A&P 1- CHAPTER 6 MASTERING ASSIGNMENTS
Define appositional growth. (Module 6.6A)
Appositional growth is an increase in bone diameter due to the addition of bone matrix at the bone's outer surface.
Which of the following is not true of the skeletal system?
It interacts with the lymphatic system to regulate calcium levels.
Which of the following is false for spongy bone? (Module 6.5C)
It makes up most of the volume of the diaphysis of long bones.
Which condition, due to excessive cartilage formation at the epiphyseal cartilages, results in individuals who are very tall, with long, slender limbs?
Marfan syndrome
In what area of a long bone would it probably be easiest to observe the cartilage the orthopedic doctor refers to?
Metaphysis
Describe the functions of osteocytes. (Module 6.4B)
Osteocytes are mature bone cells that maintain the bone matrix.
Art-labeling Activity: Surface markings of the femur and pelvis
PICTURE
Ankle fractures that affect both bones of the leg are called __________.
Pott's fractures
When testosterone is increased in males at puberty, epiphyseal plates
accelerate rapidly
The trabeculae of spongy bone
are organized along stress lines.
Elevated levels of calcium ion in the blood stimulate the secretion of the hormone
calcitonin
The expanded articular end of an epiphysis that is separated from the shaft by a narrower neck is termed a
head
Cells of the perichondrium need to take on a new role as ossification begins. They will become __________.
osteoblasts and begin to deposit bone matrix
Secondary ossification centers occur in
the epiphyses.
Which is the last phase of endochondral ossification?
An epiphyseal cartilage separates the epiphysis from the diaphysis.
Define osteon. (Module 6.5A)
An osteon is the functional unit of compact bone.
________ prevents damaging bone-to-bone contact within movable joints.
Articular cartilage
What type of bone growth is the doctor most likely looking for in the example above?
Endochondral ossification
Bill, age 15, is still growing, but his older sister Andrea, age 19, has stopped. What has changed in Andrea's bones?
Her epiphyseal plates have ossified.
Drag and drop the labels to the correct part during each stage of endochondral ossification.
PICTURE
All the following result in decreased calcium levels in the bloodstream EXCEPT __________.
PTH stimulation of osteoclasts
Describe the axial and appendicular divisions of the skeleton. (Module 6.1A)
The axial skeleton consists of the bones of the skull, vertebral column, and thorax. The appendicular skeleton consists of the bones of the limbs, pectoral girdle and pelvic girdle.
If osteoclast activity exceeds osteoblast activity in a bone, how will bone mass be affected? (Module 6.4D)
The bone mineral content will decrease and thus bone mass will decrease.
The cartilage the doctor is referring to will disappear when
The osteoblasts work faster than cartilage producing cells
The intestinal response to PTH secretion when calcium ion levels are low is that calcium is
absorbed quickly.
Osteocytes are embedded in a dense matrix of hydroxyapatite. Which of the following describes how osteocytes in compact bone receive nutrients?
by diffusion from nutrients released from vessels in the central canal that travel through canaliculi.
Which substance accounts for almost two-thirds of the weight of bone?
calcium salts
The narrow passageways that contain cytoplasmic extensions of osteocytes are called
canaliculi
A ________ fracture produces shattered bone fragments.
comminuted
A prominent ridge, as seen on the pelvis, is a
crest
The shaft of a long bone is called the
diaphysis
The articular cartilage of a typical long bone covers portions of what part of the bone?
epiphysis
List the steps involved in fracture repair, beginning just after the fracture occurs. (Module 6.12A)
fracture hematoma formation, callus formation, spongy bone formation, compact bone formation
Remnants of osteons, which have been almost completely recycled by osteoclasts, are known as __________.
interstitial lamellae
All the following are characteristics of periosteum EXCEPT __________.
it is an incomplete cellular layer that lines the medullary cavity
Which organ prevents calcium loss in response to PTH stimulation?
kidney
As blood vessels extend into the spaces left by dying chondrocytes, the models begin to ossify internally. Where does internal ossification begin?
the primary ossification center in the diaphysis