body systems

Here’s a quick overview of major organs and their primary functions, organized by body system:

Respiratory System

  • Lungs: Facilitate gas exchange; oxygen is absorbed into the blood, and carbon dioxide is exhaled.

  • Trachea: The windpipe; provides airflow to and from the lungs.

  • Bronchi: Branch off the trachea and carry air to each lung.

  • Diaphragm: Contracts to allow inhalation and relaxes for exhalation.

Cardiovascular System

  • Heart: Pumps oxygenated blood to the body and deoxygenated blood to the lungs.

  • Blood Vessels (arteries, veins, capillaries): Transport blood throughout the body.

Digestive System

  • Mouth: Begins digestion by chewing and mixing food with saliva.

  • Esophagus: Transports food from the mouth to the stomach.

  • Stomach: Breaks down food using acid and enzymes.

  • Small Intestine: Absorbs nutrients from digested food.

  • Large Intestine: Absorbs water and forms waste (feces).

  • Liver: Produces bile to aid in fat digestion and processes nutrients.

  • Pancreas: Produces digestive enzymes and insulin.

  • Gallbladder: Stores and releases bile.

Nervous System

  • Brain: Controls body functions, processes sensory information, and coordinates responses.

  • Spinal Cord: Transmits signals between the brain and body.

  • Nerves: Carry electrical signals to and from the brain, spinal cord, and body.

Urinary System

  • Kidneys: Filter blood to produce urine and regulate electrolytes.

  • Ureters: Transport urine from the kidneys to the bladder.

  • Bladder: Stores urine until excretion.

  • Urethra: Carries urine out of the body.

Endocrine System

  • Pituitary Gland: Regulates other glands and releases growth and reproductive hormones.

  • Thyroid Gland: Controls metabolism and energy usage.

  • Adrenal Glands: Produce hormones like adrenaline and cortisol.

  • Pancreas (Endocrine Function): Produces insulin and glucagon to regulate blood sugar.

Immune/Lymphatic System

  • Spleen: Filters blood and helps fight infection.

  • Thymus: Matures T-cells (a type of white blood cell).

  • Lymph Nodes: Filter lymph fluid and house immune cells.

Musculoskeletal System

  • Bones: Provide structure, protect organs, and store minerals.

  • Muscles: Enable movement by contracting and relaxing.

  • Joints: Allow flexibility and motion in the skeleton.

Integumentary System

  • Skin: Protects against infection, regulates temperature, and prevents water loss.

  • Hair: Provides insulation and protection.

  • Nails: Protect fingertips and enhance grip.

Reproductive System

  • Ovaries: Produce eggs and hormones (estrogen and progesterone).

  • Testes: Produce sperm and testosterone.

  • Uterus: Supports fetal development.

  • Penis/Vagina: Facilitate reproduction.