2. Stimulus & Responses
STIMULI
A stimulus is anything you see, hear, smell
OR taste.
Stimuli can be external or internal.
RECEPTORS
·Internal receptors
·External receptors
3. RESPONSES
A response is the body’s answer to a
stimulus.
·Muscular responses
·Glandular responses
4. SENSES (SIGHT)
The eye is the organ of sight.
It’s made up of the eyeball and protected by
eyebrows, eyelids and eyelashes
PROCESS
·FIRST light passes through the cornea.
·THEN light passes through the pupil
·AFTER THAT light passes through the lens, which
focuses the image on the retina
·FINALLY the information in the retina travels to
the brain through the optic nerve.
5.
6. SENSES (SMELL)
The nose is the organ of smell.
The receptors of smell are in the pituitary,
inside the nostrils.
7. SENSES (HEARING)
The ear is the organ of hearing. It has three parts:
·OUTER EAR: ear and ear canal
·MIDDLE EAR: eardrum and small bones
·OUTER EAR: cochlea and auditory nerve
PROCESS
FIRST the outer ear receives sounds
THEN the middle ear changes sounds into
vibrations.
FINALLY the inner ear changes vibrations into
nerve impulses that go to the brain
8.
9. SENSES (TOUCH & TASTE)
-The skin is the organ of touch. It has three
layers.
-The tongue is the organ of taste. The
receptors of taste are in the taste buds.
There are taste buds all around the
tongue.
10. NERVOUS SYSTEM
The nervous system is made up of nerve
centres and nerves.
Nerve centres:
-Interpret information
-Develop responses
11. NERVOUS SYSTEM
CENTRAL NERVOUS SYSTEM
-BRAIN: is inside the skull. It’s made up of
cerebellum, cerebrum and brain stem.
-SPINAL CORD: It’s made up of many
neurons and protected by vertebrae.
PERIPHERAL NERVOUS SYSTEM
-SENSORY NERVES
-MOTOR NERVES
