Mastering Chapter 6 HW

endochondral ossification (The figure illustrates a step in the embryonic formation of a bone from a cartilage model.)

A step in which bone-forming process is shown in the figure?

Greenstick

An incomplete fracture or cracking of the bone without actual separation of the parts. Common in children.

Comminuted

Bone fragments into many pieces.

Osteoblasts

Cells that can build bony matrix.

Osteoclasts

Cells that can dissolve the bony matrix.

Spiral

Common sports fracture resulting from a twisting force.

C. Periosteum (The external membrane of bone, the periosteum, includes a fibrous outer layer composed of dense irregular connective tissue.)

Dense connective tissue forms part of which labeled part of the adult long bone in the figure?

The main role of the appendicular skeleton is to protect and support vital organs. TRUE or FALSE

False (The main role of the appendicular skeleton involves locomotion; it also allows us to manipulate our environment. The axial skeleton is mostly involved in supporting other body parts and protecting vital organs.)

Lamellae

Layers of bone matrix.

Canaliculi

Small channels that radiate through the matrix of bone.

b. intramembranous ossification during embryonic development (The figure illustrates the formation of new bones within a fibrous membrane ("intramembranous") during embryonic development.)

The above figure depicts which of the following bone-forming processes? a. bone repair at a site of fracture b. intramembranous ossification during embryonic development c. endochondral ossification during bone formation and growth d. bone remodeling in response to changes in mechanical stress

mesenchymal cells (Mesenchymal cells are stem cells that differentiate into the matrix-forming cells of the various connective tissues, including the osteoblasts that form bone.)

The cells indicated by the arrow at the center of panel A arise from the differentiation of which precursor stem cell?

b. parietal (The cranial bones are formed by intramembranous ossification.)

The illustrated bone-forming process would be associated with which of the following bones? a. vertebrae b. parietal c. femur d. humerus e. All of the listed responses are correct.

Central (Haversian) canal (A Haversian (or central) canal runs lengthwise at the center of each osteon.)

The indicated blood vessels and nerve are found within a ______.

Endosteum

The lining of the marrow cavity.

osteon (The circular structural unit found within compact bone is termed the osteon.)

The structures in the figure collectively form a structural unit termed a(n) ______.

Each consecutive bone lamella has collagen fibers that wrap in alternating directions. TRUE or FALSE

True

d. All of the listed responses are correct. (All bones except the clavicle and those of the cranium are formed by an endochondral mechanism.)

Which of the following bones are formed by the illustrated process? a. femur b. humerus c. vertebrae d. All of the listed responses are correct.

adipose tissue (Yellow bone marrow within the medullary cavity is composed primarily of adipose tissue (fat).)

Which of the following is the major component of the part of the bone labeled E? a. dense connective tissue b. osseous tissue c. adipose tissue d. hyaline cartilage

D (The shaft of an adult long bone is composed of compact bone.)

Which of the labeled parts of the bone is composed primarily of compact bone?

Choose the TRUE statement. a. Endochondral ossification converts hyaline cartilage "bone" models into true bones (i.e., hyaline cartilage serves as a template for bone formation). b. Endochondral ossification leads to the formation of the clavicles and cranial bones. c. Most bones in the body are formed by intramembranous ossification. d. Endochondral ossification occurs within fibrous connective tissue membranes.

a. Endochondral ossification converts hyaline cartilage "bone" models into true bones (i.e., hyaline cartilage serves as a template for bone formation). (Endochondral ossification is the formation of bone within hyaline cartilage. Hyaline cartilage "bones" are used as templates for the formation of true bone. Most bones below the base of the skull form by endochondral ossification.)

