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A&P Ch. 7 Skeletal System: Bone Structure and Function

Anatomy & Physiology, BIOL 2113 Spring 2016 GPTC
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The shaft of a long bone is called the __________, while the expanded, knobby region at each end is called the __________.

metaphysis; epiphyseal line.

proximal epiphysis; distal epiphysis.

diaphysis; metaphysis.

diaphysis; epiphysis.
diaphysis; epiphysis.
If you look at the cross section of a long bone under a microscope, the rings of bone immediately internal to the periosteum of the bone are called

external circumferential lamellae.

interstitial lamellae.

canaliculi.

perforating canals.
external circumferential lamellae.
In the epiphyseal plate, the microscopic zone in which chondrocytes undergo rapid cell division and become aligned into longitudinal columns of flattened lacunae is called the

zone of resting cartilage.

zone of proliferating cartilage.

zone of hypertrophic cartilage.

zone of calcified cartilage.

zone of ossification.
zone of proliferating cartilage.
Osseous tissue matrix is composed of

adipose.
calcium phosphate.
blood.
cartilage.
calcium phosphate.
______________ is(are) found in compact bone, but not spongy bone.

Lamellae
Central canals
Trabeculae
Endosteum
Central canals
In an adult, red bone marrow is found in all of the following bones except the

radius.
ribs.
sternum.
vertebrae.
radius.
Hyaline cartilage consists of specialized cells called __________ that produce a matrix surrounding themselves. When matrix surrounds these cells they become __________ that are trapped in lacunae.

chondrocytes; chondroblasts

chondroclasts; chondroblasts

chondroblasts; chondroclasts

chondroblasts; chondrocytes
chondroblasts; chondrocytes
Hyaline cartilage

serves as a precursor for the formation of long bones in the body.

has a double-layered connective tissue sheath covering it called the periosteum.

can be found in between vertebrae serving as shock absorbing discs.

is flexible and composed of elastin.
serves as a precursor for the formation of long bones in the body.
Bone-forming cells that produce collagen and proteoglycans and release matrix vesicles are

osteogenic cells.
osteoblasts.
osteoclasts.
osteocytes
osteoblasts.
Bone cells that become surrounded by bone matrix and are located in cavities called lacunae are

osteogenic cells.
osteoblasts.
osteoclasts.
osteocytes.
osteocytes.
What is the role of nerves that supply a bone?

Signal the bone to move
Signal the bone to grow
Detect injuries in the bone
Help store calcium in the bone
Detect injuries in the bone
Appositional growth requires

resorption on the external surface of a bone.

osteoblast depositing new bone within the medullary cavity.

deposition of external circumferential lamellae.

a narrowing medullary cavity as new bone is deposited around it.
deposition of external circumferential lamellae.
Lack of sunlight will directly affect the formation of

Vitamin D3 (cholecalciferol).

7-dehydrocholesterol.

calcium.

parathyroid hormone.
Vitamin D3 (cholecalciferol).
Which step in the formation of calcitriol is regulated by parathyroid hormone?

Conversion of calcidiol to calcitriol

Conversion of 7-dehydrocholesterol to Vitamin D3

Conversion of Vitamin D3 to calcidiol

Conversion of calcidiol to cholecalciferol
Conversion of calcidiol to calcitriol
Bones are more brittle as we age because

osteoclast activity is reduced.

protein synthesis by osteoblasts is reduced.

the organic component of bone increases.

tensile strength is increased.
protein synthesis by osteoblasts is reduced.
Bone producing cells are

lamellae.
osteons.
endosteum.
osteoblasts.
periosteum.
osteoblasts.
The concentric rings of bone produced are

osteoblasts.
periosteum.
endosteum.
lamellae.
osteons.
lamellae.
The combination of all of the concentric rings of bone built around a single blood vessel is called a(n)

osteoblast.
osteon.
periosteum.
endosteum.
lamella.
osteon.
Bones in the legs, arms, spine and pelvis grow

at the same rate.
at different rates.
until age 18, then they stop.
strongest after age 30.
at different rates.
Which of the following is not considered a weight bearing activity?

Running
Walking
Jumping rope
Swimming
Swimming
Trusses and arches which help form an internal scaffolding network, are found in

trabecular bone.
children only.
adults only.
bone marrow.
trabecular bone.
At which of the following ages would calcium loss from bone be more than calcium deposits into bone, even when a high calcium diet is eaten?

10 years old
50 years old
18 months old
18 years old
50 years old
Which mineral is most important throughout life to assist in maintaining strong bone?

Phosphorus
Potassium
Sodium
Calcium
Calcium
Indicate whether each bone is a long, short, irregular, or flat bone.

