Unit 3- Sensitivity


The 5 Senses-Los 5 sentidos






Sense Organs-Órganos de los sentidos


Nervous System-Sistema Nervioso

Nervous Tissue-Tejido Nervioso

Central Nervous System-Sistema Nervioso Central

Peripheral Nervous System- Sistema Nervioso Periférico





Brain Stem-Bulbo Raquídeo

Spinal Cord-Médula Espinal

Sensory Nerves-Nervios Sensitivos

Motor Nerves-Nervios Motores

Voluntary Movement-Movimiento Voluntario

Reflex Movement-Movimiento Reflejo



Through sensitivity we respond to changes in our environment.

Humans interact with the world through senses.  First the sense organs capture information from the environment outside the body.  Second, the brain interprets the information to make it useful.  Third the brain sends out the information to the body and the body acts it out.

The sense organs have special cells called receptor cells that can detect light, pressure and sound.  Receptor cells send information to the brain through the nerves.

The nervous system is formed by the Central Nervous System and the Peripheral Nervous System. The Central Nervous System is formed by the Brain and the Spinal Cord.  The Peripheral Nervous System is formed by Nerves.  Nervous Tissue is found in every part of the body and made up of one type of cell called Neurons that can send and receive messages.

The Brain is the control center of the body and the most important organ. It has three parts:

-Cerebrum controls our voluntary actions and our emotions, and             stores memory.

-Cerebellum co-ordinates movement and balance in our body

-Brain Stem regulates the organ activity.

The Peripheral Nervous System formed by the nerves outside of the brain and spinal cord. It serves to connect the Central Nervous System to the limbs and organs.  The sensory nerves carry information from the sense organs to the central nervous system.  Motor nerves carry orders from the central nervous system to the muscles and organs.

Voluntary movements are those that we choose to do, like writing.  Reflex movements happen automatically without a conscious order from the brain.