Anatomy Structure and Organization

• Atoms


  Smallest fundamental units of the human body, made up of protons, electrons, and neutrons
• Elements that make up over 96% of the human body

  • Oxygen
  • Carbon
  • Hydrogen
  • Nitrogen
• Molecules


  Two or more atoms bound together
• Macromolecules needed for life

  • Proteins
  • Nucleic acids
  • Lipids
  • Carbohydrates
• Proteins


  Provide the majority of cell functions, used to build and prepare tissues, make enzymes, hormones, and other molecules
• Nucleic acids


  Make up RNA and DNA, specialized in storage and expression of genetic information
• Lipids


  Serve as structural components of cell membranes, energy storehouses, and important signaling molecules
• Carbohydrates


  Sugars including monosaccharides, disaccharides, and polysaccharides, used for storing energy, cellular messaging, and supporting cells and tissues
• Cell


  Fundamental unit of all life, smallest independently functioning unit of a living organism
• Types of tissues in the human body

  • Epithelial
  • Connective
  • Muscle
  • Nervous
• Epithelial tissues


  Form the body's barriers
• Connective tissues


  Include bone, cartilage, blood, and supportive tissues
• Types of muscle tissues

  • Smooth
  • Cardiac
  • Skeletal
• Smooth muscle


  Allows substances to move through the body without conscious control
• Cardiac muscle


  Allows the contractions of the heart
• Skeletal muscle


  Attaches to bones allowing for conscious movement
• Nervous tissue


  Allows for integration and communication
• Organs


  Provide specific functions in the body
• Examples of organs


  • Brain
  • Heart
  • Kidneys
  • Lungs
  • Stomach
• Organ systems


  Groups of organs working together to perform specific functions
• Organ systems in the human body

  • Digestive
  • Integumentary
  • Nervous
  • Cardiovascular
  • Respiratory
  • Skeletal
  • Muscular
  • Immune
  • Lymphatic
  • Endocrine
  • Reproductive
  • Urinary
• Digestive system


  Absorbs nutrients from food and eliminates indigestible waste
• Integumentary system


  Includes the skin, hair, nails, and exocrine glands, forms the external body covering and protects deeper tissues
• Nervous system


  Allows for fast, specific communication between the body and the brain, both conscious and unconscious
• Cardiovascular system


  Circulates blood around the body through the blood vessels
• Respiratory system


  Includes the network of airways that allows for gas exchange, taking in oxygen and expelling carbon dioxide
• Skeletal system


  Consists of bones, cartilage, tendons, and ligaments, provides support and structure, allows for movement, protects, and stores minerals
• Muscular system


  Composed of specialized muscle cells that contract to allow for movement, includes cardiac, smooth, and skeletal muscle
• Immune system


  Defends the body against physical injury and protects from pathogens
• Lymphatic system


  Composed of a network of lymphatic vessels that carry lymph, functions to drain excess fluids and proteins from tissues
• Endocrine system


  Influences body functions using hormones secreted by glands, works with the nervous system to maintain homeostasis
• Reproductive system


  Allows for the production of offspring, functions to produce egg and sperm cells, transport and sustain these cells, and nurture developing offspring
• Urinary/renal system


  Produces, stores, and eliminates urine, a fluid filtered from the blood by the kidneys
• All of these anatomical levels increase in their complexity, from atoms to the total organism