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STUDY NOTES ON ANATOMY AND PHYSIOLOGY

Objectives

  1. Identify the difference between anatomy and physiology.

  2. Define the term anatomical position.

  3. List and define the principal directional terms and sections (planes) used in describing the body and the relationship of body parts to one another.

  4. Use each word from a given list of anatomical terms in a sentence.

  5. List the nine abdominopelvic regions and the abdominopelvic quadrants.

  6. List and discuss, in order of increasing complexity, the levels of organization of the body.

  7. Differentiate among tissues, organs, and systems.

  8. Identify and define three major components of the cell.

  9. Discuss the stages of mitosis and explain the importance of cellular reproduction.

  10. Differentiate between active and passive transport processes that move substances through cell membranes, and give two examples of each.

  11. Describe the four types of body tissues.

  12. Discuss the two types of epithelial membranes.

  13. List the 11 major organ systems of the body and briefly describe the major functions of each.

Key Terms

  • Active transport (p. 1251): Movement of solutes across a cell membrane requiring energy.

  • Anatomy (p. 1245): The study, classification, and description of structures and organs of the body.

  • Cell (p. 1248): The smallest unit of life, making up all living organisms.

  • Cytoplasm (SĪ-tō-plăzm, p. 1249): The jelly-like substance inside a cell, containing organelles.

  • Diffusion (dĭ-FŪ-zhŭn, p. 1252): The passive movement of particles from a region of higher concentration to one of lower concentration.

  • Dorsal (p. 1247): Pertaining to the back.

  • Filtration (p. 1252): The process of separating substances based on size or charge through a membrane.

  • Homeostasis (hō-mē-ō-STĀ-sĭs, p. 1248): The tendency of an organism to maintain a stable internal environment despite changes in external conditions.

  • Membrane (p. 1249): A protective barrier that covers or lines a surface.

  • Mitosis (mĭ-TŌ-sĭs, p. 1250): The process of cellular division resulting in two daughter cells.

  • Nucleus (p. 1249): The control center of the cell containing genetic material.

Importance of Understanding Anatomy and Physiology

  • Caring for a sick or injured person requires knowledge of how the human body functions in order to aid in recovery. Nurses specifically need to be knowledgeable about anatomy and physiology to support their patients effectively.

  • Anatomy focuses on the structure and classification of body parts, while physiology explains the functionality and interrelations of these structures.

  • The human body functions like a finely tuned machine; malfunctioning parts can lead to disease or death, making it crucial to understand how they work together to maintain homeostasis (balance within the body).

Anatomical Terminology

  • Mastery of anatomical terms is essential for locating specific structures in the body.

  • Anatomical Position: Standing erect, facing forward, with arms at the sides and palms facing forward.

    • Emphasis on the anatomical position is crucial for understanding directional terminology.

Principal Directional Terms

  • Anterior (Ventral): The front of the body.

    • Example: The chest is anterior to the spine.

  • Posterior (Dorsal): The back of the body.

    • Example: The kidneys are posterior to the peritoneum.

  • Cranial: Toward the head.

    • Example: The brain resides in the cranial section.

  • Caudal: Toward the tail or the distal end.

  • Superior: Above or toward the head.

    • Example: The neck is superior to the shoulders.

  • Inferior: Below or toward the feet.

    • Example: The foot is inferior to the ankle.

  • Medial: Toward the midline.

    • Example: The sternum is medial within the chest.

  • Lateral: Away from the midline or toward the sides.

    • Example: The outer area of the leg is lateral.

  • Proximal: Nearest the trunk or point of origin.

    • Example: The elbow is proximal to the forearm.

  • Distal: Farthest from the trunk.

    • Example: The fingers are distal to the palm.

  • Superficial: Closer to the body's surface.

    • Example: The skin is superficial to the muscles beneath it.

  • Deep: Farther away from the surface.

    • Example: The bone is deep to surrounding muscles.

Body Planes

  • The body can be divided into three imaginary planes for study:

    1. Sagittal Plane: Divides the body into right and left portions.

      • A midsagittal cut gives equal halves.

    2. Coronal (Frontal) Plane: Divides the body into ventral and dorsal sections.

    3. Transverse Plane: Cuts the body horizontally, separating cranial and caudal portions.

Body Cavities

  • There are two major body cavities: ventral and dorsal.

    • Dorsal Cavity:

      • Contains the cranial cavity (houses the brain) and the spinal cavity (houses the spinal cord).

