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Week One Flashcards

Basic Concepts

  • Course and context: ANPH 205: Sectional Anatomy, Introduction to Sectional Anatomy (Southern Alberta Institute of Technology, SAIT). Focus on sectional anatomy as an alternative method of viewing and interpreting anatomy.
  • Learning outcomes:
    • Relate dimensional thinking to human anatomy.
    • Differentiate medical terminologies used to describe anatomy.
    • Distinguish anatomy orientation relative to transducer position and acoustic window.
    • Differentiate fundamental regions and divisions of the body.
  • Sectional anatomy overview:
    • Study of regions of the body (instead of only systems).
    • Examine three-dimensional relationships within a region (length, width, depth).
    • Structures in a viewed section are analyzed in 3 dimensions to understand spatial relationships.
    • Emphasizes anatomical relationships within a region via sectional slices.
  • How sectional anatomy supports ultrasound:
    • Ultrasound generates 2D images in multiple planes; 3D interpretation is inferred by combining 2D views across planes.
    • Imaging evolution: from early 2D radiographs (1895) to modern 3D imaging enabled by advances in computer technology.
  • Study tools:
    • Read assigned textbook pages to reinforce module concepts and view additional sonographic images/diagrams.
    • Self-test on D2L to practice; it does not count toward final grade and can be taken multiple times.

Dimensional Thinking in Medical Imaging

  • 2D vs 3D:
    • 2D imaging adds height and width to the image plane.
    • 3D imaging includes height, width, and length; all anatomical structures have 3 dimensions.
    • Accurate spatial relationships require incorporating the 3rd dimension.
  • Ultrasound interpretation:
    • Ultrasound uses 2D slices; 3D information is gleaned by viewing structures in more than one plane.
    • Sonographers routinely interpret anatomy in 3D by acquiring multiple 2D images in different planes.
  • Planes and orientation in imaging:
    • Sagittal plane (length and height): longitudinal view opening to assess length/depth.
    • Transverse plane (width and height): cross-sectional view.
    • Coronal plane (width and depth): front-to-back perspective.
  • Analogies and visualization aids (illustrative):
    • Conceptual analogies like slicing bread to view “slices” of a loaf from different angles help in understanding sectional views.
  • Note: All planes are analyzed in relation to the anatomical position and scanning orientation to preserve consistent interpretation.

Anatomy: Gross, Microscopic, and Sectional Concepts

  • Gross anatomy:
    • Study of anatomy without magnification.
    • Emphasizes body systems; focuses on shape, location, and function of structures visible to the naked eye.
  • Microscopic anatomy:
    • Study of cells and tissues under a microscope.
  • Sectional anatomy:
    • Regions of the body are studied instead of just systems.
    • Emphasizes 3D relationships within a region via sequential slices.
  • Relationship to physiology:
    • Structure (anatomy) underpins function (physiology); sectional views help relate anatomy to clinical imaging findings.

Anatomical Planes and Orientation

  • Anatomical planes (three major orthogonal planes):
    • Sagittal (longitudinal): a vertical plane that divides the body into right and left portions.
    • Midsagittal (midline): passes through the midline, creating equal right and left sides.
    • Parasagittal: divides the body into unequal right/left sections.
    • Transverse (axial, short axis): a horizontal plane dividing the body into superior and inferior portions; often used in cross-sectional imaging.
    • Coronal (frontal): a vertical plane dividing the body into anterior and posterior sections.
  • Additional related planes:
    • Midaxillary plane: a vertical plane passing through the midaxillary line.
    • Oblique: a plane angled between sagittal and/or transverse and/or coronal planes (not strictly orthogonal).
  • Key concept:
    • Anatomical relationships vary with the plane of view; imaging may use oblique planes to reflect natural organ orientation.
  • Planes vs. acoustic window:
    • Planes are mathematical constructs; acoustic window refers to where the ultrasound beam can interrogate tissue in the patient.

Acoustic Window, Scanning Planes, and Image Standardization

  • Acoustic window:
    • The location from which an ultrasound transducer scans; corresponds to the transducer position on the patient.
    • Only structures directly beneath the beam can be investigated.
    • The window is controlled by the sonographer (transducer manipulation).
  • Scanning planes:
    • 2D ultrasound images are created; structures are typically viewed in multiple planes to obtain 3D information.
    • Sagittal/longitudinal planes show length and height/depth.
    • Transverse/short axis planes show width and height/depth.
    • Oblique scans are used to demonstrate the natural orientation of organs when standard planes do not optimally display structure.
  • Image standardization:
    • Standardization of ultrasound image display is essential for accuracy and consistency.
    • The sonographer controls probe orientation, which determines image orientation and displayed relationships.
    • Incorrect orientation can lead to misinterpretation and affect patient management.
  • Transducer orientation:
    • Each transducer has a marker used to orient on the patient; the marker's direction determines what side of the monitor displays the structure.
    • Typical orientation rules (dependent on position):
    • Sagittal (patient supine): marker directed toward the patient’s head.
    • Transverse (patient supine): marker directed toward the patient’s right side (the side of contact with the transducer).
    • Coronal (patient on side): marker directed toward the patient’s head.

