Overview of Human Anatomy and Organ Systems

Overview of Human Anatomy

Definition: Study of the structure and organization of the human body.
Branches:
- Gross Anatomy: Study of structures visible to the naked eye.
- Microscopic Anatomy: Study of structures at the cellular level (histology, cytology).

Major Organ Systems

Skeletal System
- Consists of bones, cartilage, and ligaments.
- Functions: Support, protection, movement, mineral storage, blood cell production.
Muscular System
- Composed of skeletal, smooth, and cardiac muscles.
- Functions: Movement, posture, heat production.
Nervous System
- Includes the brain, spinal cord, and nerves.
- Functions: Control and communication, processing sensory information, initiating responses.
Circulatory (Cardiovascular) System
- Comprises the heart, blood vessels, and blood.
- Functions: Transport nutrients, gases, hormones; remove waste products.
Respiratory System
- Consists of lungs, trachea, bronchi, and diaphragm.
- Functions: Gas exchange (oxygen and carbon dioxide).
Digestive System
- Comprised of the gastrointestinal tract and accessory organs.
- Functions: Breakdown of food, nutrient absorption, waste elimination.
Endocrine System
- Includes glands such as the pituitary, thyroid, and adrenal.
- Functions: Hormone production and regulation of bodily functions.
Urinary System
- Composed of kidneys, ureters, bladder, and urethra.
- Functions: Removal of waste, regulation of water and electrolyte balance.
Reproductive System
- In males: testes, vas deferens, prostate.
- In females: ovaries, fallopian tubes, uterus.
- Functions: Production of gametes, hormonal regulation, reproduction.
Integumentary System
- Composed of skin, hair, nails, and glands.
- Functions: Protection, temperature regulation, sensation.

Anatomical Terminology

Planes of the Body:
- Sagittal Plane: Divides body into left and right.
- Frontal Plane: Divides body into anterior and posterior.
- Transverse Plane: Divides body into superior and inferior.
Directional Terms:
- Anterior (ventral): Front
- Posterior (dorsal): Back
- Superior: Above
- Inferior: Below
- Medial: Toward the midline
- Lateral: Away from the midline

Cellular Anatomy

Cell Structure:
- Cell Membrane: Protective barrier.
- Nucleus: Contains genetic material.
- Cytoplasm: Jelly-like substance where cellular processes occur.
- Organelles: Specialized structures (e.g., mitochondria, endoplasmic reticulum).

Tissues

Types of Tissues:
- Epithelial: Covers body surfaces and lines cavities.
- Connective: Supports, binds, and protects tissues and organs.
- Muscle: Responsible for movement.
- Nervous: Transmits impulses for communication.

Important Concepts

Homeostasis: Maintenance of a stable internal environment.
Anatomical Variability: Individual differences in anatomy (e.g., organ size, position).
Developmental Anatomy: Study of structural changes over a lifetime, from conception to old age.

Overview of Human Anatomy

Study focuses on the structure and organization of the human body.
Two main branches:
- Gross Anatomy studies structures visible to the naked eye.
- Microscopic Anatomy examines structures at the cellular level, including histology (tissues) and cytology (cells).

Major Organ Systems

Skeletal System
- Composed of bones, cartilage, and ligaments.
- Functions include support, protection, movement, mineral storage, and blood cell production.
Muscular System
- Contains skeletal, smooth, and cardiac muscles.
- Responsible for movement, maintaining posture, and generating heat.
Nervous System
- Includes the brain, spinal cord, and nerves.
- Functions in control and communication, processing sensory information, and initiating responses.
Circulatory (Cardiovascular) System
- Made up of the heart, blood vessels, and blood.
- Key functions are nutrient, gas, and hormone transport, along with waste removal.
Respiratory System
- Consists of lungs, trachea, bronchi, and diaphragm.
- Function is primarily gas exchange (oxygen and carbon dioxide).
Digestive System
- Comprises the gastrointestinal tract and accessory organs.
- Involved in breaking down food, nutrient absorption, and waste elimination.
Endocrine System
- Includes glands such as the pituitary, thyroid, and adrenal.
- Functions in hormone production and regulation of bodily functions.
Urinary System
- Composed of kidneys, ureters, bladder, and urethra.
- Responsible for waste removal and regulation of water and electrolyte balance.
Reproductive System
- Male components: testes, vas deferens, prostate.
- Female components: ovaries, fallopian tubes, uterus.
- Functions include gamete production, hormonal regulation, and reproduction.
Integumentary System
- Composed of skin, hair, nails, and glands.
- Provides protection, regulates temperature, and facilitates sensation.

Anatomical Terminology

Planes of the Body:
- Sagittal Plane: Divides body into left and right sections.
- Frontal Plane: Divides body into anterior (front) and posterior (back).
- Transverse Plane: Divides body into superior (above) and inferior (below) portions.
Directional Terms:
- Anterior (ventral): Refers to the front.
- Posterior (dorsal): Refers to the back.
- Superior: Indicates a position above.
- Inferior: Indicates a position below.
- Medial: Toward the midline of the body.
- Lateral: Away from the midline.

Cellular Anatomy

Cell Structure:
- Cell Membrane: Serves as a protective barrier for the cell.
- Nucleus: Houses genetic material (DNA).
- Cytoplasm: Jelly-like substance where cellular processes occur.
- Organelles: Specialized structures like mitochondria (energy production) and endoplasmic reticulum (protein and lipid synthesis).

Tissues

Types of Tissues:
- Epithelial Tissue: Covers body surfaces and lines cavities.
- Connective Tissue: Supports, binds, and protects various tissues and organs.
- Muscle Tissue: Facilitates voluntary and involuntary movement.
- Nervous Tissue: Transmits impulses, enabling communication within the body.

Important Concepts

Homeostasis: The process of maintaining a stable internal environment within the body.
Anatomical Variability: Recognizes individual differences in anatomy, such as variations in organ size and position.
Developmental Anatomy: Studies structural changes throughout a lifetime, from conception to old age.