Unit 7 – Human biology
The senses
LT 6.10.6
IBE - JTPS
• Why food seems to have less flavor when you
have a cold?
J-TPS (Justify –Think Pair Share)
THINK
PAIR
SHARE
Do you hear sounds with your ear, smell with your nose, or
taste with your tongue?
The senses help to maintain homeostasis
• Senses gather stimuli, and send
it to the nervous system.
• The Nervous system responds
to stimuli
Examples?
– Pupils shrink when too much
light enters the eyes.
– Goose bumps when cold air
touches skin.
What is a stimulus?
What is
homeostasis?
The senses detect physical and chemical stimuli
The eye has special light sensor
receptors called Photoreceptors
The Rods Cells
 contribute to blackand-white vision
The Cone cells
 contribute to color
vision.
People who are visually impaired live in a world
of total darkness
• - true
• - false
http://www.youtube.com/watch?v=fJhbHJcAl3
0&playnext=1&list=PL3AE98261F48BCE0A
http://www.youtube.com/watch?v=p0BBRbvde2U
http://www.youtube.com/watch?v=v9CawJSUy2c
The Ear
The ear contributes to hearing
– The sense or hearing uses mechanoreceptors that
respond to vibrations
http://www.youtube.com/watch?v=ahCbGjas
Noise-induced hearing loss
• http://www.youtube.com/watch?v=q8rfXVFkh
Hc
Taste and smell
• Taste and smell use chemoreceptors.
• Chemoreceptors detect chemicals dissolved in fluid or air
– Taste buds uses the tongue, and smell uses the nose.
http://www.youtube.com/watch?v=WavjbJhiRAE
Touch, temperature and pain
• The skin senses touch through mechanoreceptors
that can detect pressure.
• The skin can detect temperature using
thermoreceptors
• Pain receptors detect damaged tissue
pain receptor
light pressure receptor
hair follicle
heavy pressure receptor
Check for understanding
What do the sensory receptors in hair cells
detect?
1. sounds
2. vibrations
3. light
4. chemicals
Check for understanding
• Which types of sensory receptors detect a fly
landing on your arm?
1. Mechanoreceptors
2. Photoreceptors
3. Thermoreceptors
4. chemoreceptors
Check for understanding
What kind of sensory receptors are taste buds?
1. Mechanoreceptors
2. Photoreceptors
3. Thermoreceptors
4. chemoreceptors
Check for understanding
• What kind of receptors are the hair cells,
which are found in the ear?
1. Chemoreceptors
2. Thermoreceptors
3. Photoreceptors
4. mechanoreceptors
Check for understanding
• ___________ detect chemicals dissolved in
fluids
1. Mechanoreceptors
2. Photoreceptors
3. Thermoreceptors
4. Chemoreceptors
Check for understanding
• Cells in the eye that contribute to black-andwhite vision are
1. Cones
2. Rods
3. Irises
4. lenses
Check for understanding
The nervous and endocrine systems respond to
1. receptors
2. Changes
3. Messages
4. Stimuli