    • Ventral Cavity:

      • Contains the thoracic cavity (holds heart and lungs), divided into right and left pleural cavities and the mediastinum (contains trachea and blood vessels).

      • Contains the abdominopelvic cavity, which is further divided:

      • Abdominal cavity: Stomach, liver, pancreas, intestines.

      • Pelvic cavity: Contains urinary bladder and reproductive organs.

Abdominopelvic Regions

  • For precise identification of abdominal organs, the abdomen is divided into nine regions:

    1. Right hypochondriac region: Contains the right lobe of the liver and gallbladder.

    2. Epigastric region: Contains parts of the liver and stomach.

    3. Left hypochondriac region: Includes portions of the stomach and large intestine.

    4. Right lumbar region: Parts of the large and small intestines.

    5. Umbilical region: Part of the transverse colon and small intestine.

    6. Left lumbar region: Loops of small intestine and part of the colon.

    7. Right iliac (inguinal) region: Contains the cecum and parts of the small intestine.

    8. Hypogastric region: Contains loops of the small intestine, urinary bladder, and appendix.

    9. Left iliac (inguinal) region: Portions of the colon and small intestine.

Abdominopelvic Quadrants

  • The abdomen can also be divided into four quadrants for clinical purposes:

    • Right upper quadrant

    • Left upper quadrant

    • Right lower quadrant

    • Left lower quadrant

Structural Levels of Organization

  • The body is organized into structural levels, which increase in complexity:

    1. Chemical Level: Atoms and molecules (e.g., H2O).

    2. Cellular Level: Basic unit of life (e.g., muscle cells).

    3. Tissue Level: Groups of similar cells performing a function (e.g., muscle tissue).

      • Four tissue types include:

        • Epithelial tissue

        • Connective tissue

        • Muscle tissue

        • Nervous tissue

    4. Organ Level: Structures composed of two or more tissues (e.g., heart).

    5. Organ System Level: Groups of organs that work together (e.g., digestive system).

    6. Organism Level: All systems working together.

Cells

  • Components of a Cell:

    • Plasma Membrane: Encloses cytoplasm, selectively permeable.

    • Cytoplasm: Jelly-like substance inside a cell containing water, food, and organelles.

    • Nucleus: Control center for cell functions and reproduction.

    • Contains nucleolus (for ribosome formation) and chromatin (genetic material).

Mitosis

  • Key process of cell division creating two daughter cells with identical genetic information. Process phases include:

    1. Prophase: Chromosomes condense and the spindle apparatus forms.

    2. Metaphase: Chromosomes line up at the cell's equator.

    3. Anaphase: Chromatids are pulled apart to opposite sides.

    4. Telophase: The cell divides and two new nuclei form.

Movement of Materials Across Cell Membranes

  • Two categories:

  1. Passive Transport: No energy required.

    • Ex: Diffusion, osmosis, filtration.

  2. Active Transport: Energy required for processes such as:

    • Phagocytosis: Engulfing particles.

    • Pinocytosis: Engulfing fluids.

    • Sodium-Potassium Pump: Active transport of ions.

Tissues

  • Four main types of tissue:

  1. Epithelial Tissue: Covers surfaces, lacks blood vessels.

    • Types: Simple squamous, stratified squamous, simple columnar, stratified transitional.

  2. Connective Tissue: Supports and connects body parts.

    • Forms: Loose fibrous, adipose, dense fibrous, bone, cartilage, blood.

  3. Muscle Tissue: Contracts to produce movement.

    • Types: Skeletal (voluntary), Cardiac (involuntary), Smooth (involuntary).

  4. Nervous Tissue: Transmits impulses for communication and control.

Membranes

  • Epithelial Membranes: Line and cover organs and cavities; includes mucous and serous membranes.

    • Mucous Membranes: Secrete mucus, protecting surfaces open to the environment.

    • Serous Membranes: Secrete serous fluid to reduce friction between organs.

Organ Systems

  • Integumentary System: Protects body surfaces.

  • Skeletal System: Provides support and produces blood cells.

  • Muscular System: Produces movement.

  • Nervous System: Controls body functions and communication.

  • Endocrine System: Regulates hormones for long-term control.

  • Cardiovascular System: Transports materials throughout the body.

  • Lymphatic System: Supports immune functions.

  • Respiratory System: Facilitates gas exchange.

  • Digestive System: Breaks down food and absorbs nutrients.

  • Urinary System: Manages fluid balance and waste excretion.

  • Reproductive System: Facilitates reproduction and hormonal functions.