Module 4 Homework: Bone Physiology

Which of these types of bone fractures is most common in elderly patients and means that the bone is crushed into 3 or more pieces

Comminuted fractures

Interstitial growth allows bones to grow in _____ while appositional growth allows bones to grow in_____

length

width

If a patient has an epiphyseal plate, they are...

still growing

Which of these types of bone fractures is most common in young patients and means the bone breaks incompletely?

Greenstick fractures

During adolescence when bone growth is high, osteoblast activity is ___ osteoclast activity.

greater than

Which of the following is the organic component of bone tissue, absorbing mechanical stress and making it less likely to shatter?

collagen

Triglycerides are stored in the _____ of the bone. This is housed throughout the medullary cavity of the_____

yellow marrow

diaphysis

Which of the bone disorders is the normal, age-related bone loss that occurs in all people as they get older?

Osteopenia

Which of these types of bone fractures is most common in patients with osteoporosis?

Compression fractures

Which of these types of bone fractures is most likely to be caused by sports injuries and means the bone is twisted apart?

Spiral fractures

Which of the bone disorders is more likely to occur in post-menopausal women than in older men?

Osteoporosis

Which of the bone disorders is caused by low Vitamin D levels in the bloodstream?

Rickets

What is the first step in fracture repair?

formation of a hematoma

Which of these types of bone fractures is most likely to occur in the skull bones?

Depression fractures

Which of the following is not a function of bone tissue?

A) structural support

B) hematopoiesis

C) triglyceride storage

D) Vitamin D synthesis

D) Vitamin D synthesis

When blood calcium levels are too high, the thyroid gland secretes ___. This decreases osteoclast activity, allowing more calcium to be stored in bone.

calcitonin

Hematopoiesis occurs in the ______ of the bone. This is housed throughout the trabeculae in the

_____.

Red marrow

Epiphyses

What type of bone formation begins with an internal fibrous membrane? This produces flat bones, including the cranial bones and clavicles.

intramembranous ossification

Osteons are the tree-ring pattern seen in compact bone

True

The thyroid hormones are heavily involved in bone growth during infancy & childhood

False

Canaliculi allow osteocytes to communicate and exchange nutrients and wastes

True

Osteopenia can progress into osteoporosis

True

The _____ canal is found in the center of each osteon and houses blood vessels and nerves

Haversian

The lacunae are arranged in concentric circles called

Lamellae

All ____ bone is replaced every 3-4 years

Spongy

All _____ bone is replaced every 10 years

Compact

What best describes appositional growth in cartilage?

It occurs at the outer surface where chondroblasts from the perichondrium add new matrix, increasing thickness

What is the primary role of collagen fibers in bone tissue?

To give bone shape and tensile strength sacrificial bonds

What is the inorganic component of bone that makes it hard and durable?

Hydroxyapatite

Statement in Wolff’s Law

Bones remodel and become thicker in response to increased mechanical stress, such as in the dominant arm of a right-handed person

Hormone released when blood calcium levels are too low, and its effect

Parathyroid hormone (PTH); increases osteoclast activity to raise blood calcium

Protective covering surrounding the bone; contains many blood vessels and nerves

Periosteum

Shaft of the bone; composed mainly of compact bone

Diaphysis

Covers the ends of bones at joints; made of hyaline cartilage

Articular cartilage

Vascularized connective tissue lining the medullary cavity

Endosteum

Open space inside the diaphysis; contains yellow marrow

Medullary cavity

These are bone stem cells that can differentiate into osteoblasts

Osteogenic cells

These are bone-building cells that secrete collagen and calcium-binding proteins

Osteoblasts

These are mature bone cells that maintain the bone matrix

Osteocytes

These are bone-resorbing cells that break down bone tissue using enzymes

Osteoclasts

Break occurs at the growth plate

Epiphyseal fracture

Bone is built & resorbed in an unbalanced fashion

Paget’s disease

1) Osteoblasts build a bone collar on the shaft of the bone as chondrocytes in that area

2) The bone collar ossification center forms

3) The periosteal bud (blood vessels) enters the model

4) Osteoblasts & osteoclasts build the medullary cavity

5) Blood vessels enter the ends as the secondary ossification centers form

Steps of Endochondral Ossification