chapter 1

Module 1: Introduction to the Body

Instructor Information

• Instructor Name: Tita F. Viray-Innes, MSMS, BSN-RNBC, CNE-CI, CHSE, CHSOS

Learning Objectives: Lesson 1.1 - Introduction to the Body

• Define the terms anatomy, physiology, and pathology.

• Describe the process used to form scientific theories.

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

• Define the terms anatomical position, supine, and prone.

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

Learning Objectives (Continued)

• Discuss body cavities and body regions:

  • List and discuss the major cavities of the body and subdivisions of each.

  • List the nine abdominopelvic regions and the abdominopelvic quadrants.

  • Discuss and contrast the axial and appendicular subdivisions of the body and identify specific anatomical regions in each area.

• Balance of body functions:

  • Define and discuss homeostasis.

  • Compare and contrast negative and positive feedback loops with examples from the body.

Introduction

• Anatomy: Study of the structure of an organism and the relationships of its parts.

  • Anatomical parts have structures suited to perform specific functions related to size, shape, form, or position.

• Physiology: Study of functions of living organisms and their parts.

• Pathology: Scientific study of disease using principles from anatomy and physiology to determine the nature of diseases.

  • Diseases result from abnormalities in body structure or function that prevent the body from maintaining internal stability (homeostasis).

Scientific Method

• A systemic approach to discovery involving the following steps:

  1. Observation and Previous Experiments

  2. Propose Hypotheses: Formulate alternate hypotheses.

  3. Design Experiment: Create an experimental setup.

  4. Collect and Analyze Data: Evaluate the results.

  5. Redesign Experiment if Necessary: If results are inconsistent, refine the hypothesis and repeat experiments.

• Determination of hypotheses:

  • If results are consistent, the hypothesis may be accepted as a theory.

  • With a high level of confidence, it may be accepted as a scientific law.

Levels of Organization

• Organization is the most important characteristic of body structure.

• The body is a unit composed of the following smaller units:

  1. Atoms and Molecules: Chemical level

  2. Cells: Smallest living units of structure and function formed from chemical organizations.

  3. Tissues: Groups of similar cells working together to perform a common function.

  4. Organs: Composed of different tissue types (e.g., brain).

  5. Systems: Composed of various organs that work together to perform complex functions for the body.

Gross and Microscopic Levels

• Chemical Level

  • Atoms

  • Molecules

• Cellular Level

  • Cells

• Tissue Level

  • Tissues (Chapter 4, 13)

• Organ Level

  • Organs (Chapter 5)

• Organ System Level

  • Systems (Chapters 5-23)

• Organism Level

  • Organisms (Chapters 19, 21, 22, 24, 25)

Anatomical Position

• Refers to the position in which the body stands erect with feet slightly apart and arms at the sides with palms turned forward.

• The anatomical position is essential for giving meaning to directional terms.

Anatomical Directions

• The principal anatomical directions include:

  • Superior: Toward the head

  • Inferior: Away from the head

  • Anterior: Towards the front

  • Posterior: Towards the back

  • Medial: Closer to the midline of the body

  • Lateral: Further from the midline

  • Proximal: Closer to the point of attachment

  • Distal: Further from the point of attachment

Anatomical Compass Rosette

• Indicates directions related to anatomical terms:

  • A: Anterior

  • D: Distal

  • I: Inferior

  • L: Left

  • M: Medial

  • P: Posterior

  • R: Right

  • S: Superior

Planes of the Body

• To study organs or the body as a whole, it is necessary to subdivide or cut it into smaller segments using planes.

  • Sagittal Plane: Lengthwise plane dividing a structure into right and left sections.

  • Midsagittal Plane: Divides the body into equal left and right halves.

  • Frontal (Coronal) Plane: Divides a structure into anterior and posterior sections. (Front and back)

  • Transverse Plane: Horizontal plane dividing a structure into upper and lower sections.

Body Cavities

• Major Body Cavities:

  • Dorsal Body Cavities:

  • Cranial Cavity: Contains the brain.

  • Spinal Cavity: Contains the spinal column.

  • Ventral Body Cavities:

  • Thoracic Cavity:

    • Mediastinum: Midportion of the thoracic cavity containing the heart and trachea.

    • Pleural Cavities: Left and right cavities containing the lungs.

  • Abdominopelvic Cavity:

    • Abdominal Cavity: Contains stomach, intestines, liver, gallbladder, pancreas, and spleen.

    • Pelvic Cavity: Contains reproductive organs, urinary bladder, and lower part of the intestine.

Abdominopelvic Quadrants and Regions

• Quadrants:

  • Right Upper Quadrant (RUQ)

  • Left Upper Quadrant (LUQ)

  • Right Lower Quadrant (RLQ)

  • Left Lower Quadrant (LLQ)

• Regions:

  • Right Hypochondriac Region

  • Epigastric Region

  • Left Hypochondriac Region

  • Right Lumbar (Flank) Region

  • Umbilical Region

  • Left Lumbar (Flank) Region

  • Right Iliac (Inguinal) Region

  • Hypogastric (Pubic) Region

  • Left Iliac (Inguinal) Region

Body Regions

• Recognition of the human body shape and outline occurs by identifying specific body areas, important for clinical settings in assessing pain.

• The body can be divided into:

  • Axial Region: Head, neck, torso.

  • Appendicular Region: Upper and lower extremities.

Axial and Appendicular Divisions

• Axial Skeleton Includes:

  • Cephalic (head), Cranial (upper skull), Facial (face), Cervical (neck), Thoracic (chest), Abdominal, Pelvic (pelvis), Dorsal (back)

• Appendicular Skeleton Includes:

  • Upper Extremity: Brachial (arm), Antebrachial (forearm), Carpal (wrist), Digital (fingers),

  • Lower Extremity: Femoral (thigh), Crural (leg), Tarsal (ankle), Digital (toes).

Balance of Body Functions

• Importance of homeostasis for the survival of individuals and genes:

  • Homeostasis: Relative constancy of the internal environment, including temperature, salt content, acid levels (pH), fluid volume and pressure, and oxygen concentration, must remain within acceptable limits.

• The body uses:

  • Negative Feedback Loops: Involve a sensor, control center, and effector to maintain or restore homeostasis.

  • Positive Feedback Loops: Less frequent, examples include childbirth contractions.

Example of Negative Feedback Loop

• Body Temperature Regulation:

  • Cold wind disturbs body temperature, detected by cold receptors.

  • The control center (brain) signals the effector (muscles) to generate heat (shivering), thus restoring normal body temperature.

Example of Positive Feedback Loop

• Labor Contractions:

  • Stretch from the fetus moving into the birth canal detected by stretch receptors leads to stronger labor contractions through correction signals produced by oxytocin.

Normal Fluctuations

• Homeostatic conditions in the body fluctuate around a normal value.

  • Lab values reflect ranges due to variability among individuals, adjusting postures and physical conditions.

  • Example: Normal pH ranges from 7.35-7.45; Sodium (Na) levels range from 135-145.

Critical Thinking Questions

1. Identify a structure that is inferior to the heart, superior to the heart, anterior to the heart, posterior to the heart, and lateral to the heart.

2. If a person complained of pain in the epigastric region, what organs could be involved?

3. Case Study: How does Mr. Shepherd’s body maintain a relatively constant body temperature in cold conditions? What is this process called?

Classroom Activities

• Engaging interactive section titled Tournament of Terminology (Terminology Jeopardy!).

Upcoming Content

• Next Class Lecture: Chapter 2: Chemistry of Life.