44 terms

chapter 6 Bones and skeletal tissue

Hematopoiesis refers to the formation of blood cells within the red marrow cavities of certain bones.
Compact bone is replaced more often than
spongy bone
Bones are classified by whether they are weight bearing or protective in function
The periosteum is a tissue that serves only to protect the bone because it is not supplied with nerves or blood vessels
Short, irregular, and flat bones have large marrow cavities in order to keep the weight of the bones light
In newborn infants, the medullary cavity and all areas of spongy bone contain yellow bonemarrow
The structural unit of compact bone (osteon) resembles the growth rings of a tree trunk.
The term osteoid refers to the organic part of the matrix of compact bones
Sixty-five percent of the mass of bone is a compound called hydroxyapatite
All bones formed by intramembranous ossification are irregular bones
An osteon contains osteocytes, lamellae, and a central canal, and is found in compact boneonly.
The trabeculae of spongy bone are oriented toward lines of stress
Bone tissue in the skeleton of a human fetus is completely formed at six months' gestation
Each consecutive bone lamella has collagen fibers that wrap in alternating directions
Cartilage has a flexible matrix that can accommodate mitosis of chondrocytes
Closure of the epiphyseal plate stops all bone growth.
The structure of bone tissue suits the function. Which of the following bone tissues is adapted to support weight and withstand tension stress?
A) spongy bone
B) irregular bone
C) compact bone
D) trabecular bone
Answer: C
Which structure allows the diaphysis of the bone to increase in length until early childhood,as well as shaping the articular surfaces?
A) lacunae
B) Haversian system
C) epiphyseal plate
D) epiphyseal line
Answer: C
The most abundant skeletal cartilage type is ________.
A) hyaline
B) elastic
C) fibrocartilage
D) epiphyseal
Answer: A
Which of the following is not a function of the skeletal system?
A) support
B) storage of minerals
C) production of blood cells (hematopoiesis)
D) communication
Answer: D
What is the structural unit of compact bone?
A) osseous matrix
B) spongy bone
C) lamellar bone
D) the osteon
Answer: D
Bones are covered and lined by a protective tissue called periosteum. The inner (osteogenic)layer consists primarily of ________.
A) cartilage and compact bone
B) marrow and osteons
C) osteoblasts and osteoclasts
D) chondrocytes and osteocytes
Answer: C
The periosteum is secured to the underlying bone by dense connective tissue called________
A) Volkmann's canals
B) a bony matrix with hyaline cartilage
C) perforating (Sharpey's) fibers
D) the struts of bone known as spicules
Answer: C
The canal that runs through the core of each osteon (the Haversian canal) is the site of ________.
A) cartilage and interstitial lamellae
B) osteoclasts and osteoblasts
C) yellow marrow and spicules
D) blood vessels and nerve fibers
Answer: D
What are the small spaces in bone tissue that are holes in which osteocytes live called?
A) lacunae
B) Volkmann's canals
C) Haversian canals
D) trabeculae
Answer: A
For intramembranous ossification to take place, which of the following is necessary?
A) A bone collar forms around the cartilage model.
B) An ossification center forms in the fibrous connective tissue
.C) The cartilage matrix begins to deteriorate.
D) A medullary cavity forms
Answer: B
The process of bones increasing in width is known as ________.
A) closing of the epiphyseal plate
B) long bones reaching adult length and width
C) appositional growth
D) concentric growth
Answer: C
Bones are constantly undergoing resorption for various reasons. Which of the following cellsaccomplishes this process?
A) osteoclast
B) osteocyte
C) osteoblast
D) stem cell
Answer: A
Which hormone increases osteoclast activity to release more calcium ions into thebloodstream?
A) calcitonin
B) thyroxine
C) parathyroid hormone
D) estrogen
Answer: C
The universal loss of mass seen in the skeleton, which begins about the age of 40, ________
.A) is slower in females than in males
B) is absolutely uniform throughout the skeleton
C) reflects incomplete osteon formation and mineralization
D) is greater in African Americans than in Northern Europeans
Answer: C
Wolff's law is concerned with ________
.A) vertical growth of bones being dependent on age
B) the thickness and shape of a bone being dependent on stresses placed upon it
C) the function of bone being dependent on shape
D) the diameter of the bone being dependent on the ratio of osteoblasts to osteoclasts
Answer: B
Cranial bones develop ________.
A) from cartilage models
B) within fibrous membranes
C) from a tendon
D) within osseous membranes
Answer: B
Which of the following glands or organs produces hormones that tend to decrease Blood calcium levels?
A) pineal gland
B) thyroid
C) parathyroid
D) spleen
Answer: B
Osteomyelitis is ________.
A) partially due to insufficient dietary calcium
B) literally known as "soft bones"
C) due to pus-forming bacteria
D) caused by altered vitamin D metabolism
Answer: C
Cartilage grows in two ways, appositional and interstitial. What is appositional growth?
A) growth at the epiphyseal plate
B) the secretion of new matrix against the external face of existing cartilage
C) along the edges only
D) the lengthening of hyaline cartilage
Answer: B
Which of the following statements best describes interstitial growth?
A)Growth occurs in the lining of the long bones
B) Fibroblasts give rise to chondrocytes that differentiate and form cartilage.
C) Unspecialized cells from mesenchyme develop into chondrocytes, which divide and form cartilage.
D)Chondrocytes in the lacunae divide and secrete matrix, allowing the cartilage to grow from within.
Answer: D
In the epiphyseal plate, cartilage grows ________
.A) by pulling the diaphysis toward the epiphysis
B) by pushing the epiphysis away from the diaphysis
C) from the edges inward
D) in a circular fashion
Answer: B
Spongy bones are made up of a framework called ________.
A) osteons
B) lamellar bone
C) trabeculae
D) osseous lamellae
Answer: C
Osteogenesis is the process of ________.
A) making a cartilage model of the fetal bone
B) bone destruction to liberate calcium
C) bone formation
D) making collagen fibers for calcified cartilage
Answer: C
Lengthwise, long bone growth during infancy and youth is exclusively through ________.
A) interstitial growth of the epiphyseal plates
B) the secretion of bone matrix into the medullary cavity
C) differentiation of osteoclasts
D) calcification of the matrix
Answer: A
Growth of bones is controlled by a symphony of hormones. Which hormone is important forbone growth during infancy and childhood?
A) thyroid hormone
B) somatomedins
C) growth hormone
D) prolactin
Answer: C
In some cases the epiphyseal plate of the long bones of children closes too early. What might be the cause?
A) overproduction of thyroid hormone
B) elevated levels of sex hormones
C) too much vitamin D in the diet
D) osteoblast activity exceeds osteoclast activity
Answer: B
Normal bone formation and growth are dependent on the adequate intake of ________.
A) calcium, phosphate, and vitamin D
B) potassium, phosphate, and vitamin D
C) sodium, calcium, and vitamin E
D) vitamin D, phosphate, and chloride
Answer: A
Ostealgia is ________.
A) a defect called clubfoot
B) a disease of the bone
C) pain in a bone
D) fractured bone
Answer: C