Principal organ system

The human organism is made up of 11 main organ systems that work together to maintain life.

• The integumentary system consists of skin,hair,nails,sweat glands.It provides a protective covering for the body,helps to regulate body temperature and receives information about touch,pressure,temperature and pain.
• The skeletal system consists of bones,cartilage and ligaments.This provides support ,protects the body,stores calcium,produces blood cells and works with the muscular system to carry out movement.
• The muscular system consists of skeletal muscle,cardiac muscle,smooth muscle.It moves parts of skeleton like locomotion,pumps blood and moves internal materials.
• The nervous system consists of nerves and sense organs;brain and spinal cord.It is the principal regulatory system.It receives stimuli from the external and the internal environment and transmits impulses to muscles and glands.
• The endocrine system consists of pituitary,adrenal,thyroid and other ductless glands.This system works with the nervous system to regulate metabolic activities and body chemistry.It also secretes chemical messengers called hormones.
• The digestive system consists of mouth,esophagus,stomach,intestine,liver,pancreas and salivary glands.This system ingests and digests food,breaks down food and absorbs nutrients into the blood.
• The respiratory system consists of lungs,trachea and other air passageways.This system delivers oxygen to the blood and removes carbon dioxide from the body,maintains appropriate oxygen content and helps to regulate acid-base balance of blood.
• The cardiovascular system consists of heart,blood vessels and blood.It transports nutrients,oxygen,hormones and other substances to the body cells and carries wastes from the cells to the excretory organs,helps in maintaining fluid balance.
• The lymphatic(immune) system consists of lymph,lymphatic vessels,lymph nodes and other lymph structures.This systems collects excess tissue fluid and returns it to the blood,absorbs lipids from digestive tract and transports them to cardiovascular system and defends the body against organisms that cause disease.
• The urinary system consists of kidneys,bladder and associated ducts.This functions to excrete metabolic wastes and helps to regulate fluid balance and acid-base balance.
• The reproductive system consists of testes,ovaries and associated structures,The male reproductive system produces and delivers sperms ans the female reproductive system produces ova and incubates the developing offspring.Both systems release hormones that establish and maintain sexuality.