Body organization · Topic 1 of 18

Directional Terms, Planes, Cavities & Regions

Directional Terms & Body Planes

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Anatomy · body map

Directional Terms & Body Planes

Describe every location from anatomical position, using paired opposite terms, and name a cut by the plane it follows.

01 · Reference postureUpright, face forward, palms forward

02 · On a limbProximal = near trunk · distal = far

03 · PlanesSagittal = right | left

What it is

Anatomical position: upright, facing forward, palms forward must know

Superior (cranial) = above; inferior (caudal) = below must know

Anterior (ventral) = front; posterior (dorsal) = back must know

Medial = toward the midline; lateral = toward the side must know

Proximal = nearer the trunk; distal = farther from it (on a limb) must know

Supine = lying face up; prone = lying face down

Superficial = toward the surface; deep = away from the surface

Plane = imaginary flat surface; section = the cut along it

Sagittal plane = right | left (midsagittal = equal halves)

Frontal (coronal) plane = front | back

Transverse (horizontal) plane = top | bottom → cross section

The rules

Terms always assume anatomical position, whatever the real pose

Worked examples

Knee is proximal to ankle; fingers are distal to elbow

Palms forward: thumb is lateral, little finger is medial

Skin is superficial to muscle; bone is deep to muscle

Sagittal or frontal plane?

Commonly confused

	Sagittal	Frontal (coronal)
Runs	Vertically, front to back	Vertically, side to side
Divides the body into	Right and left parts	Anterior (front) and posterior (back) parts
Special cases	Midsagittal (median) = equal halves; parasagittal = unequal	—
Other name	Median plane when it runs down the midline	Coronal plane

Mix-ups to avoid

Trunk positions use superior/inferior, not proximal/distal

More detail

Show 3 more facts

Oblique plane = a cut at an angle to the three main planes

CT slices are mostly transverse; MRI can use any of the three planes

Terms come from Latin/Greek roots, so their meanings stay fixed

Pearl

Proximal is close to the trunk, distal is distant from it.

Sources · OpenStax Anatomy and Physiology 2e §1.6 Anatomical Terminology · NCI SEER Training — Anatomical Terminology · LibreTexts — Human Anatomy Laboratory Manual (Hartline) 1.3 Directional Terms · LibreTexts — Human Anatomy Laboratory Manual (Hartline) 1.4 Planes/Sections · Union Test Prep — HESI Anatomy and Physiology study guide, page 1 (body planes, directions, cavities) · Built from the verified NurseSavvy HESI A2 fact map (facts reviewed 2026-10-16). HESI is a trademark of Elsevier; NurseSavvy is not affiliated with Elsevier.

Body Cavities, Regions & Quadrants

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Anatomy · cavities & regions

Body Cavities, Regions & Quadrants

Dorsal and ventral cavities hold the organs; the diaphragm splits the ventral cavity; the abdomen maps into four quadrants or nine regions.

01 · The dividerDiaphragm: thoracic | abdominopelvic

02 · QuadrantsRUQ · LUQ · RLQ · LLQ

03 · Regional termsAntecubital = front of elbow

What it is

Antecubital = front of elbow; popliteal = back of knee

Axillary armpit · brachial upper arm · antebrachial forearm · carpal wrist

Femoral thigh · patellar kneecap · crural shin · tarsal ankle · pedal foot

Cephalic head · cervical neck · thoracic chest · inguinal groin

Parts & jobs

Two main cavities: dorsal (back) and ventral (front) must know

Dorsal = cranial cavity (brain) + spinal cavity (spinal cord) must know

Ventral = thoracic + abdominopelvic, split by the diaphragm must know

4 quadrants (RUQ, LUQ, RLQ, LLQ) meet at the umbilicus must know

Thoracic: lungs in pleural cavities, heart in the pericardial cavity

Abdominal: digestive organs; pelvic: bladder, reproductive organs

RUQ: liver, gallbladder; LUQ: stomach, spleen, pancreas

RLQ: appendix (plus right ureter, right ovary and tube)

9 regions: two horizontal × two vertical lines, a 3 × 3 grid

Middle column: epigastric → umbilical → hypogastric

Side columns: hypochondriac → lumbar → iliac (R and L)

Four quadrants or nine regions?

Commonly confused

	4 quadrants	9 regions
Lines drawn	1 vertical + 1 horizontal, crossing at the umbilicus	2 vertical + 2 horizontal (below the ribs, above the pelvis)
Detail	Simpler; used more often clinically	More detailed
Names	RUQ, LUQ, RLQ, LLQ	Epigastric, umbilical, hypogastric + hypochondriac, lumbar, iliac (R and L)
Center	Lines meet at the navel	Umbilical region is the middle square

Mix-ups to avoid

Right/left = the patient's right/left, not the viewer's

More detail

Show 6 more facts

Abdominopelvic cavity is the largest; no wall splits abdomen from pelvis

Serous membrane: parietal lines the wall, visceral covers the organ

LLQ: left ureter, left ovary and tube, loops of bowel

Scapular · vertebral · lumbar (lower back) · sacral · gluteal (buttock)

Anatomical "arm" = shoulder to elbow; "leg" = knee to ankle

Olecranal back of elbow · sural calf · calcaneal heel · buccal cheek

Pearl

Antecubital is in front of the elbow; popliteal is behind the knee.

Sources · OpenStax Anatomy and Physiology 2e §1.6 Anatomical Terminology · LibreTexts — Human Anatomy Laboratory Manual (Hartline) 1.5 Anatomical Adjectives for Body Locations · LibreTexts — Human Anatomy Laboratory Manual (Hartline) 1.6 Abdominopelvic Regions and Quadrants · LibreTexts — Medical Terminology 2e (Open RN) 2.4 Body Regions · LibreTexts — Human Anatomy Laboratory Manual (Hartline) 1.8 Body Cavities · NCI SEER Training — Anatomical Terminology (body cavities) · Union Test Prep — HESI Anatomy and Physiology study guide, page 1 (body cavities) · NurseHub — HESI A2 Anatomy & Physiology course: General Terminology lessons (incl. divisions of the abdomen) · Built from the verified NurseSavvy HESI A2 fact map (facts reviewed 2026-10-16). HESI is a trademark of Elsevier; NurseSavvy is not affiliated with Elsevier.

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