© 2015 Pearson Education, Inc.

© 2015 Pearson Education, Inc. Cell Extensions Surface extensions found in some cells Cilia move materials across the cell surface Located in the respiratory system to move mucus Flagella move the cell The only flagellated cell in the human body is sperm Microvilli are tiny, fingerlike extensions of the plasma membrane Increase surface area for absorption Common in intestines and kidneys © 2015 Pearson Education, Inc.

© 2015 Pearson Education, Inc. Cell Diversity The human body houses over 200 different cell types Don’t worry- you don’t have to know them all! Cells vary in length from 1/12,000 of an inch to over 1 yard (nerve cells) Cell shape reflects its specialized function an example of how structure determines function © 2015 Pearson Education, Inc.

© 2015 Pearson Education, Inc. Cell Diversity Cells that connect body parts Fibroblast Secretes cable-like fibers Erythrocyte (red blood cell) Carries oxygen in the bloodstream © 2015 Pearson Education, Inc.

Figure 3.8a Cell diversity. Fibroblasts Rough ER and Golgi apparatus No organelles Nucleus Erythrocytes (a) Cells that connect body parts

© 2015 Pearson Education, Inc. Cell Diversity Cells that cover and line body organs Epithelial cell Packs together in sheets Intermediate fibers resist tearing during rubbing or pulling © 2015 Pearson Education, Inc.

Figure 3.8b Cell diversity. Nucleus Epithelial cells Intermediate filaments (b) Cells that cover and line body organs

© 2015 Pearson Education, Inc. Cell Diversity Cells that move organs and body parts Skeletal muscle and smooth muscle cells Contractile filaments allow cells to shorten forcefully © 2015 Pearson Education, Inc.

Figure 3.8c Cell diversity. Skeletal muscle cell Nuclei Contractile filaments Smooth muscle cells (c) Cells that move organs and body parts

© 2015 Pearson Education, Inc. Cell Diversity Cell that stores nutrients Fat cells Lipid droplets stored in cytoplasm © 2015 Pearson Education, Inc.

Figure 3.8d Cell diversity. Fat cell Lipid droplet Nucleus (d) Cell that stores nutrients

© 2015 Pearson Education, Inc. Cell Diversity Cell that fights disease Macrophage (a phagocytic cell) Digests infectious microorganisms © 2015 Pearson Education, Inc.

Figure 3.8e Cell diversity. Lysosomes Macrophage Pseudo- pods (e) Cell that fights disease

© 2015 Pearson Education, Inc. Cell Diversity Cell that gathers information and controls body functions Nerve cell (neuron) Receives and transmits messages to other body structures © 2015 Pearson Education, Inc.

Figure 3.8f Cell diversity. Processes Rough ER Nerve cell Nucleus (f) Cell that gathers information and controls body functions

© 2015 Pearson Education, Inc. Cell Diversity Cells of reproduction Oocyte (female) Largest cell in the body Divides to become an embryo upon fertilization Sperm (male) Built for swimming to the egg for fertilization Flagellum acts as a motile whip © 2015 Pearson Education, Inc.

Figure 3.8g Cell diversity. Nucleus Flagellum Sperm (g) Cell of reproduction

© 2015 Pearson Education, Inc. Cell Physiology Cells have the ability to: Metabolize Digest food Dispose of wastes Reproduce Grow Move Respond to a stimulus © 2015 Pearson Education, Inc.