Skeletal System 1

types of facial bones

Mandible, Maxillae (maxillary) (2), Zygomatic bone (2), Nasal bone (2), Lacrimal Bone (2), Palatine bone (2), Vomer, Inferior Nasal Conchae (2)

Metacarpus

Five metacarpal bones form the palm

Phalanges

each finger has three phalanges except the thumb

distal, middle, proximal

Features of the C1 (Atlas)

no body or spinous process,

consists of anterior and posterior arches and two lateral masses,

superior surfaces of lateral masses articulate w/ the occipital condyles (allows you to nod)

Features of C2 (Axis)

Dens projects superiorly into the anterior arch of the atlas

Dens is a pivot for the rotation of the atlas (allows you to say no)

Thoracic Vertebrae

T1 to T12

All articulate with ribs at facets and demi-facets (half-facets that receive the heads of the ribs)

Long spinous process

Location of articular facets allows rotation of this area of spine

Lumbar Vetebrae

L1 to L5

Short, thick pedicles and laminae

Flat hatchet-shaped spinous processes

Orientation of articular facets locks lumbar vertebrae together so as to prevent rotation

Axial skeleton includes

skull, ribcage, sternum, vertebral column

Nasal Cavity

Roof, lateral walls and floor formed by parts of four bones (ethmoid, palatine, maxillary, inferior nasal conchae)

Nasal septum of bone and hyaline cartilage (ethmoid, vomer and anterior cartilage)

temporomandibular joint

The joint formed where the mandible and cranium meet

only freely movable joint in skull

Appendicular skeleton includes

collarbone, arms, legs, and hips

pectoral girdle

clavicle and scapula

attaches the upper limb to the axial skeleton

provide attachment sites for muscles that move the upper limb

5 functions of skeletal system

support, protection, movement, storage, and blood cell formation

Compact bone

dense smooth bone, comprised of osteons, comprising the shaft and exterior of the bone

Spongy bone

composed of small needlelike pieces of bone and lots of open space

Diaphysis

shaft of longs bones composed of compact bone

Epiphysis

ends of the long bone consisting of a thin layer of compact bone enclosing an area filled with spongy bone

Periosteum

a fibrous connective tissue membrane that covers and protects the diaphysis

Articular cartilage

covers the external surface of the epiphysis and decreases friction at the joint surfaces

Yellow bone marrow

fat stored in the diaphyses of adult long bones

Red bone marrow

produces blood cells and is found in the spongy bone of flat bones and the epiphyses of some long bones in adults

Osteoblasts

Bone building cells

Osteocytes

mature bone cells

Ossification

formation of bone

Osteoclasts

bone-destroying cells in bone that break down bone matrix and release calcium ions into the blood

Maxillae (maxillary bones)

medially fuse to form upper jaw and central portion of facial skeleton

keystone bones

articulate with all other facial bones except mandible

Mandible

lower jaw

largest, strongest facial bone

Cervical vertebrae

7 vertebrae in the neck (C1-C7)

Thoracic vertebrae

12 vertebrae in chest area; attachment for 12 ribs (T1-T12)

Lumbar vertebrae

5 vertebrae in the lower back (L1-L5)

Sacrum

5 fused vertebrae (S1 -S5)

Forms posterior wall of pelvis

Articulates with L5 superiorly, and with auricular surfaces of the hip bones laterally

Coccyx

tailbone; fusion of 3-5

Articulates superiorly with sacrum

Curvature of the Vertebral column

Increases resilience and flexibility of the spine

Concave curvatures of the VC

Cervical and lumbar

Convex curvatures of the VC

Thoracic and sacral

Abnormal spine curvatures

Scoliosis, Kyphosis, Lordosis

Thoracic cage

Composed of thoracic vertebrae, sternum, ribs and their costal cartilages

Functions of the Thoracic cage

Protects vital organs of thoracic cavity, Supports shoulder girdle and upper limbs

Provides attachment sites for many muscles, including intercostal muscles used during breathing

Sternum

Three fused bones: Manubrium, body, Xiphoid processes

Manubrium (Sternum)

Articulates with clavicles and ribs 1 and 2

Body (Sternum)

Articulates with costal cartilages of ribs 2 through 7

Structure of Typical Rib

Main parts: Head, Neck, Tubercle, Shaft

Xiphoid (Sternum)

