Anatomical Planes and Directions Anatomical Position Definition A

Anatomical Planes and Directions

Anatomical Position � Definition: A reference position that gives meaning to the directional terms used to describe the body parts and regions � The body is in a standing posture with the arms at the sides, palms turned forward, feet together and pointed forward, and head pointed forward

Midline Definition: A reference line extending down the middle of the body, encompassing the vertebral column, spinal cord, and naval

Body Planes Used to cut the body into smaller sections in order to facilitate study of body cavities, organs, systems, etc. Especially useful in medical imaging studies

Median Plane Definition: The midline, longitudinal plane dividing the head and torso into equal right and left halves The middle sagittal plane Encompasses the vertebral column and spinal cord

Sagittal Plane Definition: The longitudinal plane dividing the body into left and right parts Parallel to the median plane and may be applied to the head, torso, and limbs Not limited to the midline

Frontal (Coronal) Plane Definition: The longitudinal plane dividing the body into equal or unequal front and back parts The term “coronal” is used by radiologists in reference to MRIs and CT scans

Transverse Plane Definition: The horizontal plane that divides the body or body parts into upper and lower segments A cross section perpendicular to the longitudinal planes

Craft Time!!!!! Construct a plane model ◦ No, not a paper airplane… A 3 -D model of the body planes, like this: ◦ Color-code it and label it to help you identify the planes

Left Definition: To the left side of the midline References the subject’s left, not your left Example: The stomach is to the left of the liver

Right Definition: To the right side of the body or structure being studied Example: The right lung is bigger than the left lung

Lateral Definition: Toward the side; away from the midline Example: The eyes are lateral to the nose

Medial Definition: Toward the midline: away from the side Example: The eyes are medial to the ears

Anterior Definition: Toward the front of the body Example: The nose is on the anterior side of the head

Posterior Definition: Toward the back of the body Example: A mullet is long on the posterior side of the body

Superior Definition: Toward the top of the body Example: The shoulders are superior to the hips

Inferior Definition: Toward the bottom of the body Example: The liver is inferior to the heart

Dorsal Definition: Along (or toward) the vertebral surface of the body Example: The SI joints are on the dorsal surface

Ventral Definition: Along (toward) the belly surface of the body Example: The naval is on the ventral surface

Caudal Definition: Toward the tail Example: The neck is caudal to the skull

Cephalad Definition: Toward the head Example: The neck is cephalad to the tail

Proximal Definition: Toward the trunk Describes relative position in a limb or other appendage Example: The joint is proximal to the toenail

Distal Definition: Away from the trunk or point of attachment Example: The hand is distal to the elbow

Visceral Definition: Toward an internal organ; away from the outer wall Describes positions inside a body cavity Example: The organ is lined with the visceral layer of the membrane

Parietal Definition: Toward the wall; away from internal structures Example: The abdominal cavity is lined with the parietal peritoneal membrane

Deep Definition: Toward the inside of a part; away from the surface Example: The thigh muscles are deep to the skin

Superficial Definition: Toward the surface of a part; away from the inside Example: The skin is a superficial organ

Medullary Definition: Refers to an inner region, or medulla Example: The medullary cavity is where bone marrow is produced

Cortical Definition: Refers to the outer region, or cortex Example: Cortical bone covers the external surface of the bone

Intrinsic Definition: Inherent or inside Example: The lumbricals are intrinsic hand muscles Example: An intrinsic motivation is doing something because it makes you happy

Extrinsic Definition: Outer or from the outside Example: The thumb flexor muscle is an extrinsic hand muscle Example: An extrinsic motivation for doing something is monetary compensation

Valgus Definition: An angulation outward and away from the midline of the body, as exhibited by the distal segment of the bone or joint Example: Someone who is knock-kneed has valgus of the ankles

Varus Definition: An angulation inward and toward the midline of the body, as exhibited by the distal segment of the bone or joint Example: Someone who is bow-legged has varus of the ankles

Ipsilateral Definition: Situated on or affecting the same side of the body Example: The right eye and the right ear are ipsilateral body parts

Contralateral Definition: Situated on or affecting the opposite side of the body Example: The eyes are on contralateral sides of the head