Anatomy: Anatomical Position, Planes, Directions, and Body Regions – Study Notes

Anatomic Position

Provides a common reference frame for describing anatomy
Standing upright with feet parallel and on the floor
Head level and looking forward
Arms at sides with palms facing forward and thumbs pointing away from the body
Always use correct anatomical position when describing structures
Copyright note indicates source: McGraw-Hill Education (not needed for study content)

Purpose: give the relative position or direction of one body structure to another
Terms are paired and opposite
- Anterior/ventral = toward front or belly
- Posterior/dorsal = toward back
- Example: The heart is posterior to the sternum
Superior vs. inferior
- Superior = toward the head
- Inferior = toward the feet
Caudal vs. cranial
- Caudal = toward the tail
- Cranial = toward the head
Medial vs. lateral
- Medial = toward the midline
- Lateral = away from the midline
Ipsilateral vs. contralateral
- Ipsilateral = same side
- Contralateral = opposite side
Deep vs. superficial
- Deep = internal
- Superficial = external
Proximal vs. distal
- Proximal = close to the trunk
- Distal = far from the trunk
Describes limb anatomy relative to the point of attachment
Practical note: these terms enable precise communication in clinical and educational contexts

Sections vs. planes
- Section: an actual cut or slice through a structure
- Plane: an imaginary flat surface passing through the body or a structure
Purpose: to visualize internal and 3-D relationships

Coronal (frontal) plane: divides body into anterior (front) and posterior (back) parts
Transverse (horizontal) plane: divides body into superior (upper) and inferior (lower) parts
Sagittal plane: divides body into left and right portions
Midsagittal (median) plane: left and right portions are equal
- ext{Left portion} = ext{Right portion}
Parasagittal planes: divide the body into unequal left and right parts
Oblique plane: passes through the specimen at an angle
Visuals often show examples of coronal, transverse, and midsagittal sections

Two main body regions: axial and appendicular
- Axial region: head, neck, and trunk
- Appendicular region: upper and lower limbs (appendages)
Several more specific regional terms describe areas within these subdivisions

Nasal — Nose
Oral — Mouth
Cervical — Neck
Deltoid — Shoulder
Axillary — Armpit
Brachial — Arm
Antecubital — Front of elbow
Antebrachial — Forearm
Coxal — Hip
Carpal — Wrist
Palmar — Palm
Digital — Finger
Femoral — Thigh
Patellar — Patella (kneecap)
Cephalic — Head
Frontal — Forehead
Orbital — Eye
Buccal — Cheek
Mental — Chin
Sternal — Sternum (center of chest)
Pectoral — Chest
Mammary — Breast
Cranial — Skull
Auricular — Ear
Thoracic — Chest region (includes pectoral, axillary, sternal areas)
Vertebral — Spinal column
Occipital — Back of head
Inguinal — Groin
Pelvic — Pelvis
Pubic — Pelvic region (anterior)
Gluteal — Buttock
Perineal — Diamond-shaped region between thighs (anus and external reproductive organs)
Dorsum (of the hand/foot) — Back of the hand; Dorsum of the foot is the top/front of the foot
Manus — Hand
Digits (Phalanges) — Fingers or toes
Dorsal — Back
Sacral — Sacral region
Hallux — Great toe
Tibial — Medial aspect of the leg
Fibular (peroneal) — Lateral aspect of the leg
Calcaneal — Heel
Tarsal — Ankle
Plantal (Plantar) — sole of the foot
Pes — Foot
Radial — Lateral aspect (thumb side) of the forearm
Ulnar — Medial aspect (pinky side) of the forearm
Umbilical — Navel
Pollex — Thumb
Note: Some regions have overlapping or region-bearing descriptions (e.g., “Mammary” is part of chest)

Thoracic:
- Axillary (armpit)
- Mammary (breast)
- Pectoral (chest)
- Sternal (sternum)
Abdominal (abdomen)
Pelvic (hip)
Inguinal (groin)

“The word region should follow each region name listed in the table” (Table 1.3 format)
Some regions have synonymous or alternate names (e.g., dorsum, dorsal; fibular vs. peroneal; ulna vs. ulnar references)
The table provides descriptions for each region, e.g.,
- Abdominal: Region inferior to the thorax and superior to the pelvic brim of the hip bones
- Inguinal: Groin (creas in the junction of the thigh with the trunk)
- Perineal: Diamond-shaped region between the thighs containing the anus and external reproductive organs
Notable paired descriptors:
- Medial vs. lateral; proximal vs. distal (as in limbs)
- Ipsilateral vs. contralateral (same vs. opposite side)
- Anterior vs. posterior; superior vs. inferior; caudal vs. cranial

Axial vs. Appendicular designation helps organize clinical anatomy and imaging plans
Planes and sections are practical tools for radiology (CT, MRI) and surgical planning
Consistent nomenclature reduces miscommunication in medical settings

Anatomical position is the universal reference posture
Planes divide the body into standard views: coronal (anterior/posterior), transverse (superior/inferior), sagittal (left/right)
Midsagittal plane is the equal division; parasagittal planes are unequal divisions; oblique is angled
Major body regions are grouped into axial versus appendicular, with explicit regional terms for head, trunk, limbs, and their subregions
Many regional terms reflect common locations (e.g., occipital = back of head; frontal = forehead; calcaneal = heel; plantar = sole)