1. Scapula

2. Carpal bone

3. Femur

4. Vertebrae
1. flat bone

2. short bone

3. long bone

4. irregular bone
Match brief descriptions of

1. Medullary Cavity

2. Metaphysis

3. Endosteum

4. Periosteum
1. Hollow, cylindrical space within the diaphysis
contains bone marrow

2. Region between diaphysis and epiphysis
contains the growth plate

3. Layer of cells that covers all internal surfaces of the bone

4. Dense irregular connective tissue covering the outer surface of bone
Match brief description of

1. Endochondral Ossification

2. Intramembranous Ossification
1. Begins with a hyaline cartilage model

2. Ossification that develops from mesenchyme
Match each hormone with its effect on the skeletal system.

1. Calcitonin

2. Thyroid Hormone

3. Parathyroid Hormone
1.Encourages calcium deposition from blood into bone

2.Influences the basal metabolic rate of bone cells

3. Stimulates osteoclasts to resorb bone and increase blood calcium
What are the primary organs of the skeletal system?
Bones.
List the two types of bone connective tissue present in most of the bones of the body:
Compact & Spongy.
Another name for "dense cortical bone"
Compact bone.
Compact bone is:
relatively dense connective tissue that appears white, smooth, and solid.
What makes up 80% of the total bone mass?
Compact bone.
Another name for "cancellous" or "trabecular" bone:
Spongy bone.
Spongy bone is located where?
Internal to compact bone, appears porous, and makes up 20% of the total bone mass.
Semi-rigid connective tissue that is more flexible than bone?
Cartilage.
Attaches ribs to the sternum (costal cartilage)?
Hyaline cartilage.
Weight-bearing cartilage that withstands compression:
Fibrocartilage.
Dense regular connective tissue that anchors bone to bone?
Ligaments.
Dense regular connective tissue that anchors muscle to bone?
Tendons.
What serves as attachment sites for skeletal muscles, other soft tissues, and some organs?
Bones.
What is Hemopoiesis?
The process of blood cell production, occurring in red bone marrow connective tissue that contains stem cells that form blood cells and platelets.
What is stored in bones?
Calcium and phosphate. (Considered the reserves of the minerals of the body.)
List the 4 types of bones:
1) Long
2) Short
3) Flat
4) Irregular
What bones are found in the upper limbs? (Ex. arm, forearm, palm, and fingers)
Long bones.
What bones are found in the lower limbs?
(Ex. thigh, leg, sole of the foot, and toes)
Long bones.
What bone has a length nearly equal to width?
Small bones.
Provide 2 examples of a short bone:
Carpals (wrist bones) & tarsals (bones in foot)
What is a sesamoid bone, and provide an example:
Small/Sesame seed-shaped bones along the tendons of some muscles, which are classified as a short bone. Ex. Patella (Kneecap)
Is a sesamoid bone a short or long bone?
Short.
What type of bone is the Patella (Kneecap) made up of?
Sesamoid bone (Type of short bone)
What bone type has thin surfaces that are slightly curved?
Flat bones.
Provide an example of a flat bone:
Roof of the skull, scapulae (shoulder blades), sternum, and the ribs.
What type of bone have complex shapes, and provide an example of one.
Irregular bones. - Vertebrae, ossa coxae (hip), some bones of skull: ethmoid, sphenoid, etc.
The "ossa coxae" is an example of what type of bone?
Irregular.
The "sphenoid" is an example of what type of bone?
Irregular.
The "Carpals" are an example of what type of bone?
Short bone.
What is the most common bone shape within the human body?
Long bone.
The shaft of a long bone is called?
Diaphysis.
What does the diaphysis provide?
The elongated, usually cylindrical, diaphysis provides for the leverage and major weight support of a long bone.
The hollow, cylindrical space within the diaphysis is called the?
Medullary Cavity.
Where is the epiphyseal line found in a long bone?
The proximal epiphysis.
Articular cartilage of a long bone is located where?
Proximal & Distal epiphysis.
What is the expanded knobby region located at each end of a long bone called?
Epiphysis.
What is the difference between the proximal epiphysis and the distal epiphysis?
The proximal epiphysis is the end of the bone closest to body trunk, and the distal epiphysis is the end farthest from the trunk.
Which epiphysis is located at the end farthest from the trunk of a long bone?
DISTAL epiphysis.
What covers the joint surface of an epiphysis?
Articular cartilage. (Thin layer of hyaline cartilage)
Region in a mature bone sandwiched between the diaphysis and epiphysis of a long bone?
Metaphysis.
A tough sheath that covers the outer surface of the bone except for the areas covered by articular cartilage:
Periosteum.
What is the endosteum?
An incomplete layer of cells that covers all internal surfaces of the bone within the medullary cavity.
What is the nutrient foramen, and how is it utilized?
A small opening, or hole in a bone. Where either one nutrient artery enters or one nutrient vein exits the bone.
Blood vessel enter bones from the ______.
periosteum.
Another name for red bone marrow:
Myeloid tissue.
What is bone marrow?
The soft connective tissue of bone that includes red & yellow bone marrow.
What contains reticular connective tissue, immature blood cells, and fat?
Red bone marrow.
As children mature into adults what happens to their bone marrow?
Much of the red bone marrow degenerates and turns into a fatty substance called "Yellow Bone Marrow".
In a bone marrow transplant, does the bone marrow need to be matched between donors? Also, what type of bone marrow may be transplanted?
Yes. Bone marrow must be matched between donor and recipient, so the immune system will not attack the tissue as something foreign.

