Introduction to Human Anatomy and Physiology

Introduction to Anatomy                

• Learning changes everything.

• Chapter covered in McKinley O’Loughlin Pennefather-O’Brien's text, Human Anatomy, Sixth Edition.

• Copyright by McGraw Hill, 2021. Use restricted to classroom instruction.

Objective of the Chapter

• Explain the similarities and differences between anatomy and physiology.

Definition of Anatomy and Physiology

• Anatomy:

  • Definition: The study of structure.

  • Etymology: Greek for "to cut apart."

• Physiology:

  • Definition: The study of function.

  • Interrelation: Anatomy and physiology are interdependent.

  • Example:

    • Anatomy: The small intestine contains simple columnar epithelium.

    • Physiology: The epithelium of the small intestine absorbs nutrients.

• Both anatomists and physiologists utilize the scientific method:

  • Steps:

  1. Observe natural phenomena.

  2. Develop and test hypotheses.

Objective: Microscopic and Gross Anatomy

• Describe microscopic anatomy and its subdivisions.

• Define gross anatomy and compare its subdisciplines.

Categories of Anatomy

• Microscopic Anatomy:

  • Definition: The study of structures too small to be seen with the unaided eye.

  • Subdivisions:

  • Cytology: Study of cells.

  • Histology: Study of tissues.

• Gross Anatomy:

  • Definition: The study of structures that can be observed without a microscope.

Subdisciplines of Gross Anatomyjh

• Comparative Anatomy:

  • Focus: Similarities and differences across species.

• Developmental Anatomy:

  • Focus: Structural changes from conception through maturity.

• Embryology:

  • Focus: Developmental changes occurring prior to birth.

• Regional Anatomy:

  • Focus: Studies all structures within a single region (e.g., muscles, nerves, blood vessels of the neck).

• Surface Anatomy:

  • Focus: Studies superficial and internal structures in relation to their location on the body surface.

• Systemic Anatomy:

  • Focus: Studies structures involved in specific activities (e.g., digestive system).

• Pathologic Anatomy:

  • Focus: Anatomical changes resulting from disease.

• Radiographic Anatomy:

  • Focus: Study of structures visualized through medical imaging procedures (e.g., ultrasound, MRI, X-ray).

• Surgical Anatomy:

  • Focus: Anatomical landmarks relevant before and after surgery (e.g., using hip bones to locate the L4 vertebra).

Objective: Levels of Organization in the Human Body

• Rank the major levels of organization from least to most complex:

  1. Atoms

  2. Molecules

  3. Cells

  4. Tissues

  5. Organs

  6. Systems

  7. Organism

Objective: Organ Systems

• List the 11 organ systems of the body and their major organs:

  1. Integumentary System:

     • Major Functions: Provides protection, regulates body temperature, synthesizes vitamin D, prevents water loss.

  2. Skeletal System:

     • Major Functions: Provides support and protection, blood cell production (hemopoiesis), stores calcium and phosphorus, anchors muscles.

  3. Muscular System:

     • Major Functions: Produces body movement, generates heat.

  4. Nervous System:

     • Major Functions: Body movement control, responses to stimuli, regulatory role over other body systems.

  5. Endocrine System:

     • Major Functions: Secretes hormones regulating bodily functions (growth, chemical levels, reproduction).

  6. Cardiovascular System:

     • Major Functions: Heart and blood vessels; transports hormones, nutrients, gases, and wastes.

  7. Lymphatic System:

     • Major Functions: Filters lymph fluid, immune response initiation.

  8. Respiratory System:

     • Major Functions: Gas exchange between blood and lungs.

  9. Digestive System:

     • Major Functions: Digests food, absorbs nutrients, expels waste.

  10. Urinary System:

      • Major Functions: Filters blood, expels waste products in urine.

  11. Reproductive System:

      • Male Functions: Produces sperm, male hormones; transfers sperm.

      • Female Functions: Produces oocytes, female hormones, site of fertilization, supports fetal development, produces breast milk.

Objective: Anatomic Position and Body Planes

• Anatomic Position:

  • A common reference in anatomy.

  • Description: Standing upright, feet parallel and flat, head level and facing forward, arms at sides, palms forward.

• Body Planes:

  • Coronal (Frontal) Plane: Divides body into anterior (front) and posterior (back) parts.

  • Transverse (Cross-Sectional, Horizontal) Plane: Divides body into superior (upper) and inferior (lower) parts.

  • Midsagittal (Median) Plane: Divides body into equal left and right halves; other sagittal planes divide into unequal left and right parts.

  • Oblique Planes: Pass through the specimen at an angle.

Objective: Compare Anatomic Directions

• Provides relative position of body structures with these directional terms:

  • Anterior (ventral) vs. Posterior (dorsal): E.g., the heart is posterior to the sternum.

  • Superior vs. Inferior: Direction towards the head vs. towards the feet.

  • Medial vs. Lateral: Towards the midline vs. away from the midline.

  • Ipsilateral vs. Contralateral: Same side vs. opposite side.

  • Deep (internal) vs. Superficial (external): Relative depth.

  • Proximal vs. Distal: Close to the trunk vs. far from the trunk.

Objective: Major Regions of the Body

• Regional Anatomy: Two main body regions:

  • Axial Region: Comprising the head, neck, and trunk (vertical axis).

  • Appendicular Region: Comprising the upper and lower limbs.

• Specific terms describe areas within these major regions.

Specific Key Body Regions

• Cephalic (head)

• Cranial (skull)

• Cervical (neck)

• Thoracic (chest)

• Abdominal (abdomen)

• Pelvic (pelvis)

• Other notable areas: Deltoid, Brachial, Femoral, Popliteal, etc.

Objective: Body Cavities and Membranes

• Body Cavities: Divided into two main types:

  • Posterior Aspect:

    • Cranial Cavity: Formed by skull bones.

    • Vertebral Canal: Formed by the vertebral column.

  • Ventral Cavity:

    • Two smaller cavities separated by the diaphragm:

    • Thoracic Cavity: Superior to diaphragm.

    • Abdominopelvic Cavity: Inferior to diaphragm, including abdominal and pelvic cavities.

Composition of Serous Membranes in Cavities

• Ventral Body Cavity Membranes:

  • Lined by serous membranes with two parts:

  • Parietal Layer: Lines the internal surfaces of body walls.

  • Visceral Layer: Covers the external surfaces of organs.

  • Serous Cavity: Space between the layers, filled with serous fluid that reduces friction.

• Membranes of Thoracic Cavity:

  • Mediastinum: Central part housing heart and major vessels.

  • Pericardium: Around the heart (parietal, visceral).

  • Pleura: Around lungs (parietal, visceral).

• Membranes of Abdominopelvic Cavity:

  • Peritoneum: Surrounds abdominal organs with parietal and visceral parts.

Objective: Abdominopelvic Regions and Quadrants

• Abdominopelvic regions for organ location:

  • Nine Regions:

    • Epigastric, Umbilical, Hypogastric, right/left hypochondriac, lumbar, iliac regions.

  • Four Quadrants:

    • Right upper quadrant, Left upper quadrant, Right lower quadrant, Left lower quadrant.