Human Anatomy Levels of Organization

Cells: Basic unit of life; specialized cells form tissues.
Tissues: Groups of similar cells; four main types:
- Epithelial
- Connective
- Muscle
- Nervous
Organs: Structures made of two or more tissue types performing specific functions.
Systems: Groups of organs working together (e.g., circulatory, respiratory).

Skeletal System
- Composed of bones and cartilage.
- Provides structure, protection, and support.
- Facilitates movement in conjunction with muscles.
Muscular System
- Consists of skeletal, smooth, and cardiac muscles.
- Responsible for movement, posture, and heat production.
Circulatory System
- Includes heart, blood vessels, and blood.
- Transports nutrients, gases, hormones, and waste products.
Respiratory System
- Comprises the lungs, trachea, and alveoli.
- Facilitates gas exchange (oxygen and carbon dioxide).
Digestive System
- Involves organs like the stomach, intestines, liver, and pancreas.
- Breaks down food, absorbs nutrients, and eliminates waste.
Nervous System
- Encompasses the brain, spinal cord, and nerves.
- Controls body functions via electrical signals.
Endocrine System
- Made of glands (e.g., pituitary, thyroid) producing hormones.
- Regulates metabolism, growth, and homeostasis.
Immune System
- Comprises lymph nodes, spleen, and white blood cells.
- Defends the body against pathogens.
Integumentary System
- Includes skin, hair, and nails.
- Protects the body and regulates temperature.
Reproductive System
- Male: testes, penis; Female: ovaries, uterus.
- Responsible for producing offspring.

Dorsal Cavity: Houses the brain and spinal cord.
Ventral Cavity: Divided into:
- Thoracic Cavity: Contains heart and lungs.
- Abdominopelvic Cavity: Contains digestive organs, kidneys, reproductive organs.

Planes of the Body:
- Sagittal: Divides body into left and right.
- Frontal (coronal): Divides body into anterior and posterior.
- Transverse: Divides body into superior and inferior.

Understanding anatomy for medical practice, including:
- Imaging techniques (e.g., MRI, X-ray).
- Surgical anatomy for procedures.

These notes provide a concise overview of human anatomy, its organization, major systems, and essential terminology.

Cells: The building blocks of life; specialized cells combine to create tissues.
Tissues: Comprise four main types:
- Epithelial: Covers surfaces and lines cavities.
- Connective: Supports and binds other tissues.
- Muscle: Enables movement.
- Nervous: Facilitates communication and control.
Organs: Structures consisting of two or more tissue types that perform dedicated functions.
Systems: Groups of organs that collaborate to perform complex functions (e.g., the respiratory system works alongside the circulatory system).

Skeletal System:
- Composed of bones and cartilage.
- Provides structure and protection and supports body movements.
Muscular System:
- This includes skeletal (voluntary), smooth (involuntary), and cardiac (heart) muscles.
- Responsible for movement, maintaining posture, and generating heat.
Circulatory System:
- Made up of the heart, blood vessels, and blood.
- Responsible for the transportation of nutrients, gases, hormones, and waste.
Respiratory System:
- Composed of lungs, trachea, and alveoli.
- Essential for gas exchange, facilitating oxygen intake and carbon dioxide removal.
Digestive System:
- Includes the stomach, intestines, liver, and pancreas.
- Functions to break down food, absorb nutrients, and eliminate waste.
Nervous System:
- Encompasses the brain, spinal cord, and peripheral nerves.
- Controls and coordinates body functions through electrical signals.
Endocrine System:
- Composed of glands like the pituitary and thyroid.
- Produces hormones that regulate metabolism, growth, and homeostasis.
Immune System:
- Includes lymph nodes, the spleen, and white blood cells.
- Protects the body against infectious agents and pathogens.
Integumentary System:
- Consists of skin, hair, and nails.
- Provides protection and helps regulate body temperature.
Reproductive System:
- Male system: includes testes and penis.
- Female system: includes ovaries and uterus.
- Vital for producing offspring.

Dorsal Cavity: Encloses the brain and spinal cord.
Ventral Cavity: Contains major organs and is divided into:
- Thoracic Cavity: Houses the heart and lungs.
- Abdominopelvic Cavity: Contains digestive organs, kidneys, and reproductive organs.

Planes of the Body:
- Sagittal Plane: Divides the body into left and right halves.
- Frontal (Coronal) Plane: Divides the body into anterior and posterior sections.
- Transverse Plane: Divides the body into superior and inferior parts.

Embryology: Examines development from fertilization to birth.
Growth and Maturation: Studies anatomical changes throughout different life stages.