HW CH6

Which of the following is incorrectly matched?

Articular cartilage - composed of elastic cartilage to allow flexibility

Why would running and jumping have a larger effect on bone health than walking?

Osteoblasts are more active and osteoclast maintain normal activity when there is mechanical stress placed on bones.

PTH will increase _______ activity while Calcitonin will decrease __________ activity.

Osteoclast; osteoclast

Which of the following is mismatched?

Osteoclasts -are derived from osteoblasts and break down bone tissue

Which of the following regions of bone would not undergo bone remodeling as frequently as the other regions?

compact bone

Osteons are found in _____, while trabeculae are found in _____.

compact, spongy

Cells active when cartilage needs to be removed so new bone can be produced.

osteoclasts

This cell is active once the matrix of bone calcifies. The cells sits in a lacunae.

osteocytes

In endochondral ossification, what is the original source of osteoblasts?

osteoprogenitor cells

Which of following selections lists bone cells in the order from unspecialized stem cell to highly specialized mature bone cell?

osteoprogenitor cells, osteoblasts, osteocytes

Which of the following tissues are part of bone? 1. epithelial tissues. 2. muscular tissues. 3. nervous tissues. 4. connective tissues.

1, 3, 4

Which statements describe spongy bone? 1. Composed of trabeculae. 2. Made up of osteons. 3. Found in higher amounts in the diaphysis. 4. Found lining the superficial regions of all bones. 5. Arranged along lines of force that are encountered. 6. Gaps filled with marrow. 7. Maintains strength with light weight. 8. Has the same purpose structurally as compact bone. 9. Has lamellae, osteocytes, lacunae and canaliculi. 10. Has lamellae, osteocytes, lacunae, canaliculi, and central canals.

1, 5, 6, 7, 9

Which is the proper sequence of steps in the healing of a fracture (the steps are listed below but are not in the correct sequence of events): 1 osteoblasts form trabecular bone that joins together the fractured ends of the bone and bony callus replaces fibrocartilage callus 2 bone remodeling occurs and compact bone replaces the spongy bone around the periphery of the fracture site 3 fibroblasts and chondrocytes from the periosteum form the fibrocartilage callus 4 a fracture hematoma forms and bone cells in the region of the fracture die 5 phagocytes and osteoclasts begin to remove the dead cells and damaged tissue around the hematoma

4, 5, 3, 1, 2

Place the events of a fracture repair in order. A: A hematoma will form and will form a temporary connection between the ends of the bones. B: Fibroblasts and chondroblasts migrate from the periosteum and begin to produce fibrocartilage to connect the ends of the bones. C: Osteoclasts resorb dead portions of the new bony area, and compact bone replaces spongy bone. D: Osteoprogenitor cells differentiate into osteoblasts and produce spongy bone. E: Phagocytes and osteoclasts begin to remove dead and damaged tissue.

A, E, B, D, C

Bone growth and remodeling are influenced by all of the following except:

Amount of fibrocartilage available.

A skeleton that exhibits a partially closed epiphyseal plate would likely be that of a:

An adolescent

Which statement describes blood calcium levels accurately?

Blood calcium levels increase when bone breaks down, and decreases when bone is built.

Which of the following statements are true?

Compact bone contains osteons while spongy contains trabeculae. Compact bone makes up most of the bone of the diaphysis while spongy bone makes up most of the epiphysis. Spongy bone makes up most of the structure of short, flat and irregular bones and the inside of the epiphysis of long bones. Spongy bones make bone lighter and aids in stress resistance. All of these statements are true.

Which of the following statements is/are incorrect?

Endochondral ossification begins with development of an ossification center.

Increasing mechanical stress will cause bone to become stronger by:

Increasing deposition of mineral salts

The all of the following are part of the bone matrix except:

Muscle fibers

The type of bone fracture characterized by the broken ends of the bone protruding through the skin is known as a(n)

Open (compound) fracture

Which of the following selections correctly lists the sequence of events that occur during intramembranous ossification?

Ossification center develops > Calcification > Formation of trabeculae > Development of new periosteum.

Which is NOT a part of the events that result in parathyroid hormone's control of blood calcium levels?

