Body Organization

 The body has levels of organization that build on each other. Cells make up tissues, tissues make up organs, and organs make up organ systems. The function of an organ system depends on the integrated activity of its organs.

The circulatory system: It transports oxygen, nutrients, and other substances to the cells and transports wastes, carbon dioxide, and other substances away from the cells; it can also help stabilize body temperature and pH. 

The immune system: It defends against infection and disease, and transfers lymph between tissues and the blood stream.

The digestive system: It processes foods and absorbs nutrients, minerals, vitamins, and water. 

The endocrine system: It provides communication with the body via hormones and direct long term change in other organ systems to maintain homeostasis. 

The respiratory system: It delivers air to where gas exchange can occur.

The skeletal system: It supports and protects soft tissues of the body; provides movement at joints; produces blood cells; and stores minerals.

The muscular system:  It provides movement, support and heat production.

The integumentary system:  It provides protection from injury and fluid loss and provides physical defense against infection by microorganisms.

The nervous system: It collects, transfers and processes information and directs short term change in other organ systems.  

The excretory system: It removes excess water, salts, and waste products from the blood and body and controls pH.

The reproductive system: It produces gamete cells-sex cells- and sex hormones.