Trident Tech Mr. Walker A&P 1 Seeley's Principles of Anatomy & Physiology
Classification of Bone Shapes
1. Flat Bone
2. Long Bone
3. Short Bone
4. Irregular Bone
5. Sutural Bone - minor
6. Sesamoid Bone - minor
Flat Bones
Are thin and flattened bones. They possess a broad flat surface for muscle attachment or protection of underlying organs.

Include: sternum, ribs, scapula and certain skull bones.
Long Bones
Longer than wide. Have a shaft and bulbus ends

Include: Humerus, clavicle, Radius, Ulna, femur, tibia, fibula, metacarpals, metatarsals, and phalanges.

Long portion = Diaphysis,
Widens = Metaphysis,
End = Epiphysis.
Elongated shaft of a long bone.
Flared portion of a long bone, between the diaphysis (shaft) of the bone and the epiphyseal plate at the end of the bone.
End of a long bone.
Short Bones
Cubed-shaped. Nearly in length and width. Texture is spongy except for the thin layer of compact bone at the surface. Found in wrist and ankle
Irregular Bones
Do not fit into any of the other bone categories, made up of both spongy and compact bone. Complicated shapes.
Sutural Bones
Small irregular bones located in sutures between certain cranial bones.
Wormian Bones
small flat, irregularly shaped bones between the flat bones of the skull. Borders are like pieces of a jigsaw puzzle, range in size from a grain of sand to a quarter.
Sesamoid Bone
Generally small, flat, and shaped somewhat like a sesame seed. They develop inside tendons, located near joints at the knees, hands, and the feet.
5 Functions of Skeletal System
1. provide shape & support
2. enable movement
3. protect internal organs
4. produces blood cells
5. stores certain materials until body needs them (fats, calcium)
3 Types of Skeletal Cartilage
hyaline, elastic, fibrocartilage
Hyaline Cartilage
Forms the larynx, the costal cartilages of the ribs, and the embryonic skeleton, firm, structurally amorphous matrix heavily invaded with fibers; appears glassy and smooth.
Elastic Cartilage
Cartilage with abundant elastic fibers; more flexible than hyaline cartilage., Found in ear, epiglottis, Eustachian tube, eu-nose.
A weight-bearing cartilage that withstands compression; forms the intervertebral discs, the pubic symphysis & cartilage pads of the knee joints (menisci).
Spongy Bone
Layer of bone tissue having many small spaces and found just inside the layer of compact bone.
Compact Bone
Hard, dense bone tissue that is beneath the outer membrane of a bone.
Epiphyseal Plate
Growth plate, made of cartilage, gradually ossifies.
Cartilage is replaced by bone through a process called:
Epiphyseal Line
The cartilage present at the junction of the diaphysis and epiphyses; a remnant of the epiphyseal plate.
Yellow Marrow
Found mostly at the end of bones in adults, it is made mainly of fat.
Red Marrow
Typically found within the trubecular cavities of spongy bone of long bones and in the dipole of flat bones.
Dense irregular connective tissue that lines the medullary cavities of long bones.
Articular Cartilage
Covers end of bones to prevent friction.
A dense fibrous membrane covering the surface of bones (except at their extremities) and serving as an attachment for tendons and muscles.
Meduliary Cavity
marrow cavity w/in diaphysis of long bones.
Perforating Fibers
- collagen fibers connect with fibers of bone, joint capsules, attached tendons, and ligaments
Nutrient Arteries
Single or few large arteries; enter at mid-diaphysis into medullary cavity; supply inner compact and spongy bone.
Axial Skeleton
Portion of the skeletal system that consists of the skull, rib cage, and vertebral column.
Appendicular Skeleton
Bones of the limbs and limb girdles that are attached to the axial skeleton; Extremeities; shoulder girdle, arm bones, pelvic girdle, and leg bones.
Microscopic Structure of Compact Bone
Compact Bone
1. Central Canal
2. Osteon
3. Circumferential Lamellae

Spongy Bone
1. Endosteum - webby
2. Red Marrow contaning
Central Canal
Part of Compact Bone that contains, Nerve, Vein & Artery
A cylinder of tissue around a central canal. Contains Lamellae and Lacunae, calaliculus.
Circumferential Lamellae
lamellae wrapped around the long bone; binds osteons together...Superficial to periosteum.
Endochondral ossification
Process of transforming cartilage into bone.
Define Osteology
Study of bones
What are the 3 major components of the skeletal system.
Ligaments - attach bone to bone
What is the function of a ligament?
To attach bone to bone.
Ligaments are made of what kind of tissue?
Dense Regular
What are the two types of supporting tissue in the body?
Bone and Cartilage.
Where does cartilage come from?
Mesoderm - primary germ layer of the embryo.
Embryonic mesenchyme tissue - stem cells
Chondrocytes - maintain cartilage tissue. Live in the Lacuna
Describe the embryonic skeleton formation.
Made from Fibrous Connective Tissue Membranes - minimal.