Site of muscle attachment, Not ossified until ~ age 40

True ribs

1st 7 pairs of ribs that attach directly to the sternum by cartilage

False ribs

last 5 pairs of ribs that attach indirectly or are not attached to the sternum

Floating ribs

Bottom 2 false ribs that have no sternal attachment

Clavicle

collar bone

Scapula

shoulder blade

Upper limb

30 bones of each upper limb

Bones of the arms

Humerus, radius, ulna, carpal bones(8), metacarpal(5), phalanges(14)

Humerus

upper arm bone

Radius

forearm bone on the thumb side

Ulna

forearm bone on the little-finger side

Carpals

8 bones of the wrist area

Proximal row: Scaphoid, lunate, triquetrum, and pisiform proximally

Distal row: Trapezium, trapezoid, capitate, and hamate distally

Pelvic bones

(coxal bone, os coxae)

Three fuse bones: ilium, ischium, pubis

Bones of the hip

Ilium - Superior region of the coxal bone,

Ischium - Posteroinferior

Pubis - Anterior portion of hip bone

Femur

thigh bone, largest, strongest bone

Tibia

shinbone

Fibula

lower leg bone that lies alongside the tibia and forms the outer part of the ankle

Patella

kneecap bone

Foot

7 tarsals bone in the ankle, 5 metatarsal bones, 14 phalanges

Arches of the foot

Maintained by interlocking foot bones, ligaments, and tendons

Allow foot to bear weight

Three arches of the foot

Lateral longitudinal

Medial longitudinal

Transverse

Calcaneus

large tarsal bone also known as the heel bone

Metatarsals

5 bones that make up the sole of the foot

Frontal bone

forms the forehead, the bony projections under the eyebrows, and the superior part of each eye's orbit

Parietal bones

paired bones that form most of the superior and lateral walls of the cranium

Temporal bones

bones that lie inferior to the parietal bones

Occipital bone

most posterior bone in the cranium

Sphenoid bone

bat-shaped, keystone bone, articulates with all other cranial bones

Ethmoid bone

irregular shaped bone that lies anterior to the sphenoid and forms the roof of the nasal cavity and part of the medial walls of the orbits

Deepest skull bone

Zygomatic

cheekbones;

Nasal Bones and Lacrimal Bones

nasal bones: bridge of the nose

lacrimal bones: in medial wall of orbits

Palatine Bones

Posterior one-third of hard palate

Posterolateral walls of the nasal cavity

Small part of the orbits

Vomer

Plow shaped

Lower part of nasal septum

orbits

encase eyes and lacrimal glands, sites of attachment for eye muscles,

formed by parts of seven bones(frontal, sphenoid, zygomatic, maxilla, palatine, lacrimal, ethmoid)

inferior nasal conchae

form part of lateral walls of nasal cavity

Haversion Canal

central canal of the osteon, houses the blood vessels to nourish the bone

Intramembranous ossification

type of ossification that occurs in the soft spots of a baby's head

Endochondral ossification

type of ossification that occurs in a long bone to allow for both growth as well as repair of the bone

Long bones

longer than they are wide, these types of bones act as levers to aid in movement

Short bones

tend to be cube shaped, these types of bones provide support and stability with little movement

Sesamoid bones

shaped like a sesame seed and embedded in a tendon, these types of bones modify pressure, reduce friction, and occasionally alter the direction of muscle pull

Flat bones

thin and flat with roughly parallel surfaces, these types of bones have a large surface area for the attachment of skeletal muscles.

irregular bones

complex shapes with short, flat, notched, or ridged surfaces, these types of bones provide protection of tissue and muscle attachment points

hyoid bone

Not a bone of the skull U-shaped bone in the neck that supports the tongue.

Attachment for muscles of swallowing and speech

ball and socket joint

shoulder and hip; 360 degrees of rotation

hinge joint

Joint between bones (as at the elbow or knee) that permits motion in only one plane

saddle joint

type of joint found at the base of each thumb; allows grasping and rotation

condyloid joint

biaxial (wrist, fingers, toes)

pivot joints

neck and elbow joints

fibrous joint

connect bones without allowing any movement (like sutures)

Cartlaginous joints

joints held up by cartilage, limited movement

synovial joints

freely movable joints

fracture

broken bone

simple fracture

bone is broken cleanly; the ends do not penetrate the skin

compound fracture

break in the bone where the bone comes through the skin; open fracture

compressed fracture

Bone is crushed, common in porous bones (osteoporosis)

osteroporosis

A condition in which the body's bones become weak and break easily; common in older individuals

Osteoarthritis

inflammation and wearing of the bone and joint cartilage