Introduction to Human Body Physiology

Introduction to the Human Body

• Catabolism releases energy from food
• Anabolism requires energy to build complex substances

Overview of Physiology

• Physiology studies the function of the human body at many levels (e.g., organ systems).
• Subdivisions can be based on organ systems (e.g., renal or cardiovascular physiology).
• Key tools needed to study physiology:
  • Ability to assess function at different levels (from the entire body down to the cellular level).
  • Familiarity with physical principles (e.g., electrical currents, pressure, movement).
  • Understanding of basic chemical principles.

Levels of Structural Organization

• Chemical: Atoms and molecules.
• Cellular: Cells and their organelles.
• Tissue: Groups of similar cells.
• Organ: Contains 2 or more tissue types.
• Organ system: Organs working together.
• Organismal: All organ systems together.

Overview of Organ Systems

• Integumentary: Encloses internal structures, contains many sensory receptors (skin, hair, nails, cartilage).
• Skeletal: Supports the body, enables movement (bones, joints, cartilage).
• Muscular: Enables movement (with skeletal system), maintains body temperature (muscles, tendons).
• Nervous: Detects and processes sensory information, activates bodily responses (brain, spinal cord, nerves).
• Endocrine: Secretes hormones, regulates bodily processes (pituitary, thyroid, pancreas, adrenal glands, testes, ovaries).
• Cardiovascular: Delivers oxygen and nutrients, equalizes temperature (heart, blood vessels).
• Lymphatic: Returns fluid to blood; defends against pathogens (lymph nodes, spleen).
• Respiratory: Removes carbon dioxide, delivers oxygen (nasal passage, trachea, lungs).
• Digestive: Processes food, removes wastes (stomach, liver, gall bladder, large intestine, small intestine).
• Urinary: Controls water balance, removes wastes (kidneys, urinary bladder).
• Reproductive: (Male): Produces sex hormones and gametes, delivers gametes to the female (epididymis, testes). (Female): Produces sex hormones and gametes, supports embryo/fetus until birth, produces milk for infant (mammary glands, ovaries, uterus).

Functions of Human Life - Metabolism

• Anabolism: Combines simpler molecules into larger, complex substances.
• Catabolism: Breaks down complex substances into smaller, simpler molecules, releasing energy.

Functions of Human Life - Other Factors

• Responsiveness: Ability to adjust to internal and external environmental changes.
• Movement: Includes actions at joints and movement of individual organs and cells.

Requirements for Human Life

• Nutrients: Chemicals for energy and building cells (carbohydrates, fats, proteins, minerals, vitamins).
• Oxygen: Essential for energy release (ATP production).
• Water: Most abundant chemical in the body, site of chemical reactions.
• Normal Body Temperature: Affects rate of chemical reactions.
• Appropriate Atmospheric Pressure: Necessary for breathing and gas exchange.

Homeostasis

• Maintenance of a stable internal environment despite external changes (dynamic equilibrium).
• Homeostatic control mechanisms involve continuous monitoring and regulation of factors, accomplished by nervous and endocrine systems.
• Homeostasis disturbance increases disease risk and contributes to age-related changes.

Medical Imaging

• X-ray: High-energy electromagnetic radiation; penetrates solids and ionizes gases.
• Computed Tomography (CT): Noninvasive technique, uses computers to analyze several cross-sectional X-rays to reveal detailed body structures.

Negative Feedback

• A system that resists deviations from a set point, the goal is to maintain stability/homeostasis.
• Components of negative feedback:
  • Sensor (receptor) monitors physiological value.
  • Control Center compares to normal range.
  • Effector reverses/corrects changes.

Positive Feedback

• A change intensifying the physiological change, until the stimulus ends.

Explore the fundamentals of human body physiology, focusing on the levels of structural organization and key physiological concepts. This quiz covers topics like catabolism, anabolism, and the various organ systems, providing a comprehensive overview of how the human body functions.