1. The human body

2. The three vital functions and the systems
Nutrition
Interaction
Reproduction
Digestive system
Excretory system
Circulatory system
Respiratory system
The five senses
Muskuloskeletal system
Nervous system
Male and female reproductive system

3. The human body and nutrition
The digestive system breaks down the food we eat into smaller molecules that our body can absorb .
Key words: esophagus, stomach, intestines.
The respiratory system absorbs oxygen into the body and releases carbon dioxide.
Key words: trachea, lungs.
The circulatory system transports blood all over the body.
key words: heart, blood vessels.
The excretory system eliminates de waste (deshecho) our body produces.
key words: kidney (riñones) and bladder (vegija)

4. The human body and the interaction
The interaction function enables (permite) living things receive information either from the environment (medio) or from their own body and control and coordinate the activities.
How it works (funciona)?
Identify the stimulus (sg). A stimulus is any action or change. It can be:
External stimuli (pl) are changes that happen in our environment outside (fuera) the body. Our senses capture the stimuli.
Internal stimuli are changes that happen inside (dentro) our body by the receptor organs.
The brain receives and processes the information and decides the order.
The order becomes (se convierte en) a response and our body reacts. The responses can be:
Motor responses happen when the muscles move.
Glandular responses happen when organs called glands produce a substance. For example: sweat (sudor)

5. The interaction: the sensory system (5 senses)
Smell (olfato): olfatory receptors are in the nasal cavity next to the pituitary area.
Taste (gusto): taste receptors, called taste buds, are on the tongue and help us to differenciate the flavours (sabores). Picture of the tongue.
Touch (tacto): touch receptors, located in the skin, can detect temperature, pressure, pain and texture.
Sight (vista): the eyes are the organ that let us see. Light enters the eyes through the pupil, the lens and the retina, that sends the stimuli throough the optic nerve. Picture of the eye.
Hearing (oido): the outer ear collects the sound, which passes through the inner ear cannal, the middle ear and the three small bones, reaches the cochlea and the auditory nerve. Picture of the ear.