Ch 6 Skeletal System

How would removing hydroxyapatite from bone matrix affect the physical properties of a bone? The bone would be stronger. The bone would be more flexible. The bone would be less compressible. The bone would be more brittle. The bone would be less flexible.

The bone would be more flexible.

Calcitriol is required for __________. activating osteoclasts inhibiting osteoclasts collagen synthesis absorbing dietary calcium and phosphate

absorbing dietary calcium and phosphate

Which of following is a function of the skeletal system? blood cell production calcium homeostasis body support protection of internal organs All of the answers are correct.

all of the above

________ prevents damaging bone-to-bone contact within movable joints. Elastic cartilage Serous fluid A serous membrane A synovial membrane Articular cartilage

articular cartilage

The central canal of an osteon contains osteocytes. concentric lamellae. lacunae. bone marrow. blood vessels.

blood vessels

Which of the following functions of the skeletal system is most affected by gravity? body support protection of internal organs lipid storage blood cell production

body support

During appositional growth the epiphysis fuses with the diaphysis. bones grow wider. compact bone replaces spongy bone. bones grow longer. cartilage replaces bone

bones grow wider

Through the action of osteoclasts, new bone is formed. fractured bones regenerate. osteoid is calcified. bony matrix is dissolved. an organic framework is formed.

bony matrix is dissolved

The deposition of calcium salts in bone tissues is referred to as osteogenesis. ossification. hardening. remodeling. calcification.

calcification

Elevated levels of calcium ion in the blood stimulate the secretion of the hormone thyroid hormone. calcitonin. parathyroid hormone. testosterone. growth hormone.

calcitonin

The most abundant mineral in the human body is sodium. potassium. phosphorus. calcium. hydrogen.

calcium

Bone growth in length occurs by mitosis of growth of trabeculae. cartilage cells in the diaphyseal side of the metaphysis. osteoblasts in the endosteum. concentric lamellae. cartilage cells in the epiphyseal side of the metaphysis.

cartilage cells in the epiphyseal side of the metaphysis.

Which cells divide rapidly on the epiphyseal side at the epiphyseal plate, resulting in lengthening of the bone? Chondrocytes Fibroblasts Osteoblasts Osteocytes

chondrocytes

The layers of bone tissue immediately deep to the periosteum are concentric lamellae. trabeculae. circumferential lamellae. epiphseal ridges. osteoid plates.

circumferential lamellae

The proximal and distal ends of a long bone are called the periphyses. epiphyses. epiphyseal plates. metaphyses. diaphyses.

epiphyses

After a fracture of the diaphysis has healed, the thickened region that results is called the condyle. epiphyseal plate. dense tuberosity. external callus. fracture facet.

external callus

A shallow depression on a bone is termed a sulcus. fissure. facet. fossa. line.

fossa

Which statement is true regarding calcium in bone matrix? Calcium is the organic part of the matrix. Calcium provides flexibility to the bone matrix. Once deposited, calcium cannot be removed from bone. Calcium is secreted by osteoblasts into the matrix. Calcium is found in crystals called hydroxyapatite.

found in hydroxyapatite crystals

Excessive growth hormone prior to puberty could result in gigantism. osteoporosis. dwarfism. rickets. osteopenia

gigantism

Which of the following is formed immediately after a fracture? internal callus external callus spongy bone hematoma

hematoma (blood clot)

Secondary ossification centers occur in dermal bones. at the periosteum. in the metaphyses. in the epiphyses. in the diaphysis.

in the epiphyses

The humerus is an example of a(n) ________ bone. irregular sesamoid short long flat

long

When the epiphyseal plate is replaced by bone, puberty begins. long bones have reached their adult length. the bone becomes more brittle. appositional bone growth begins. interstitial bone growth begins.

long bones stop growing

Which of the following labels best matches osteocyte? mature bone cell immature bone cell secretes organic matrix dissolves matrix stem cell

mature bone cell

Adipose tissue is stored within the medullary cavity. metaphysis. diaphysis. spongy bone. epiphysis.

medullary cavitity

Intramembranous ossification begins with differentiation of ________ cells. osteocyte osteoclast osteolytic osteoblast mesenchymal

mesenchymal

Which of these is NOT a primary function of the skeletal system? blood cell production protection movement storage of minerals and lipids

movement

Stem cells that can differentiate into osteoblasts are called ________ cells. osteoprogenitor osteocreator osteopropagator osteotrophic osteoforming

osteoprogenitor

________ marrow is found between the trabeculae of spongy bone. Gray Red Yellow Blue White

red

AA lack of exercise could cause bones to become longer. cause bones to store more calcium. cause bones to lose their medullary cavity. cause bones to become thicker. result in porous and weak bones.

result in porous and weak bones.

________ hormones stimulate osteoblasts to produce bone matrix. Pancreatic Thyroid Growth Parathyroid Sex

sex

Which of these is NOT part of the skeletal system? cartilage ligaments bones tendons

tendons

A ________ is a smooth, grooved bone process shaped like a pulley. tubercle trochanter tuberosity trabeculae trochlea

trochlea

A small rough bump on bone where a tendon attaches is called a trochlea. trochanter. tuberosity. trabecula. tubercle.

tuberosity

The articular cartilage of a typical long bone is composed of what type of cartilage? osseous cartilage fibrocartilage synovial cartilage hyaline cartilage elastic cartilage

hyaline cartilage

What type of tissue is replaced in the embryo during endochondral ossification? Wharton's jelly mesenchymal tissue fibrocartilage hyaline cartilage connective tissue membranes

hyaline cartilage

Parathyroid hormone functions in all of the following ways except stimulating osteoclast activity. increasing the rate of calcium absorption. decreasing the rate of calcium excretion. raising the level of calcium ion in the blood. inhibiting calcitonin secretion.

inhibiting calcitonin secretion.

