Human Organ Systems

Study Notes

Organ Systems

Nervous System: controls body functions, interprets and responds to stimuli
- Central Nervous System (CNS): brain, spinal cord
- Peripheral Nervous System (PNS): nerves, ganglia
Circulatory System: transports oxygen, nutrients, and waste products
- Heart: pumps blood
- Blood vessels: arteries, veins, capillaries
Respiratory System: brings oxygen into the body, removes carbon dioxide
- Lungs: exchange oxygen and carbon dioxide
- Trachea, bronchi, diaphragm: facilitate breathing
Digestive System: breaks down food into nutrients
- Mouth: mechanical and chemical digestion
- Esophagus: food transport
- Stomach: chemical digestion
- Small intestine: nutrient absorption
- Large intestine: water absorption, waste elimination
Endocrine System: produces hormones that regulate body functions
- Glands: pituitary, thyroid, adrenal, pancreas, etc.
Immune System: defends against pathogens and diseases
- White blood cells: recognize and attack foreign substances
- Lymphatic system: filters and transports immune cells
Muscular System: moves body, maintains posture, and regulates body temperature
- Skeletal muscles: voluntary movement
- Smooth muscles: involuntary movement
- Cardiac muscles: heart function
Skeletal System: provides support, protection, and movement
- Bones: 206 bones in the adult human skeleton
- Joints: connect bones, allow for movement
Integumentary System: protects body, regulates body temperature
- Skin: outer layer, protects against external factors
- Hair, nails, sweat glands: accessories

Body Cavities

Cranial Cavity: contains the brain
Thoracic Cavity: contains the heart, lungs, and major blood vessels
Abdominal Cavity: contains the digestive organs
Pelvic Cavity: contains the reproductive organs

Body Regions

Head: contains the brain, sensory organs, and facial features
Neck: connects the head to the body
Thorax: contains the chest and rib cage
Abdomen: contains the digestive organs
Pelvis: contains the reproductive organs and lower back
Upper Limbs: arms and hands
Lower Limbs: legs and feet

Organ Systems

Nervous System: controls body functions, interprets and responds to stimuli, comprising Central Nervous System (brain, spinal cord) and Peripheral Nervous System (nerves, ganglia)
Circulatory System: transports oxygen, nutrients, and waste products via the heart (pumps blood) and blood vessels (arteries, veins, capillaries)
Respiratory System: brings oxygen into the body and removes carbon dioxide through the lungs (exchange oxygen and carbon dioxide), trachea, bronchi, and diaphragm (facilitate breathing)
Digestive System: breaks down food into nutrients through mechanical and chemical digestion in the mouth, food transport in the esophagus, chemical digestion in the stomach, nutrient absorption in the small intestine, and water absorption and waste elimination in the large intestine
Endocrine System: produces hormones that regulate body functions through glands such as the pituitary, thyroid, adrenal, pancreas, and others
Immune System: defends against pathogens and diseases through white blood cells (recognize and attack foreign substances) and the lymphatic system (filters and transports immune cells)
Muscular System: moves body, maintains posture, and regulates body temperature through skeletal muscles (voluntary movement), smooth muscles (involuntary movement), and cardiac muscles (heart function)
Skeletal System: provides support, protection, and movement through 206 bones in the adult human skeleton, and joints that connect bones and allow for movement
Integumentary System: protects body, regulates body temperature, and consists of skin (outer layer, protects against external factors), hair, nails, and sweat glands (accessories)