Human Anatomy Exam 2

Osteocyte

mature bone cell that maintains the bone matrix

Canaliculi

pink

Osteocyte

blue

Matrix

orange

Osteoblast

immature bone cell that secretes osteoid, the organic bone matrix

Osteoprogenitor cell

stem cell that divides to produce osteoblasts

Osteoclast

multinucleate cell that secretes acids and enzymes to dissolve bone matrix

compact bone

external wall of bone

Spongy bone

internal layer; protects medullary cavity

Yellow marrow

tissue dominated by adipocytes (found in shaft and end of long bones)

Red marrow

Tissue dominated by blood cells (found in flat bones and long bones)

concentric lamellae

green; each osteon are parallel to the long axis of the bone (bull’s eye target)

Circumferential lamellae

lavender; located at the internal and external surface of the bone

Interstitial lamellae

blue; fill the space between osteons

canaliculi

lavender

concentric lamellae

blue

central canal / harvesian canal

pink

osteon

yellow

lacunae

green

trabeculae

Arrangement of spongy bone is into parallel thick branching plates of bars

epiphysis

purple

metaphysis

blue

diaphysis

pink

Periosteum

Function: Isolates and protect the bone. Provides a route and attachment point for insertion of tendons and ligaments, which Is Important in bone growth and repair.

What kind of tissue is the periosteum?

Dense irregular connective tissue

Endosteum

Lines the medullary cavity (marrow). Lines the inner surfaces of the central canals and perforating canals. Covers the trabeculae of spongy bone. Important in bone growth and repair.

Epiphyseal vessels

pink; Supply medullary cavities of the epiphyses (through foramina)

Metaphyseal vessels

purple; Supply to diaphyseal surface (bone is replacing cartilage)

Nutrient vessels

blue; enter through nutrient foramen

Periosteal vessels

green; Supply superficial osteons (compact bone)

Sutural bones

small, flat, oddly shaped bones found between the flat bones of the skull along the sutures. They develop from separate centers of ossification. 

Pneumatized bones

bones that are hollow or contain numerous air pockets, such as the ethmoid bone.

Short Bones

Their external surfaces are covered by compact bone, but the interior contains spongy bone. Examples of short bones include the carpal bones (wrists) and tarsal bones (ankles)

Irregular Bones

Have complex shapes with short, flat, notched, or ridged surfaces. Their internal structure is equally varied. The vertebrae that form the spinal column and several bones in the skull are examples of irregular bones. 

Flat Bones

Have thin, roughly parallel surfaces of compact bone. In structure, a flat bone resembles a spongy bone sandwich; such bones are strong but relatively light. Flat bones form the roof of the skull, the sternum, the ribs, and the scapulae. They protect underlying soft tissues and have an extensive surface area for the attachment of skeletal muscles. 

Long Bones

Relatively long and slender. They have a diaphysis, two metaphyses, two epiphyses, and a medullary cavity. Found in the upper and lower limbs. Examples: humerus, radius, ulna, femur, tibia, and fibula

Sesamoid Bones

Usually small, round, and flat. They develop inside tendons and are most often encountered near joints of the knee, the hands, and the feet. Few individuals have sesamoid bones at every possible location, but everyone has patellae, or kneecaps

Foramen

Round or oval opening through a bone

Groove

Furrow

Fissure

Narrow, slit like opening

Notch

Indentation at the edge of a structure

Fossa

Shallow basin like depression in a bone, often serving as an articular surface

Meatus

Canal-like passageway

Sinus

Cavity within a bone, filled with air and lined with mucous membrane

Head

Red; bony expansion carried on a narrow neck

Facet

orange; Smooth, nearly flat articular surface

Condyle

yellow; Rounded articular projection, often articulates with a corresponding fossa

Tuberosity

green; large rounded projection; may be roughened

Crest

yellow; Narrow ridge of bone, usually prominent

Trochanter

blue; Very large, blunt, irregularly shaped process (the only examples are on the femur

Line

Purple; Narrow ridge of bone; less prominent than a crest

Tubercle

Lavender; Small rounded projection or process

Epicondyle

Red; Raised area on or above a condyle

Spine

beige; Sharp, slender, often pointed projection

Process

Any projection or bump

Ramus

An extension of a bone that forms an angle with the rest of the structure

Comminuted

Bone fragments into three or more pieces. Particularly common in the aged, whose bones are more brittle.

Compression

Bone is crushed. Common in porous bones (i.e., osteoporotic bones) subjected to extreme trauma, as in a fall. 

Spiral

Ragged break occurs when excessive twisting forces are applied to a bone

Epiphyseal

Epiphysis separates from the diaphysis along the epiphyseal plate. Tends to occur when cartilage cells are dying and calcification of the matrix is occuring

Depressed

Broken bone portion is pressed inward. Typical of skull fracture

Greenstick

Bone breaks incompletely, much in the way in the way a green twig breaks. Only one side of the shaft breaks; the other side bends. Common in children, whose bones have relatively more organic matrix and are more flexible than those of adults

206

Number of bones

80

Number of bones in the axial skeleton

29

Skull and associated bones

Skull

Cranium and facial bones

8

Number of cranium bones

14

number of facial bones

Associated bones

Auditory ossicles and hyoid

6

Number of auditory ossicles

25

Number of thoracic cage bones

Thoracic cage

Sternum and ribs

24

Number of rib bones

26

Number of bones in the vertebral column

Vertebral column

Vertebrae, sacrum, coccyx

24

Number of bones in the vertebrae

Maxillae

Purple; 2 bones

Nasal bone

Orange; 2 bones

Zygomatic bone

Blue; 2 bones

Lacrimal bone

Yellow; 2 bones

Vomer

Green; 1 bone

Mandible

Pink; 1 bone

Occipital bone

Yellow; 1 bone

Parietal bone

green; 2 bones

Frontal bone

Blue; 1 bone

Temporal bone

Purple; 2 bones

Sphenoid

orange; 1 bone

Ethmoid

Pink; 1 bone

Hyoid

Cranial cavity

Fluid filled chamber that supports the brain

Lambdoid suture

purple

Sagittal suture

magenta

Coronal suture

Red

Squamous suture

orange

Frontonasal suture

Calvaria

Cranial vault

Hypoglossal canal

Orange

Foramen magnum

Yellow

Occipital condyle

Green

Superior nuchal line

green