Introduction to Human Anatomy, Physiology, and Anatomical Terminology

Course Infrastructure and Expectations

• Visible Body Application: The primary tool for the course contains images and videos specifically embedded to aid in understanding complex physiology, such as calcium or glucose homeostasis.

• Visible Body Videos: These are used for step-by-step processes where one reaction leads to another. These will be assigned periodically as preparation for practicums.

• Auditory Learning: The Visible Body software includes a feature to read text aloud (e.g., "Abdomen can be divided into…") for students who prefer auditory input.

• Visible Body Registration: Access requires making an account and paying through the registration link found in Blackboard under "Getting Started with Visible Body."

• Anatomical Scavenger Hunt: This is a foundational lab assignment that should be completed concurrently with learning the material to avoid a shaky foundation before moving into biochemistry.

Course Schedule and Grading

• Weekly Structure:

  • Week 1: Syllabus, expectations, levels of organization, anatomical terminology, and homeostasis.

  • Week 2: Basics of macromolecules and chemical organization.

• Assessments:

  • Exam and Practicum $1$: Covers Introduction to Anatomy, Chemistry of Life, Cell Structure and Function, and the Human Microbiome.

  • Dates: Lecture Exam on Tuesday, September $15$; Lab Practicum on Thursday, September $17$.

  • Time Block: All assessments occur from $02:30$ to $04:30$.

• Assessment Styles:

  • Lecture Exam: Includes $50$ multiple-choice questions.

  • Lab Practicum: Requires freehand writing and pulling answers entirely from memory; no multiple-choice options are provided.

• Grade Calculation:

  • Exam/Practicum Average ($60\%$ of total grade): Calculated by taking the lecture exam grade plus the practicum grade and dividing by $2$. This average represents $20\%$ of the total grade per module, across three modules ($3 \times 20\% = 60\%$).

  • Quizzes ($10\%$): Administered in two styles: traditional paper quizzes ($10$ minutes) and group-based substantiation quizzes where students must provide proof for their answers.

  • Lab Reports ($20\%$): Derived from Visible Body fill-in-the-blank assignments. These can be completed in groups, and the final deadline for all labs is December $1$ at $11:59$.

  • Cumulative Final ($10\%$): Covers approximately $17$ chapters of material.

• Grading Scale:

  • A: $90\text{--}100$

  • B: $80\text{--}89$

  • C: $70\text{--}79$

  • D: $60\text{--}69$

Study Strategies for Anatomy

• The Mirror Method: Stand in front of a bathroom mirror and record yourself on a phone. Touch the specific body region while saying the anatomical term out loud. Listen to your own voice and watch the recording to reinforce learning through visual, auditory, and tactile pathways.

• Consistency: Anatomy requires daily study to retain the heavy vocabulary load (approximately $190$ terms for the first section).

• Categorization: Organize flashcards into specific categories (Directions, Planes, Regions, Cavities, Membranes, Abdominal Regions) to narrow down choices when answering exam questions.

Hierarchy of Organization and Clinical Application

• Levels of Complexity: The universe and the human body are organized mathematically from small to large:

  • Subatomic Particles: Protons, neutrons, and electrons.

  • Atoms: Formed when subatomic particles bond.

  • Molecules: Formed when atoms bond.

  • Organelles: "Little organs" (e.g., nucleus, cell membrane, endoplasmic reticulum) that make up a cell.

  • Cells: The focus of cytology.

  • Tissues: Collections of cells (the focus of October lectures).

  • Organs: Collections of tissues working together.

  • Organ Systems: $11$ distinct systems forming the human organism.

  • Higher Levels: Organisms form communities, populations, ecosystems, planets, galaxies, and universes.

• Clinical Example: Biopsy: A small excision of tissue to study under a microscope to detect cancer within an organ.

• Clinical Example: Proton Therapy (MD Anderson): By attacking cancer at the subatomic level (protons), doctors can prevent cancer molecules from ever manifesting into organelles, cells, or tissues.

Anatomy vs. Physiology

• Anatomy: The structural "what" of the body (e.g., identifying the heart).

• Physiology: The functional "how" of the body (e.g., explaining how the heart pumps blood).

  • Physiology Example: Explaining muscular contraction through neurological stimulation from the medulla oblongata, neural impulses, and the sinoatrial node.

