Osteology and Skeleton Flashcards
What are the 4 basic tissues of the human body?
Epithelial, muscle, neural, and connective tissue
What is the function of each type of bone cell?
Osteoblasts- form bone
Osteocytes- maintain or nurture bone
Osteoclasts- remodel bone
What is the primary constituent of ground substance?
Glycosaminoglycans
What is the principal type of protein fiber in bone?
Collagen Type I
What is the most frequently described deposit in bone?
Hydroxyapatite
What is Wolff’s Law as it pertains to bone?
Living tissue will respond to stressors; bone is formed or absorbed in response to stress
What are the three responses of bone that allow it to be describes as “living”?
It has the ability to heal, to remodel under stressors and to age
What is bone the embryological derivative of?
Mesenchyme or cartilage
What is the name given to the pattern of ossification in mesenchyme?
Intramembranous ossification
What is the timing for the appearance of intramembranous ossification?
From the second to third month in utero
What is the timing for the appearance of ossification in cartilage?
From the second to fifth month in utero
What part of the skull is derived from endochondral ossification?
Chondrocranium
Which bone of the appendicular skeleton is formed by both endochondral and intramembranous ossification?
The clavicle
What are the primary sources of variation observed in bone?
Sexual dimorphism (gender variation), ontogenetic variation (growth or age variation), geographic or population-based variation (ethnic variation), and idiosyncratic variation (individual variation)
What are the six more commonly used classifications of normal bone?
Long bones, short bones, flat bones, irregular bones, paranasal sinuses or pneumatic bones and sesamoid bones
What are the classifications given to abnormal bone stressed in Spinal II?
Heterotopic bone and accessory bone
What is the name given to bone formed in a non-bone location?
Heterotopic bone
What is the name given to bone formed from existing bone?
Accessory bone
What is the characteristic feature of a long bone?
It is longer than it is across (length greater than breadth)
What are the names given to parts of a long bone?
The diaphysis (shaft) and typically two epiphyses (extremities)
What is the primary characteristic of short bones?
They are essentially cuboidal
What are examples of short bones?
Most of the bones of the carpus and tarsus
What are examples of flat bones?
The parietal bone and sternum
What are examples of pneumatic bone?
Frontal, ethmoid, maxilla, sphenoid and temporal
What is the characteristic of sesamoid bone?
The bone develops within a tendon
What are the consistent examples of sesamoid bones?
Patella and pisiform
What are examples of heterotopic bone?
Calcific deposits in the pineal gland, heart and ligaments
What are examples of accessory bone?
Para-articular processes and bony spurs of vertebrae
What are the four basic surface feature categories?
Elevations, depressions, tunnels or passageways and facets
When do the surface features of bone become prominent?
During and after puberty
What are the types of osseous linear elevation?
The line, ridge, and crest
What are the types of rounded osseous elevations?
Tubercle, protuberance, trochanter, tuber or tuberosity, and malleolus
What are the categories of sharp osseous elevations?
Spine and process
What are the categories of osseous depressions?
Linear and rounded depressions
What are the categories of osseous linear depressions?
Notch or incisure, groove, and sulcus
What are the categories of rounded osseous depressions?
The fovea and fossa
What are the names given to openings on the surface of the bone?
Ostium or orifice and hiatus
What are the names given to osseous ostia which completely penetrate bone?
Foramen or canal
What is the definition of an osseous foramen?
An ostium passing completely through a thin region of bone
What is the definition of an osseous canal?
An ostium passing completely through a thick region of bone
What is the name given to an ostium which does not completely penetrate through a region of bone but appears as a blind-ended passageway?
Meatus
What is the definition of an osseous fissure?
An irregular slit-like or crack-like appearance between the surfaces of adjacent bones
What are the categories of osseous facets?
Flat facets and rounded facets
What are the categories of rounded osseous facets?
Articular heads and articular condyles
How many bones form the typical adult skeleton?
206 bones
What are the subdivisions of the skeleton?
The axial skeleton and appendicular skeleton
How many bones form the typical adult appendicular skeleton?
126 bones
How many bones form the typical adult axial skeleton?
80 bones
What is the total number of bones forming the typical adult skull?
28 bones
What bones form the neurocranium of the typical adult skull?
The frontal, parietal, temporal, occipital, sphenoid, and ethmoid
How many bones form the typical adult neurocranium?
8 bones
How many bones form the facial skeleton (splanchnocranium or visceral skeleton)?
14 bones
What is the name given to the presacral region of the typical adult vertebral column or spinal column?
The spine
What is the total number of bones forming the typical adult spine?
24 bones
How many bones are present in the typical adult sternum?
1 bone
What regions are present along the typical adult sternum?
The manubrium sterni, the corpus sterni and the xiphoid process
How many ribs are present in the typical adult skeleton?
12 pair or 24 ribs