The process of bones increasing in width is known as ______________.

appositional growth

Osteogenesis is the process of ______________.

bone formation

Choose the CORRECT pairing. a. osteomalacia: excessive mineralization of the bone b. rickets: deficiency of vitamin A c. Paget's disease: excessive and haphazard bone deposition and resorption d. osteoporosis: increased bone density

c. Paget's disease: excessive and haphazard bone deposition and resorption

Bones do NOT have a role in ________. a. fat storage b. blood cell formation c. glycogen production d. support e. movement

c. glycogen production (Glycogen production (glycogenesis) is not a role of bone; it takes place primarily in muscle and liver cells.)

Which of the following is stored in bones? a. calcitonin b. iodine c. phosphate d. vitamin C e. glycogen

c. phosphate (Bone is a reservoir for calcium and phosphate.)

Hematopoiesis is a term for which of the following physiological processes? a. release of minerals into the blood b. bone formation during growth c. energy storage in fat tissue d. blood cell formation

d. blood cell formation (Red bone marrow found within certain regions of spongy bone is the site of blood cell formation from the differentiation of hematopoietic stem cells.)

The correct order (from start to finish) of fracture repair is _______________.

hematoma formation, fibrocartilaginous callus formation, bony callus formation, and bone remodeling (From start to finish, a fracture is repaired by: (1) formation of a hematoma, (2) formation of a fibrocartilaginous callus, (3) formation of a bony callus, and (4) bone remodeling. Use the pneumonic HFBR (His Femur Better Repair!) to help you remember the order. H = hematoma, F = fibrocartilaginous callus, B = bony callus, R = remodeling.)

In adults, yellow marrow is located _________________________.

in the medullary cavity of long bones

When chondrocytes in lacunae divide and form new matrix, it leads to an expansion of the cartilage tissue from within. This process is called __________________.

interstitial growth (Interstitial growth occurs when chondrocytes divide and form new matrix, thereby expanding the cartilage tissue from within. (Note: the word inter means between, and stitial means space; these are common roots for anatomical terms.))

Lengthwise, long bone growth during infancy and youth is exclusively through _______________________.

interstitial growth of the epiphyseal plates

Hyaline cartilage ________________________.

is found on the ends of bones that form movable joints (Hyaline cartilage is found on the ends of bones that form movable joints, where it is referred to as articular cartilage.)

What controls bone remodeling?

mechanical stress and hormones (Remodeling goes on continuously in the skeleton, regulated by genetic factors and two control loops that serve different "masters." One is a negative feedback hormonal loop that maintains Ca2+ homeostasis in the blood. The other involves responses to mechanical and gravitational forces acting on the skeleton.)

Bones are covered and lined by a protective tissue called periosteum. The inner (osteogenic) layer consists primarily of ___________________.

osteoblasts and osteoclasts

Which hormone increases osteoclast activity to release more calcium ions into the bloodstream?

parathyroid hormone

The axial skeleton includes the ________.

ribs (The ribs are part of the axial skeleton.)

What is endochondral ossification?

the formation of bone from pre-existing hyaline cartilage models (Endochondral ossification is the formation of bone from hyaline cartilage models. The hyaline cartilage must be broken down and replaced with the bone tissue.)

What is osteoid?

the organic part of the matrix of bone (Osteoid is the organic part of the (extracellular) bone matrix and includes ground substance, composed of proteoglycans and glycoproteins, and collagen fibers.)

The notable hardness of bone is attributed to _______________________.

the presence of inorganic hydroxyapatites (The exceptional hardness of bone, which allows it to resist compression, is attributed to the presence of mineral salts called hydroxyapatites. The hydroxyapatites, mainly calcium phosphates, form the inorganic matrix of bone.)

Cartilage grows in two ways, appositional and interstitial. What is appositional growth?

the secretion of new matrix against the external face of existing cartilage

Wolff's law is concerned with _________.

the thickness and shape of a bone being dependent on stresses placed upon it

The epiphyseal plate is _________________.

where long bone lengthening occurs (Long bones elongate from growth at the epiphyseal plate, a layer of hyaline cartilage between the epiphyses and diaphysis of long bones.)