Anatomical Language and Body Planes

• XY1040 covers anatomical language and body planes

Anatomical language:

• Studying anatomy is like learning a new language due to its basis in ancient Latin and Greek.
• The Latin and Greek languages have English equivalents for all the anatomical terms.
• Many Latin-based words are similar to their English counterparts, while some are completely different.

Definitions:

• Standard/norm: a set of characteristics occurring most often
• Variation: a small deviation from the standard without any functional changes
• Anomaly: a significant deviation from the standard causing functional changes

Normal anatomical position:

• The body is standing upright.
• Feet are at shoulder width and parallel, with toes pointing forward.
• The upper limbs are held out to each side.
• Palms of the hands face forward.

Overview of the skeleton:

• Axial skeleton: skull (cranium), vertebral column (spine), thorax (chest), ribs (costae), sternum (breastbone)
• Appendicular skeleton: skeleton of the limbs, bones of the lower limb

Body Planes:

• Three major groups of planes pass through the body in the anatomical position
• Frontal/coronal planes: oriented vertically, divides the body into anterior and posterior parts
• Sagittal planes: oriented vertically, but are at right angles to the coronal planes, divides the body into right and left parts, the median sagittal plane dividing the body equally
• Transverse/horizontal planes: divides the body into superior and inferior parts

Lines of the Body:

• Anteriormedianline (lineamedianaanterior): runs vertically through the center of the thorax and abdomen
• Sternalline (lineasternalis): runs vertically along the lateral side of the sternum
• Parasternalline (lineaparasternalis): runs vertically between the sternal and midclavicular lines
• Midclavicularline (lineamedioclavicularis): runs vertically through the midpoint of the clavicle
• Anterioraxillaryline (lineaaxillarisanterior): runs vertically through the anterior axillary skin fold
• Midaxillaryline (lineaaxillarismedia): runs vertically through the apex of the axilla
• Posterioraxillaryline (lineaaxillarisposterior): runs vertically through the posterior axillary skin fold
• Scapularline (lineascapularis): runs vertically through the middle of the inferior angle of the scapula
• Paravertebralline (lineaparavertebralis): runs vertically along the side of the vertebral column
• Posteriormedianline (lineamedianaposterior): runs vertically through the middle of the vertebral column, passing through the spinous processes of the vertebrae

Body cavities:

• Cranial cavity: contains the brain; created by the cranial bones
• Thoracic cavity: contains the lungs and heart; enclosed by the rib cage and diaphragm
• Abdominopelvic cavity: the largest cavity is divided into the abdominal and pelvic cavities; the abdominal cavity contains digestive organs; the pelvic cavity contains organs of reproduction

Quadrants of the Abdomen:

• The abdomen is divided into 4 quadrants: right upper, left upper, right lower, and left lower.

Regions of the Abdomen:

• The abdomen is divided into 9 regions: right hypochondriac, epigastric, left hypochondriac, right lumbar, umbilical, left lumbar, right iliac, hypogastric, and left iliac.

Anatomical Terminology:

• Anterior (ventral): To the front / in front of
• Posterior (dorsal): To the back / behind
• Superior: Above
• Cranial: towards the cranium
• Inferior: Below
• Caudal: towards the feet
• Lateral: Away from the midline
• Medial: Towards the midline
• Distal: Further away from the trunk or origin
• Proximal: Closer to the trunk or origin
• Superficial: Closer to the surface of the skin
• Deep: Further away from the surface of the skin
• Ascending: leading upwards
• Transverse: direction that is at an angle of 90°
• Descending: going downwards

Anatomical Terminology - Movements:

• Adduction: returning a body part to its normal resting position
• Abduction: moving a body part away from its resting anatomical position
• Extension: increasing the joint angle
• Flexion: decreasing a joint angle
• Internal rotation: rotating a joint towards the midline
• External rotation: rotating a joint away from the midline
• Elevation: refers to lifting
• Depression: refers to lowering
• Circumduction: compound movement at ball and socket joints, combination of flexion, abduction, extension, and adduction, circular motion
• Supination: rotation of the forearm and hand until the hand palm points ventrally, the radius and ulna lie parallel to each other in complete supination
• Pronation: rotation of the forearm and hand results in the palm pointing dorsally, the radius crosses over the ulna during pronation

Osteology:

• The study of bone (osseous) tissue, a type of connective tissue characterized by a hard mineralized ground substance, collagen fibers, and specialized cells.
• Provides structural, supportive, and protective functions.

Anatomical classification of bones:

Based on their shape and length on gross appearance

• Long: examples femur, tibia, humerus
• Irregular: examples vertebra, maxilla, and temporal bone
• Flat: examples sternum and scapula
• Short: examples carpal and tarsal bones

Bone as an organ:

• Long bones have two parts: diaphysis and epiphysis
• The articular surface of the epiphysis is covered with hyaline cartilage
• The epiphysis is filled with red bone marrow
• Between the epiphysis and diaphysis lies the metaphysis, including the epiphyseal plate (growth plate)
• The hollow region in the diaphysis is called the medullary cavity, which is filled with yellow marrow in adults

Depressions and openings:

• Foramen (plural: foramina): an opening for the passage of blood vessels and/or nerves
• Fossa: a shallow depression or cavity
• Meatus: a tube-like passageway within a bone
• Notch: a depression from one side of a bone to another
• Sinus: a recess, cavity, or hollow air-filled space within a bone

Raised features:

• Crest: a prominent border or ridge
• Epicondyle: a smaller projection situated above a condyle
• Linea: a narrow, line-like ridge (less prominent than a crest)
• Process: a prominent projection of a bone
• Ramus (plural: rami): a branch-like process
• Spine: a sharp, slender ridge
• Trochanter: a relatively large, blunt projection of bone (found only on the femur)
• Tubercle: a small, knob-like process (usually smoother than a tuberosity)
• Tuberosity: a larger, roughened, knob-like process or thickened area of a bone

Muscular terms:

• Ligament: a band of connective tissue that connects bones to each other.
• Tendon: a band of connective tissue that connects muscles to bones.
• Aponeurosis: a broad, flat sheet of connective tissue that anchors a muscle or connects a muscle to the part it moves.
• Origin: the point of attachment of a muscle that moves the least when the muscle is contracted.
• Insertion: the point of attachment of a muscle that moves the most when the muscle is contracted.
• Fascia: a sheet of connective tissue that encases structures or acts as a separation between different layers of tissue.

Joints:

• The sites where two skeletal elements come together are termed joints.
• Two general categories of joints: Synovial and solid joints.
• Synovial joints: skeletal elements separated separated by a cavity.
• Solid joints: no cavity exists, components held together by connective tissue.