Multicellular Organisms Cellular Differentiation Tissues Organs Organ Systems

Cellular Differentiation – Recap! Cell specialization takes place early in the development of multicellular organisms Each cell undergoes changes and develops characteristics to make it unique from other cells Once a cell has differentiated it can perform a very specific function within the organism.

Examples of differentiated cells in our bodies: Muscle Cells Fat Cells Epithelial Cells Nerve Cells

Tissues Organs Organ Systems What happens next? Tissues Organs Organ Systems

Tissues A group of cells that are similar in shape and function are called a TISSUE In animals, there are 4 basic types of tissues; epithelial tissue, muscle tissue, connective tissue and nervous tissue. E.g. Blood – connective tissue External covering and lining for mouth, heart, liver, eyes – epithelial tissue In plants – tissues made from thick walled plant cells are used for structure

Organs Organs are different tissues that group together to form larger structures that work together to achieve one or more functions within the organism. Skin is the largest human organ and it is made up of connective, epithelial, nervous and fat tissues Skins provides structural support and barrier that protects our insides from our outside! Other animal organs are:

Organ Systems Organs never work alone 2 or more organs working together to perform a related function are a organ system. Organ systems often overlap and share organs Organ systems are interdependent – they need contact with the brain in order to function properly. Plants have 2 major organ systems: the root system and the shoot system How many different animal systems can you think of?

Human Organ Systems

Check Your Learning In your own words, write a definition for cell, tissue, organ, and organ system. Give an example of each of these in your body. Name the 5 organ systems in your body that you learned about in this section. What is the major function or each of these systems? What are the 4 types of tissues found in most organ systems?