• Hypercalcemia Scenario: When calcium levels rise above $11\,mg/dL$, the thyroid gland secretes calcitonin. This hormone halts osteoclast activity and decreases calcium resorption, pushing excess calcium from the bloodstream into the bones for bone remodeling.

The 11 Organ Systems

1. Integumentary System

• Components: Skin, hair, nails, and multicellular exocrine glands.

• Exocrine Glands: These glands use ducts to push secretions (not hormones) to the skin surface.

  • Sebaceous glands: Produce oil; over-activity leads to acne.

  • Sudoriferous glands: Produce sweat.

  • Ceruminous glands: Produce wax (earwax).

2. Skeletal System

• Components: Bones, cartilage, and ligaments.

• Ligaments: Connect bone to bone.

• Functions:

  • Provides structure and rigidity.

  • Calcium Reservoir: Stores calcium necessary for neurotransmission and muscle contraction. Without sufficient calcium, muscle contraction—including the heart—is impossible.

  • Hematopoiesis: Manufacturing of blood within the bone marrow. Cancers like leukemia or lymphoma require bone marrow transplants because the blood is made here.

• Cartilage: A flexible, aseasonal, and avascular (lacking blood supply) connective tissue. Its lack of blood supply is why the nose and ears feel colder than the rest of the face.

3. Muscular System

• Components: Skeletal muscles and tendons.

• Tendons: Connect bone to muscle.

• Functions: Movement and heat production.

  • Striations: Muscle fibers look like threads that produce friction when they push past each other.

  • Shivering: Involuntary muscle contractions to produce heat byproduct from friction, preventing the body from freezing.

4. Lymphatic (Immune) System

• Function: Immunity (resisting infection) and fluid retention.

• Interstitium: The body fluid that bathes every organ and surface. When the lymphatic system fails to drain this fluid to the kidneys, it results in lymphedema (swelling).

• Organs:

  • Lymph Nodes: Swell during infection (cervical, axillary nodes).

  • Spleen: Recycles red blood cells, which must die there because they lack a nucleus for self-repair.

  • Thymus: Responsible for immunocompetence; active in early childhood as the immune system develops antibodies.

  • Tonsils: Protect the oral cavity from airborne pathogens.

5. Respiratory System

• Function: Gas exchange and phonation (sound production via the larynx/voice box).

• Components: Nose, pharynx (shared with digestive), larynx, trachea (windpipe), bronchi, and lungs.

• Tracheal Cartilages: Rigid rings that hold the windpipe open. They do not contract/relax, so a collapsed trachea requires a trach tube to maintain breathing.

6. Urinary System

• Function: Manufacturing, transporting, storing, and voiding urine produced from the blood.

• Process:

  • Kidneys ($2$): Manufacture urine from blood.

  • Ureters ($2$): Transport urine.

  • Urinary Bladder ($1$): A hollow structure that stores up to a liter of urine and changes shape to accommodate volume.

  • Urethra ($1$): Voids urine. In males, it also voids semen; in females, the urethral orifice is distinct from the vaginal orifice.

7. Nervous System

• Function: The control center for all other systems via electrical impulses. Muscle will atrophy (waste away) if it does not receive nerve stimulation.

• Components: Brain, spinal cord, and sense organs.

• Diagnostic Tools: A doctor shines light in eyes to check if pupils constrict; lack of constriction indicates brain damage.

8. Endocrine System

• Function: Manufacturing hormones (chemical messengers) that travel through the blood.

• Master Gland: The pituitary gland in the brain.

• Homeostasis: The thyroid and parathyroid glands are essential for regulating calcium levels.

9. Cardiovascular (Circulatory) System

• Components: Heart, blood vessels, and blood.

• Function: Unites all systems by delivering oxygen. A blockage (arterial blockage) leads to lack of oxygen, resulting in necrosis (tissue death), which is the cause of a stroke.

10. Digestive System

• Function: Fourfold process to obtain nutrients.

  • Ingestion: Taking food in.

  • Digestion: Breaking food down.

  • Absorption: Taking in minerals/nutrients (primarily in the intestines).

  • Excretion: Eliminating waste.

• Components: Mouth, esophagus (tube to stomach), stomach, and intestines.

11. Reproductive System

• Male: Principal job is manufacturing sperm (the reproductive body) in the testicles. Sperm is produced every $24$ to $37$ days.

• Female: Ovaries contain eggs. Unlike males, females are born with their lifetime supply of approximately $500,000$ eggs; they do not manufacture new ones.

