SENSITIVITY ANDCOORDINATION. By Adrián Muñiz

U N I T

2

STIMULI AND RESPONSESA stimulus is anything that affects any of the body’s activities.

There are two types of stimuli:INTERNAL: they come from inside our bodies.EXTERNAL: these come from outside the body.

Response:It Is the body answer to a stimulus.e.g. We eat when we are hungry.

Stimulus

Response

STIMULI RECEPTORS

The body has different receptors to receive different types of stimuli.

There are two types of receptors:

Internal receptors. They receive the internal stimuli our bodies produce. They are all over the body.

External receptors. They receive external stimuli. They are in the sensory organs.

http://vimeo.com/7592583(Video)

RESPONSES

The body responds to any stimulus. There are two basic types of responses:

Muscular responses: These are movements the muscles make in response to a stimulus.

Glandular responses: These are when glands produce various substances in response to a stimulus.

THE SENSES (1)

Sight: The eye is the body’s organ for the sense of sight.The eye is made up of the eyeball and protected by the eyebrows,eyelids and eyelashes

Hearing: The ear is the body’s organ for the sense of hearing.The ear has three parts: 1-The outer ear 2-The middle ear 3-The inner ear

Touch: The body’s organ for the sense of touch is the skin.The skin is made up of three layers: 1-Epidermis 2-Dermis 3-Hypodermis

THE SENSES (2)

Smell: The body’s organ for the sense of smell is the nose.The receptors of smell are in the pituitary, a structure inside the nostrils.The organ for the sense of smell is the nose.

Taste: The body’s organ for the sense of taste is the tongue.The receptors of taste are in the taste buds.

THE NERVOUS SYSTEM AND HOW IT WORKS(1)

The nervous system receives and interprets the information of the internal and external receptors,and it develops and transmits a response.It is made up of nerves and nerve centres. Nerves transmit information. They are the peripheral nervous system. The nerve centres interpret the information and develop responses. They form the central nervous system.

The central nervous system: It has two parts: Brain: It is inside the skull.It has three main parts:cerebrum,cerebellum and brain stem. Spinal cord: It is a thick cord made up of many neurons thats goes through the inside of the spine.

THE NERVOUS SYSTEM AND HOW IT WORKS(2)

The peripheral nervous system It is made up of nerves: Sensory nerves.They transmit information from the sensory organs and internal organs to the central nervous system. Motor nerves.They transmit responses from the central nervous system to the muscles and glands of our bodies.

THE NERVOUS SYSTEM AND HOW IT WORKS(3)

Neurons Neurons are cells that belong to the nervous system.They have a star-like shape made up of three parts :a cell body,dendrites and axons.

THE NERVOUS SYSTEM AND HOW IT WORKS(4)

VOLUNTARY MOVEMENTS This is how the nervous system reacts to a stimulus with voluntary movements. 1-Sense nerves 2-Brain 3-Motor nerves

Involuntary movements With involuntary movements or reflexes,it is the spinal cord and not the brain that develops a response

THE END!!