Anatomy Overview

The human body is composed of several systems that work together to maintain overall health and function. The study of anatomy focuses on the structure and organization of these systems, including the skeletal, muscular, nervous, circulatory, respiratory, digestive, endocrine, integumentary, urinary, and reproductive systems.

Skeletal System

The skeletal system provides support, protection, and movement for the body. It is composed of 206 bones that are connected by joints, ligaments, and tendons. The skeletal system also produces blood cells and stores minerals such as calcium and phosphorus.

Bones

Bones are the rigid, calcified structures that make up the skeleton. They are classified into two main categories: long bones (e.g., femur, humerus) and flat bones (e.g., sternum, cranium). Bones contain a spongy tissue called bone marrow, which produces blood cells.

Muscular System

The muscular system enables movement, maintains posture, and regulates body temperature. It is composed of three types of muscles: skeletal muscles, smooth muscles, and cardiac muscle. Skeletal muscles are attached to bones and enable voluntary movements, while smooth muscles are found in the walls of hollow organs and enable involuntary movements. Cardiac muscle is found in the heart and pumps blood throughout the body.

Nervous System

The nervous system controls and coordinates the body's functions, including movement, sensation, perception, and cognition. It is composed of two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS includes the brain and spinal cord, while the PNS consists of nerves that connect the CNS to the rest of the body.

Circulatory System

The circulatory system transports oxygen, nutrients, and waste products throughout the body. It is composed of the heart, blood vessels (arteries, veins, and capillaries), and blood. The heart pumps blood through the blood vessels, which supply oxygen and nutrients to tissues and organs.

Respiratory System

The respiratory system brings oxygen into the body and removes carbon dioxide. It is composed of the nose, mouth, pharynx, larynx, trachea, bronchi, and lungs. The lungs expand and contract to facilitate gas exchange, while the diaphragm and other muscles enable breathing.

Digestive System

The digestive system breaks down food into nutrients that can be absorbed and utilized by the body. It is composed of the mouth, esophagus, stomach, small intestine, and large intestine. The digestive system also includes accessory organs such as the liver, pancreas, and gallbladder.

Endocrine System

The endocrine system produces hormones that regulate various bodily functions, including growth, development, metabolism, and reproductive processes. It is composed of glands such as the pituitary gland, thyroid gland, adrenal glands, pancreas, and gonads (ovaries and testes).

Integumentary System

The integumentary system protects the body from external damage and regulates body temperature. It is composed of the skin, hair, nails, and associated glands (sweat glands and sebaceous glands).

Urinary System

The urinary system removes waste products and excess fluids from the body. It is composed of the kidneys, ureters, bladder, and urethra. The kidneys filter blood to produce urine, which is then stored in the bladder and eliminated through the urethra.

Reproductive System

The reproductive system produces sex cells (sperm or eggs) and supports the development of a fetus during pregnancy. It is composed of the male and female reproductive organs, including the gonads (ovaries and testes), ducts (fallopian tubes and vas deferens), and accessory glands (prostate gland and seminal vesicles).