6.1 Introduction to Basic Structure of the Human Body The human body often described as an efficient, organized machine. When functions incorrectly disease occurs To know what is abnormal, we start with what is normal So we begin by studying the normal Anatomy: the structure and form of an organism and the Physiology: the study of the processes of living organisms

6.1 Introduction Pathophysiology: the study of how disease occurs and the responses of living organisms to disease processes. Cells: Microscopic structures that perform all the functions of life The human body contains trillions of cells They vary in shape, size, and function

Intro Most cells have these basic parts: Cell Membrane – outer protective covering Cytoplasm – semi-fluid inside the cell Organelles – structures help cell to function located in cytoplasm Nucleus – mass in the cytoplasm, the “brain” Nucleolus – located inside the nucleus, important for cell reproduction Chromatin – Located in the nucleus, made of DNA Centrosome – Located in the cytoplasm near nucleus, contains 2 centrioles

Intro & Cells Mitochondria – rod-shaped organelles located throughout the cytoplasm Golgi apparatus – stack of membrane layers in the cytoplasm Endoplasmic Reticulum – Fine network of tubular structures Lysosomes – oval or round bodies found throughout the cytoplasm Pinocytic Vesicles – Pocket like folds in the cell membrane

Cell Reproduction Mitosis – Form of asexual reproduction, the process of a cell dividing into two identical cells Meiosis – This process uses two separate cell divisions to produce four new cells ( Sex cells divide this way) Scientists are attempting to determine if stem cells can be transplanted into the body and used to cure diseases such as diabetes mellitus, Parkinson's Heart disease , osteoporosis and arthritis

Tissue Tissue – Cells of same type join together for a common purpose Tissue Fluid - is 60 – 90 % H2O Dehydration – Insufficient amount of tissue fluid Edema – Excess amount of tissue fluid (Swelling of Tissues) Four main groups of Tissues: Epithelial Tissue – Covers the surface of the body (Main tissue of the skin) Connective Tissue – Supporting fabric of organs and other body parts Two main types: Soft Connective ex. Adipose (fatty tissue) Fibrous ex. Ligaments and tendons

Tissues Continued Connective Continued Hard connective tissue – cartilage and bone Nerve Tissue – Made up of special cells called neurons (Nerves, Brain, and Spinal Cord) Muscle Tissue – Produces power and movement by contraction of muscle fibers. 3 Main types of Muscle Tissue: Skeletal – attach to bones for movement Cardiac – Causes the heart to beat Visceral (Smooth) – Present in walls of respiratory, digestive, urinary tract, and blood vessels.

Organs and Systems Organ – 2 or more tissues joined together for a specific function System – Organs and other body parts joined together to perform a particular function There 12 basic systems of the body: Integumentary – Skin Skeletal – Bones Muscular – Muscles Circulatory – Heart Lymphatic – Lymph Nervous – Brain, Nerves, Spinal Cord

Systems Continued: Special Senses –Eyes, Ears, Taste, Smell , Sense of Balance Respiratory – Lungs Digestive – Stomach, Intestines Urinary(Excretory) – Kidneys Endocrine – Glands Reproductive – Sex Organs Summary: Cells combine to form tissues, tissues combine to form organs, organs and other body parts combing to form systems.