Introduction to Anatomy

• Anatomy is the study of the structure of the body
• Human anatomy specifically focuses on the structure of the human body
• Physiological anatomy studies the structures of the body, emphasizing how these structures contribute to function
• Anatomy for nursing integrates anatomical knowledge to provide effective patient care

Levels of Structural Organization

• The human body has different levels of structural organization
• Chemical level: Atoms combine to form molecules
• Cellular level: Molecules form organelles, such as the nucleus and mitochondria, which make up cells
• Tissue level: Similar cells and surrounding materials make up tissues
• Organ level: Different tissues combine to form organs, such as the heart and stomach
• System level: Organs working closely together form organ systems, such as the digestive system
• Organismal level: Organ systems combine to make up the organism, i.e., the human body

Basic Anatomical Terminology

• Anatomical position: Body standing erect, facing forward, upper limbs at the sides, palms forward
• Superior (cranial): Toward the head end or upper part of a structure or the body; above
• Inferior (caudal): Away from the head end or toward the lower part of a structure or the body; below
• Anterior (ventral): Toward or at the front of the body; in front of
• Posterior (dorsal): Toward or at the back of the body; behind
• Medial: Toward or at the midline of the body; on the inner side of
• Lateral: Away from the midline of the body; on the outer side of
• Intermediate: Between a more medial and a more lateral structure
• Proximal: Closer to the origin of the body part or the point of attachment of a limb to the body trunk
• Distal: Farther from the origin of a body part or the point of attachment of a limb to the body trunk
• Superficial (external): Toward or at the body surface
• Deep (internal): Away from the body surface; more internal

Body Planes

• Sagittal plane: Divides the body into right and left parts
• Midsagittal (median) plane: Sagittal plane that lies exactly in the midline
• Frontal (coronal) plane: Divides the body into anterior and posterior parts
• Transverse (horizontal) plane: Divides the body into superior and inferior parts
• Oblique section: Cuts made diagonally

Body Cavities

• Dorsal body cavity: Protects the fragile nervous system organs
  • Cranial cavity: Encloses the brain
  • Vertebral cavity: Encloses the spinal cord
• Ventral body cavity: Houses the internal organs (collectively called viscera)
  • Thoracic cavity: Contains the heart and lungs
  • Abdominopelvic cavity: Contains the digestive, urinary, and reproductive organs

Tissues

• Epithelial tissue: Covers body surfaces and lines hollow organs, body cavities, and ducts
• Connective tissue: Protects, supports, and binds organs together
• Muscular tissue: Responsible for movement
• Nervous tissue: Allows for internal communication by electrical signals

Skeletal System

• Bones, cartilage, and joints provide the framework of the body
• Supports and protects the body organs
• Provides a system of levers the skeletal muscles use to move
• Bone Functions: Support, protection, movement, mineral and growth factor storage, blood cell formation, triglyceride (fat) storage, hormone production

Muscular System

• Skeletal muscles attach to bones or other tissues to cause movement:
  • Provides motion
  • Maintains posture
  • Produces heat
• Smooth and cardiac muscles control movement of internal organs

Nervous System

• Brain, spinal cord, and nerves control communication throughout the body
• Fast-acting control system of the body
• Responds to internal and external changes by activating appropriate muscles and glands

Endocrine System

• Glands secrete hormones that regulate processes such as growth, reproduction, and nutrient use (metabolism) by body cells

Cardiovascular System

• Heart and blood vessels circulate blood, carrying oxygen and nutrients to the body cells and carrying away wastes
• Blood: Transports oxygen, carbon dioxide, nutrients, wastes, hormones, and more

Lymphatic System/Immunity

• Lymphatic vessels, lymph nodes, and lymphoid organs
• Returns fluids leaked from blood vessels to blood
• Disposes of debris
• Involved in immunity

Respiratory System

• Lungs and associated structures supply oxygen and remove carbon dioxide
• Keeps blood constantly supplied with oxygen and removes carbon dioxide

Digestive System

• Oral cavity, esophagus, stomach, small intestine, large intestine, rectum, anus, and accessory organs
• Breaks down food into absorbable units that enter the blood for distribution to body cells
• Indigestible foodstuffs are eliminated as feces

Urinary System

• Kidneys, ureters, urinary bladder, and urethra
• Eliminates nitrogenous wastes from the body
• Regulates water, electrolyte, and acid-base balance of the blood

Reproductive System

• Male: testes, scrotum, penis, and duct system
• Female: ovaries, uterine tubes, uterus, and vagina
• Overall function is to produce offspring
• Testes produce sperm and male sex hormone
• Ovaries produce eggs and female sex hormones