Comprehensive Introduction to Human Anatomy and Physiology for EMS Study Guidelines for EMS

Course Logistics and Administration

  • EMS Testing and Calendar:
    • The course calendar contains assignments staggered across different days to prevent everything from appearing on a single day.
    • Once an assignment is completed, a line is placed through it on the course calendar.
    • In-class quizzes are listed on the calendar (22 per module), but EMS testing requirements are managed separately.
    • Module 1 Exception: The instructor decided not to load EMS testing requirements for Module 11 to allow students to find their pace. It becomes strictly required starting in Module 22.
    • Quizzes: While the syllabus says "in-class quizzes," these are actually to be completed individually at home. The instructor prefers dismissing class 3030 minutes early rather than using class time for testing.

Fundamentals of Anatomy, Physiology, and Pathophysiology

  • Anatomy: The field of study focused on the physical structure of the body and its systems.
  • Physiology: The study of the normal functions and activities of the body and its systems.
  • Pathophysiology: The study of functional changes that accompany a particular disease or syndrome.
    • Example: Diabetes is discussed in the context of pathophysiology, specifically how the body changes when the pancreas no longer produces insulin.

Topographical Anatomy and Body Planes

  • Anatomic Position: A standard position where the person stands with feet planted on the ground and palms facing forward.
  • Vertical Planes:
    • Sagittal Plane: Separates the body into right and left portions.
    • Frontal (Coronal) Plane: Runs down the side of the body, separating it into front and back. It does not need to divide the body into equal halves.
  • Horizontal Plane:
    • Transverse Plane: Separates the body into upper and lower portions. It can run through the trunk or any other part of the body.
  • Oblique Planes: Odd-angle or diagonal planes that slice through any part of the body at various angles.

Structural Foundations of the Human Body

  • Hierarchy of Structure:
    • Cells: The basic foundation and source of energy and structure; the body cannot function without them.
    • Tissues: Groups of cells that share common functions (e.g., cardiac cells forming cardiac tissue).
    • Organs: Groups of tissues that perform similar or interrelated jobs.
    • Body Systems: Multiple organs working together to perform a collective function (e.g., the digestive system).

The Skeletal System: Overview and Axial Skeleton

  • Functions: Provides recognizable shape (prevents the body from being a "pile of goo"), protects vital organs, and serves as a framework for muscle attachment. It also produces red blood cells in the bone marrow and acts as a reservoir for minerals and electrolytes.
  • Total Count: Approximately 206206 bones.
  • The Axial Skeleton: Includes bones along the body's long axis.
    • Skull (Cranium):
      • Cranial Bones: Protect the brain (forming the cranial vault). Includes the occipital, parietal, temporal, frontal, sphenoid, and ethmoid bones. These are joined at suture lines, which are immovable joints.
      • Facial Skeleton: 1414 bones that dictate facial features and form the entrances to the respiratory and digestive tracts.
      • Mandible: The lower, movable portion of the jaw.
      • Maxillae: The upper, immovable portion of the jaw containing the upper teeth.
      • Zygomats (Zygomatic Bones): The orbits of the eyes.
      • Other bones (Landmarks): Lacrimals, nasals, vomer (referred to as "boomer"), palatines, and nasal conchae.
    • Spinal Column: Comprised of 3333 vertebrae in 55 sections:
      • Cervical Spine (Neck): 77 vertebrae. C1C1 and C2C2 are the Atlas and Axis, allowing head rotation.
      • Thoracic Spine (Upper Back): 1212 vertebrae, each with a pair of ribs attached.
      • Lumbar Spine (Lower Back): 55 vertebrae.
      • Sacrum: 55 fused vertebrae forming the back wall of the pelvis.
      • Coccyx (Tailbone): 44 fused vertebrae.
      • Memory Tool: "Cereal at 77 (C-spine), Tea at 1212 (Thoracic), Supper/Late lunch at 55 (Lumbar)."
    • Thoracic Cage (Chest): Contains the heart, lungs, esophagus, and great vessels.
      • Ribs: 1212 pairs total. Ribs 11 through 77 are "true ribs" (direct connection to sternum). Ribs 88 through 1212 are "false ribs."
      • Sternum: Composed of the manubrium, the body, and the xiphoid process (a critical landmark for CPR).

