Introduction to Human Body Chapter 27 Biology: Exploring Life

November 13, 2008 Human Anatomy and Physiology Anatomy is the study of the parts and structures of an organism Physiology is the study of how structures function Like all substances, the human body is composed of atoms, which in turn make molecules. Atoms and molecules form chemical elements and compounds.

Certain combinations of chemicals exhibit the characteristic called life, which means that that combination of chemicals can move, grow, convert food into energy, and reproduce. The smallest bunches of chemicals that exhibit life are called cells. Cells include bacteria and organisms such as amoebas. Certain combinations of chemicals exhibit the characteristic called life, which means that that combination of chemicals can move, grow, convert food into energy, and reproduce. The smallest bunches of chemicals that exhibit life are called cells. Cells include bacteria and organisms such as amoebas.

All plants and animals, including humans, are made of cells. Cells form more- complex structures called tissue. Tissue can be organized to perform a specific function within a plant or animal. This organized structure is called an organ. Organs that work together to carry out related functions are called organ systems or simply systems. The integrated systems thus make up the living creature called an organism. All plants and animals, including humans, are made of cells. Cells form more- complex structures called tissue. Tissue can be organized to perform a specific function within a plant or animal. This organized structure is called an organ. Organs that work together to carry out related functions are called organ systems or simply systems. The integrated systems thus make up the living creature called an organism.

The levels of body structure are: 1. Cell -- like an individual heart muscle cell 2. Tissue – like the heart muscle 3. Organ – like the heart 4. Organ system like the circulatory system 5. Organism – a human

Types of tissues 11/14/08 Your body contains about 250 different types of cells. When a group of cells that are alike in structure and function are together, they are called tissue. 4 TYPES OF TISSUE 1. Epithelial Tissue – is loosely packed cells that form a sheet like covering that are on the outside of your body and form the lining of your internal organs

2. Connective Tissue –functions to hold together and support other types of tissue. It also cushions, insulates and connects organs. Examples: bone, cartilage, blood and fat 3. Nervous Tissue – forms the communication system of your body, helps coordinate movements, includes all your senses, memory and intelligent. A neuron is a nerve cell.

4. Muscle tissue – responsible for all movement, includes muscle in internal organs and heart muscle. Muscles are either voluntary (you can control) or involuntary (you cannot control) Three types of muscles: a.Skeletal muscle – attaches to your bones b.Cardiac muscle – found in heart c.Smooth muscle – found in internal organs

DO NOT COPY THIS SLIDE. JUST DO THE FOLLOWING: Beside each of the three types of muscles, write if it is voluntary or involuntary.