Directional Terminology

  • Right and Left: always refer to the patient’s right/left, not the observer.
  • Superior (cranial/cephalic): toward the head or above another part.
  • Inferior (caudal): toward the feet or below another structure.
  • Anterior (ventral): toward the front of the body/structure.
  • Posterior (dorsal): toward the back of the body/structure.
  • Medial: toward the midline of the body or structure.
  • Lateral: toward the side of the body or structure.
  • Proximal: closer to the trunk or point of attachment.
  • Distal: farther from the trunk or point of attachment.
  • Superficial (external): toward or near the body surface.
  • Deep (internal): away from the body surface.
  • Ipsilateral: structures on the same side.
  • Contralateral: structures on opposite sides.
  • Visceral: related to the viscera (internal organs).
  • Parietal: related to the wall of the body.

Patient Positioning Terminology

  • General concept: patient position is described relative to anatomical position during a scan.
  • Common positions:
    • Prone: patient lying face down.
    • Supine: patient lying face up.
    • Lateral: patient lying on the right or left side (lateral decubitus).
    • True lateral: body at 90° from supine or prone; position named by the side touching the table (e.g., Left lateral).
    • Lateral oblique: body angled less than 90° from supine/prone; position named for surface/side nearest the table (e.g., Left posterior oblique, LPO).
    • Erect: standing or sitting upright.
    • Semi-erect: partially upright (usually partial sitting with back between supine and erect).
    • Trendelenburg: feet higher than the head.
    • Reverse Trendelenburg: feet lower than the head.

Body Cavities: Dorsal and Ventral

  • Body cavities: natural spaces containing internal organs; they protect, support, and allow organ movement/expansion.
  • Dorsal (posterior) cavity:
    • Associated with the central nervous system.
    • Contains cerebrospinal fluid (CSF) in its cavities.
    • Subdivided into cranial cavity (brain) and spinal (vertebral) cavity (spinal cord and nerves).
  • Ventral (anterior) cavity:
    • Larger than the dorsal cavity.
    • Contains viscera (internal organs).
    • Subdivided into thoracic cavity and abdominopelvic cavity by the diaphragm.

Thoracic Cavity (Ventral Cavity subdivision)

  • Thoracic cavity components:
    • Pleural cavities: right and left, containing the lungs; lined with pleura to reduce friction.
    • Mediastinum: central compartment between the pleural spaces; contains the heart, great vessels, thymus, trachea, esophagus, nerves, and lymph nodes.
    • Pericardial cavity: anterior compartment within the mediastinum; contains the heart.
  • Boundaries: thoracic boundaries formed by ribs, sternum, vertebrae, diaphragm, and associated muscles.

Abdominopelvic Cavity

  • Location: large cavity extending from the diaphragm to the pelvis; lined with a serous membrane.
  • Subdivisions:
    • Abdominal cavity: upper portion; from the inferior surface of the diaphragm to the superior bony pelvis.
    • Pelvic cavity: lower portion; within the pelvic bones, extending from the iliac crests to the pelvic floor.
  • Abdominal contents and retroperitoneal positioning:
    • Organs include liver, pancreas (part), stomach, spleen, gallbladder, small intestine, and most of the large intestine.
    • Some organs lie retroperitoneally along the posterior abdominal wall (e.g., kidneys, adrenal glands, part of pancreas).
  • Pelvic contents:
    • Bladder, distal ureters, reproductive organs, distal small bowel, rectum, sigmoid colon, vessels, lymph nodes, etc.
  • True vs False pelvis (pelvic regions):
    • True pelvis: area below the pelvic brim; contains bladder and reproductive organs.
    • False pelvis: area above the pelvic brim; contains parts of small intestine and colon.
  • Dividing lines in the pelvis:
    • An oblique plane from the sacral promontory to the superior surface of the pubic symphysis divides true and false pelvis.