And Hyaline Cartilage which makes most of the bones in the body from a template of Hyaline

Cartilage then differentiates into endochondral bone.
Describe the process leading to Endochondral Bone
1. Most bone is developed from a cartilage model.

2. Pariocardium becomes vascularaized to a greater degree

3. Cartilage Matrix is calcified and chondrocytes die. Osteoblast form collar of bone on the calcified cartilage matrix.

4. Osteoblast build an outer surface of compact bone beneath the periosteum forming cavity.

5. Primary ossification centers form in the Diaphysis during fetal development.

6. Osetoclast remove the cancellous bone from the shaft interior, leaving marrow cavity that houses fat.
Osteochondral progenitor cell
Embryonic cells cluster where bone will eventually form, then become ____________________ and then chondrocytes. These cells produce a hyaline cartilage model surrounded by perichondrium, except where joints form.
Formation of Embryonic Skeletal System
1. Hyaline cartialge skeleton is formbed by 6-8 weeks. The head is formed by intrmebranous ossification and the body is formed by endochondral occifiation.
A. Intramembranous:
1. Mesenchymal stem cells in a fibrous membrane undergo ossificaiton forming th eflat bones iof the cranium, mandible and clavicles.
2. Blood vessels grow into area to supply osteoblasts with nutrients.
3. Bone tissue forms trapping blood vessels inside bone and ossification proceeds.
4. spongy bone developes first then compact bone develops as spongy bone remodels.
b. Endochondral Occification of skeletal bones of the fetus.
1. Chondrocytes in perichondrium differentiate into osteoblasts. Turning Parichondrium into periosteum.
2. Chondrocytes in the center of the bone die forming the medullary cavities.
3. Osteoprogenitor cells move in and differentiate osteo cells.
4. Vascularzation
5. Remodeling Creates Marrow Cavity
6. The epiphysess fills with spongy bone.
What is Membrane Bone
bone developed from fibrous membranes in a process called intramembranous ossification
Steps of Endochondral Ossification
1. Most bones develop from a carilage model
2. The cartilage matrix is calcified and chondrocytes die
3. Osteoprogenirator cells move in and start to differentiate.
4. Blood vessles enter developing bone bringing nutrients
5. Osteoblast build an outer surface of compact bone
6. Primary ossification centers form marrow cavity
7. Cartilage starts to ossify to form skeletal bones.
Does Hyaline cartilage in normal conditions ossify?
No. Articular cartilage does not ossify.
Bone Sandwich
compact bone - spongy/cancellous bone - compact bone. Found in flat bones.
Anatomy of an Osteon
1. Central Canal
2. Canaliculi
3. Lacuna
4. Osteocyte
5. Lamellae
What is the Central Canal?
Canals within bone filled with blood vessels to deliver oxygen and nutrients.
What is the purpose Canaliculi?
Canals through the osteon lamellae which osteocytes receive nutrients.
Concentric rings of hard calcified intercellular substance.
What is a Lacuna?
The cavity in bone or cartilage for cells.
What is a Chondrocyte?
A cartilage cell.
What is an Osteocyte?
Mature bone cells that maintain the bone matrix.
What are the 4 major cells of osseous tissue?
1. Osteoprogeneteter
2. Osteoblast
3. Osteocyte
4. Osteoclast
Where do osteoclast come from?
They differentiate in reb bone marrow in hematopoietic tissue. They DO NOT come from osteoprogenitor cells.
Can osteocytes divide?
No. They are trapped in the lacunae/
What are the main functions of an osteocyte?
1. Produce protien
2. Help repair damaged bone - maintain the matrix.
Define Wolff's Law
Bone will Grow or Remodel in Response to Stresses, Muscle Activity, Repair of Bone Fractures...
A group of inherited disorders of connective tissue (often referred to as "brittle bone disease"
Also called mineralization: the process of deposition of mineral salts such as calcium and magnesium phosphates into a tissue. Different from Ossification.
Intramembranous ossification
Formation of flat bones of the cranium and mandible during embryonic development - 6-8 weeks.
When does endochondral ossification occur?
During 6-8 weeks of embryonic development. It is the fomation of body bones by Hyaline Cartilage.
Interstitial growth of long bones.
Growth from inside long bones. Chondrocytes (round cells, found internally) divide and secrete new matrix,expanding cartilage from within, making the cartilage longer.
Appositional Growth of long bones.
Growth from outside....cartilage forming cells ( from the surrounding perichondrium that secrete a new matrix against the external face of existing cartilage, building onto exisisting cartilage making cartilage thicker . Similar to how trees grow.
Dense irregular connective tissue membrane covering cartilage
Bone Remodeling Process
1. Osteoclasts release H ions into interstitail fluid.
2. H ions attract chloride ions to for HCl
3. HCl dissolves calcium salts (bone ground substance)
4. Plays role in Ca++ regulation in body fluids and bones.
Calcium Homeostasis
Maintained by opposite effects of Calcitonin (takes calcium out of the blood) and Parathyroid Hormone/PHT (putting calcium back in the bone)
Abnormally high concentrations of calcium circulating in the blood instead of being stored in the bones.
A condition characterized by an abnormally low concentration of calcium in the blood.
What is the body's response to Hypercalcemia?
The thyroid releases calciton into the blood stream and send a signal to the kidney's to release expel calcium thus reducing calcium in the blood. Also triggers digestive track to absorb more calcium.
What is the body's response to Hypocalcemia?
The parathyroid realeases PTH (parathyroid hormone) to increase calcium in the blood. This is done through stimulation of osteoclasts to release calcium from the bone.
Form of Vitamin D. that acts like a hormone is activated by the kidneys and increases calcium uptake from the gut.
Functions of Calcitrio
1. Stimulates resorption of calcium and phosporus from bone
2. Some inhibition of ca++ loss in urine from the kidneys
3. Stimulates calcium and phosphorus absorption in the small intestine.
What is the importance of Calcium & Phosporus in the body?
Calcium: Muscle contraction, Nerve impulsees, bone matrix, blood clotting
Phosphorus: ATP, Phospholipids, bone matrix

