Human Anatomy Quiz 2 (chapter 6)

Question 1

Chondrocranium

Answer 1

that part of the neurocranium forming the base of the skull. Parts of several bones are involved and endochondral ossification occures.

Question 2

Costal cartilages

Answer 2

the hyaline cartilage structures that attach to the anterior ends of the ribs. Those of the ture ribs articulate directly with the sternum, those of ribs 8, 9, and 10 form the costal arch on each side, and those of ribs 11 and 12 end in the soft tissue ofthe body wall.

Question 3

Endochondral (intracartilaginous) ossification

Answer 3

bone tissue formation that involves an initial hyaline cartilage model. Endochondral ossification is a multi-step process involving mineralization and then resorption of the cartilage before bone tissue is formed.

Question 4

Epiphyseal cartilage

Answer 4

a hyaline cartilage “growth plate” in an immature bone. A developing long bone typically has an epiphyseal cartilage at each end of its diaphysis.

Question 5

Epiphyseal Line

Answer 5

radiographic evidence of recent mineralization of an epiphyseal cartilage. Epiphyseal lines become less distinct with time and ultimately disappear altogether.

Question 6

Frontanel

Answer 6

a “soft spot” in the skull of a neonate occurring along sutures where adjacent flat bones are incompletely ossified. Six of these are typically present: unpaired anterior and posterior fontanels, and paired anterolateral and posterolateral frontanels.

Question 7

False rib

Answer 7

a rib whose costal cartilage does not make direct contact with the sternum. The lower five ribs on each side are false ribs, and the last two pairs of false ribs whose costal cartilages end blindly in the soft tissues of the body wall are (also) called floating ribs.

Question 8

Fracture

Answer 8

a crack or break in a bone typically caused by trauma. If properly “set” to prement movement, and if the blood supply to the fragments remains intact, fractures may heal in a few weeks or require several months.

Question 9

Intercostal spaces

Answer 9

the spaces between adjacent ribs and costal cartilages. These spaces are occupied by nerves. These foramina are formed by the juxtaposition of the superior and inferior vertebral notches of the adjacent vertebral arches.

Question 10

Intervertebral foramina

Answer 10

the paired openings on the sides of the vertebral column that transmit the spinal nerves. These foramina are formed by the juxtaposition of the suerior and inferior vertebral notches of the adjacent vertebral arches.

Question 11

Intramembranous ossification

Answer 11

direct osteogenesis occuring within a thin sheet of connective tissue proper (a “membrane”). All bones utilize at least some intramembranous ossification on their outer surfaces as they grow in diameter, and some flat bones use this form of ossification exclusively.

Question 12

Metaphysis

Answer 12

the portion of a developing diaphysis that lies next to an epiphyseal cartilage. This area has very high metabolic activity and is often the focus of neoplastic and infectious processes.

Question 13

Neurocranium

Answer 13

the cranial vault that surrounds and protexts the brain. It is formed by 8 bones: the unpaired frontal, occipital, ethmoid, and sphenoid bones, and the paired parietal and temporal bones.

Question 14

Osteon

Answer 14

a group of concentric osseous lamellae surrounding a central canal. Osteons are formed when an osteoclast “drills” a passageway through compact bone tissue and is followed by osteoblasts which secrete concentric layers of osteoid.

Question 15

Paranasal sinus

Answer 15

an air-filled diverticulum in the frontal bone, maxillae, sphenoid bone, or ethmoid bone. Simillar small diverticuli from the tympanic cavities invaginate the temporal bones (mastoid cells).

Question 16

Primary center of ossification

Answer 16

the 1st locus in a developing bone that contain bone tissue. Subsequent separate areas that ossify in the same bone are called secondary centers of ossification

Question 17

Sutural (“wormian”) bones

Answer 17

small “islands” of bone tissue that sporadically occur within the sutures that unite the flat bones of the skull (especially the lambdoid suture). These have no clinical significance and their nomen was coined when they were incidentally observed.

Question 18

Thoratic (rib) cage

Answer 18

the bony framework formed by the sternum, ribs, and thoracic vertebrae. It surrounds and protects deeper thoracic organs.

Question 19

True rib

Answer 19

a rib whose costal cartilage makes direct contact with the sternum. The first 7 ribs on each side.

Question 20

Vertebral column

Answer 20

the spine. formed by 26 bones: seven cervical, 12 thoracic, and 5 lumbar vertebrae, as well as the os sacrale and os coccyx.

Question 21

Viscerocranium

Answer 21

the skeleton that supposts and shapes the face. Formed by 14 bones: the unpaired vomer and mandible, and the paired maxillae, inferior nasal conchae, zygomatic, palaine, nasal and lacrimal bones.

Question 22

Compare endochondral vs. intramembranous ossification in regard to what they each contnribute to skeletal development and the specific steps involved.

Answer 22

Endochondral Ossification:
steps - 1. hyaline cartilage model of the bone forms from tissues derived from the mesoderm. 2. cartilage mineralized and becomes calcified cartilage. 3. the mineralized cartilage is reabsorbed by chondrocytes. 4. cells differentiate into osteoblasts, secrete osteoid, and complete formation of definitive bone tissue.
This is the mechanism by which majority of bones develop. Primary method where long bones increase in length.
Intramembranous Ossification:
does not require cartilaginous model or mineralization. Fibroblasts undergo metaplasia nad differentiate into osteoblasts. This kind is involved in the original formation of some flat bones of the body and is the mechanism by which most bones grow diametrically.

Question 23

define and differentiate primary vs. secondary centers of ossification

Answer 23

Primary center of ossification: first area in a develop9ing bone where Endochondral ossification occurs.
Secondary centers of ossification: other areas in the same bone that complete same Endochondral ossification after the primary center does.