Apuntes T1 Natural

T1. THE HUMAN BODY

The human body is divided in 3 parts: head, trunk and limbs. In the head there is the face with the forehead, chin and 2 cheeks.

The trunk has 2 parts: the thorax and the abdomen. The limbs include the upper limbs and the lower limbs.

Inside your body

Your body is made of bones and muscles. The bone of your head is the skull. Inside the skull there is the brain.

Your trunk contains organs that make you work: heart, lungs, kidneys, stomach and intestines.

The skin

The skin is an organ that covers your body. The skin feels different sensations and sends the information to your brain through the nerves. The skin can be tanned when the melanin reacts against the sunlight.

People are different

There are some things that make people different: sexual characteristics (women and men), body constitution (robust or slim), height (tall or short) and personal traits (color of the eyes, the skin or hair, etc).

Stages of life

There are 4 stages of life: childhood, adolescence, adulthood and old age. 

1)    Childhood: from birth until 12 years old.

2)   Adolescence: from 12 to 18 years old. Body changes.

3)   Adulthood: from 18 to 65 years old.

4)   Old age: from 65 years old onwards. Bones become frail and wrinkles appear.

Life processes

There are 3 main processes of life: nutrition, reproduction and sensitivity.

Nutrition:

During the process of nutrition you eat and absorb nutrients that become energy. Finally, your body expels waste. 

All the body systems are involved in nutrition. The digestive system absorbs nutrients from the food you eat. The respiratory system provides oxygen used to get energy from the nutrients. The circulatory system puts oxygen and nutrients in touch. 

Finally, Excretory system expels what your body doesn´t need.

Sensitivity:

Sensitivity is the ability to detect and respond to changes in the environment. The 5 senses provide the information to do so: sight, hearing, touch, taste and the sense of smell. The information captured by your senses travel through the nerves until your brain. Orders are given to muscles as reactions.

Reproduction:

People have sexual reproduction, that is that a male and a female must come together to reproduce. People are viviparous, that means that the baby is developed inside the womb of the mother. Most physical characteristics are inherited.