Internal stimuli come from inside the body and activate internal receptors, while external stimuli from outside the body activate external receptors located in sensory organs like the eyes, nose, tongue, ears and skin. Internal receptors detect internal stimuli like hunger and pain, while external receptors allow us to see, smell, taste, hear and feel touch. Responses to stimuli can include muscular movements or glandular secretions.

1. ● Internal stimuli come from inside our bodies, like the feeling of thirst.
● External stimuli come from outside the body, like the smell of a cake or
texture of a jumper.
● Internal receptors receive the internal stimuli our bodies produce. They
are all over our body. They let us feel hunger or pain.
● External receptors receive external stimuli. They are in the sensory
organs: the eyes, the nose, the tongue, the ears and the skin.

2. RESPONSES
 Muscular responses are the movements
our muscles make in response to a
stimulus.
 Glandular responses occur when glands
produce various substances in response
to a stimulus.

3. SIGHT
The eye is the organ of sight. It is made up
of the eyeball and protected by the
eyebrows, eyelids and eyelashes.
retina
iris

4. SMELL
The nose is the organ of smell. The
receptors of smell are in the pituitary
gland, inside the nostrils.
nostrils
pituitary

5. HEARING
 The outer ear includes de ear and ear
canal.
 The middle ear includes the eardrum
and the small bones.
 The inner ear includes the cochlea and
the auditory nerve.
eardrum
ear
ear canal
cochlea
small bones

6. THE NERVOUS SYSTEM
 The central nervous system have two parts:
- The brain is inside the skull.
- The spinal cord.
 The peripheral nervous system is made up
of:
- Sensory nerves. cerebellum
cerebrum
- Motor nerves.
brain stem
spinal cord

7. THE SKELETON
The skeleton is made up of all the bones in the
body. Parietal
frontal
occipital nasal
temporal cheekbone nasal
sternum cheekbone
ribs r jawbone
spine clavicle
ulna scapula
radius humerus
metacarpal carpal
hipbone phalanges
fibula
femur
metatarsal
tibia
tarsal
phalanges

8. THE MUSCULATURE
The musculature is the set of muscles in
the body. masseter
orbicular
buccinator trapezius
sternocleidomastoid deltoid
deltoid triceps
pectoral dorsal
biceps
intercostal
abdominal gluteus
quadriceps
tendon
calf muscles
tibial

9. Work performed by:
Yulia Sofía Castaño
David Fernández Alonso
6º A - E. Primary
Medalla Milagrosa School