The lacunae of osseous tissue contain chondroblasts. capillaries. blood cells. osteocytes. bone marrow.

osteocytes

The most abundant cell type in bone is osteoprogenitor cells. osteoblasts. osteocytes. osteolytes. osteoclasts.

osteocytes

The organic component of the matrix in developing or repairing bone is called hydroxyapatite. calcium phosphate. mesenchymal tissue. osteoid. osteon.

osteoid

The structural units of mature compact bone are called trabeculae. osteocytes. canaliculi. osteons. lamellae.

osteons

Stem cell whose divisions produce osteoblasts -osteoprogenitor cell -osteoclast -osteocyte -osteoblast

osteoprogenitor cell

Migration of blood vessels into the central region of the cartilage bone model, starting bone development, occurs at which site? epiphysis secondary ossification center primary ossification center periosteum

primary ossification center

Intramembranous ossification produces flat bones, as in the bones of the roof of the skull. occurs in all bones before birth. occurs in the diaphysis of a long bone. explains how a juvenile's bone can grow in length. occurs inside a bag of cartilage

produces flat bones

Which hormone increases blood calcium upon secretion? growth hormone parathyroid hormone (PTH) calcitonin estrogen and testosterone

pth

The ongoing process of tearing down and rebuilding bone matrix is called remodeling. osteolysis. restoration. ossification. resorption.

remodeling

Bone is composed of ________ percent cells. 2 10 25 50 15

2

Mature bone cell that maintains the bone matrix -osteoprogenitor cell -osteoclast -osteocyte -osteoblast

Osteocyte

How is bone built?

Osteoprogenitor cells -> osteoblasts (which produces osteoid that creates the matrix) -> calcify into osteocytes ----- osteoclasts break down bone

When production of sex hormones increases at puberty, epiphyseal plates increase slowly. are hardly affected. become narrower. accelerate rapidly, but mostly in thickness. widen.

become narrower

The hormone calcitonin functions to stimulate osteoclast activity. decrease the level of calcium ion in the blood. decrease the rate of calcium absorption. decrease the rate of calcium excretion. stimulate osteoblasts and inhibit osteoclasts.

decrease level of calcium ions in blood

The trabeculae of spongy bone are concentrated in the cortex of the diaphysis. are organized parallel to the long axis of the bone. are composed mostly of cartilage. are organized along stress lines. will collapse under stress.

organized along stress lines

immature bone cell that secrets osteoid, the organic component of bone matrix -osteoprogenitor cell -osteoclast -osteocyte -osteoblast

osteoblast

multinucleate cell that secretes acids and enzymes to dissolve bone matrix -osteoprogenitor cell -osteoclast -osteocyte -osteoblast

osteoclast

The carpal bones are examples of ________ bones. sesamoid flat irregular long short

short

The type of bone that is adapted to withstand stresses that arrive from many directions is ________ bone. osteon spongy lamellar compact irregular

spongy

________ bone reduces the weight of the skeleton and reduces the load on muscles. Compact Short Irregular Spongy Long

spongy

The interconnecting tiny arches of bone tissue found in spongy bone are called trabeculae. lacunae. osteons. interstitial lamellae. concentric lamellae.

trabeculae

Which bone cells are responsible for the formation of new bone matrix? Osteogenic cells are the bone cells that produce new bone matrix. Osteoclasts are the bone cells that produce new bone matrix. Osteoblasts are the bone cells that produce new bone matrix. Osteocytes are the bone cells that produce new bone matrix.

Osteoblasts are the bone cells that produce new bone matrix.

In normal adult bones, osteoclasts continue to be active long after osteoblast activity ceases. there is no turnover of minerals. osteoblast activity exceeds osteoclast activity, once bone has been formed. exercise will have no effect on bone remodeling. a portion of the protein and mineral content is replaced each year.

a portion of the protein and mineral content is replaced each year.

Endochondral ossification begins with the formation of a(n) cartilage model. fibrous connective-tissue model. calcified model. membranous model. osteoid model.

cartilage model

Primary ossification centers develop in long bones in the proximal epiphysis. metaphysis. diaphysis. periosteum. distal epiphysis.

diaphysis

Which portion of the developing long bone ossifies before the other portions? Diaphysis Epiphyseal Line Metaphysis Epiphysis

diaphysis

The shaft of long bones is called the paraphysis. epiphysis. endophysis. metaphysis. diaphysis.

diaphysis.

Calcitonin causes what response in the kidneys? decreased absorption of calcium inhibited osteoclast activity elimination of calcium ions into the urine increased rate of calcium uptake by the kidney

elimination of calcium ions into urine

The lining of the medullary cavity is called the periosteum. paraosteum. endosteum. epiosteum. mediosteum.

endosteum

Cells that are found in small depressions on the endosteal surfaces are the osteocytes. osteoblasts. osteoclasts osteogenic cells. osteolytic cells.

osteoclasts

Which of the following is formed by intramembranous ossification? clavicle carpal bones femur roof of the skull the roof of the skull and the clavicle

roof of skull AND clavicle (it produces large flat bones)

When stress is applied to a bone, the minerals in the bone produce a weak electrical field that attracts osteoblasts. osteoclast activity increases and osteoblast activity decreases. the bone compensates by becoming thinner in the region of stress. blood supply through the nutrient artery diminishes and thus remodeling proceeds at a much slower rate. the bone becomes thin and brittle and ultimately fractures.

the minerals in the bone produce a weak electrical field that attracts osteoblasts.

Which of the following bones is classified as "irregular" in shape? metatarsal patella vertebra ulna frontal

vertebra