1.5 An Introduction to Organ Systems

• What are the vital characteristics and processes shared by all living organisms?

  Responsiveness, growth and differentiation, reproduction, and movement
• What is responsiveness in living organisms?

  • Ability to respond to changes in the environment
  • Involves both immediate and longer-lasting adjustments
• How do organisms demonstrate adaptability?


  By making longer-lasting adjustments to their environments
• What is growth and differentiation in organisms?

  • Growth: Increase in size by increasing cell size or number
  • Differentiation: Specialization of cells to perform specific functions
  • Results in changes in form and function over a lifetime
• What is the purpose of reproduction in organisms?

  • To create subsequent generations of their own kind
  • Applies to both unicellular and multicellular organisms
• What types of movement do organisms exhibit?

  Internal movement (transporting materials inside the body) and external movement (moving through the environment)
• What is an example of internal movement in organisms?


  Transporting food, blood, or other materials inside the body
• What is an example of external movement in organisms?


  Moving through the environment
• What do organisms rely on to provide energy for various functions such as responsiveness and growth?

  Chemical reactions
• What is the term used to refer to all the chemical operations underway in the body?

  Metabolism
• What are the two types of metabolic reactions?

  Catabolism and anabolism
• What does catabolism involve?

  The breakdown of complex molecules into simple ones
• What does anabolism involve?

  The synthesis of complex molecules from simple ones
• What is required for normal metabolic operations?


  The absorption of materials from the environment
• What do cells require to generate energy efficiently?

  Various nutrients and oxygen
• What does the term respiration refer to?


  Cells' absorption, transport, and use of oxygen
• What must be removed from the body due to metabolic operations?

  Potentially harmful wastes
• What is the process of removing harmful wastes from the body called?

  Excretion
• What are the 11 organ systems in the human body?

  Integumentary, Skeletal, Muscular, Nervous, Endocrine, Cardiovascular, Lymphatic, Respiratory, Digestive, Urinary, Reproductive
• What are the major functions of the Integumentary system?


  • Protects against environmental hazards
  • Controls temperature
• What are the major functions of the Skeletal system?

  • Supports and protects soft tissues
  • Stores minerals
  • Forms blood
• What are the major functions of the Muscular system?

  • Provides movement and support
  • Generates heat
• What are the major functions of the Nervous system?

  • Directs immediate responses to stimuli
  • Coordinates the activities of other organ systems
• What are the major functions of the Endocrine system?

  • Directs long-term changes in the activities of other organ systems
• What are the major functions of the Cardiovascular system?

  • Distributes cells and dissolved materials
  • Includes nutrients, wastes, and gases
• What are the major functions of the Lymphatic system?

  • Defends against infection and disease
• What are the major functions of the Respiratory system?

  • Delivers air to sites where gas exchange occurs
  • Facilitates gas exchange between the air and circulating blood
• What are the major functions of the Digestive system?

  • Processes and digests food
  • Absorbs nutrients
  • Stores energy reserves
• What are the major functions of the Urinary system?

  • Eliminates excess water, salts, and wastes
  • Controls pH
  • Regulates blood pressure
• What are the major functions of the Reproductive system?

  • Produces sex cells
  • Produces hormones
• What is the primary function of the integumentary system?

  Protects against environmental hazards and helps control body temperature
• What are the primary components of the integumentary system and their functions?

  • Skin (Cutaneous Membrane): Covers surface, protects deeper tissues
  • Epidermis: Nourishes epidermis; provides strength; contains glands
  • Dermis: Contains hair follicles and sensory receptors
  • Hair Follicles: Produce hair; innervation provides sensation
  • Hairs: Provide protection for the head
  • Sebaceous Glands: Secrete lipid coating that lubricates hair shaft and epidermis
  • Sweat Glands: Produce perspiration for evaporative cooling
  • Nails: Protect and stiffen distal tips of digits
  • Sensory Receptors: Provide sensations of touch, pressure, temperature, and pain
  • Subcutaneous Layer: Stores lipids; attaches skin to deeper structures
• What does the epidermis do?

  Nourishes epidermis; provides strength; contains glands
• What is the role of hair follicles in the integumentary system?

  They produce hair and provide sensation through innervation
• What is the function of sebaceous glands?

  Secrete lipid coating that lubricates hair shaft and epidermis
• How do sweat glands contribute to body temperature regulation?

  They produce perspiration for evaporative cooling
• What is the function of nails in the integumentary system?

  Protect and stiffen distal tips of digits
• What sensations do sensory receptors in the integumentary system provide?

  They provide sensations of touch, pressure, temperature, and pain
• What is the role of the subcutaneous layer in the integumentary system?

  Stores lipids and attaches skin to deeper structures
• What are the primary functions of the skeletal system?

  Supports and protects tissues; stores minerals; forms blood cells