Cell Structure

Microscopic Observations of

Cells Membranes

Membrane Structure Membrane Junctions

Cell Organelles

Nucleus Ribosomes

Endoplasmic Reticulum Golgi Apparatus Endosomes Mitochondria

Lysosomes

Peroxisomes

Cytoskeleton

SUMMARY KEY TERMS REVIEW QUESTIONS

Vander et al.: Human I I. Basic Cell Functions I 3. Cell Structure I I © The McGraw-Hill

Physiology: The Companies, 2001 Mechanism of Body Function, Eighth Edition

As we learned in Chapter 1, cells are the structural and functional units of all living organisms. The word "cell" means "a small chamber" (like a jail cell). The human body is composed of trillions of cells, each a microscopic compartment (Figure 3-1). In this chapter, we describe the structures found in most of the body's cells and state their functions. Subsequent chapters describe how these structures perform their functions.

The cells of a mouse, a human being, and an elephant are all approximately the same size. An elephant is large because it has more cells, not because it has larger cells. A majority of the cells in a human being have diameters in the range of 10 to 20 p,m, although cells as small as 2 p,m and as large as 120 p,m are present. A cell 10 p,m in diameter is about one-tenth the size of the smallest object that can be seen with the naked eye; a microscope must therefore be used to observe cells and their internal structure.

Cellular Organization

FIGURE 3-1

Cellular organization of tissues, as illustrated by a portion of spleen. Oval, clear spaces in the micrograph are blood vessels.

From Johannes A. G. Rhodin, "Histology, A Text & Atlas," Oxford University Press, New York, 1974.

FIGURE 3-1

Cellular organization of tissues, as illustrated by a portion of spleen. Oval, clear spaces in the micrograph are blood vessels.

From Johannes A. G. Rhodin, "Histology, A Text & Atlas," Oxford University Press, New York, 1974.

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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  • lotta
    What are the key cell structures in the human body?
    6 years ago

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