1. Unit 2 sensitivity and
coordination
Maria boizas

2. Stimuli
A stimulus is anything you
see,hear,touch,smell or taste.
 There are two types of stimuli:
 Internalstimuli
 External stimuli

3. The smell of a flower is an external
stimuli.

4. receptors
 Thereare two types of receptors:
Internal receptors
External receptors

5. Responses
A response is the body’s answer to a
stimulus
 There are two different types of
responses:
 Muscular responses
 Glandular responses

6. Chewing is a muscular response

7. The senses

8. sight
 The eye is the organ of sight.
it is made up of the eyeball and
protected by the eyebrows,eyelids
and eye lashes.

9. Process of sight
 First light goes through the cornea.
 Then light passes through the pupil,the
opening of the iris.
 After that light passes through the lens
with focuses the image on the retina.
 The information in the retina travels to
the brain through the optic nerve

10. smell
 Thenose is the organ of smell.The
receptorsof smell are in the pituitary
gland,inside the nostrils.

11. hearing
 The ear is the organ os hearing.
 It has three parts:
 The outer ear
 The middle ear
 The inner ear

12. The process of hearing
 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

13. touch
 The skin is the organ of touch.
 It is made up of three layers:
 Epidermis
 Dermis
 Hypodermis

14. taste
 The tongue is the organ of taste.
 The receptors of taste are in the taste
buds.
 There are taste buds all around the
tongue.

15. The nervous system
The nervous system is made up of
nerve centres and nerves.

16.  The
peripheral nervous system is
made up of:
 Sensory nerves
 Motor nerves
 The central nervous system has two
parts:
 The brain
 The spinal cord

18. neurons
 They are made up of a cell body,dendrites
and axons.
 Neurons receive information from other
neurons.

19. Voluntary and involuntary
movements
 Ourbodies react to stimuli making
voluntary or involuntary movements.

20. Voluntary movements
 When we see the clouds our sensory
nerves inform the brain about this.
 Our brain processes the information and
produces a response.
 Our motor nerves transmit a response to
the muscles.

21. Involuntary movements
 The spinal cord produces a response in
the case of involuntary movements.
 Sensory nerves transmit information about
involuntary movements to the spinal cord.
 The spinal cord produces a very fast
response.

22. The skeletal system
 Theskeletal and muscular system is in
charge of carrying muscular responses
created by the nervous system.it is
made up of the skeleton and the
musculature.

23. The skeleton
 The skeleton is made up of all the bones
in the body.
 Head bones:skull bones and facial bones.
 Trunk bones:spine and rib cage.
 Limb bones:there are two groups the upper
limb bones and the lower limb bones.

25. joints
 The joints are located where two or more
bones meet.Bones are connected by
ligaments.
 There are three types of joints:
 Moveable joints
 Semi-moveable joints
 Fixed joints

27. The musculature
 The musculature is the set of muscles in the
body.locomotor muscles are conected to the
bones.when they contract or relax,they move the
bones.
 Head muscles:masseter,buccinator and orbicular.
 Trunk muscles:sternocleidomastoid,abdominal,
pectoral,intercostal and trapezius.
 Limb muscles:biceps,triceps,deltoid,quadriceps,
gluteus and calf muscles.
.

28. The end