Anatomical Position and Terms

Anatomical Position

• Standing upright, with head and eyes directed straight ahead.
• Upper limbs are at the sides, slightly away from the trunk.
• Palms face forward.
• Thumbs point away from the body.
• Lower limbs are parallel.
• Feet are flat on the ground and facing forward.
• The body is assumed to be standing
• Head, eyes, and toes directed anteriorly (forward).
• Upper limbs by the sides with the palms facing anteriorly.
• Lower limbs close together with the feet parallel and the toes directed anteriorly.

Anatomical Terms

• Anterior (frontal): Towards the front.
• Posterior (dorsal): Towards the back.
• Superior: Towards the head.
• Inferior: Towards the feet.
• Proximal: Closer to the root (e.g., the elbow is proximal to the wrist on the upper extremity).
• Distal: Away from the root (e.g., the elbow is distal to the shoulder joint on the upper extremity).
• Median: A point or area on the midsagittal plane (median plane).
• Medial: A point or area that is closer to the midsagittal plane than another.
• Lateral: A point or area that is more distant from the mid-sagittal or median plane. For example the outer side of the elbow is lateral when compared with the inner side.

Planes of the Body

• Frontal or Coronal Plane: Divides the body into anterior and posterior portions.
• Transverse Plane: Divides the body or limbs into upper and lower parts.
• Median (midsagittal) Plane: Vertical plane passing longitudinally through the center of the body, dividing it into right and left equal halves.
• Sagittal Planes: Vertical planes passing through the body parallel to the median plane.

Skin

• The skin is the outside covering of body tissue, accounts for 12% of body weight.
• Epidermis: most superficial layer, a cellular layer which creates a tough protective outer surface.
• Dermis: a basal (deep) layer.

Fascia

• Connective tissue that surrounds muscles, blood vessels, and nerves, binding those structures together.
• Consists of a superficial fascia and a deep fascia.

Systemic Anatomy

• Body system = group of organs that work together to carry out a particular function.
• The skeletal system consists of bones and cartilage.
• The articular system consists of joints.
• The Muscular system
• The cardiovascular system.
• The respiratory system.
• The digestive system.
• The urinary system
• The reproductive system
• The nervous system.
• The endocrine system

Skeletal System

• Axial skeleton: bones of the head (skull), neck (cervical vertebrae), and trunk (ribs, sternum, vertebrae, and sacrum).
• Appendicular skeleton: bones of the limbs (upper and lower), including those forming the pectoral (shoulder) and pelvic girdles.
• An adult human skeleton is made up of 206 bones and 32 teeth.

Bone

• Bone is a living tissue that is a highly specialized hard form of connective tissue that makes up most of the skeleton.
• Functions of Bones:
  • Protection for vital structures.
  • Support for the body.
  • The mechanical basis for movement.
  • Storage for salts (e.g., calcium).
  • A continuous supply of new blood cells (produced by the marrow within many bones).

Cartilage

• A semi-rigid connective tissue where more flexibility is necessary. (e.g., the costal cartilages that attach the ribs to the sternum).

Types of Bones in the Human Body

• Long bones: bones that are longer than they are wide. Examples include:
  • Clavicle, Humerus, Radius, Ulna, metacarpal and phalanges bones of the upper limbs.
  • Femur, Tibia, Fibula, metatarsals and phalanges bones of the lower limbs.
• Short bones: bones that are as wide as they are long. Examples include carpal bones in the hand and tarsal bones in the foot.
• Flat bones: examples include the scapula (shoulder blade), sternum (breast bone) and cranium (skull).
• Irregular bones: bones that do not fall into any other category due to their non-uniform shape. Examples include the vertebrae and sacrum.
• Sesamoid bones: usually short or irregular bones, imbedded in a tendon. The most obvious example of this is the patella (knee cap).
• Sesamoid bones are usually present in a tendon where it passes over a joint to protect the tendon.
• Pneumatic bones: are bones which contain air filled cavities as bones enclosing paranasal sinuses.

Axial Skeleton Details

• Skull
  • Consists of 22 bones: 8 cranial bones or brain base and 14 facial bones.
  • Encases and protects the brain and organs of special sense (organs of vision, hearing, balance, taste and smell).
• Vertebral column
  • Consists of 33 vertebrae which are named according to their region and position, from top to bottom.
  • Cervical: 7 vertebrae (C1-C7).
  • Thoracic: 12 vertebrae (T1-T12).
  • Lumbar: 5 vertebrae (L1-L5).
  • Sacrum: 5 (fused) sacral vertebrae (S1-S5).
  • Coccyx: 4 (3-5) (fused) coccygeal vertebrae (tailbone).
  • Vertebrae are separated from each other by intervertebral discs.
• Thoracic cage: consists of thoracic vertebrae, 12 pairs of ribs, the sternum, and the costal cartilages (that attach the ribs to the sternum).

Appendicular Skeleton

• Upper Limb: composed of the shoulder girdle, arm, forearm and hand.
• Bones of the Shoulder Girdle: the scapula and clavicle.
• Clavicle: a long bone with a shaft and two ends.
  • Medial (sternal) end: articulates with the sternum to form the sternoclavicular joint.
  • Lateral (acromial) end: articulates with the acromion of scapula to form the acromioclavicular joint.
• Scapula: flat and triangular in shape with three borders (superior, medial, and lateral), two surfaces (anterior and posterior), and two processes (acromion and coracoid process).
  • Glenoid cavity: It lies on the lateral angle to articulate with the head of the humerus to form the shoulder joint.
• Humerus: the bone of the arm with a shaft and two ends.
  • Upper (proximal) end: contains the Head which is an articular smooth surface that enters in the formation of the shoulder joint.
  • Lower (distal) end: consists of the trochlea and capitulum, both of which share in the elbow joint.
• Tibia: a long bone with a shaft and two ends. -Upper end: composed of 2 condyles (medial and lateral) articulate with the 2condyles of femur in the knee joint. -Lower end: It articulates with the tarsal bones below, to form the ankle joint.
• Fibula: a long bone with a shaft and two ends.