Photoreceptors transform the light and
color into impulses that are transmitted
to the brain via the OPTIC NERVE
– Blind Spot
• The brain decodes
the message!
– Which lobe??
Which one is the biggest???
Are they moving????
Smell/Taste
What do Smell and Taste
have in common?
• They are both chemical senses!
– Molecules in the air or our mouths
dissolve and bind to receptors which
send signals to the brain!
What do you smell?
• Rate from 1-10 how strong this smell is!
• Olfactory receptors located in the nasal
cavity
– Called Olfactory epithelium
• Molecules dissolve in mucus =>
stimulate receptors => signals
olfactory bulbs => brain
• Olfactory areas of the brain communicate
with areas responsible for emotion and
memory
– Can you think of any examples?
ANIMAL SMELL
• Humans can distinguish 10,000 different
smells
• There is only 1 type of receptor but patterns
of activation allow us to differentiate
• Animals often have incredible senses of smell!
• Can you think why?
– Finding food
– Finding mates
– Avoiding predators
– …..
Can you still smell the orange?
• Rate the orange smell from 1-10 now … is
there a difference?
• ADAPTATION!
• Can you think of any examples?
– New buildings
– Christmas tree
– Perfume
– Fresh paint
– ……
Taste and smell work together!
– Does food taste the same when
you have a cold?
– Why not?
• Flavour is actually the
combination of smell, taste,
texture and temperature.
Taste cell receptors cluster into
taste buds (or papillae)
• Where do we have taste buds?
– Tongue
– Roof of mouth
– Upper esophagus
• Taste buds have taste pores allowing
contact with food molecules
• Signals about taste are then sent to
the brain!
There are 4 basic tastes!
– Sweet
– Salty
– Sour
– Bitter
– Umami?
• All parts of your tongue can taste all tastes but
there are places where certain receptors are
concentrated! ….. Or are there?
• Let’s map your tongue!
Bitter
Sour
Salty
Sweet
Hearing
What is sound?
• Sound is made from an object when it
produces vibrations through matter
– Called Sound Waves!
• Matter can be solid (earth), liquid (water) or
gas (air)
– Usually we hear sound though air!
How do we hear different sounds?
– We hear different pitches
because the air vibrates at a
different frequency
– We hear different volumes
because of the waves
amplitude
• Can you guess the vibration?
–
–
–
–
Police sirens
Thunder
Mouse squeak
Cat purr
 Freq  Amp
 Freq  Amp
 Freq Amp
 Freq Amp
In order to hear we need a way to take
information about vibrations and send it to
the brain!
Path of a sound wave ….
Outer ear (Pinna) =>
Outer ear (Eardrum) =>
Middle ear (Ossicles) =>
Inner ear (Cochlea) =>
Inner ear (hair cells) =>
Auditory nerve =>
Temporal lobe!
How well do you localize sound?
The Barn Owl
Need to hunt well at night and
localize in 3D
Use Asymmetric ears and
Feathers instead of Cartilage
Touch
TOUCH
• We experience TOUCH all
over our bodies
• Touch begins at nerve
endings (TOUCH
RECEPTORS) under your
skin
• Receptors send information
about touch to your brain
(which part?)
TOUCH RECEPTORS
• 4 types of touch receptors :
– PAIN
– PRESSURE
– VIBRATION
– TEMPERATURE
• Why is touch important? What would
happen if you couldn’t feel pain?
The HOMUNCULUS
• Not all parts of your
body experience touch
equally
– Which ones feel the
most? Why?
• The Homunculus:
– Where in the parietal
lobe information in
processed
– Size=number of
receptors/sensitivity to
touch
Touch Activity!
Summary Quiz!
senses
• With the 5………
the brain is able to perceive
the world around you.
• Receptors take information from the Environment
………..
and through neurons relay it to the Brain
……
• Animals develop specialized
senses due to Adaptation
..…..…..
Let’s label the lobes!