Introduction to Human Anatomy and Physiology

Introduction to Human Body

  • Proficiency in anatomy and physiology is fundamental to careers in health professions.

Anatomy vs. Physiology

  • Anatomy: The study of structure and organization of the human body.

  • Physiology: The study of body functions.

Topics of Anatomy

  • Gross Anatomy: Study of body structures seen with the naked eye.

    • Systemic Anatomy: Study of related functions together as a system (e.g., skeletal system).

    • Regional Anatomy: Study of all structures in a single region (e.g., head or arm).

  • Microscopic Anatomy: Study of structures visible only under a microscope.

    • Cytology: Study of cells.

    • Histology: Study of tissues.

  • Developmental Anatomy: Structural changes throughout life, including embryology (pre-birth changes).

  • Pathological Anatomy: Structural changes due to disease.

  • Radiographic Anatomy: Studies internal structures through imaging techniques (e.g., X-rays).

Topics of Physiology

  • Physiology involves the chemical and physical processes that enable body function and maintain homeostasis (defined later).

  • Students generally find physiology more challenging than anatomy; understanding anatomy is necessary for studying physiology.

Levels of Structural Organization

  • Previous courses cover Chemical, Cellular, and Tissue levels.

  • Focus of BIO 201 is on Organ, Organ System, and Organismal Levels.

Organ Systems of the Human Body

  • Organs work together in systems:

    • Integumentary System: Skin, hair, nails

    • Skeletal System: Bones, cartilage, joints

    • Muscular System: Muscles, tendons

    • Nervous System: Brain, spinal cord, peripheral nerves

    • Endocrine System: Hormone-producing glands (e.g., pituitary gland, thyroid)

    • Cardiovascular System: Heart, blood vessels

    • Lymphatic System: Lymph nodes, spleen

    • Respiratory System: Lungs, trachea

    • Digestive System: Stomach, intestines, liver

    • Urinary System: Kidneys, bladder

    • Male Reproductive System: Testes, prostate

    • Female Reproductive System: Ovaries, uterus

Homeostasis

  • Homeostasis: Process by which the body maintains a stable internal environment despite external changes.

    • Examples of variables include:

    • pH

    • Ion concentrations (sodium, potassium)

    • Body temperature

    • Water volume

    • Blood pressure

    • Nutrient concentrations (glucose)

    • Waste products (CO₂)

    • Oxygen levels

    • Failure to maintain homeostasis disrupts normal function, potentially leading to disease.

Homeostatic Mechanisms

  • Negative Feedback System: Resists deviations from a set point; includes:

    • Variable: (e.g., body temperature)

    • Stimulus: Causes change in the variable leading to an imbalance

    • Sensor/Receptor: Monitors variable and sends signal to control center

    • Control Center: Typically the brain; compares data to the set point and directs response

    • Effector: Carries out response to correct imbalance

  • Example: Body temperature regulation through sweating (cooling) and shivering (heating).

Positive Feedback System

  • Positive feedback causes body status changes rather than returning to homeostasis.

    • An example is childbirth.

    • Stimulation leads to more stimulation, moving body away from homeostasis.

    • Requires an "off switch" to prevent excessive escalation.

Feedforward Control

  • Anticipatory response to potential changes, maintaining stability.

    • Example: Salivation in anticipation of food.

Regional Terms

  • Axial Region: Head, neck, thoracic, abdominal, pelvic areas.

  • Appendicular Region: Arms and legs.

  • Anatomical terms are used to describe these regions and should be learned for lab

  • Key regions include:

    • Femoral: Thigh

    • Mental: Related to chin area.

    • Only terms in the lab exercises need to be learned for exams.

Anatomical Position

  1. Stand with feet and eyes forward.

  2. Palms facing forward with thumbs away from body.

  3. All directional terms are based on this position.

Directional Terms

  • Terms used to describe the location of body structures relative to one another:

    • Anterior (Ventral): Front direction (toes anterior to foot).

    • Posterior (Dorsal): Back direction (popliteus posterior to patella).

    • Superior (Cranial): Above another part (orbits superior to oris).

    • Inferior (Caudal): Below another part (pelvis inferior to abdomen).

    • Lateral: Towards the side of the body (thumb lateral to digits).

    • Medial: Towards the middle (hallux medial to other toes).

    • Proximal: Closer to attachment (brachium proximal to antebrachium).

    • Distal: Farther from attachment (crus distal to femur).

    • Superficial: Closer to the body’s surface (skin superficial to bones).

    • Deep: Farther from body’s surface (brain deep to skull).

Plans of the Body

  • Frontal (Coronal) Plane: Divides into anterior and posterior sections.

  • Sagittal (Midsagittal) Plane: Divides into right and left portions.

  • Transverse Plane: Divides into superior and inferior parts.

Body Cavities

  • Dorsal Cavity: Includes cranial (brain) and vertebral (spinal cord) cavities.

  • Ventral Cavity: Divided by diaphragm into thoracic and abdominal cavities.

    • Thoracic Cavity: Contains heart and lungs.

    • Abdominal Cavity: Contains digestive organs.

    • Pelvic Cavity: Contains urinary and reproductive structures.

Regions and Quadrants of the Peritoneal Cavity

  • Nine Abdominal Regions: Detailed division of the abdominal cavity.

  • Four Abdominal Quadrants: Alternative division for clinical purposes.

Serous Membrane

  • Serous Cavities: Lined by serous membranes; examples:

    • Visceral: Touches the organ.

    • Parietal: Lines the cavity walls (e.g., parietal pleura, pericardium).

Medical Imaging Techniques

  • X-Ray: Uses high-energy radiation to visualize internal structures like bones.

  • CT Scan: Produces cross-sectional images of the body.

  • MRI: Uses magnetic fields to visualize organs.

  • PET Scan: Uses radiopharmaceuticals to track blood flow and activity.

  • Ultrasound: Non-invasive imaging commonly used during pregnancy.

Copyright Information

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