Type: Red bone marrow.
Where is donor bone marrow most commonly harvested from? Also, where would it be injected into the recipient?
Harvested from: Iliac crest of the hip bone, or less commonly, from the sternum.

Inject into: bloodstream.
Primary component of bone is:
Bone connective tissue.
Stem cells derived from mesenchyme:
Osteoprogenitor.
Formed from osteoprogenitor stem cells:
Osteoblasts.
What do osteoblasts secrete?
Osteiod.
Mature bone cells drives from osteoblasts that have lost their bone-forming ability when enveloped by calcified osteoid:
Osteocytes.
What are osteoclasts?
Large, multinuclear, phagocytic cells, drives from fused bone marrow cells similar to those that produce monocytes.
Where are osteoclasts located?
Adjacent to a depression or pit on the bone surface called resorption lacuna.
What is the resorption lacuna?
Depression or pit on the bone surface.
The matrix of bone connective tissue has what 2 type of components?
Organic & Inorganic.
Inorganic portion of the bone matrix is made up from salt crystals such as:
Calcium Phosphate (Ca₃(PO₄)₂
Calcium Phosphate interacts with Calcium Hydroxide to from?
Hydroxyapatite, which deposit around the long axis of collagen fibers in the extracellular matrix.
How does bone form formation start?
Begins when osteoblasts secretes osteoid.
What is calcification?
Occurs to osteiod formation when hydroxyapatite crystals deposit in the bone matrix.
What is the process whereby bone matrix is destroyed by substance released from osteoclasts?
Bone resorption.
What is compact bone compared of?
Small cylindrical structures called osteons.
A channel that lies in the center os the osteon and runs parallel to it:
The central canal.
Rings of bone connective tissue that surround the central canal and form the bulk of the osteon.
Concentric lamellae.
Mature bone cells found in small spaces between adjacent concentric lamellae. (Also maintain the bone matrix)
Osteocytes.
Small spaces that house an osteocyte are called _____.
Lacunae.
What are canalicauli?
Tiny interconnecting channels within bone connective tissue.
Perforating canals resemble central canals in that they also contain ___ and ____.
Blood vessels & Nerves.
Rings of bone immediately internal to the periosteum of the bone (external circumferential lamellae) or to the endosteum (internal circumferential lamellae):
Circumferential lamellae.
Leftover parts of osteons that have been partially resorbed (look like a "bite" has been taken out of them):
Interstitial lamellae.
What are incomplete and typically have no central canal?
Interstitial lamellae.
Unlike compact bone, spongy bone contains no ______.
Osteons.
Enhances calcium absorption from GI tract:
Vitamin D
Used for collagen formation:
Vitamin C
When Hydroxyapatite crystals deposit, this is called:
Calcification.
Destruction of bony matrix occurs by: (This might occur when blood calcium levels are low)
osteoclasts
Blood Calcium Levels Normal range?
8.9-10.1 mg/dL
What occurs at at periosteal and endosteal surfaces?
Bone Remodeling.
Bone Remodeling is caused by:
Hormones and mechanical stress
What is interstitial growth?
Growth in length; Depends on growth of cartilage within epiphyseal plate; Occurs in Zones 2 and 3
What type of growth occurs in zones 2 & 3?
Interstitial growth
5 Zones of epiphyseal plate:
1) Resting
2) Proliferating
3) Hypertrophic
4) Calcified
5) Ossified
When does the skeleton begin forming?
During weeks 8-12 of gestation.
Intramembranous ossification

Endochondral ossification
Ossification that develops from mesenchyme

Begins with a hyaline cartilage model
Appositional growth is:
An increase in width along the cartilages outside edge, or periphery. (Growth in WIDTH(
What type of growth occurs within the internal regions of cartilage?
Interstitial growth. (Growth in LENGTH)
What begins during embryonic development?
Cartilage Growth.
What requires osteoclast activity to hollow out medullary cavity?
Appositional growth.
Calcitriol:
Activated form of Vitamin D.
When does the epiphyseal plates ossify and form epiphyseal lines?
Late teens to adult.
Rickets is caused by a deficiency in what vitamin in childhood?
Vitamin D.
What is osteoporosis?
A disease that result in decreased bone mass and leads to weakened bones prone to fracture.
Best treatment for osteoporosis?
Prevention. -Maintaining good nutrition and physical activity to ensure adequate bone density.
Can calcium supplements with vitamin D stimulate new bone growth?
No, they help maintain bone health, but they by themselves will not stimulate new bone growth
Induces liver to produce somatomedin:
Growth hormone
Influences basal metabolic rate in bone cells:
Thyroid hormone
Increase rate of cartilage growth and bone formation:
Estrogen/testosterone
High amounts of what hormone increase bone loss?
Glucocorticoids, (mostly cortisol)
Provide an overview of Endochondral Ossification:
The process occurs in progressive stages (6), Bone growth is complete when each epiphyseal plate has ossified and the epiphyseal line has formed. Depending upon bone, between ages of 10-25yrs.
What produces flat bones, e.g.; facial bones (zygomatic bone, maxilla), mandible, central part of the clavicle?
Intramembranous ossification.