Overview of Anatomy and Organ Systems

Definition: Study of the structure of the body and its parts.
Branches:
- Gross Anatomy: Study of structures that can be seen with the naked eye.
- Microscopic Anatomy: Study of structures at the cellular and tissue level.
  - Histology: Study of tissues.
  - Cytology: Study of cells.

Anatomical Position: Standing upright, facing forward, arms at the sides, palms facing forward.
Planes of the Body:
- Sagittal Plane: Divides body into left and right.
- Frontal (Coronal) Plane: Divides body into anterior and posterior.
- Transverse Plane: Divides body into superior and inferior.

Skeletal System: Provides structure, support, and protection; consists of bones and joints.
Muscular System: Facilitates movement; consists of skeletal, smooth, and cardiac muscles.
Nervous System: Controls body functions through nerve impulses; includes the brain, spinal cord, and nerves.
Circulatory System: Transports blood, nutrients, and gases; includes heart and blood vessels.
Respiratory System: Facilitates gas exchange; includes lungs and airways.
Digestive System: Breaks down food for nutrient absorption; includes mouth, stomach, intestines.
Endocrine System: Regulates bodily functions through hormones; includes glands such as the thyroid and adrenal.
Lymphatic/Immune System: Protects against disease and maintains fluid balance; includes lymph nodes and vessels.
Urinary System: Eliminates waste and regulates water and electrolytes; includes kidneys and bladder.
Reproductive System: Responsible for producing offspring; includes male and female reproductive organs.

Epithelial Tissue: Covers body surfaces and lines cavities; functions in protection, absorption, and secretion.
Connective Tissue: Supports, binds, and protects other tissues; includes bone, blood, and adipose tissue.
Muscle Tissue: Responsible for movement; types include skeletal, cardiac, and smooth muscle.
Nervous Tissue: Composed of neurons and glial cells; responsible for transmitting impulses.

Dorsal Cavity: Contains the cranial and spinal cavities.
Ventral Cavity: Contains thoracic and abdominopelvic cavities.
- Thoracic Cavity: Houses lungs and heart.
- Abdominopelvic Cavity: Contains digestive organs, kidneys, and bladder.

Regions of the Body:
- Cranial: Head
- Cervical: Neck
- Thoracic: Chest
- Abdominal: Abdomen
- Pelvic: Pelvis
- Limbs: Upper and lower extremities

Definition: The body's ability to maintain a stable internal environment despite external changes.
Importance: Critical for overall health and function; involves feedback systems (negative and positive feedback).

Anatomy is foundational for understanding the body, its structures, and their functions, essential for fields like medicine, biology, and health sciences.

Anatomy involves examining the body's structure and components.
Gross Anatomy: Focuses on macroscopic structures visible without magnification.
Microscopic Anatomy: Involves the study of tissues and cells using microscopes.
Histology: Specialized field concentrating on various tissue types.
Cytology: Focuses specifically on the composition and function of cells.

Anatomical Position: Standard stance for anatomical reference where the body is upright and facing forward with arms at the sides.
Sagittal Plane: Splits the body into left and right sections.
Frontal (Coronal) Plane: Divides the body into front (anterior) and back (posterior) segments.
Transverse Plane: Separates the body into upper (superior) and lower (inferior) portions.

Skeletal System: Comprises bones and joints; provides structural integrity and protection.
Muscular System: Contains skeletal, smooth, and cardiac muscles; essential for movement.
Nervous System: Manages communication across the body; includes the brain, spinal cord, and peripheral nerves.
Circulatory System: Responsible for blood circulation, nutrient, and gas transport via the heart and blood vessels.
Respiratory System: Enables oxygen and carbon dioxide exchange through the lungs and airways.
Digestive System: Responsible for food breakdown and nutrient absorption, involving organs like the mouth, stomach, and intestines.
Endocrine System: Controls body processes through hormone secretion, involving glands such as the thyroid and adrenal glands.
Lymphatic/Immune System: Defends against pathogens and maintains fluid balance; consists of lymph nodes and vessels.
Urinary System: Responsible for waste elimination and electrolyte management; includes kidneys and bladder.
Reproductive System: Generates offspring through specific male and female reproductive structures.

Epithelial Tissue: Forms protective layers on body surfaces and lines internal cavities; plays roles in absorption and secretion.
Connective Tissue: Provides structural support and connects other tissues; includes variations like bone, blood, and adipose tissue.
Muscle Tissue: Facilitates bodily movement; categorized into skeletal, cardiac, and smooth muscle types, each with specific functions.
Nervous Tissue: Comprised mainly of neurons and supporting cells; crucial for electrical impulse transmission.

Dorsal Cavity: Encases the cranial cavity (brain) and spinal cavity (spine).
Ventral Cavity: Split into the thoracic cavity (houses the lungs and heart) and the abdominopelvic cavity (contains digestion and excretion organs).

Homeostasis: The body's mechanism to preserve a stable internal environment amid external variations.
Importance: Essential for sustaining health; utilizes feedback systems, such as negative (counteracting change) and positive (enhancing change) feedback loops.

Understanding anatomy offers foundational knowledge critical in fields such as medicine, biology, and health sciences, emphasizing the interplay of body structures and their functions.