The Appendicular Skeleton

  • Definition: Bones that are appendages of the axial skeleton, including arms, legs, and the pelvis.
  • Upper Extremities:
    • Shoulder Girdle (Pectoral Girdle): Consists of the clavicle, scapula, and humerus. The glenohumeral joint is highly mobile but lacks stability, making it prone to dislocation.
    • Arm and Forearm: The humerus (upper arm), the radius (thumb side/lateral), and the ulna (pinky side/medial). The radius and ulna cross over each other when the hand rotates.
    • Hand and Wrist: 88 carpals (wrist), 55 metacarpals (palm), and 1414 phalanges (fingers/thumb).
  • Pelvic Girdle: Ring of bone connecting lower limbs to the axial skeleton.
    • Bones: Fusion of the Ilium, Ischium, and Pubis.
    • Pubic Symphysis: A cartilaginous joint joining the left and right pubic bones. In males, it is located right above the base of the penis; in females, it is located very low in the pelvic region.
    • Landmarks: Iliac crest (belt line) and Greater Trochanter (outer part of the femoral head used for splinting).
  • Lower Extremities:
    • Femur: Longest and strongest bone in the body. The femoral head connects to the acetabulum.
    • Leg: Tibia (shinbone) and Fibula (smaller lateral bone).
    • Patella: Knee cap.
    • Ankle and Foot: 77 tarsal bones. The Calcaneus is the largest (heel bone). The foot has 55 metatarsals and 1414 phalanges (the big toe, like the thumb, only has 22).

Joints and Articulations

  • Categorization by Function (Range of Motion):
    • Synarthrosis: Immovable (e.g., skull sutures, first rib/sternum).
    • Amphiarthrosis: Slightly movable (e.g., distal joint between tibia/fibula, pubic symphysis).
    • Diarthrosis: Fully movable (e.g., elbow, shoulder, ankle).
  • Categorization by Structure:
    • Fibrous Joints: Thick connective tissue (e.g., sutures, gomphosis joints holding teeth).
    • Cartilaginous Joints: Sychindrosis (ribs/manubrium) or Symphysis (vertebral discs).
    • Synovial Joints: Feature an articular capsule and cartilage. Types include:
      • Gliding: C1C1 and C2C2 (allows chicken-like movement).
      • Hinge: Knees and elbows.
      • Pivot: Allows rotation.
      • Condyloid: The wrist.
      • Saddle: The thumb (only 22 in the body).
      • Ball and Socket: Hips and shoulders (highest range of motion).

The Muscular System

  • Overview: Contains over 600600 muscles, comprising approximately 40%40\% of body mass. Facilitates movement, posture, protection, and heat production.
  • Types of Muscle:
    • Skeletal Muscle: Voluntary muscle under direct brain control. Attached to bones.
    • Smooth Muscle: Involuntary; found in blood vessels and intestines.
    • Cardiac Muscle: Found only in the heart. Involuntary. Critical Note: Cardiac muscle cannot be repaired. Ischemia results in permanent scarring and heart failure.

The Respiratory System

  • Key Definitions:
    • Ventilation: The mechanical process of moving air in and out of the lungs.
    • Respiration: The gas exchange of oxygen (O2O_2) and carbon dioxide (CO2CO_2) at the cellular/alveolar level.
    • Oxygenation: Providing oxygen to organs and tissues.
  • Upper Airway: Divided at the larynx (voice box). Includes the nose, mouth, tongue, and jaw.
    • Nasal Turbinates: Folds in the nasal cavity that churn and warm air.
    • Pharynx Layers: Nasopharynx (air only), Oropharynx (air and food), and Laryngopharynx.
    • Epiglottis: Leaf-shaped flap that prevents food/liquid from entering the trachea.
  • Lower Airway: Includes the trachea, bronchi, bronchioles, and alveoli.
    • Trachea: Tube with CC-shaped cartilaginous rings to prevent collapse. Ends at the Carina.
    • Lungs: Right lung has 33 lobes; left lung has 22 lobes (to accommodate the heart).
    • Pleura: Visceral pleura (covers lungs) and Parietal pleura (covers chest wall).
    • Alveoli: Grape-like sacs where gas exchange occurs via diffusion.
  • Physiology of Breathing:
    • Diaphragm: Primary muscle, containing both voluntary and involuntary fibers. Inhalation is an active process; exhalation is typically passive.
    • Neural Control: Managed by the Medulla Oblongata and the Pons.
    • Chemical Control: Primarily driven by high CO2CO_2 levels causing a decrease in pH (acidosis).
    • Hypoxic Drive: A backup system where breathing is stimulated by low O2O_2 levels (common in COPD patients).
  • Lung Volumes:
    • Tidal Volume: Approximately 500 cc500\,cc for a normal adult.
    • Minute Volume: Respiratory Rate×Tidal VolumeRespiratory\,Rate \times Tidal\,Volume.
    • Dead Space: Areas with no gas exchange (bronchi/bronchioles).
  • Breathing Quality:
    • Normal: Regular rhythm, clear audible sounds, equal chest rise and fall.
    • Inadequate: Labored patterns, use of accessory muscles, rates below 1212 or above 2222 breaths per minute, cyanotic skin, and tripoding (sniffing position).