PTH acts on the parafollicular cells of the thyroid gland to increase the level of the hormone calcitonin

Mary, an avid runner, was complaining that her lower leg hurt. After going to the doctor, they did not see anything on x-rays of her tibia or fibula. The doctor ordered a bone scan and saw tiny fissures throughout her tibia without any other tissue damage. What is Mary's likely diagnosis?

Stress fracture

If collagen is removed from bone, what happens to the bone? Choose the best answer.

The bone becomes stiff and brittle.

Which of the following statements is incorrect?

The skeleton provides a structural framework for the body. The cranium, rib cage and vertebrae protect important internal organs from injury. Bone releases minerals as needed to maintain homeostasis. Bone stores calcium and phosphorus All of these statements are correct.

Why do greenstick fractures commonly occur in children?

Their bones contain higher amounts of collagen.

Gravity and the pull of muscles against bone are the main mechanical stresses experienced by bone. Stress promotes deposition of mineral salts, collagen, and the strengthening of bone in stressed areas. Which of the following individuals would have a lower rate of bone deposition and would therefore be at greater risk for bone loss through bone resorption?

a secretary who works at a desk job and does not do any regular weight-bearing exercise

What are the extracellular fluid filled extensions of the lacunae called?

canaliculi

List the order of the zones in an epiphyseal plate from the diaphyseal region to the distal epiphysis. A: Zone of calcified cartilage B: Zone of hypertrophic cartilage C: Zone of proliferating cartilage D: Zone of resting cartilage

a,b,c,d

By which process, as an individual grows to adulthood, is the thickness (diameter) of bone increased?

appositional growth

The ______ is composed of hyaline cartilage and reduces friction between bones involved in a joint.

articular cartilage

Which two minerals are needed in large quantities when bones are growing?

calcium and phosphorous

Which two minerals are stored in major quantities in bone tissue?

calcium and phosphorus

The shaft of a long bone is the

diaphysis.

The ______ is composed of hyaline cartilage and allows the diaphysis to grow in length.

epiphyseal plate

Which region of a long bone articulates with other bones?

epiphysis

Which is not a function of calcium in the body?

epithelium function

Osteoporosis is most common in elderly women because of the lack of __, which would inhibit ___.

estrogen; osteoclast activity

Near the center of the diaphysis, the nutrient artery and vein pass through a hole in the compact bone called the nutrient ________.

foramen

Which of the following is the correct sequence of steps in the repair of a bone fracture?

fracture hematoma, fibrocartilaginous callus formation, bony callus formation, bone remodeling

Which type of fracture is considered a partial fracture and is only seen in children?

greenstick

The process of intramembranous ossification generates bone within a pre-existing template composed of mesenchymal tissue. In contrast, endochondral ossification generates bone within a pre-existing template composed of _____.

hyaline cartilage

During endochondral ossification in a fetus, bones initially develop as a cartilage model that was formed from

mesenchyme.

In which region of a long bone, such as the humerus, would you find the epiphyseal plate (growth plate)?

metaphysis

The _______ is the region of long bone that contains hyaline cartilage used for growth in length.

metaphysis

If bone is analogous to a bank, calcium is analogous to ______.

money

The process of bone formation is referred to as ____.

ossification

The cells active in fracture repair during the production of the hard (spongy bone) callus.

osteoblasts

Which is formed from the fusion of as many as 50 monocytes (a type of white blood cell)?

osteoclast

How are osteons in compact bone tissue aligned? How does the osteon arrangement affect bone strength?

parallel to the length of the diaphysis; the shaft resists bending even when stresses are applied in certain directions.

What hormone(s) is/are released from the control center when the control center receives cAMP input; also important in increasing blood calcium serum levels. Choose the best answer.

parathyroid

Bone mass reduction is promoted by which hormone?

parathyroid hormone

Which hormone is the MOST important for Ca2+ regulation?

parathyroid hormone

What area of long bone is composed of dense irregular connective tissue and osteogenic cells?

periosteum

Which of the following hormones are more important post-puberty for bone growth?

sex hormones

Stan is a 35 year old man who is a dedicated long distance runner. He spends hours every week running along neighborhood streets. Recently Stan has had to go to the doctor due to pain in his lower legs that intensifies when he tries to run. There is no swelling or obvious damage, so he is surprised to hear the doctor say he has a fracture of his tibia. Stan is most likely to have which type of fracture?

stress fracture

Compact bone is composed of units called osteons. In contrast, spongy bone is composed of _____.

trabeculae