Articles

An introduction to how the body functions as a cohesive unit through its interconnected organ systems, each playing a specialized role to maintain homeostasis.

The skeletal system provides structural support, protects vital organs, and serves as a framework for muscle attachment. It includes bones, cartilage, ligaments, and joints. Bones also store minerals like calcium and produce blood cells in the bone marrow.

This system enables body movement through muscle contractions. It consists of three types of muscles: skeletal (voluntary), smooth (involuntary, found in internal organs), and cardiac (specific to the heart). The muscular system also helps regulate body temperature by generating heat.

The nervous system is the body’s control center, responsible for sensing, processing, and responding to stimuli. Composed of the brain, spinal cord, and peripheral nerves, it facilitates communication between the body and its environment and regulates vital functions like heart rate and breathing.

Also called the circulatory system, this system transports oxygen, nutrients, hormones, and waste products like carbon dioxide throughout the body. It includes the heart, blood vessels (arteries, veins, and capillaries), and blood.

The respiratory system enables gas exchange by supplying oxygen to the bloodstream and removing carbon dioxide. It includes the lungs, trachea, bronchi, and diaphragm, working closely with the cardiovascular system to deliver oxygen to tissues.

This system breaks down food into nutrients that the body can absorb and use for energy, growth, and repair. Key organs include the mouth, esophagus, stomach, intestines, liver, and pancreas. It also eliminates waste products.

The endocrine system regulates bodily functions through hormones secreted by glands such as the thyroid, adrenal glands, pancreas, and pituitary gland. These hormones control growth, metabolism, reproduction, and other essential processes.

The reproductive system allows for the generation of offspring. In males, it includes the testes, vas deferens, and penis, while in females, it includes the ovaries, fallopian tubes, uterus, and vagina. Most reproductive functions are regulated by hormones.

The lymphatic system is critical for fluid balance and immune defense, consisting of lymph nodes, lymphatic vessels, and the spleen. The immune system defends the body against pathogens through white blood cells, antibodies, and other mechanisms.

Also known as the renal system, it filters waste products and excess fluids from the blood. The kidneys, ureters, bladder, and urethra make up this system. It also regulates electrolyte balance and blood pressure.

The integumentary system, which includes the skin, hair, nails, and associated sweat and oil glands, acts as the body’s first line of defense. It protects against environmental damage, regulates body temperature, and provides sensory information.

Although not classified as a separate system, the special senses—sight, hearing, taste, smell, and touch—are essential for interpreting the environment. These senses rely on organs like the eyes, ears, tongue, nose, and skin.

Explains how the body maintains stable internal conditions through processes like temperature regulation, pH balance, and glucose control. Covers examples of negative and positive feedback loops.

Examines the components of blood, including red and white blood cells, platelets, and plasma. Explains their roles in oxygen transport, immunity, clotting, and maintaining homeostasis.