Anatomical Positions and Planes

Anatomical Position

• Standing upright
• Head and eyes directed straight ahead
• Upper limbs at the sides, slightly away from the trunk
• Palms facing forward
• Thumbs pointing away from the body
• Lower limbs parallel
• Feet flat on the ground and facing forward

Anatomical Planes

• Sagittal plane: Divides the body into left and right halves
• Coronal plane: Divides the body into front and back halves
• Transverse plane: Divides the body into upper and lower halves
• Superior: Towards the head
• Inferior: Towards the feet
• Anterior: Towards the front
• Posterior: Towards the back
• Medial: Towards the midline of the body
• Lateral: Away from the midline of the body
• Proximal: Closer to the point of attachment
• Distal: Farther from the point of attachment

Anatomical Terms of Position

• Median: In the middle plane
• Medial: Closer to the median plane
• Lateral: Farther from the median plane
• Superior: Above
• Inferior: Below
• Anterior: Front
• Posterior: Back
• Superficial: Closer to the surface
• Deep: Farther from the surface
• Internal: Inside an organ or cavity
• External: Towards the outside of an organ

Terms of Position Continued

• Anterior: Nearer to the front
• Posterior: Nearer to the back
• Superficial: Nearer to the surface
• Deep: Farther from the surface
• Internal: Inside an organ or cavity
• External: Towards the outer aspect of an organ

Terms of Position (Continued)

• Proximal: Closer to the trunk
• Distal: Farther from the trunk
• Ipsilateral: Same side of the body
• Contralateral: Opposite side of the body

The Skeleton

• Divided into two parts: axial and appendicular
• Axial skeleton: Skull, vertebral column, ribs, and sternum (thorax)
• Appendicular skeleton: Shoulder girdle, arms, hands, pelvic girdle, legs, and feet

Skull

• Consists of 22 bones
• 21 fixed bones and 1 moveable (mandible)

Thoracic Cage

• Sternum
• 12 ribs
  • 7 true ribs
  • 3 false ribs
  • 2 floating ribs

Vertebral Column

• Composed of separate bones called vertebrae
• 7 cervical
• 12 thoracic
• 5 lumbar
• 5 sacrum
• 2-4 coccygeal

Cervical Vertebrae

• Typical (C3-C6):
  • Transverse process with foramen
  • Transverse foramina
  • Bifid spine
• Atlas (C1): No body
• Axis (C2): Odontoid process (dens)
• Seventh Cervical Vertebra (C7): Long, non-bifid spine

Thoracic Vertebrae

• 12 in number
• Each has a body, pedicle, transverse process, lamina, spine, vertebral foramen, and articular processes.
• Atypical vertebrae: T1, T10, T11, and T12 have variations

Typical Rib (3rd-9th)

• Head
• Neck
• Tubercle
• Costal groove
• Inner surface
• Upper border
• Lower border
• Anterior end (concave)
• Rib angle
• Two articular demifacets separated by a crest

Atypical Ribs

• First rib
• Second rib
• Floating ribs

Sternum

• Formed from 3 parts: manubrium, body, and xiphoid process
• Junction between manubrium and body is called sternal angle, a disc between T4 & T5
• Articulates with clavicles and upper 7 costal cartilages

Lumbar Vertebrae

• 5 in number
• 5th lumbar vertebra (atypical): Larger body, bulky, thick and attached transverse processes to the whole pedicle forming a wide base

Upper Limb Bones

• Shoulder girdle: Clavicle (ventral), Scapula (dorsal)
• Arm: Humerus
• Forearm: Radius (lateral), Ulna (medial)
• Hand: Carpals, metacarpals, phalanges

Lower Limb Bones

• Pelvic girdle: Hip bone
• Thigh: Femur
• Leg: Tibia (medial), Fibula (lateral)
• Foot: Tarsals, metatarsals, phalanges