Human Anatomy and Physiology

The smallest living unit of the body is the cell, and it's so amazing, it deserves a lesson of its own. Even though almost all cells are microscopic, they're packed with many distinct kinds of organelles and surrounded by complex membranes. You'll be amazed at their complexity as you learn about their functions. You'll also learn how cells reproduce. The lesson will end with a discussion on cancer—which is cell reproduction gone amok.

This lesson will tackle the subject of heredity and the basics of genetics. You'll learn how genes affect your physical and mental characteristics, and how your parents' genetic material influenced these traits. You'll learn the significant differences between reproductive cells and all of the other cells in your body. The lesson will also spend time on a man who lived in the 1800's—Gregor Mendel, the Father of Genetics—because his insights paved the way for the modern understanding of heredity. The lesson will close with information on specific mutations in the genetic code that can cause genetic disorders.

This lesson focuses on the nervous system. You'll learn how it's organized, its different functions, and the structures that make thinking, feeling, and moving possible. You'll also learn how the nervous system works when you think you're in danger or you've suddenly experienced physical pain. You'll use your knowledge of chemistry in this lesson when it explains how neurons (nerve cells) generate nervous impulses. The lesson will end with a discussion of six different disorders of the nervous system—what causes them and how they affect the people who suffer from them.

Your bones have several functions, and some aren't very obvious. For example, red blood cells are made in your bones, and bones store minerals that are essential for the function of your nerves and muscles. This lesson on the skeletal system will explore the structure and function of bones, and then cover the different types of joints and the amazing structure of your spinal column. You'll learn about three common disorders of this system and what you can do to keep your bones strong.

Like the skeletal system, the muscular system is crucial for movement, but it has other functions, too. Like bones, muscles are also a lot more complicated than they appear. You'll spend time learning about both the structures that you can see and the structures that you can't see without a microscope. The lesson will go over some of the specific muscles in the body and how they work together to perform specific movements. You'll also learn why even simple movements involve chemical reactions and a close coordination between the muscular system and the nervous system. The last chapter will cover several common injuries to various parts of the muscular system.

This lesson focuses on the respiratory system. As you're probably aware, it's the group of organs that allow you to get that crucial substance, oxygen, to all the cells in your body. You'll learn about the anatomy of your respiratory organs and which muscles are crucial for breathing. You'll also become aware of the differences between ventilation, external respiration, internal respiration, and cellular respiration. You'll also learn about illnesses that can affect the respiratory system, compromising a person's ability to breathe.

This lesson will explore the composition of blood, the various blood cells, and the various kinds of blood vessels in your body. The heart is a crucial part of the circulatory system, so this lesson will teach you about its chambers, valves, coronary vessels, and electrical system. You'll learn how blood travels around your body and its essential functions. The last chapter will spend time on two of the most common health problems people experience—high blood pressure and coronary artery disease. You'll finish this lesson knowing why it's so important to take care of this organ system.

In this lesson, you'll learn all about the disease-fighting ability of your body. This lesson will explain the several types of germs that can make a person sick, as well as some of the many ways your body fights back to keep you well, including defenses you're born with and those you develop later on. Your body also has a system of vessels (similar to blood vessels) called the lymphatic system. You'll learn about its disease-fighting role as well as some of its other functions. You'll also learn about some of the other organs in your body that engage in the battle against disease. The end of this lesson will teach you how the body's disease-fighting ability can be compromised, and why sometimes the body turns on its own cells.

This lesson will take a close look at two different organ systems—the integumentary system (the skin and its accessory organs) and the urinary system. Both of these systems work to get rid of waste products that would kill you if they built up in your body. You'll learn, too, how important these two systems are in maintaining homeostasis. This lesson will spend quite a bit of time on the structure of these two systems. People are often surprised to learn how complex even the skin can be. And the structures and functions of the urinary system, particularly the kidneys, are quite amazing. At the end of this lesson, you'll learn about kidney failure and the challenges of dialysis and kidney transplantation.

You may never think about food the same way again after this lesson on the digestive system! You'll learn about all the different structures involved with converting food into the chemicals your body needs to grow, repair tissues, and perform all the functions of life. The lesson also covers the role of the three main types of foods and the importance of many different vitamins and minerals. By the time you've finished this lesson, you'll understand the value of eating a variety of foods and how healthy food choices will enhance your well-being. The last chapter will cover two common digestive system disorders and one of the most common kinds of cancer—colon cancer.

This course ends with a discussion about the endocrine and reproductive systems. You'll learn how the endocrine and nervous systems work together to regulate all of your body's functions. You'll learn about different endocrine glands, the hormones they produce, and how they influence each other. Homeostasis again becomes something important to talk about because of the crucial role of the endocrine system. This lesson also covers both the male and female reproductive systems. You'll learn about their anatomy and how the endocrine system affects their organs, making reproduction possible. We'll end this chapter with a discussion about three fairly common disorders—diabetes, prostate cancer, and endometriosis.