Main Systems of the Human Body

The systems of the human body work together as a true cooperative to maintain the health and effeciency of the body. Each system has its own function.  The exact number and extent of the body's system is controversial for example the musculoskeletal system is made up of the bones, joints and the muscles. Although these systems can be given seperate categories they all work together as a unit and each one depends on the other for physical and physiological support.  Most systems have general body tissues such as connective tissues which support, deleniate and cushion many organs.  All the systems are essential for survival except for the reproductive system.

Muscular System:

The muscles of the body work together with the skeleton to provide the pulling force for varied degress of movement. These movements range from powerful to finely tuned.  Involuntary muscles are the muscles which move mostly automatically to control internal processes of the body.  The muscles require nerves to control them and blood to keep them supplied with oxegen and energy.

Skeletal system :

The skeleton is defined as a solid framework that supports the body. The bones work as levers and anchor plates to allow for movement.  Bones also play a part in other body systems.

Nervous System :

The brain is the seat of both conciousness and creativity and through the spinal cord and nerve branches, it controls all body movements using its motor output.  The brain also receives sensory information from outside and within the body.  Much of the brains activity happens unconciously as it works with the endocrine glands to monitor and maintain other body systems.  The Nervous System can be broken down into smaller systems which are part of the nervous system such as the autonomuic nervous system which consists of the sympathetic nervous system and the parasympathetic nervous sytem. 

Endocrine System :

The glands and cells of the endocrine system produce chemical messengers called hormones e.g testosterone which circulate in the blood and other fluids.  Hormones also govern long term processes e.g growth.  The endocrine system has close links to the nervous system.

Cardiovascular System:

The most basic function of the cardiovascular system or the circulatory system is to pump blood around the body.  It supplies all organs and tissues with freshly oxegenated nutrient-rich blood.  Any waste products of cell function are removed with the blood as it leaves.  The circulatory system also transports other vital substances e.g nutrients and hormones.

Respiratory System :

The respiratorty system is the only system that is not essential for us humans to survive.  The respiratory tract and its breathing muscles carry air in and out of the lungs.  As this happens gases are exchanged the body inhales oxegen from the air while carbon dioxide waste is passed back into the air on exhalation.  A secondary function of the respiratory system is vocalization (speech).

Integumentary system:

The skin, hair and nails together form the bodys outer protective covering.  They stop hazards such as physical injury, microorganisms and radiation.  The skin also regulates the body through sweating and ahir adjustment. A layer of fat under the skin acts as an insulator, an energy store and a shock absorber.

Lymph and Immunity System:

The immune systems inticate and interrelationships of physical, celllular and chemical defences provide crucial resistance to many threats e.g infectious diseases.  The slowly circulating lymph fluid helps to distribute nutrients and also collects waste.  It also delivers immunity-providing white blood cells when needed.

Digestive System:

The process of digestion has many stages.  The digestive tract's nine metres of tubing which runs from mouth to anus has a compolex range of functions. It chops and chews food, stores the food and then digests it. It then eleminates the waste and passes nutrients up to the liver. Healthy digestion depends on the proper functioning of the immune and digestive systems.

Reproductive System:

Unlike any other system the reproductive system is not essential for maintaining life and it differs dramtically between male and female. It only functions for part of the human life span.