Needs Vitamin D to help body absorb Ca & P.
Skeletal Fracture
Fracture of the distal radius is one of the most common
Open Fracture
A fracture bone that pierces the skin.
Closed Fracture
A fractured bone that does not pierce the skin.
Compound Fracture
A complete break in the bone where the bone ends separate and break through the skin; also known as an open fracture
Simple Fracture
A break in the bone that may be complete or incomplete, but doesn't break through the skin; also known as a closed fracture
Pott's Fracture
Fracture of the fibula near the ankle, often accompanied by a break in the medial malleolus of the tibia and/or rupture of the internal lateral ligament.
Colle's Fracture
"fractured wrist" This occurs at the lower end of the radius when a person tries to stop a fall by landing on his or her hands.
Linear Fracture
A fracture that runs parallel to long bones
Comminuted Fracture
Bone breaks and fragments of bone are found in the tissue.
Spiral Fracture
Name the type of fracture where the bone twists resulting in one or more breaks
Impacted Fracture
Fracture in which bone fragments are pushed into each other. Mostly in joints.
Oblique Fracture
Break runs along a slant to the length of the bone; it is at approximately a 45 degree angle to the shaft of the bone
Transverse Fracture
Straight line fracture
Greenstick Fracture
A break on one side of a bone that does not damage the periosteum on the opposite side. This type of fracture is often seen in children.
Aging and bone
Bone and the matrix decrease
Loss of matrix callogen causes bones to become brittle
Less osteocyte production becomes slower to osteoclasts activity.
Vitamine D/Calcitrol Synthesis
1. UV light stimulates Karatinocytes to convert cholesterol to vitamine D3.
2. D3 enters blood stream and goes to the liver and adds a hydroxygroup.
3. The travels to the Kidneys where it converts to Calcitrol.
4. Calcitrol is the ACTIVE form of vitamin D.
One of the three primary (embryonic) germ layers: forms external structures such as the skin, hair, nails, and inner linings of the mouth and anus, as well as the entire nervous system.
One of the three primary (embryonic) germ layers that forms tissues such as muscle, bone, and blood vessels (Meso = middle)
One of the three primary (embryonic) germ layers that forms the lining of the digestive tube and its associated structures.
Why is Vitamin D/Calcitrol important
1. Need for the Phospolipids in Plasma Membrane
2. Calcium Phosphate in bones
3. Blood
4. Muscle contractions
5. Neuro Transmistions
Regarding skeletal system function,

A) bone often serves as a model for cartilage growth.
B) tendons connect bone to bone.
C) blood cells are produced in the marrow of many bones.
D) cartilage serves as an important mineral storage area.
E) all of these
C) blood cells are produced in the marrow of many bones.
Which of these connective tissue types has proteoglycans in its matrix?

