Human Systems Body Organization Human Body 100 trillion

Human Systems: Body Organization

Human Body • 100 trillion cells • More than 100 kinds of cells • Organization – cells, tissues, organ systems • Coordination • Maintaining internal environment (homeostasis)

Cells, tissues, organs • Cells must do many things to maintain homeostasis • Cells – different types of function and specialization

Cells, tissues, organs • Tissues form organs • Different functions in same place - coordination

Organ systems • Organs form organ systems • Stomach helps in food digestion but cannot digest food alone • Additional help needed by other organs of the digestive system • Mouth (saliva secretion), pancreas, gall bladder, intestine • Nervous system – brain, spinal cord, nerves • Organs perform specialized function in a coordinated manner

Cells, tissues, organs

Organ systems • Organ systems work together to perform body processes • E. g. cardiovascular system (circulatory system) works with respiratory system to perform exchange of gases. • Nervous system works with skeletal and muscular systems for producing movements. • Urinary, digestive and respiratory systems work together for excretion of wastes. • Digestive and circulatory systems work together to obtain and distribute nutrients.

Organ systems • Interdependence of organ systems • Some organs perform jobs essential for more than one system • E. g. pancreas – digestive and endocrine systems • Stomach – digestive system and communication • Liver – carbohydrate, protein, lipid metabolism, drug metabolism, detoxification, waste (urea) management, store materials

Organ systems • When systems fail – Systems must function properly and work together in order to maintain homeostasis – Failure of even a part of a system can result in a disorder affecting the whole organism – may result in death

Organ systems • E. g. angina – a heart disorder – Blood supply to heart is restricted – Heart cannot pump blood efficiently – Depletion of oxygen in body cells • E. g. diabetes – a pancreatic disorder – Problem in insulin production or action – Increase in blood glucose level – Can damage eyes, kidneys, brain, nerves, movement of substances, limbs, digestive system