2.2 Bone Tissue

The major organic component of bone extracellular matrix is __________.

collagen

Small cavities that are located between lamellae and contain osteocytes are called __________.

lacunae

Which shape of bone contains a medullary cavity and epiphyseal lines?

long

Bone cells that are found in the endosteum and periosteum and build new bone matrix are called __________.

osteoblasts

Which type of cell is responsible for bone deposition?

osteoblasts

The large, multinucleated cells responsible for bone resorption are called __________.

osteoclasts

___________ are responsible for bone resorption, during which they break down the bone ECM.

osteoclasts

The type of bone that has irregularly arranged collagen bundles, abundant osteocytes, and little inorganic matrix, is classified as __________.

primary bone

What type of bones are also known as "Woven Bones"?

primary bones

Which of the following hormones does NOT cause bone growth?

parathyroid hormone (It causes bone resorption but not bone growth)

Which of the following events does NOT happen during endochondral ossification? a. Secondary ossification centers develop. b. Mesenchymal cells differentiate into osteoblasts. c. Osteoclasts form a medullary cavity. d. Osteoblasts replace the calcified cartilage with early spongy bone.

b. Mesenchymal cells differentiate into osteoblasts. (This happens during intramembranous ossification.)

During testing of a young girl, a doctor found an elevated level of estrogen caused by a tumor. He informed the parents to expect a. the young girl to have stunted growth until the tumor was removed and then above average growth height. b. the young girl to show significant growth in a very short period but her overall height to be less than average. c. the young girl to have normal growth of her bones with no side effects. d. the young girl to have significant growth throughout her teenage years due to a delayed closing of her epiphyseal plates.

b. the young girl to show significant growth in a very short period but her overall height to be less than average.

If a bone is lacking collagen in its organic matrix, such as with the disease osteogenesis imperfecta, the bone would

be brittle and shatters easily.

If primary bone were not replaced by secondary bone,

bone would be less resistant to tensile and compressive forces.

Osteogenesis imperfecta is a congenital bone disease caused by a collagen deficiency. Which of the following would be a symptom of osteogenesis imperfecta?

brittle bones

Why is short stature the effect of growth hormone deficiency during childhood?

A deficiency in growth hormone causes stunted or even halted growth. Children with this disorder are affected by dwarfism, grow slowly, and have puberty that may be delayed by several years or even indefinitely.

Which of the following happens closest to the diaphysis of a bone that is growing in length?

Calcified cartilage is replaced with bone.

How does excess growth hormone allow the bone to continue to grow after the epiphyseal plate has closed?

Excess growth hormone will continue to stimulate appositional growth even after the epiphyseal plate has closed. (Growth hormone promotes appositional growth, so if secreted in excess, the bones will grow in width, even if they can no longer grow in length.)

What type of cartilage remains in the bone epiphyseal plate and as articular cartilage?

Hyaline Cartilage

Why would children suffering from malnutrition experience a decrease in mitosis in the hyaline cartilage at the epiphyseal plate, slowing the longitudinal growth of long bones?

Malnutrition in children often leads to a decreased rate of mitosis in different cell populations. The decreased rate of mitosis would reduce the number of chondroblasts at the epiphyseal plate, and therefore slow the production of hyaline cartilage and the longitudinal growth of the bones. In addition, malnutrition would lead to an insufficient intake of calcium salts, vitamin D, vitamin C, and other nutrients needed for ossification, which could weaken the bones and further delay their growth.

Which of the following events happens during intramembranous ossification?

Mesenchymal cells differentiate into osteoblasts.

What type of bones are also known as "Lamellar bones"?

Secondary bones

How would bone growth be affected in children suffering from malnutrition?

They would experience a decrease in mitosis in the hyaline cartilage at the epiphyseal plate, slowing the longitudinal growth of long bones.

______________ are small, branching "ribs" of bone found in spongy bone.

Trabeculae

Appositional growth allows bones to __________.

grow in width

Which of the following gives bone its strength and ability to withstand compression and protect?

hydroxyapatite crystals

Which of the following is not one of the effects of growth hormone on bones? a. increase in the activity of osteoclast b. increase in the activity of osteogenic cells c. stimulation of osteoblasts in the periosteum d. increase in the rate of mitosis of chondrocytes in the epiphyseal plate

increase in the activity of osteoclast (Increase in osteoclast activity leads to bone resorption, not growth. It is one of the effects of parathyroid hormone, not growth hormone.)

In certain diseases, osteoclast activity takes over osteoblast activity, which will cause the bone to

increase the breakdown of the ECM without it being rebuilt, leading to a weakening of the bone.

Flat bones such as the bones of the skull form via __________.

intramembranous ossification

Compact bone forms concentric rings that make it extremely hard and strong to

resist stress and protect the inner spongy bone.

The type of bone that has fully formed lamellae with regularly arranged collagen bundles and a higher percentage of inorganic matrix is classified as __________.

secondary bone

Predict the effect of growth hormone deficiency during childhood.

short stature

If osteoclasts failed to function properly during ossification,

weaker, less organized primary bone would remain.