Human Physiology A short introduction to the field of human physiology

Introduction n Living systems possess a special organization n Physiology studies two related aspects of that organization: structure and function n For this reason physiology is closely related to Anatomy and Biochemistry

Homeostasis n This is the name for the processes which keep the condition and environment of the tissues in the proper condition to sustain life.

Cells n Cells are the basic units of life n they make up tissues and organs in the body n Cells can only come from other cells (The CELL THEORY)

Tissues n muscle n nervous n epithelial n connective

Glands n Epithelial tissue n Specialized for secretion n Exocrine glands: secrete through ducts to the outside of the body n Endocrine glands: ductless glands which produce hormones which are released into the blood

Organs n Two or more types of primary tissue n Organized to perform a particular function

Examples of Organs n Stomach n Heart n Liver n Kidneys n brain n many others

Homeostasis: The Essence of Life n Cells live in a fairly constant environment n The cells, in turn, constitute the tissues which provide that environment Body systems Homeostasis Cells

Body Systems n Nervous n Endocrine n Immune n Circulatory n Muscle/skeletal n Integument n Respiratory n Urinary n Digestive n Reproductive

Negative Feedback Fall in temperature Heat Connecting Circuit Thermostat Furnace + + -

Negative Feedback Fall in blood pressure Increase in blood pressure Nerves Pressure sensors Heart and blood vessels + + -

Failure of Homeostasis n Often leads to sickness and eventually death