Lecture 11,12,13

What primary function is attributed to the inorganic material within bone matrix?

Giving hardness and strength.

Which component makes up approximately one-third of the bone matrix?

Collagen protein.

What are the cells responsible for building new bone?

Osteoblasts.

A child experiencing bending bones in the lower extremity and inability to support weight likely suffers from a condition resulting from not enough of which material in bone development?

Mineral (calcium).

Which type of bone texture is described as a dense outer layer?

Compact bone.

Where is red bone marrow found within spongy bone?

In the spaces of the looser trabeculae.

What specialized tissue is found on the ends of moving bones, described as slippery and hard hyaline cartilage?

Articular cartilage.

Which bone tissue is a cellular layer lining hollow long bones?

Endosteum.

A distinguishing characteristic of flat bones is that they continue to grow for how long?

For your entire life.

The ends of long bones are anatomically referred to as what?

Epiphyses.

What type of bone marrow is primarily found within the medullary cavity of the diaphysis of long bones?

Yellow bone marrow.

Which of the following vessels supplies the diaphysis of a long bone?

Nutrient artery and vein.

What is the functional unit of compact bone that provides longitudinal strength to long bones?

Osteon.

Which characteristic describes compact bone?

Composed of parallel osteons.

Why does spongy bone not require a central canal?

It is surrounded by red bone marrow with blood.

Cartilages are classified as what type of connective tissue?

Supporting connective tissues.

Where do cells within cartilage typically reside?

In caves called lacunae.

Which of the following is described as the strongest type of cartilage?

Hyaline cartilage.

What type of cartilage is found on the ends of long bones?

Hyaline cartilage.

Which of the following locations is where elastic cartilage can be found?

Pinna of ear.

What type of fibers are abundant in the matrix of fibrocartilage?

Collagen fibers.

Bones play an important role as reservoirs for what?

Minerals.

What is the organic material in bone matrix primarily composed of?

Collagen protein and ground substance.

Which bone cell category is responsible for bone destruction?

Osteoclasts.

What happens to bones in older adults if they do not have enough protein?

They become more brittle and prone to fracture.

Which of the following is a characteristic of spongy bone?

It contains red bone marrow in its spaces.

The periosteum is described as a dense fibrous connective tissue found where?

On the outside surface of bones.

Red bone marrow found in the epiphyses of long bones is responsible for producing what?

Blood cells.

Broken bones typically bleed a lot due to their extensive supply of what?

Blood vessels.

Which type of cartilage is known for its role as a shock absorber?

Fibrous cartilage.

When does bone development (ossification) begin during embryonic development?

C) During the sixth week

At what point during embryonic development can most of the bones of the adult skeleton be identified?

C) At 12 weeks

Which prenatal diagnostic tool uses sound waves to visualize the living fetus?

C) Ultrasound

By what specific week do bones typically become visible using ultrasound?

C) Week 12

Which type of bone cell is primarily responsible for building new bone tissue?

C) Osteoblast

Which type of bone cell is responsible for remodeling bone and removing bone during endochondral ossification?

D) Osteoclast

What is the term for the process by which flat bones are built?

D) Intramembranous ossification

From what type of tissue do flat bones primarily develop during intramembranous ossification?

C) Mesenchyme (flat connective tissue)

Which bones are typically formed through intramembranous ossification?

C) Skull bones, ribs, and sternum

What type of bone contains red bone marrow in the spaces formed by intramembranous ossification?

B) Spongy bone

How long do flat bones continue to grow?

B) Until young adulthood

In intramembranous ossification, after osteoblasts enter fibrous connective tissue, what do they secrete?

C) Osteoid

What is the term for the process by which long bones are built?

C) Endochondral ossification

Long bones primarily develop from what type of cartilage?

C) Hyaline cartilage

In endochondral ossification, which part of the long bone develops first?

D) The diaphysis

During endochondral ossification, what happens to chondrocytes in the diaphysis?

C) They grow larger and then die

After chondrocytes die in the diaphysis, what develops around the cartilage model?

B) A bony collar

What do osteoblasts do after the development of the bony collar in endochondral ossification?

C) They enter the spaces and develop spongy bone

What is the name for the process of bone growth in length?

C) Interstitial growth

Where does interstitial growth primarily occur?

C) At the epiphyseal cartilage (plate)

When does bone growth in length typically stop?

