Anatomical Directional Terms and Body Planes Study Notes
Anatomical Position, Directional Terms, and Planes
Origin and purpose: A standardized set of directional terms, planes, cavities, and regions to clearly locate anatomical features and discuss clinical scenarios.
Reference: Material includes pretest and post-test questions with answers to reinforce terminology and concepts.
Anatomical Position and Basic directional terms
Anatomical position (definition): A person is standing erect, facing forward, feet parallel, arms hanging at the sides, and palms facing forward. This position standardizes orientation for study and discussion of anatomy.
Prone vs. Supine (from pretest and body-position sections)
Prone: lying face-down. Probability\text{ correct answer on Pretest (2 of 20): } c. Prone.
Supine: lying face upward (on the back).
Cephalic (toward the head) vs Caudal (toward the tail or lower part of the body).
Example from pretest: "toward the head" = Cephalic. Answer: d. Cephalic.
Medial vs Lateral
Medial: toward the midline of the body.
Lateral: away from the midline.
Proximal vs Distal (from the pretest and general terminology)
Proximal: closer to the point of origin or attachment (e.g., shoulder as reference point for elbow).
Distal: farther from the point of origin or attachment (e.g., fingers from shoulder).
Anterior (ventral) vs Posterior (dorsal)
Anterior/Ventral: toward the front of the body.
Posterior/Dorsal: toward the back of the body.
Superior (cranial or cephalic) vs Inferior (caudal)
Superior: toward the head or upper part of a structure.
Inferior: away from the head toward the lower part.
Example from directional terms: a knee is Superior to the ankle and Inferior to the thigh.
External vs Internal
External: on the outside of the body.
Internal: on the inside, inside organs.
Superficial vs Deep
Superficial: toward the body surface.
Deep: away from the surface.
Central vs Peripheral
Central: around the center of the body.
Peripheral: toward the extremities or outer regions.
Additional reference terms (per Table 2–1 in the textbook): see external/internal, superficial/deep, central/peripheral as foundational terms.
Planes and sections of the body
Plane: an imaginary line that divides the body or an organ into sections for study.
Transverse (Horizontal) Plane
Divides the body into Superior (top) and Inferior (bottom) portions.
Also called cross-section.
Directional terms used to describe areas divided by the transverse plane include Superior and Inferior.
Median (Midsagittal) Plane
Divides the body into right and left halves.
Medial: toward the midline; Lateral: away from the midline.
Frontal (Coronal) Plane
Divides the body into Front (Anterior/Ventral) and Back (Posterior/Dorsal) sections.
Practical examples
A knee is Superior to the ankle and Inferior to the thigh.
Key directional terms for clinical anatomy and mapping
Superior (cranial or cephalic) vs Inferior (caudal)
Anterior (ventral) vs Posterior (dorsal)
Medial vs Lateral
Proximal vs Distal
External vs Internal
Superficial vs Deep
Central vs Peripheral
These terms support precise description of pain location, injury, or anatomy relative to planes and positions.
Body Cavities and their contents
Cavities provide protection and organization for organs.
Dorsal cavity (back side)
Subdivisions: Cranial cavity (brain) and Vertebral (spinal) cavity (spinal cord).
Ventral cavity (front side)
Larger anterior cavity subdivided by the diaphragm into:
Thoracic cavity: contains Heart, Lungs, Large blood vessels; contains digestive organs in the upper abdominal portion.
Abdominopelvic cavity: houses most abdominal and pelvic organs; stomach, intestines, liver, gallbladder, pancreas, spleen, etc.
Pericardial cavity
A specific subcavity within the thoracic cavity that contains the heart.
Smaller cavities (listed as examples):
Nasal cavity, Buccal (oral) cavity, Orbital cavity (eyes).
Pelvic contents: urinary organs, reproductive organs, and the last part of the large intestine.
Note on clinical relevance: certain positions can affect organ function or patient safety (see Pathology Connections below).
Thoracic and Abdominopelvic contents (summary)
Thoracic cavity contains:
Heart, Lungs, Large blood vessels
Digestive organs in the upper abdominal portion include Stomach, Intestines, Liver, Gallbladder, Pancreas, Spleen.
Abdominopelvic cavity contains:
Digestive organs spread throughout; urinary and reproductive organs in the pelvic region.
Pericardial cavity contains the heart and is a subcomponent of the thoracic cavity.
Abdominal Regions (9-region plan) and contents
Nine-region grid subdivides the abdomen to locate organs precisely.
Upper row:
Right Hypochondriac Region: Liver; Gallbladder; Right kidney; Small intestine; Ascending colon. 7\text{ regions in the upper row}
Epigastric Region: Stomach; Liver; Pancreas; Duodenum; Spleen; Adrenal glands.
Left Hypochondriac Region: Stomach; Spleen; Left kidney; Pancreas; Descending colon.