The Circulatory System

  • Circuits:
    • Systemic: Oxygen-rich blood from left ventricle to body, returning to right atrium.
    • Pulmonary: Oxygen-poor blood from right ventricle to lungs, returning to left atrium.
  • Heart Anatomy:
    • Atria: Upper chambers.
    • Ventricles: Lower chambers. The left ventricle is the high-pressure pump with thick muscle.
    • Valves: Tricuspid, Mitral, Pulmonary, and Aortic. Prevent backflow (regurgitation).
  • Parameters:
    • Heart Rate: 6060 to 100 bpm100\,bpm for adults.
    • Stroke Volume: Blood moved in one beat.
    • Cardiac Output: Heart Rate×Stroke VolumeHeart\,Rate \times Stroke\,Volume.
  • Electrical Conduction: SA node (pacemaker) →\rightarrow AV node →\rightarrow Bundle of His →\rightarrow Purkinje fibers.
  • Vessels:
    • Arteries: Carry blood away from the heart. High pressure. Only the pulmonary artery carries deoxygenated blood.
    • Veins: Carry blood toward the heart. Low pressure. Features valves to prevent pooling. Includes the Superior and Inferior Vena Cava.
    • Capillaries: Microscopic tubes allowing one cell at a time; the site of gas/nutrient exchange.
  • Pulse Points: Carotid, Radial, Brachial (pediatrics), Femoral, Popliteal (behind knee), Posterior Tibial, and Dorsalis Pedis.
  • Blood Components:
    • Plasma: Liquid portion.
    • Red Blood Cells (Erythrocytes): Carry oxygen via hemoglobin.
    • White Blood Cells (Leukocytes): Immune defense.
    • Platelets: Essential for clotting.
  • Blood Pressure:
    • Systole: Pressure when the heart contracts.
    • Diastole: Pressure when the heart relaxes and refills.

The Nervous System

  • Central Nervous System (CNS): Brain and spinal cord.
  • Peripheral Nervous System (PNS):
    • Somatic: Voluntary actions.
    • Autonomic: Involuntary actions.
      • Sympathetic: Fight or Flight; releases epinephrine/norepinephrine via adrenal glands.
      • Parasympathetic: Feed and Breed; slows heart rate.
  • Brain Regions:
    • Cerebrum: Frontal lobe (personality), Parietal lobe (spatial), Occipital lobe (vision), Temporal lobe (taste/hearing).
    • Cerebellum: Balance and coordination.
    • Brain Stem: Midbrain, Pons, Medulla. Controls life-sustaining functions.

Digestive and Other Systems

  • Abdominal Quadrants:
    • Right Upper (RUQ): Liver, gallbladder, colon.
    • Left Upper (LUQ): Stomach, spleen, colon, pancreas.
    • Right Lower (RLQ): Cecum, ascending colon, appendix.
    • Left Lower (LLQ): Descending colon, sigmoid colon.
  • Digestive Organs:
    • Stomach: Churns and breaks down food.
    • Small Intestine: Chemical breakdown and nutrient absorption.
    • Large Intestine (Colon): Absorbs water and stores waste.
    • Liver: Detoxifies, stores sugar, produces bile and clotting factors.
    • Pancreas: Exocrine (juices for digestion) and Endocrine functions.
  • Lymphatic System and Spleen:
    • Spleen: Filters blood and stores it. Highly vascular; susceptible to "fractures" in trauma.
    • Lymph Nodes: Filter impurities; swell during infection.

Questions & Discussion

  • Question (Vertebrae/Heart Rate): A student asks if cervical vertebrae control heart rate.
  • Response: The instructor clarifies that it is the nerves within the spinal column, not the vertebrae themselves, that regulate functions like heart rate.
  • Anecdote (Emergency Interventions): The instructor discusses the cricothyroid membrane as a landmark for emergency airway procedures (cricothyrotomy) and the role of clinical pressure during intubation.
  • Anecdote (Firefighter Training): Discussion regarding "RIT" (Rapid Intervention Team) or "RIC" training, involving blindfolded entanglement drills and escaping through narrow windows in full gear.
  • Anecdote (Potomac Incidents): Discussion about the Potomac river, including jumpers from the 340340 Bridge and the physical dangers of the river (algae, brain-eating amoebas, and current speeds near Brunswick and Point of Rocks).
  • Anecdote (Train Suicides): Discussion of MARC train suicide attempts at Penn Station and Germantown, along with DOT standards requiring engineer replacement after a fatal strike.