Body Systems Cells make up tissues, and tissues make up organs. A group of organs that serves a specific function in the body is called a system. The human body has numerous body systems, and each system has the purpose of maintaining homeostasis

integumentary system

The __ provides a protective covering for the entire body—it's called the skin. The skin and all its accessory organs protect the body, provide temperature regulation, and help with sensory reception.

Atoms

are the smallest components in the body that have unique characteristics. Each atom is made of protons, electrons, and neutrons. When atoms bond together, they form elements. For example, atoms of oxygen bond together to form the element oxygen, which as you know is essential to life.

The respiratory system

brings in oxygen from the outside environment for the cells; it eliminates carbon dioxide and other cellular waste products by exhaling them back to the outside world.

The digestive system

has the function of digesting the nutrients you eat, absorbing those nutrients, and eliminating the waste products of digestion.

The lymphatic system

helps protect the body from infection by filtering the blood and stimulating the immune system.

Homeostasis

is a fundamental characteristic of living beings; it reflects a balance of the body and body systems. When there is an imbalance, the result is a disease or disorder. For example, diabetes results from an imbalance of insulin, glucagon, and glucose in the blood. The goal of the body's organs and systems is to achieve and maintain homeostasis.

Physiology

refers to the study of how the anatomical parts function. For example, the processes of breathing and metabolism are both physiological processes of the body.

Anatomy

refers to the study of the structure of the body and reflects structural elements such as cells, tissues, and organs. For example, the heart and bone tissue are both anatomical components of the body.

The nervous system

is composed of the brain, spinal cord, and nerves of the body. Its main function is to allow the body to communicate with the brain and to provide control over the various body functions.

The endocrine system

is composed of the glands of the body. Its main function is to provide hormonal communication within the body and to control various functions through hormones and other chemicals.

The cardiovascular system

is composed of the heart, blood vessels, and blood. Its main functions are to transport oxygen and carbon dioxide to and from the lungs, to deliver nutrients and hormones throughout the body, and to provide a way for wastes to be removed from the body.

The skeletal system

is composed of the joints and bones of the body. Its main purposes are to form the body's framework or structure, to provide protection for organs, and to allow the body to move.

The muscular system

is composed of various muscles and muscle groupings with the purpose of providing movement, maintaining posture, and producing heat.

The urinary system

is made up of the kidneys and other organs; its function is to produce urine, to transport it to the urinary bladder, and then to eliminate it from the body by urinating.

Disease

is when an organ or system of the body does not function properly. For example, atherosclerosis is a disease where the arteries of the body are blocked by plaque buildup, which can potentially lead to heart attack and stroke.