A) bone
B) cartilage
C) ligaments
D) tendons
E) both c and d
B) cartilage
Cells that produce new cartilage matrix are called

A) chondroblasts.
B) chondrocytes.
C) chondroclasts.
D) osteoblasts.
E) fibroblasts.
A) chondroblasts.
The perichondrium

A) surrounds each lacuna in the matrix.
B) contains mainly loose connective tissue.
C) contains blood vessels and nerves.
D) is important for the storage of fat.
E) covers the surface of articular cartilage.
C) contains blood vessels and nerves.

A) often occurs in thin plates or sheets.
B) receives nutrients and oxygen by diffusion.
C) is easily replaced if damaged.
D) has a good blood supply.
E) A and B
E) A and B
Which of these correctly describes appositional growth of cartilage?

A) Chondrocytes in the center of the cartilage lay down new matrix.
B) Fibroblasts produce new chondroblasts.
C) Chondroblasts in the perichondrium lay down new matrix.
D) New osteons are formed from osteoblasts.
E) Canaliculi connect between chondrocytes to allow transport of nutrients.
C) Chondroblasts in the perichondrium lay down new matrix.
Which of these bone types is NOT matched with the correct example?

A) long bone-humerus
B) short bone-clavicle
C) flat bone-scapula
D) irregular bone-vertebrae
B) short bone-clavicle
In a long bone, the epiphyseal plate is

A) located in the center of the diaphysis.
B) the outer membrane layer on the diaphysis.
C) the location where growth occurs.
D) produced when the epiphyseal line changes to bone.
E) the location for fat storage.
C) the location where growth occurs.
The ends of long bones are called

A) diaphyses.
B) epiphyses.
C) lamellae.
D) trabeculae.
B) epiphyses.
The surface of the medullary cavity of long bones is lined with a connective tissue membrane called

A) periosteum.
B) epiphyseal plates.
C) endosteum.
D) perichondrium.
E) lamellae.
C) endosteum.
Which portion of a long bone stores yellow marrow in adults?

A) the epiphysis
B) the medullary cavity
C) periosteum
D) compact bone
E) the epiphyseal plate
B) the medullary cavity
Which of these locations does NOT contain red marrow in an adult?

A) ribs
B) skull
C) proximal femur
D) sternum
E) vertebrae
B) skull
The outer layer of bone, composed of dense, irregular, collagenous connective tissue that contains blood vessels and nerves is called

A) endosteum.
B) concentric lamellae.
C) periosteum.
D) the epiphyseal plate.
E) the diaphysis.
C) periosteum.
Which of these statements is NOT true regarding bone?

A) Osteoblasts produce bone matrix.
B) Osteocytes are osteoblasts that have become surrounded by matrix.
C) Osteoclasts break down bone.
D) Osteocytes are connected to each other by Volkmann's canals.
E) Osteocytes are found in lacunae.
D) Osteocytes are connected to each other by Volkmann's canals.
Bundles of collagen fibers that penetrate the periosteum into the outer part of the bone are called

A) endosteums.
B) diaphyses.
C) epiphyses.
D) perforating fibers.
E) trabeculae.
D) perforating fibers.
Which of these substances is present in the largest quantity in bone?

A) collagen
B) hydroxyapatite
C) proteoglycan aggregates
D) lacunae cartilage
B) hydroxyapatite
Hydrogen ions are pumped across the ruffled border, producing an acid environment. This describes the activity of

A) osteoblasts.
B) osteocytes.
C) osteoclasts.
C) osteoclasts.
__________ are stem cells that have the ability to become osteoblasts or chondroblasts.

A) Osteocytes
B) Osteoclasts
C) Osteoprogenitor cells
D) Osteons
E) Chondrocytes
C) Osteoprogenitor cells
Given these cells: 1. osteoblasts 2. osteocytes 3. osteoprogenitor cells Which of these sequences represents the order in which they are produced?