Methodologies for Body Mapping

  • Purpose: identify specific areas and locate structures within the large abdominopelvic cavity.
  • Quadrant method:
    • Simple method for generalized location of symptoms or pain.
    • Two perpendicular lines intersect at the umbilicus (approximately at the level of the vertebral bodies L3-L4).
    • Four quadrants created: RUQ, LUQ, RLQ, LLQ.
  • Regional method:
    • Provides more precise descriptions of location for systems, pain, or pathology.
    • Regions formed by four planes: two vertical (right and left midclavicular) and two horizontal (subcostal and transtubercular).
    • Nine distinct regions created, smaller in area than the quadrant system.
  • Surface landmarks (easily palpable):
    • Sternal notch, xiphoid process, subcostal margin, iliac crest, symphysis pubis.
  • Exercise prompt (from slides): identify structures in each region and name one organ per region.
    • 1) Right hypochondriac: e.g., liver, gallbladder.
    • 2) Epigastric: e.g., stomach, part of pancreas.
    • 3) Left hypochondriac: e.g., spleen.
    • 4) Right lumbar: e.g., kidney (right), portions of colon.
    • 5) Umbilical: e.g., small intestine.
    • 6) Left lumbar: e.g., kidney (left), descending colon.
    • 7) Right iliac (inguinal): e.g., appendix.
    • 8) Hypogastric (pubic): e.g., bladder, reproductive organs.
    • 9) Left iliac (inguinal): e.g., sigmoid colon.

Regional Anatomy and Key Organs (Nine-Region System)

  • Right hypochondriac region: liver and gallbladder commonly located here; portion of the right kidney may be nearby.
  • Epigastric region: stomach; portions of the pancreas; liver may extend into this region.
  • Left hypochondriac region: spleen; parts of stomach; tail of pancreas.
  • Right lumbar region: ascending colon; right kidney.
  • Umbilical region: parts of small intestine (jejunum/ileum); portions of transverse colon.
  • Left lumbar region: descending colon; left kidney.
  • Right iliac (inguinal) region: appendix commonly.
  • Hypogastric (pubic) region: bladder; reproductive organs (e.g., uterus in females).
  • Left iliac (inguinal) region: sigmoid colon; parts of ileum.

Practical Implications and Exam-Relevant Details

  • Orientation and imaging accuracy:
    • Correct orientation of the transducer marker and image display is critical to prevent misinterpretation.
    • Different scanning planes must be used to obtain complementary views for accurate 3D understanding.
  • Regional anatomy mapping supports clinical reasoning:
    • Quadrant and nine-region systems aid in localizing pain, symptoms, or injury.
    • Knowledge of surface landmarks improves the ability to locate underlying structures on imaging.
  • Common pitfalls:
    • Assuming planes align perfectly with anatomy; real anatomy is often oblique relative to standard planes.
    • Misinterpreting right/left due to patient positioning or observer perspective.
  • Ethical/practical considerations:
    • Adhere to standardized orientation to reduce diagnostic errors.
    • Ensure patient comfort and safety while positioning for imaging.
  • Formulas and notations used in the course:
    • Planes are orthogonal with a right-angle relationship: 90^{\circ} between sagittal, transverse, and coronal planes.
    • Quadrant division: two perpendicular lines intersecting at the umbilicus at around the level L3-L4 form RUQ, LUQ, RLQ, LLQ.
    • True vs False pelvis plane-based separation uses an oblique line from sacral promontory to the superior surface of the pubic symphysis.

References and Administrative Notes

  • Primary reference: Curry, R. A., & Prince, M. (2021). Sonography: Introduction to normal structure and function (5th ed.). Saunders.
  • Material is copyrighted by SAIT; use is governed by SAIT Fair Dealing Policy and related copyright notices.
  • Additional figures and diagrams referenced are for educational illustration and may be sourced from public domains or course materials.

Quick Glossary of Key Terms

  • Anatomical position: standard reference posture used to describe locations.
  • Planes: sagittal, midsagittal, parasagittal, transverse, coronal, oblique.
  • Acoustic window: transducer position/location from which the scan is obtained.
  • Quadrants: RUQ, LUQ, RLQ, LLQ.
  • Regions: nine-region abdominal division (right hypochondriac, epigastric, left hypochondriac, right lumbar, umbilical, left lumbar, right iliac, hypogastric, left iliac).
  • Cavities: dorsal (cranial, spinal) and ventral (thoracic, abdominopelvic).
  • Subdivisions of thorax: pleural cavities, mediastinum, pericardial cavity.
  • Subdivisions of abdomen/pelvis: abdominal cavity, pelvic cavity; true vs false pelvis.
  • Orientation markers: right/left refer to patient; head vs feet, anterior vs posterior, etc.