The body is surrounded by the external environment that provides nutrients and oxygen that are necessary for life. The external environment also receives waste materials from the body. Communication with the external environment involves the special senses, and verbal and non-verbal activities. All of these are controlled by the nervous system.
Special senses are senses that have specialized organs devoted to them. These include:
- Vision (the eye)
- Hearing and balance (the ear including auditory system and vestibular system)
- Smell (the nose)
- Taste (the tongue)
Senses are separate and distinct from one another but they are used alone very rarely. For example, taste and smell are closely used when enjoying food even though they are separate senses with their own receptor organs.
The brain compares incoming information from the special senses with information that is already stored in memory and sends an appropriate response to the effector organs through the motor nerves. These responses protect the body from danger or enable activities such as eating.
Verbal communication is the use of sounds and language to relay a message.Sound is produced when air passes through the spaces between the vocal cords of the larynx.The larynx, or voice box, is located in the neck and performs several important functions in thebody. Speech is the manipulation of this sound by using the muscles of the throat and cheeks and moments of the tongue and lower jaw.
The production of vocal sound and speech is known as phonation.
Nonverbal communication is the process of sending and receiving messages without using words. It can include pitch, speed, tone and volume of voice, gestures and facial expressions, body posture, stance, and proximity to the listener, eye movements and contact.
Body movementsare brought about by special structures called as joints. A joint is a point at which two separate bones meet. Skeletal muscles which are responsible for body movements are located between the bones and the skin. They are stimulated bythe somatic nervous system controls all voluntary muscular systems. Certain non-verbal communications such as facial expressions do not involve movement of bones.