Module 4: Skeletal System

Condylar Process of Mandible

External Acoustic Meatus

Parietal Bone

Ramus of Mandible

Temporal Bone

Zygomatic Process of Temporal Bone

Ethmoid Bone

Frontal Bone

Inferior Nasal Concha

Lacrimal Bone

Mandible

Maxilla

Mental Foramen

Middle Nasal Concha

Nasal Bone

Parietal Bone

Sphenoid Bone

Temporal Bone

Vomer

Zygomatic Bone

Occipital Bone

Foramen Magnum

Occipital Condyle

Palatine Bone

Zygomatic Bone

Frontal Sinus

Sphenoid Sinus

Ethmoidal Cells

Maxillary Sinus

Squamous Suture

Coronal Suture

Lambdoid Suture

Sagittal Suture

Lacunae

Tiny spaces occupied by osetocytes

Canaliculi

Tiny channels in which the processes of osteocytes exchange nutrients and wastes

Hematopoiesis

Blood formation

Skull, ribs, sternum, clavicles, vertebrae, hip bone

Areas of red marrow in adults

Hydroxyapatite

Calcium Phosphate

Osteogenesis imperfecta

Hereditary collagen defect, in which forming bones are brittle, and fetus may have many bone fractures

Primary Ossification Center

Area in center of diaphysis, where bone tissue first replaces cartilage

Secondary Ossification Center

Area of the epiphyses, where spongy bone forms later in development

Intramembranous Ossification

Mesenchyme differentiates into osteoblasts, build bone, and periosteum forms

Endochondral Ossification

Hyaline cartilage is ossified first by primary centers (diaphysis) and then secondary centers (epiphysis)

Zone of resting cartilage

Layer closest to end of epiphysis; resting cells; anchor epiphyseal plate to epiphysis

Zone of Proliferating Cartilage

Rows of young cells, undergoing mitosis

Zone of Hypertrophic Cartilage

Rows of older cells left behind when new cells appear; thicken epiphyseal plate, lengthening the bone; matrix calcifies, cartilage cells (chondrocytes) die

Zone of Calcified Cartilage

Thin layer of dead cartilage cells and calcified matrix

Vitamin D

Calcium absorption; deficiency causes rickets, osteomalacia

Vitamin A

Osteoblast and osteoclast activity; deficiency retards bone development

Vitamin C

Collagen synthesis; deficiency results in slender, fragile bones

Growth Hormone

Stimulates cartilage cell division; insufficiency in a child can result in pituitary dwarfism; excess causes gigantism in child, acromegaly in adult

Thyroid Hormone

Causes replacement of cartilage with bone in epiphyseal plate, osteoblast activity

Parathyroid Hormone

Stimulates osteoclasts, bone breakdown

Sex Hormone

Promote bone formation; stimulate ossification of epiphyseal plates

Condyle

Rounded process that usually articulates with another bone

Crest

Narrow, ridge-like projection

Epicondyle

Projection above a condyle

Facet

Small, nearly flat surface

Fissure

Cleft or groove

Fontanel

Soft spot in the skull where membranes cover the space between bones

Foramen

Opening through a bone that usually serves as a passageway for blood vessels, nerves, or ligaments

Fossa

Relatively deep pit or depression

Fovea

Tiny pit or depression

Head

Enlargement on the end of a bone

Linea

Narrow ridge

Meatus

Tube-like passageway within a bone

Process

Prominent projection on a bone

Ramus

Branch or similar extension

Sinus

Cavity within a bone

Spine

Thorn-like projection

Sulcus

Furrow or groove

Suture

Interlocking line of union between bones

Trochanter

Relatively large process

Tubercle

Knob-like process

Tuberosity

Knob-like process usually larger than a tubercle

7

Number of cervical vertebrae

12

Number of thoracic vertebrae

5

Number of lumbar vertebrae

5

Number of sacral vertebrae

4

Number of coccyx vertebrae

Body

Drum-shaped, anterior portion

Pedicles

Stalks that project from body, form sides of vertebral foramen

Laminae

Plates that arise from pedicles, fuse to become  spinous process

Spinous Process

Posterior projection of spine

Transverse Process

Lateral projection of spine

Vertebral Foramen

Opening for spinal cord

Superior and inferior articular processes

Project upward and downward, to articulate with adjacent vertebrae

Facets

Cartilage-covered articulating surfaces of articular processes

Transverse formina

openings for arteries leading to brain; only found on cervical vertebrae

Vertebral Prominens

C7, spinous process is longer than those of other cervical vertebrae

Atlas

C1, supports head, articulates with occipital condyles

Axis

C2; Atlas pivots around the dens of Axis

Thoracic Vertebrae

Long, pointed spinous process, slopes downward

Lumbar Vertebrae

Thick, short spinous processes, almost horizontal

Median Sacral Crest

Fused spinous processes of vertebrae

Posterior Sacral Foramina

Openings for blood vessels and nerves on sacrum

Sacroiliac joints

transmit weight from spine to legs

Sacral Promontory

Projection at upper margin of sacrum

Sacral Canal

Formed by vertebral foramina on sacrum

Sacral Hiatus

Opening at inferior tip of sacrum