A) 1,2,3
B) 1,3,2
C) 2,1,3
D) 2,3,1
E) 3,1,2
E) 3,1,2
Fetal bone tissue that has collagen fibers randomly oriented in many directions is

A) lamellar bone.
B) long bone.
C) short bone.
D) woven bone.
D) woven bone.
Which of these structures is found in compact bone, but not in cancellous bone?

A) osteoclasts
B) canaliculi
C) lamellae
D) central (haversian) canals
E) osteocytes
D) central (haversian) canals
Cancellous bone

A) has no osteocytes.
B) is located in the diaphyses of long bones.
C) is composed of delicate interconnecting rods or plates called trabeculae.
D) does not contain marrow.
E) forms the outer surface of most bones other than long bones.
C) is composed of delicate interconnecting rods or plates called trabeculae.
Which of these structures is found within an osteon?

A) concentric lamella
B) interstitial lamella
C) circumferential lamella
D) periosteum
E) all of these
A) concentric lamella
Given these passageways:
1. canaliculi
2. central (haversian) canal
3. blood vessels in periosteum
4. perforating (Volkmann's) canal

Which of these represents the correct order as nutrients pass from outside the bone to the osteocytes?
A) 1,2,3,4
B) 2,4,1,3
C) 3,4,2,1
D) 3,1,4,2
E) 4,3,2,1
C) 3,4,2,1
Which of these bones is produced at least partly by intramembranous ossification?

A) clavicle
B) frontal
C) mandible
D) parietal
E) all of these
E) all of these
Intramembranous ossification is usually complete by __________ years of age, whereas endochondral ossification is usually complete by __________ years of age.

A) 2, 25
B) 5, 10
C) 10,2
D) 10, 25
E) 25, 5
A) 2, 25
Membrane-covered spaces between developing skull bones are called

A) centers of ossification.
B) central canals.
C) fontanels.
D) perforating canals.
E) endochondral openings.
C) fontanels.
Endochondral ossification

A) occurs primarily in the bones of the skull.
B) involves calcification of the cartilage matrix.
C) produces bone in connective tissue membranes.
D) occurs when chondrocytes replace osteoblasts in the matrix.
B) involves calcification of the cartilage matrix.
Secondary ossification centers

A) are located in the diaphysis of the bone.
B) are located in the epiphysis of the bone.
C) are located in the fontanels.
D) appear during early fetal development.
E) are locations for intramembranous ossification.
B) are located in the epiphysis of the bone.
In endochondral ossification, the perichondrium that surrounded the hyaline cartilage becomes

A) circumferential lamellae.
B) osteons.
C) lacunae.
D) perforating canals.
E) periosteum.
E) periosteum.
Given these zones within the epiphyseal plate:
1. zone of calcification
2. zone of hypertrophy
3. zone of proliferation
4. zone of resting cartilage
Arrange them in the correct order, from the epiphysis to the diaphysis.

A) 1,2,3,4
B) 1,3,4,2
C) 2,4,1,3
D) 3,2,1,4
E) 4,3,2,1
E) 4,3,2,1
Growth in the length of a long bone stops when

A) the articular cartilage becomes completely ossified.
B) the epiphyseal plate becomes completely ossified.
C) appositional growth at the periosteum stops.
D) intramembranous ossification is complete.
B) the epiphyseal plate becomes completely ossified.
Which type of bone growth is responsible for an increase in the diameter of bones?

A) appositional growth
B) interstitial growth
C) endochondral growth
D) trabecular growth
E) intramembranous growth
A) appositional growth
Which of these statements concerning bone growth are correct?

A) Increased amounts of testosterone and estrogen cause a rapid increase in bone growth.
B) Testosterone and estrogen prevent ossification of the epiphyseal plate.
C) Too little growth hormone can cause a condition called acromegaly.
D) Too much growth hormone can cause dwarfism.
E) Achondroplastic dwarfism is caused by too much thyroid hormone.
A) Increased amounts of testosterone and estrogen cause a rapid increase in bone growth.
Osteomalacia can occur as a result of a

A) vitamin C deficiency.
B) vitamin D deficiency.
C) lack of thyroid hormone.
D) lack of growth hormone.
E) lack of sex hormones.
B) vitamin D deficiency.
A deficiency of vitamin C in the diet can result in

A) decreased collagen synthesis.
B) scurvy.
C) poor wound healing.
D) growth retardation in children.
E) all of thesE.
E) all of these
Arrange the following events in the correct order of occurrence after a bone is broken.