Middle row:
Right Lumbar Region: Ascending colon; Right kidney; Gallbladder.
Umbilical Region: Small intestine (duodenum, ileum, jejunum); Transverse colon; Pancreas; Umbilicus (navel).
Left Lumbar Region: Descending colon; Left kidney.
Lower row:
Right Iliac (Inguinal) Region: Cecum; Appendix; Right ovary and uterine tube (female).
Hypogastric (Suprapubic) Region: Urinary bladder; Sigmoid colon; Rectum; Reproductive organs (uterus, ovaries, prostate).
Left Iliac (Inguinal) Region: Sigmoid colon; Left ovary and uterine tube (female).
These regions help locate pathology and guide exams, imaging, and surgery planning.
Additional anatomical landmarks and body regions (to aid localization)
Major vertebral sections and their typical counts:
Cervical: 7 vertebrae (C1–C7)
Thoracic: typically 12 vertebrae (T1–T12)
Lumbar: 5 vertebrae (L1–L5)
Sacrum: fused from 1 bone into a single sacrum comprised of S1–S5 segments
Coccyx: typically 4 fused/cygni segments (coxal bones vary by individual)
Other important body regions used in clinical assessments:
Axillary region (armpit) – commonly used for lymph node palpation.
Brachial region – upper arm, commonly used for blood pressure assessment.
Femoral region – thigh, used for pulses and catheter insertions.
Patellar region – area around the kneecap, used for reflex testing.
Pubic region – pelvic area, used in pelvic exams and herniation assessments.
See Table 2–2 in the textbook for additional regional references.
Pathology connections: clinical implications of positions and plane concepts
Trendelenburg position (head lower than feet)
Can help drain secretions from the base of the lungs (beneficial in some airway conditions).
Should be avoided in patients with cerebral injury or bleeding because it increases intracranial pressure by increasing blood flow to the brain.
Heightened risk of aspirating vomitus into the lungs; patients should not eat within 2–4 hours of being placed in this position.
Orthopnea (shortness of breath when lying flat)
Patients may need to be propped up with pillows to aid diaphragmatic movement and breathing.
Jugular venous distension (JVD) while upright
Indicates severe heart failure due to increased venous pressure and poor venous return.
Orthostatic hypotension
Dizziness when moving from seated to standing; heart cannot compensate for the gravitational effect causing reduced cerebral blood flow.
Apply what you’ve learned: examples and reasoning
Pain location can guide diagnosis: asking about exact location, type, intensity, and onset helps determine likely organ systems involved.
When describing a location, use the correct directional terms and planes to communicate accurately (e.g., pain in the Epigastric region near the stomach and liver; or pain in the RLQ suggesting appendicitis risk).
Median/typical questions and answers (from the Pretest and Post-Test)
Pretest (2 of 20): Which position is lying face-down? Answer: Prone.
Pretest (4 of 20): Which term means "toward the head"? Answer: Cephalic.
Pretest (6 of 20): Another term for the median plane is the: Answer: Midsagittal plane.
Pretest (8 of 20): Opposite of proximal? Answer: Distal.
Pretest (10 of 20): The brain and spinal cord are located in which cavity? Answer: Dorsal cavity.
Pretest (12 of 20): How many cervical vertebrae are there? Answer: 7.
Pretest (14 of 20): Which abdominal region is located superior to the umbilical region? Answer: Epigastric.
Pretest (16 of 20): The depressed area in front of the elbow is called the: Answer: Ante-cubital (antecubital).
Pretest (18 of 20): The plantar region is located in the: Answer: Sole of the foot.
Pretest (20 of 20): In which body region are the buttocks located? Answer: Gluteal.
Post-Test (2 of 20): What position is characterized by standing erect, face forward, palms forward, arms at sides, feet parallel? Answer: Anatomical.
Post-Test (4 of 20): Which term describes being able to breathe easier in an upright position? Answer: Orthopnea.
Post-Test (6 of 20): Which plane divides the body into upper and lower portions? Answer: Transverse.
Post-Test (8 of 20): Sudden obstruction of a blood vessel by debris is known as: Answer: Embolism.
Post-Test (10 of 20): Which cavity contains the digestive organs? Answer: Abdominopelvic cavity.
Post-Test (12 of 20): Which vertebrae are located in the chest? Answer: Thoracic.
Post-Test (14 of 20): Which region contains the lower ribs? Answer: Hypochondriac.
Post-Test (16 of 20): Which region houses the navel? Answer: Umbilical.
Post-Test (18 of 20): Necrosis means: Answer: Tissue death.
Post-Test (20 of 20): Tenderness in which quadrant can indicate appendicitis? Answer: Right Lower Quadrant (RLQ).
Note: This collection consolidates the main ideas and details from the provided transcript, organized into a comprehensive study aid with clear definitions, clinical correlations, regional mappings, and evaluative Q&A to support exam preparation.