TB exam2 part3

The process of bones increasing in width is known as ________.
A) appositional growth
C) closing of the epiphyseal plate
B) epiphyseal plate closure
D) concentric growth

a

Which hormone increases osteoclast activity to release more calcium ions into the bloodstream?
A) thyroxine B) calcitonin
C) parathyroid hormone D) estrogen

c, PT

What is absolutely required for bone growth or healing from a fracture?
A) osteocytes
C) dietary intake of calcium and vitamin D
B) osteoclasts D) osteoblasts

d

Wolff’s law is concerned with ________.
A) the function of bone being dependent on shape
B) the thickness and shape of a bone being dependent on stresses placed upon it
C) the diameter of the bone being dependent on the ratio of osteoblasts to osteoclasts D) vertical growth of bones being dependent on age

b

Which of the following glands or organs produces hormones that tend to decrease blood calcium levels?
A) spleen B) thyroid C) parathyroid
D) pineal gland

b

Osteomyelitis is ________.
A) partially due to insufficient dietary calcium
B) caused by altered vitamin D metabolism C) due to pus-forming bacteria
D) literally known as "soft bones"

c

Cartilage grows in two ways, appositional and interstitial. What is appositional growth? A) along the edges only of existing osteons, making each osteon larger
B) the secretion of new matrix against the external face of existing cartilage C) growth at the epiphyseal plate
D) the lengthening of hyaline cartilage

b

Which of the following statements best describes interstitial growth?
A) Unspecialized cells from mesenchyme develop into chondrocytes, which divide and form cartilage.
B) Growth occurs in the lining of the long bones.
C) Fibroblasts give rise to chondrocytes that differentiate and form cartilage.
D) Chondrocytes in the lacunae divide and secrete matrix, allowing the cartilage to grow from within.

d

In the epiphyseal plate, cartilage grows ________.
A) in a circular fashion
B) by pulling the diaphysis toward the epiphysis
C) from the edges inward
D) by pushing the epiphysis away from the diaphysis

d

The structural unit of spongy is called ________. A) lamellar bone
C) trabeculae
B) osseous lamellae D) osteons

c

Osteogenesis is the process of ________.
A) making collagen fibers for calcified cartilage
B) bone formation
C) making a cartilage model of the fetal bone D) bone destruction to liberate calcium

b

Lengthwise, long bone growth during infancy and youth is exclusively through ________.
A) the secretion of bone matrix into the medullary cavity
B) differentiation of osteoclasts into osteocytes
C) calcification of the matrix of the zone underlying articular cartilage
D) interstitial growth of the epiphyseal plates

d

Growth of bones is controlled by a symphony of hormones. Which hormone is of greatest importance for bone growth during infancy and childhood?
A) prolactin B) somatomedins
C) growth hormone D) thyroid hormone

c

In some cases the epiphyseal plate of the long bones of children closes too early. What might be the cause?
A) osteoblast activity exceeds osteoclast activity B) elevated levels of sex hormones
C) overproduction of thyroid hormone
D) too much vitamin D in the diet

b

Normal bone formation and growth are dependent on the adequate intake of ________.
A) sodium, calcium, and vitamin E B) calcium, phosphate, and vitamin D
C) potassium, phosphate, and vitamin D
D) vitamin D, phosphate, and chloride

b

What tissue forms the model for endochondrial ossification?
A) cartilage B) fascia C) membranes D) bone

a

A bone embedded in a tendon is called a(n) ________ bone.

sesamoid

A central (Haversian) canal may contain arteries, veins, capillaries, lymph vessels, and ________ fibers.

nerve

A long bone forms by a process known as ________ ossification.

endochondral

What term describes in growth in the diameter of long bones?

Appositional

List the steps in the repair process of a simple fracture.

Hematoma formation, fibrocartilaginous callus formation, bony callus formation, and remodeling.

Several hormones control the remodeling of bones. Which two respond to changing blood calcium levels?

PTH and calcitonin are the major determinants of whether and when remodeling will occur in response to changing blood calcium.