1. osteoblasts produce ossification
2. hematoma formation
3. internal fibrocartilage callus and external bone-cartilage callus formation
4. woven bone is remodeled to form compact bone

A) 1,2,3,4
B) 2,3,4,1
C) 2,3,1,4
D) 2,4,1,3
E) 2,4,3,1
C) 2,3,1,4
PTH is secreted from the __________ , whereas calcitonin is secreted from the __________ .

A) thyroid gland, pancreas
B) thyroid gland, parathyroid gland
C) pancreas, pituitary
D) parathyroid gland, thyroid gland
E) adrenal gland, thyroid gland
D) parathyroid gland, thyroid gland
Parathyroid hormone causes

A) increased chondroblast activity.
B) increased bone breakdown.
C) decreased blood calcium levels.
D) increased calcium lost in the urine.
E) all of these
B) increased bone breakdown.
Which of these disorders is caused by a bacterium?

A) acromegaly
B) osteogenesis imperfecta
C) osteomalacia
D) osteomyelitis
E) osteoporosis
D) osteomyelitis
Functions of cartilage include which of the following?

A) supporting soft tissues
B) providing a gliding surface at articulations
C) providing a model for the formation of most bones
D) all of the above
D) all of the above
Which selection correctly pairs the type of cartilage with one of its locations in the body?

A) hyaline cartilage, trachea
B) fibrocartilage, epiphyseal plates
C) elastic cartilage, menisci
D) hyaline cartilage, epiglottis
A) hyaline cartilage, trachea
Fibrocartilage is found in which of these structures?

A) auricle of the ear and external auditory canal
B) larynx and articular surfaces of bones
C) intervertebral discs and pubic symphysis
D) all of the above
C) intervertebral discs and pubic symphysis
Functions of bone include all of the following except

A) storage of mineral and energy reserves
B) transport of materials
C) production of blood cells
D) support and protection
B) transport of materials
Hemopoiesis is the process of

A) bone formation
B) cartilage formation
C) blood cell production
D) entrapment of blood vessels by developing bone
C) blood cell production
____________ ossification produces the flat bones of the skull, some of the facial bones, the mandible, and the central part of the clavicle.

A) endochondral
B) intramembranous
C) both a and b
D) neither a nor b
B) intramembranous
Through the process of endochondral ossification, a fetal ____________ model transforms into bone.

A) mesenchyme
B) elastic cartilage
C) fibrocartilage
D) hyaline cartilage
D) hyaline cartilage
Which bone cells secrete osteoid (the initial semisolid form of bone matrix)?

A) osteocytes
B) osteoprogenitor cells
C) osteoblasts
D) osteoclasts
C) osteoblasts
Which of the following are components of compact bone, but not of an osteon?

A) perforating canals and circumferential lamellae
B) central canal and concentric lamellae
C) osteocytes, lacunae, and canaliculi
D) all of the above are parts of an osteon
A) perforating canals and circumferential lamellae
At each end of a long bone is an expanded, knobby region called the

A) head
B) metaphysis
C) diaphysis
D) epiphysis
D) epiphysis
Long bones such as the humerus have solid external walls of ____________ bone, with ____________ bone found primarily within the epiphyses.

A) spongy, compact
B) diploë, circumferential
C) compact, spongy
D) none of the above
C) compact, spongy
Which of the following does not accurately describe spongy bone?

A) contains slightly larger osteons than compact bone
B) composed of parallel lamellae with osteocytes in between
C) provides great resistance to stresses applied in many directions
D) forms an open meshwork of narrow plates called trabeculae
A) contains slightly larger osteons than compact bone
Yellow bone marrow contains a large proportion of

A) reticulocytes
B) fatty tissue
C) fibroblasts
D) elastic fibers
B) fatty tissue
The endosteum

A) covers all internal surfaces of a bone, such as the medullary cavity
B) is active during bone growth, repair, and remodeling
C) is an incomplete cellular membrane
D) all of the above
D) all of the above
All of the following occur during appositional bone growth except

A) osteoblasts in the periosteum lay down layers of bone matrix
B) the bone widens as the number of circumferential lamellae increases
C) growth occurs primarily in the cartilage of the epiphyseal plates
D) osteoclasts expand the medullary cavity by resorbing bone matrix
C) growth occurs primarily in the cartilage of the epiphyseal plates
As with cartilage growth, a long bone's growth in length is called

A) interstitial growth
B) appositional growth
C) osteoid deposition
D) none of the above
A) interstitial growth
Interstitial growth of a bone occurs in the

A) articular cartilage
B) epiphyseal plate
C) diaphyseal line
D) center of the shaft
B) epiphyseal plate
A typical bone has which of the following major sets of blood vessels?

