Human Biology

Which of these amazing statements about

human biology are fact, and which are

fiction?• There is fat on the bottom of your feet

• Your jaws move

• Newborns are protected from disease

You’re organized!• You are one person, one organism. But the body

you have is made of billions of individual cells. Those cells are organized:

• Groups of cells with similar structure and function are called tissues.

• Tissues are organized into functional units called organs.

• Groups of organs that work together to perform specific functions for the organism comprise organ systems.

THERE ARE FOUR MAIN TYPES OF TISSUES:1. CONNECTIVE TISSUE. Joins together body

structures, providing protection and support. It can be hard, soft, or liquid. Examples:

2. MUSCLE TISSUE. Made of cells that contract in res_

ponse to signals from the spinal chord and brain. All body movement, included that of internal or_ gans, is carried out by muscle tissue.

3. EPITHELIAL TISSUE. Tissue that covers the body and

its organs.

4. NERVOUS TISSUE. Composed of two types of cells,

carries information throughout the body. One type of cell, called a neuron, conducts signals in the form of electrical impulses. The other type of cell, called glial, supports, protects, and coordinates the neurones.

Basic body plan• Human body has bilateral symmetry which can be

described by four terms: ANTERIOR (top), POSTERIOR (bottom), VENTRAL (front), and DORSAL (back).

• Humans have a high degree of CEPHALIZATION, which means that the sense organs and the structures that control the body are located in its anterior part.

• The internal organs are located within large spaces called BODY CAVITIES. When the body grows or moves, internal organs are stably contained within the body cavities.

Human body systems• Which human body systems can you name?

• Do you know their specific functions?

• Can you tell the organs that make up those human body systems?