1 Anatomy & Physiology: Understanding the Human Body

2 Definitions Anatomy and physiology are interrelated subjects Anatomy is the study of the structure of an organism. Physiology is the study of the function of an organism.

3 Levels of structural organization

4 Chemical level –atoms and molecules Cellular level –Cells: smallest living part of the body Tissue level –Tissue: group of cells that work together to perform the same task –4 basic tissue types: epithelial, muscle, connective and nervous Organ level –Organ: group of 2 or more tissue types that work together to perform a specific function System level –Organ system: a group of organs working together to preform one of the body’s major functions –sometimes an organ is part of more than one system Organismal level – the organism OR living thing

5 All living organisms are composed of cells  The cell is the smallest living part of our body  It is the building block of our entire body  Cells vary in size, shape and function  All cells need food, water, and oxygen to live and function THE HUMAN CELL

6 The cell can be considered as a factory with lots of machines inside, each performing a different job Structures of the cell - organelles Cell membrane:  outer covering of the cell  holds substances inside  maintains the shape of the cell The nucleus:  central portion of the cell  directs the cell’s activities  contains the chromosomes  Chromosomes (made up of DNA): the bearer of genes, which carry inherited traits such as eye colour Cytoplasm:  surrounds the nucleus  contains machinery of the cell (organelles).

7 Types of cells:  Nerve cells (neurons): have long, thin extensions that can transmit nerve impulses over a large distance  Epithelial Cells: thin, flat, and tightly packed so that they form a protective layer  Muscle Cells: slender rods that attach to the ends of the structures they move There are many different types of cells, each with a different shape and function. Types of Cells

Types of tissues Connective Tissue holds body parts together and connects them. Body parts like bones, ligaments, and tendons are held together by this type of tissue. Epithelial Tissue covers the internal and external body surfaces. Examples of this tissue are the skin and the linings of internal organs. Muscle Tissue expands and contracts, allowing the body to move. Nervous Tissue carries messages from all parts of the body to the central nervous system (CNS).

Organs and Organ Systems Organ Systems  have separate and distinct functions, but they rely on one another to perform their tasks  made up of organs