Anatomy and Physiology Chapter 1

The Human Body: An Orientation

• Anatomy and Physiology: Anatomy refers to the structure of body parts, while physiology deals with their functions. The two disciplines are interconnected through the principle of complementary structure and function.

• Structural Organization Levels:

  • Chemical level: Atoms, molecules, and organelles
  • Cellular level: Single cells
  • Tissue level: Similar cells grouped together
  • Organ level: Different tissues forming organs
  • Organ system level: Interacting organs
  • Organism level: Entire living entity

• Requirements for Life:

  • Key functions include digestion, metabolism, reproduction, growth, excretion, responsiveness, movement, and maintaining boundaries.

Body Organ Systems

• Integumentary System: Comprises skin, hair, nails; protects, synthesizes vitamin D.

• Skeletal System: Composed of bones and joints; site of blood cell formation and mineral storage.

• Muscular System: Aids in movement, posture maintenance, and heat production through skeletal muscles.

• Nervous System: Involves the brain, nerves, and spinal cord; activates muscles and glands based on internal/external stimuli.

• Endocrine System: Glands like ovaries and adrenal gland secrete hormones to regulate growth, reproduction, and metabolism.

• Cardiovascular System: Consists of heart and blood vessels; transports oxygen, CO2, nutrients, and wastes.

• Lymphatic System: Includes lymph nodes and vessels; returns leaked fluids to blood and clears debris.

• Respiratory System: Comprises nasal cavity and lungs; oxygenates blood and removes CO2 from the body.

• Digestive System: Breaks down food into absorbable units and eliminates indigestible food as waste.

• Urinary System: Filters nitrogenous wastes and regulates blood's water and electrolyte balance.

• Reproductive System: In males, involves testis and prostate for sperm production; in females, includes ovaries and uterus for egg production and nurturing of the fetus.

Survival Needs of Organisms

• Nutrients: Essential substances like carbohydrates, proteins, fats, and minerals for energy.

• Oxygen: Vital for cellular energy production.

• Water: The most abundant molecule, crucial for bodily functions.

• Normal Body Temperature: Maintains appropriate rates of chemical reactions, optimal at 37 °C.

• Atmospheric Pressure: Required for sufficient breathing and gas exchange.

Homeostasis

• Definition: The ability to maintain stable internal conditions despite external changes; achieved through organ system collaboration.

• Control Mechanisms:

  • Receptors: Detect changes in the environment.
  • Control Center: Processes information and determines a response.
  • Effectors: Carry out responses to restore balance.

• Feedback Mechanisms:

  • Negative Feedback: Reduces stimulus effects, stabilizing conditions (e.g., blood glucose regulation).
  • Positive Feedback: Enhances original stimulus (e.g., labor contractions).

Anatomical Terms and Body Planes

• Directional Terms:

  • Superior (up), Inferior (down), Anterior (front), Posterior (back), Medial (middle), Lateral (side), Proximal (near), Distal (far), Superficial (surface), Deep (internal).

• Planes:

  • Sagittal: Divides left/right
  • Frontal (coronal): Divides front/back
  • Transverse: Divides top/bottom

Body Cavities

• Dorsal: Cranial (brain) and Vertebral (spinal cord).

• Ventral: Thoracic (heart, lungs), Abdominal (digestive organs), Pelvic (reproductive organs).

Chemistry and Physiological Reactions

• Atom Structure:

  • Protons (positive), Neutrons (neutral), Electrons (negative).

• Chemical Bonds:

  • Ionic (electron transfer), Covalent (electron sharing), Hydrogen (attraction between molecules).

• Biochemistry: Focuses on the chemical composition of living matter.

• Inorganic vs Organic Compounds:

  • Inorganic: Water, salts, acids (non-carbon based).
  • Organic: Carbohydrates, fats, proteins, nucleic acids (carbon-based).

Organic Compounds and Their Functions

• Carbohydrates:

  • Include monosaccharides (e.g., glucose), disaccharides (e.g., sucrose), and polysaccharides (many sugars).

• Lipids:

  • Types include triglycerides, phospholipids, steroids, and eicosanoids; insoluble in water.

• Proteins: Make up 20-30% of cell mass; formed by amino acids through peptide bonds. Structure includes primary, secondary, tertiary, and quaternary forms.

• Enzymes: Proteins that act as biological catalysts, increasing reaction speed and specificity.

Cell Membrane Transport Mechanisms

• Active Transport and Vesicular Transport: Require ATP; used for large/specific molecule transport across membranes.

• Types of Active Transport:

  • Primary: Direct use of ATP.
  • Secondary: Utilizes gradients established by primary transport.

Cell Cycle and Division

• M Phase includes Mitosis (nucleus divides) and Cytokinesis (cytoplasm divides).

• Control Signals: Go signals stimulate division (e.g., hormone influence), while stop signals prevent overcrowding (e.g., contact inhibition).

Translation Process in Protein Synthesis

• Initiation:

  • Small ribosomal subunit binds to mRNA; initiation complex forms as tRNA pairs with start codon (AUG).

• Elongation:

  • tRNA brings specific amino acids to ribosome; peptide bonds grow polypeptide chain.

• Termination:

  • Occurs at stop codon; completed polypeptide is released.

These notes provide an organized overview of key concepts related to human body organization, homeostasis, chemistry, and biological processes fundamental for understanding anatomy and physiology.

Explore the foundational concepts of anatomy and physiology with this quiz on Chapter 1. Learn about the human body's structural organization, from the chemical level to the organism level, and understand the interrelationship between the structure and function of body parts. Test your knowledge and comprehension of these essential biological principles.