Anatomical Position and Terms

• Anatomical position: standing upright, head and eyes directed straight ahead, upper limbs at the sides, slightly away from trunk, palms facing forward, thumbs pointing away from the body, lower limbs parallel, feet flat on the ground and facing forward

Anatomical Position Details

• Body assumed to be standing in the anatomical position
• Head, eyes, and toes directed anteriorly (forward)
• Upper limbs are positioned by the sides with palms facing anteriorly
• Lower limbs are close together with feet parallel and 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; for example, the elbow is proximal to the wrist on the upper extremity
• Distal: Away from the root; for example, 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 closer to the midsagittal plane than another
• Lateral: A point or area more distant from the midsagittal or median plane; for example, the outer side of the elbow is lateral compared to 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: A 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

• Skin is the outside covering of body tissue, accounting for 12% of body weight
• Epidermis: A superficial cellular layer, creating a tough protective outer surface
• Dermis: A basal (deep) layer

Fascia

• Fascia: Connective tissue that surrounds muscles, blood vessels, and nerves, binding those structures together
• Superficial fascia and a deep fascia

Systemic Anatomy

• Body system: group of organs working together to carry out a particular function

Skeletal System

• Skeletal system consists of bones and cartilage
• Articular system consists of joints
• Muscular system, cardiovascular system, respiratory system, digestive system, urinary system, reproductive system, nervous system, endocrine system

Skeletal System Parts

• 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 pectoral (shoulder) and pelvic girdles

Bone

• Bone: Living tissue, a highly specialized hard form of connective tissue
• Functions of bones: protection for vital structures, support for the body, mechanical basis for movement, storage for salts (e.g., calcium), and a continuous supply of new blood cells

Cartilage

• Cartilage: Semi-rigid connective tissue, more flexibility (e.g., costal cartilages attaching ribs to sternum)

Types of Bones in the Human Body

• Six types of bones are present in the human body.

Long Bones

• Long Bones (bones of limbs).
• They are longer than they are wide.
• Examples include clavicle, humerus, radius, ulna, metacarpals and phalanges (upper limbs) and femur, tibia, fibula, metatarsals and phalanges (lower limbs)

Short Bones

• As wide as they are long
• Examples include carpal bones in the hand and tarsal bones in the foot

Flat Bones

• A classic example is the scapula (shoulder blade) as well as the sternum (breast bone), 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, embedded in a tendon
• An example is the patella (knee cap)
• Present in a tendon where it passes over a joint to protect the tendon

Pneumatic Bones

• Bones which contain air filled cavities
• The bones enclosing paranasal sinuses

Adult Human Skeleton

• Adult Human Skeleton is made up of 206 Bones and 32 teeth

Axial Skeleton details

• The Skull: 22 bones; cranial bone or brain base (8) and facial bones (14)
• The protects the brain and organs of special sense (organs of vision, hearing, balance, taste and smell)
• Vertebral column: 33 vertebrae, named according to region and position, from top to bottom

Vertebral column breakdown

• 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)

Ribs

• First seven pairs "true ribs", ribs 8-10 "false ribs", pairs 11 and 12 are "floating ribs"

Appendicular Skeleton

• Upper Limb: composed of the shoulder girdle, arm, forearm, and hand
• Shoulder girdle: scapula and clavicle (together, these 2 bones surround the upper part of the shoulder like a belt)

Clavicle

• Has a shaft and two ends (medial and lateral)
• 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 shape, three borders (superior, medial, lateral), two surfaces (anterior and posterior), two processes (acromion and coracoid)
• Glenoid cavity: lies on the lateral angle to articulate with the head of the humerus to form the shoulder joint

Humerus

• Like any long bone, has a shaft and two ends
• Upper-end contains the Head which is an articular smooth surface that enters in the formation of the shoulder joint
• Lower-end: consists of the trochlea and capitulum, both of which share in the elbow joint

Tibia

• Like any long bone, has a shaft and two ends
• Upper-end: composed of 2 condyles (medial/lateral) articulate with the 2 condyles of the femur in the knee joint
• Lower end: articulates with the tarsal bones below, to form the ankle joint
• Fibula: Like any long bone, fibula has a shaft and two ends
• Lower End: Expanded, consists of medial and lateral condyles that articulate with the condyles of the tibia in the knee joint