A) primary, secondary, and tertiary
B) Haversian, Volkmann's, and connecting
C) epiphyseal, metaphyseal, and diaphyseal
D) nutrient, metaphyseal, and periosteal
D) nutrient, metaphyseal, and periosteal
Which of the following is a thyroid gland hormone that encourages calcium deposition from blood into bone and inhibits osteoclast activity?

A) growth hormone
B) somatomedin
C) calcitonin
D) thyroid hormone
C) calcitonin
Stimulated by sex hormones, bone growth accelerates dramatically at the time of

A) birth
B) puberty
C) primary ossification
D) secondary ossification
B) puberty
Dietary factors necessary for normal bone growth include

A) vitamins A, C, and D
B) vitamins B, E, and calcitonin
C) both a and b
D) neither a nor b
A) vitamins A, C, and D
____________ produce new bone, while ____________ resorb bone.

A) osteoclasts, osteocytes
B) osteoblasts, osteoclasts
C) osteoclasts, osteoblasts
D) osteocytes, osteoblasts
B) osteoblasts, osteoclasts
Bone remodeling normally involves which of the following?

A) changes in bone architecture and the skeleton's total mineral deposits
B) activity at both the periosteal and endosteal surfaces of a bone
C) continual deposition and removal of bone tissue
D) all of the above
D) all of the above
Aging affects bone tissue in which of the following ways?

A) tensile strength decreases and bones become brittle
B) bones demineralize and become thinner and weaker
C) both of the above
D) neither of the above
C) both of the above
What is broken in a Colles fracture?

A) proximal end of the ulna
B) neck of the femur
C) distal end of the radius
D) surgical neck of the humerus
C) distal end of the radius
Tiny, seed-shaped bones along the tendons of some muscles are classified as

A) flat bones
B) sesamoid bones
C) short bones
D) both b and c
D) both b and c
A typical example of a long bone is the

A) patella
B) tibia
C) ethmoid
D) sternum
B) tibia
Vertebrae are classified as

A) short bones
B) long bones
C) irregular bones
D) flat bones
C) irregular bones
In flat bones of the skull, a region of ____________ is sandwiched between two layers of compact bone.

A) diploë
B) periosteum
C) yellow bone marrow
D) both b and c
A) diploë
Sensory nerves innervate which parts of a bone?

A) the bone matrix and marrow cavity
B) the periosteum and endosteum
C) both a and b
D) neither a nor b
C) both a and b
Which of the following tissues is found in the fewest body locations?

A) fibrocartilage
B) elastic cartilage
C) cortical bone
D) trabecular bone
B) elastic cartilage
During early embryonic development, cartilage grows both internally and along its periphery. The former is called ____________ growth; the latter, ____________.

A) appositional; interstitial
B) interstitial; appositional
C) osteogenic; chondrogenic
D) chondrogenic; osteogenic
B) interstitial; appositional
One of the main differences between the two growth patterns of cartilage is the source of new

A) chondroblasts
B) chondrocytes
C) cartilage matrix
D) perichondrium
A) chondroblasts
Why does all growth normally cease in mature cartilage?

A) the matrix of mature cartilage is not able to expand
B) cartilage has no blood supply and thus no energy source for growth
C) once mature, cartilage is converted to bone by endochondral ossification
D) both a and b
D) both a and b
Chondrocytes die and stem cells in the perichondrium form osteoblasts during which of these processes?

A) appositional growth of cartilage
B) interstitial growth of bone
C) intramembranous ossification
D) endochondral ossification
D) endochondral ossification
Calcification occurs in ____________ during dermal ossification but in ____________ during endochondral ossification.

A) the dermis; hyaline cartilage
B) mesenchyme; fibrocartilage
C) osteoid; hyaline cartilage
D) osteoid; fibrocartilage
C) osteoid; hyaline cartilage
A layer of dense irregular connective tissue typically covers all of the following except

A) hyaline cartilage
B) fibrocartilage
C) elastic cartilage
D) compact bone
B) fibrocartilage
Which of the following is not a function of periosteum?