Why are the bones of young children much more flexible than those of the elderly?

Bones of children are not completely calcified, with a higher ratio of more flexible organic fibers. Bones in the elderly are more completely calcified, which gives the characteristic of rigidity.

Inflammation of bony tissue is called ________.

osteitis

Bones appear to be lifeless structures. Does bone material renew itself?

Bone only appears lifeless in gross anatomy. Microscopically, bone is full of cells and blood vessels that maintain and renew bone tissue. Approximately 5% to 7% of our bone mass is recycled each week. Up to 0.5 g of calcium may enter or leave the bones each day, depending on the negative feedback hormonal mechanism and gravitational forces.

Compare the function of the organic materials in the bone matrix with the function of the 100) inorganic materials in the matrix.

The organic matrix contributes to the bone structure and its tensile strength, while the inorganic matrix contributes to hardness and resistance to compression.

What are the differences between the diaphysis and the epiphyses of long bones?

Diaphyseal bone is composed almost entirely of compact bone (except in irregular and short bones), while the epiphyses are composed almost entirely of spongy bone. The epiphyses are on the ends of the bone; the diaphysis is the "shank" of the bone. The diaphysis in long bones has a large medullary cavity, whereas the epiphyses do not.

Describe how oxygen is carried from outside a bone to an individual osteocyte.

Blood vessels enter through the periosteum into a perforating canal. The vessel may follow along the axis of the bone through a central canal. Osteocytes have long, almost dendritic-like extensions or arms that reach out through tiny holes called canaliculi. The canaliculi connect one cell to another and to the central canal. Oxygen leaves the blood vessel in the central canal and travels through the canaliculi from cell to cell until it reaches the cell in question.

How is the beginning of intramembranous ossification different from endochondral ossification?

Intramembranous ossification starts in connective tissue from mesenchymal cells that become osteoblasts. These osteoblasts cluster together into an ossification center. Endochondral ossification starts with a hyaline cartilage "template." Mesenchymal cells become osteoblasts and begin forming bone around the cartilage.

If your doctor notices a marked decrease in calcium ion levels in your blood, what gland might he suspect is not functioning properly and why?

The parathyroid gland normally responds to low calcium ion levels in the blood and releases PTH, which mobilizes osteoclasts to step up bone destruction, releasing more calcium into the bloodstream. Persistent low blood calcium level therefore implies insufficient PTH, suggesting injury or failure of the parathyroid glands.

The fingers have three of these bones and the thumb has only two.

Phalanges

This bone articulates with the glenoid fossa.

Humerus

Forearm bone that articulates with most of the carpals.

Radius

Contains the joint that allows you to rotate your head "no."

cervical

Transverse foramina present.

cervical, axis

These bones have the thickest centrum with short blunt spinous processes.

Lumbar vertebrae

Allows the head to nod "yes."

atlas

The fibula is the major weight-bearing bone of the leg. t/f

f

The vertebral column is held in place primarily by the anterior and posterior longitudinal ligaments. t/f

t

Body weight is carried primarily by the talus and calcaneus. t/f

t

The most common site of fracture in the humerus is the anatomical neck. t/f

f

The layman’s name for the scapula is the collarbone. t/f

f

Costal cartilages join most ribs to the sternum. t/f

t

The tubercle of a rib articulates with the transverse process of a vertebra. t/f

t

In women of childbearing age, the dimensions of the true pelvis are of utmost importance. t/f

t

The term vertebrochondral ribs refers to ribs that attach to each other before they attach to the sternum. t/f

t

In the anatomical position, the lateral forearm bone is the radius. t/f

t

Lordosis affects the thoracic vertebrae. t/f

f

All vertebrae possess a body, a spine, and transverse foramina. t/f

f

The dens articulates with the axis. t/f

f

The ischium articulates with both the ilium and the pubis. t/f

t

Which forms the largest portion of the coxal bone? A) pelvic B) pubis C) ischium D) ilium

d