The Human Body II

Presentation made by students of 6º

SightSightThe eye is the organ used The eye is the organ used for sight. Light enters the for sight. Light enters the eye through the pupil. The eye through the pupil. The iris contracts or dilates to iris contracts or dilates to regulate the amount of light regulate the amount of light our eyes need. Then, light our eyes need. Then, light crosses the lens and crosses the lens and reaches the retina. The reaches the retina. The retina transmits the retina transmits the information to the brain information to the brain trough the optic nerve.trough the optic nerve.

The parts of the eyeThe parts of the eyeSclera: protects the inner parts of the eye.Sclera: protects the inner parts of the eye.Conjunctiva: covers the sclera.Conjunctiva: covers the sclera.Cornea: protects the eye from the exterior.Cornea: protects the eye from the exterior.Choroid: layer located between the sclera Choroid: layer located between the sclera

and the retina.and the retina.

Yaiza and IvánYaiza and Iván

The sense of smellThe sense of smellThe sense The sense of smell is of smell is the sense the sense that we that we use to use to smell. It’s smell. It’s found in found in the nasal the nasal cavity, cavity, inside our inside our nose.nose.

There are There are approximately 10 approximately 10 million sensory million sensory receptors cells in receptors cells in our nose.When a our nose.When a smell enters our smell enters our nose these cells nose these cells gather information gather information and send a message and send a message to our brain.to our brain.

The sense of tasteThe sense of taste

The sense of taste is located in The sense of taste is located in our tongue. The tongue is a our tongue. The tongue is a

muscular organ with about 3000 muscular organ with about 3000 taste buds. Taste buds transmit taste buds. Taste buds transmit

sensations of taste.sensations of taste.

We can distinguish We can distinguish four flavours: sweet, four flavours: sweet, sour, salty and bitter.sour, salty and bitter.

The Sense of Hearing The Sense of Hearing

The sense of hearing is located in our ears.The sense of hearing is located in our ears.

The outer ear collects the sounds and transmits these The outer ear collects the sounds and transmits these vibrations to the eardrum.Then,in the middle ear,the vibrations to the eardrum.Then,in the middle ear,the

vibrations pass on to the hammer stirrup and vibrations pass on to the hammer stirrup and anvil.They carry these vibrations to the inner anvil.They carry these vibrations to the inner

ear.Sound passes into the cochlea and finally to the ear.Sound passes into the cochlea and finally to the brain through the auditory nervebrain through the auditory nerve

Victor and ArianneVictor and Arianne

The Parts of the EarThe Parts of the Ear The outer ear,the middle ear The outer ear,the middle ear

and the inner ear are the three and the inner ear are the three main parts of the ear.main parts of the ear.

There are three tiny bones There are three tiny bones called hammer,stirrup and called hammer,stirrup and anvil.anvil.

We also have the eardrum and We also have the eardrum and the auditory nerve in our ear.the auditory nerve in our ear.

The sense of touch The sense of touch

by Laura. Bby Laura. BThe sense of the touch is located in our The sense of the touch is located in our skin. The skin has two parts: epidermis skin. The skin has two parts: epidermis and dermis. The top part of the skin is and dermis. The top part of the skin is called epidermis and the inner part of called epidermis and the inner part of

the is calledthe is called dermis.dermis.

Touch detectorsTouch detectors Touch detectores Touch detectores

are located in our are located in our epidermis. They epidermis. They send information to send information to the brain. The brain the brain. The brain can interpret many can interpret many different kinds of different kinds of sensations. They sensations. They include include temperature, temperature, texture, shapes texture, shapes and sizes.and sizes.

The nervous systemThe nervous system

Our body has a system that controls all of the Our body has a system that controls all of the information and the responses. This system is information and the responses. This system is

called the nervous system.called the nervous system.

The central nervous system formed by the The central nervous system formed by the encephalon and spinal cordencephalon and spinal cord

The peripheral nervous systemThe peripheral nervous system

The peripheral nervous system covers our The peripheral nervous system covers our whole body and is formed by the nerves whole body and is formed by the nerves

The peripheral and central The peripheral and central nervous systemnervous system

The central nervous system and the The central nervous system and the peripheral nervous system continuously peripheral nervous system continuously transmit information and orders to each transmit information and orders to each other.other.

The skeletonThe skeleton

All the bones and All the bones and cartilages in our body cartilages in our body form the skeleton. The form the skeleton. The skeleton is made up skeleton is made up of 206 bones. Our of 206 bones. Our bones are hard and bones are hard and rigid. Our skeleton rigid. Our skeleton and cartilage grow and cartilage grow with us.with us.

The head and the limbsThe head and the limbs

In the head we have the skull that has many In the head we have the skull that has many different parts.different parts.

In the arms and legs we have lots In the arms and legs we have lots of bonesof bones

MusclesMuscles

Muscles are made of Muscles are made of tissue. They can tissue. They can contract or relax. contract or relax.

Muscles are important Muscles are important because they produce because they produce

movement. Some movement. Some muscles are attached to muscles are attached to

bones by tendons. bones by tendons. When we move a muscle When we move a muscle we also move the bone.we also move the bone.

Voluntary or involuntaryVoluntary or involuntary

Muscles can be Muscles can be voluntary, like voluntary, like the biceps and the biceps and the masseter, or the masseter, or involuntary, like involuntary, like the muscles in the muscles in the heart or the the heart or the stomach. There stomach. There are more than are more than 600 muscles in 600 muscles in our body.our body.

Muscles workMuscles work When muscles work When muscles work

they need more they need more energy and oxygen , energy and oxygen , so they receive more so they receive more blood than when blood than when they are resting . they are resting . Pairs of muscles Pairs of muscles work against each work against each other. One muscle other. One muscle contracts while the contracts while the other one relaxes. other one relaxes. For example, when For example, when the biceps contracts the biceps contracts the triceps relaxes.the triceps relaxes.