A) anchors blood vessels and nerves to the surface of the bone
B) isolates and protects the bone from surrounding structures
C) provides a smooth surface for articulation between bones
D) participates in appositional bone growth and fracture repair
C) provides a smooth surface for articulation between bones
Osteons are to dense bone as ____________ are to cancellous bone.

A) trabeculae
B) interstitial lamellae
C) parallel lamellae
D) canaliculi
A) trabeculae
By interconnecting the lacunae and the blood supply, ____________ allow osteocytes to transfer nutrients and wastes through an otherwise impenetrable solid matrix.

A) perforating canals
B) canaliculi
C) central canals
D) lamellae
B) canaliculi
Arrange the following from lowest to highest in terms of their contribution to the mass of bone tissue: (1) collagen fibers; (2) osteocytes, osteoblasts, and osteoclasts; and (3) calcium phosphate.

A) 1, 2, 3
B) 3, 1, 2
C) 2, 1, 3
D) 2, 3, 1
C) 2, 1, 3
What change in physical structure would result from an excess of organic components relative to the amount of hydroxyapatite in the matrix of a bone?

A) greater rigidity
B) greater strength
C) decreased flexibility
D) increased flexibility
D) increased flexibility
A major difference between compact and spongy bone is that

A) spongy bone forms only from mesenchyme
B) there are no osteons in spongy bone
C) spongy bone contains no hydroxyapatite
D) the trabeculae of compact bone are larger
B) there are no osteons in spongy bone
During bone remodeling, if the rate of osteolysis exceeds the rate of osteogenesis, the bone becomes

A) longer and thinner
B) thicker along the shaft
C) demineralized
D) stronger
C) demineralized
Under what circumstances does fibrocartilage normally ossify?

A) endochondral ossification
B) fracture repair
C) lamellar bone formation
D) interstitial growth
B) fracture repair
While eating fried chicken from a popular chain restaurant, David notices that the ends of the bones in the wing and drumstick are smooth, featureless, and covered with a thick cap of cartilage. What is the most likely explanation?

A) articular cartilage is much thicker in chickens than in humans
B) bird bones have completely different features from human bones
C) the chicken was so young that the bones were not fully ossified
D) none of the above
C) the chicken was so young that the bones were not fully ossified
Lengthwise bone growth involves the final steps of

A) osteoporosis and osteopenia
B) fracture healing
C) intramembranous ossification
D) endochondral ossification
D) endochondral ossification
In interstitial bone growth, what happens when the zone of ossification overtakes the zone of resting cartilage?

A) the epiphyseal plate becomes the epiphyseal line
B) lengthwise growth of the bone terminates (at least at one end)
C) the metaphysis converts from hyaline cartilage to bone
D) all of the above
D) all of the above
____________ is a continual, hormonally controlled process that is essentially a race between osteoblasts and osteoclasts.

A) appositional growth
B) interstitial growth
C) bone remodeling
D) endochondral ossification
C) bone remodeling
Which types of fractures are inherently more likely in children than in adults?

A) epiphyseal and greenstick
B) transverse and comminuted
C) Colles and spiral
D) open and closed
A) epiphyseal and greenstick
The inadequate mineral deposition in bone caused by a vitamin D deficiency during childhood is called

A) scurvy
B) rickets
C) osteomyelitis
D) osteomalacia
B) rickets
The two hormones that have opposite effects on the rate of osteolysis are

A) somatotropin and somatomedin
B) growth hormone and thyroid hormone
C) parathyroid hormone and calcitonin
D) estrogen and testosterone
C) parathyroid hormone and calcitonin
Ironically, high levels of ____________ at puberty not only accelerate lengthwise bone growth but also trigger its ultimate end.

A) sex hormones
B) thyroid gland hormones
C) anterior pituitary gland hormones
D) parathyroid hormone and somatomedin
A) sex hormones
Arrange the following in order of the average age at which they complete ossification, from youngest to oldest: (1) clavicle; (2) lateral epicondyle of humerus; and (3) proximal radius.

A) 1, 2, 3
B) 2, 3, 1
C) 3, 1, 2
D) 3, 2, 1
B) 2, 3, 1
Osteopenia and ____________ both reduce bone mass, but the former is a normal part of aging whereas the latter is a disease.

A) osteomalacia
B) osteomyelitis
C) hyperostosis
D) osteoporosis
D) osteoporosis