• Note: The estimated cost to raise a child in America is approximately $1.8$ million dollars (financial and emotional labor) through age $18$.

Anatomical Terminology

Directional Terms (Opposites)

• Medial vs. Lateral: Toward the midline (nose) vs. away from the midline (ears).

• Proximal vs. Distal: Close to the point of attachment (shoulder is proximal to forearm) vs. distant from the point of attachment (hand is distal to shoulder).

• Superior vs. Inferior: Above (head) vs. below (neck).

• Anterior (Ventral) vs. Posterior (Dorsal): Front (mammary) vs. back (gluteal).

• Superficial vs. Deep: Close to the surface (skin) vs. further into the body (bones).

Body Planes

• Sagittal: Splits into left and right.

  • Midsagittal: Equal left and right portions.

  • Parasagittal: Unequal left and right portions.

• Transverse: Splits the body into superior (top) and inferior (bottom) halves.

• Frontal (Coronal): Splits the body into anterior (front) and posterior (back) portions.

Body Cavities

• Dorsal Cavity: Contains the Cranial and Vertebral cavities.

• Ventral Cavity: Contains the Thoracic and Abdominal-pelvic cavities.

  • Thoracic Cavity: Divided into Superior Mediastinal, Pericardial (heart), and Pleural (lungs) cavities.

Body Membranes

• Structure: A sheet of tissue with two "sides."

  • Parietal: The outermost/superficial layer.

  • Visceral: The innermost/deep layer that touches the organ.

• Specific Membranes:

  • Heart: Pericardium (Cavity: Pericardial).

  • Lungs: Pleura (Cavity: Pleural).

  • Digestive Organs: Peritoneum (Cavity: Abdominal-pelvic).

Abdominal Regions and Quadrants

The Nine Regions

• Right/Left Hypochondriac: Under (hypo) the cartilage (chondro) of the ribs.

• Right/Left Lumbar: Near the lumbar vertebrae of the lower back.

• Right/Left Iliac: Near the iliac crest of the hip bone.

• Epigastric: On top of (epi) the stomach (gastric).

• Umbilical: Centered on the umbilicus (navel).

• Hypogastric: Underneath (hypo) the stomach.

The Four Quadrants

• Divided by the umbilicus into Right Upper (RUQ), Right Lower (RLQ), Left Upper (LUQ), and Left Lower (LLQ).

• Clinical Relevance: Appendix is in the RLQ; Liver is in the RUQ; Spleen is in the LUQ.

Homeostasis and Feedback Loops

• Homeostasis: A physiologic process governing how the body communicates to maintain internal equilibrium.

• Three Components:

  1. Receptor: Detects the stimulus (change in environment, e.g., heat).

  2. Control Center: Receives input and determines the action (e.g., the brain).

  3. Effector: Carries out the action (e.g., sweat glands or muscles).

Negative (Inhibitory) Feedback

• Definition: Reverses the change to return to a set point. It opposes the stimulus.

• Examples: Sweating to cool down ($\text{heat} \rightarrow \text{cool}$), shivering to warm up ($\text{cold} \rightarrow \text{heat}$), and insulin secretion to lower blood sugar.

Positive (Amplificatory) Feedback

• Definition: Amplifies or exaggerates the stimulus. It wants the change "stronger, harder, faster, and longer."

• Normal Examples: Childbirth (oxytocin increases until the baby is born) and blood clotting.

• Pathological Examples: Cancer Metastasis: Cancer spreading from lungs to liver is an amplification of the disease.

• Ultimate Positive Feedback: Death (thanatology). Organ systems fail in a cascading fashion—one system shuts down, triggering others to shut down until everything is quiet.

Questions & Discussion

• Question: What is a biopsy?

• Response: It is the small excision of tissue (e.g., from a breast) to study under a microscope to check for cancer cells.

• Question: What is lymphedema?

• Response: It is a disorder where the lymphatic system fails to drain interstitial fluid, leading to chronic swelling and accumulation of fluid in the tissues.

• Resource Note: Hannah Bowen, a successful nursing student and tutor, shared her contact information for students needing help with concepts like histology or study organization.

• Question: Can you use two planes at the same time for a picture?

• Response: Yes, especially in imaging like MRI or CT to get comprehensive views of structures.

• Discussion on Positive Feedback: The term "positive" does not mean "good." Positive feedback loops in medicine, such as the spread of cancer or the cascade toward death, are often fatal because they move the body away from its balanced state.