Review of Axial and Appendicular Skeletons

The Skull Make up of the skull- 22 bones –8 cranial bones –13 facial bones –mandible

The Cranium Encloses and protects the brain, provides attachments for muscles and contains air-filled sinuses that reduce its weight The frontal bone contains the supraorbital foramina and frontal sinuses Parietal bones lie at the sides of the skull and join at the sagittal suture

The Cranium The occipital bone includes the lamboidal suture, foramen magnum and the occipital condyles The temporal bone includes the squamosal suture, external auditory meatus, mandibular fossae, mastoid process, styloid process and zygomatic process

The Cranium The winged sphenoid bone includes the sella trucica and sphenoid sinuses The ethmoid bone includes the cribriform plates, a perpendicular plate, superior and middle nasal conchae, ethmoidal sinuses and the crista galli

The Face Made up of 13 immovable facial bones and the mandible Provide attachments for muscles of mastication and expression

The Face The maxillae form the upper jaw, hard palate, floor of the orbits, sides of the nasal cavity, house the upper teeth and contain large maxillary sinuses Palatine bones are L-shaped bones located behind the maxillae that form the floor of the nasal cavity and hard palate

The Face Zygomatic bones make up the cheekbones and join with the temporal bones to form the zygomatic arches The lacrimal bones form part of the medial walls of the orbits Nasal bones form the bridge of the nose The vomer bone makes up a portion of the nasal septum

The Face Inferior nasal conchae are fragile, scroll- shaped bones that support mucous membrane within the nasal cavity The mandible or lower jaw supports the lower teeth and includes a mandibular condyle, coronoid process and alveolar arch

Infantile Skull Incompletely developed and features fontanels or soft spots to aid passage through the birth canal Includes a small face with a prominent forhead and large orbits

Vertebral Column Typical Vertebrae –Have a drum-shaped body that supports weight –Pedicels, laminae, spinous processes and vertebral arch extend from the body and surround the vertebral foramen –Articulating surfaces include: superior and inferior articulating processes and transverse processes which provide points of attachment for muscles –Intervertebral foramina provide passageways for spinal nerves

Cervical Vertebrae Seven bones that are the smallest of the vertebrae and comprise the neck and head The 1st is the atlas which appears as a bony ring and supports the head The 2nd is the axis, with its tooth-like dens that pivots within the atlas Bifid spinous processes and transverse foramina separate cervical vertbrae from the others

Thoracic & Lumbar Vertebrae There are 12 thoracic vertebrae that articulate with the ribs These are larger and stronger than cervical vertebrae The lumbar vertebrae are made up of 5 massive vertebrae that support the weight of the body

Sacrum and Coccyx The sacrum is a triangular structure at the base of the vertebral column and is made up of 5 vertebrae fused into 1 bone The spinous processes fuse to form a ridge of tubercles that have dorsal sacral foramina along their sides The ventral surface has 4 pairs of pelvic sacral foramina that provide passageways for nerves and blood vessels The coccyx is the lowermost portion of vertebral column and is composed of 4 fused vertebrae

Thoracic Cage Includes the ribs, thoracic vertebrae, sternum and costal cartiages Supports the pectoral girdle and upper limbs, functions in breathing and protects the thoracic and upper abdominal organs

Ribs There are normally 12 pairs of ribs that attach to the thoracic vertebrae First 7 pairs are true ribs- join directly to the sternum through costal cartilage Remaining 5 pairs are false ribs- the first 3 pairs are vertebrochondral ribs and the last two are floating ribs

Sternum Also called the breastbone and is located along the anterior midline of the thoracic cage Consists of an upper manubrium, middle body and lower xyphoid process

Pectoral Girdle Makes an incomplete ring that supports the upper limbs It is made up of two scapulae and two clavicles Clavicles –Elongated S-shaped bones located at the base of the neck that function to brace the scapulae

Pectoral Girdle Scapulae –Flat, triangular bones on either side of upper back –The spine divides the scapula into unequal portions –The spine leads to the acromion process (articulates with the clavicle) and coracoid process (provides attachment for limb and chest muscles) –The glenoid cavity articulates with the head of the humerus

Upper Limb Upper limb= arm, forearm and hand Humerus –Makes up the upper arm, extending from the scapula to the elbow. –Articulates with the scapula at its head and the radius at the capitulum and with the ulna at the trochlea –Other features: greater and lesser tubercles, intertubercular groove, anatomical and surgical necks, deltoid tuberosity, epicondyles, coronoid fossa and olecranon fossa

Radius & Ulna Radius –Located on the thumbs side of the forearm, extending from the elbow to the wrist –The flattened head pivots with the humerus –Other features: radial tuberosity and styloid process Ulna –Longer of the two forearm bones and has a trochlear notch that articulates with the humerus –Other features: olecranon process, coronoid process, radial notch, head, styloid process

Hand The wrist is made up of eight carpal bones bound into a carpus The framework of the hand is made up of five metacarpal bones The fingers are composed of three phalanges in each finger, except the thumb which lacks the middle phalanx.

Upper Limb

Pelvic Girdle Consists of two coxal bones and the sacrum; it supports the trunk of the body on the lower limbs Supports and protects the lower abdominal and pelvic organs Coxal bones: made up of three bones- ilium, ischium, and pubis that are fused in the region of the acetabulum, the cuplike depressions that articulates with the head of the femur

Pelvic Girdle Ilium is the largest and most superior portion of the coxal bone and joins the sacrum at the sacroiliac joint –Features: iliac crest and anterior superior iliac spine Ischium form the L-shaped portion that supports weight during sitting –Features: ischial tuberosity and ischial spine

Pelic Girdle Pubis- comprises the anterior portion of the coxal bones and articulates at the symphysis pubis –The large opening, obturator foramen lies within each pubis The greater pelvis is above the pelvic brim and the lesser pelvis is below it

Male vs. Female Pelvises Male: pelvis is shaped something like a funnel Female: broader, shallower shape, more like a basin Female: pelvic outlet and inlet are much wider Male coxal bone is generally larger than the individual female hip bones

Lower Limb Femur –Thighbone extends from the hip to the knee and is the longest bone in the body –The head articulates with the acetabulum; it articulates with the tibia at the medial and lateral condyles –Other features: fovea capitis, neck and greater and lesser trochanters –The patella (knee cap) is located in the tendon that passes over the knee

Tibia Shinbone supports the weight of the body and articulates with the femur (medial and lateral condyles) and with the tarsal bones of the foot Anterior tibial tuberosity is the point of attachment for the patellar ligament Other features: medial malleolus (inner ankle)

Fibula The slender bone that lies lateral to the tibia and does NOT bear body weight Lateral malleolus form the lateral ankle

Foot The ankle is composed of seven tarsal bones forming a tarsus –The talus articulates with the tibia and fibula –The calcaneus supports the body weight The instep of the foot consists of five metatarsal bones and provide an arch Each toe is made up of three phalanges, with the exception of the great toe, which lacks a middle phalanx