B) When the epiphyseal plate closes and forms the epiphyseal line

What is the epiphyseal plate primarily composed of while bone is still growing in length?

C) Cartilage

What is the process by which bones get thicker or wider?

D) Appositional growth

In appositional growth, which cells make matrix on the bone surface?

C) Osteoblasts

As bones thicken through appositional growth, what happens to the bone in the medullary cavity?

B) Osteoclasts reabsorb bone, making the bone more hollow

What is a functional unit in compact bone called?

C) Osteon

During appositional growth, what is formed around surface blood vessels to strengthen bones?

B) New osteons

Layers of bone matrix laid around the bone surface during appositional growth are called what?

C) Circumferential lamellae

When do long bones typically stop growing in length?

C) Late childhood/young adulthood

Which type of bone development involves replacing a hyaline cartilage model with bone?

D) Endochondral ossification

What condition results from not enough mineral (calcium) in child development, causing bones in the lower extremity to bend and be unable to support weight?

C) Rickets

In older adults, what happens to bones when there is not enough protein?

B) They become more brittle, like chalk.

What is the skeleton's primary role concerning calcium?

C) It serves as the body's calcium reserves.

When is calcitonin made, and what is one of its actions regarding bones?

C) It is made when calcium is high and encourages bone growth.

What hormone is made when calcium levels are low and stimulates osteoclasts?

D) Parathyroid hormone

Healthy bone requires a balance of which three factors?

B) Hormones, mineral, and protein

What specific effect does growth hormone have on bone growth?

B) It stimulates the growth of cartilage in the epiphyseal plate.

How do sex hormones primarily affect bone growth during puberty?

B) They accelerate bone growth, particularly bone length.

What is a direct result of pituitary growth failure?

B) Reduced epiphyseal cartilage activity, resulting in abnormally short long bones.

Achondroplasia is a genetic condition characterized by which of the following?

B) Epiphyseal cartilage growing slowly and being replaced by bone early in life, leading to short, stocky limbs.

In individuals with achondroplasia, which part of the body is typically of normal size?

D) The trunk

Which of the following is an inherited metabolic condition characterized by excessive cartilage formation at epiphyseal cartilages, resulting in a very tall person with very long, slender limbs?

C) Marfan syndrome

Marfan syndrome commonly causes problems in which of the following body systems?

C) Cardiovascular system

What is the typical cause of Gigantism?

B) An overactive pituitary gland causing overproduction of growth hormone before puberty.

Which of the following is a common treatment approach for gigantism?

C) Surgery, radiation, or medications to suppress growth hormone release.

Acromegaly is characterized by the overproduction of growth hormone after epiphyseal plates close, leading to what specific bone changes?

B) Bones getting thicker, especially in the face, jaw, and hands.

In congenital talipes equinovarus (clubfoot), how are the affected feet typically positioned?

B) Feet turn medially and are inverted.

Bone remodeling occurs in response to which of the following?

B) Physical stress or a bone break.

What is the definition of a fracture?

C) A crack or a break in a bone due to extreme mechanical stress.

What is the very first step in the process of fracture repair?

C) Fracture hematoma formation

During the callus formation step of fracture repair, what is the internal callus primarily composed of?

B) Spongy bone

What is the primary function of the external callus in fracture repair?

C) To stabilize the outer edges of the fracture.

Which step in fracture repair involves the replacement of spongy bone by compact bone and remodeling over time to eliminate evidence of the fracture?

D) Compact bone formation

What distinguishes an open (compound) fracture from a closed (simple) fracture?

B) An open fracture involves a break in the skin, while a closed fracture does not.

Which type of fracture is typically produced by twisting stresses and spreads along the length of the bone?

C) Spiral fracture

What is the defining characteristic of a displaced fracture compared to a nondisplaced fracture?

C) A displaced fracture produces new and abnormal bone arrangements, while a nondisplaced fracture retains normal alignment.

A fracture where one side of the shaft is broken and the other side is bent, typically occurring in children because their long bones have yet to fully ossify, is known as what type of fracture?

C) Greenstick fracture

What is the fundamental process that characterizes osteoporosis as a disease state?

B) Bone resorption exceeding deposition.

In osteoporosis, which type of bone tissue typically deteriorates first?

B) Spongy bone

Vertebral fractures in severe osteoporosis are noted to be more common in which populations?

D) Asian and White populations more than LatinX and Black populations.