Principles of the skeletal system

Question 1

What are the components of the skeletal system?

Answer 1

The skeletal system comprises bones, cartilage, ligaments, and tendons.

Question 2

What is the function of cartilage in the skeletal system?

Answer 2

Cartilage serves as a precursor to most bones and also covers most mature joints.

Question 3

What is the role of ligaments in the skeletal system?

Answer 3

Ligaments hold bones together at joints, providing stability and preventing excessive movement.

Question 4

What is the function of tendons in the skeletal system?

Answer 4

Tendons attach muscles to bones, allowing for movement and facilitating muscle control.

Question 5

What are the components of the axial skeleton?

Answer 5

The axial skeleton includes the skull, vertebrae, ribs, sternum, hyoid bone, sacrum, and coccyx.

Question 6

What are the components of the appendicular skeleton?

Answer 6

The appendicular skeleton comprises the bones of the limbs, including the pectoral and pelvic girdles.

Question 7

What are long bones?

Answer 7

Long bones are tubular in shape, with a long axis and two ends that articulate with other bones. Examples include the humerus.

Question 8

What are short bones?

Answer 8

Short bones are cuboidal in shape. Examples include the carpal bones of the wrist.

Question 9

What are flat bones?

Answer 9

Flat bones are thin and possibly curved. They protect internal organs. Examples include the cranial bones of the skull.

Question 10

What are sesamoid bones?

Answer 10

Sesamoid bones are small bones that lie within tendons. An example is the patella (kneecap).

Question 11

What are irregular bones?

Answer 11

Irregular bones have complex shapes that do not fit into the other categories. Examples include the vertebrae of the spine and the bones of the face.

Question 12

What is an infraspinous fossa?

Answer 12

The infraspinous fossa is an external depression on the posterior aspect of the scapula bone.

Question 13

What is a supraspinous fossa?

Answer 13

The supraspinous fossa is an external depression on the posterior aspect of the scapula bone located above the spine of the scapula.

Question 14

What is a fossa?

Answer 14

A fossa is a shallow depression or concave surface on a bone.

Question 15

What is a groove?

Answer 15

A groove is a long, narrow, and shallow channel or furrow on a bone.

Question 16

What is a notch?

Answer 16

A notch is an indentation or v-shaped cut on the edge of a bone.

Question 17

What is a sulcus?

Answer 17

A sulcus is a groove or furrow, often smaller and more shallow than a groove, found on the surface of a bone.

Question 18

What are facets in relation to bone structure?

Answer 18

Facets are small projections on a bone that are covered with cartilage. They provide smooth surfaces for articulation with other bones.

Question 19

What are condyles?

Answer 19

Condyles are rounded articular surfaces found on certain bones. They are usually smooth and convex and serve as points of articulation with other bones.

Question 20

What is a head in bone anatomy?

Answer 20

In bone anatomy, a head refers to a rounded or expanded articular end of a bone. It is usually larger than the rest of the bone and is involved in joint articulation.

Question 21

What is a joint in arthrology?

Answer 21

A joint, also known as an articulation, is any point where two bones meet.

Question 22

What are the major categories of joints?

Answer 22

Fibrous joints: Joints where the bones are connected by fibrous connective tissue. They allow little to no movement.
Cartilaginous joints: Joints where the bones are connected by cartilage. They allow limited movement.
Synovial joints: Joints where the bones are separated by a synovial cavity and are surrounded by a joint capsule. They allow a wide range of movement and are the most common type of joint in the body.

Question 23

What is a synarthrosis joint?

Answer 23

A synarthrosis joint is a fibrous joint where bones are united by dense regular connective tissue. These joints allow little to no movement.

Question 24

What are the two types of joints where bones are linked by cartilage?

Answer 24

Synchondrosis: Bones are bound by hyaline cartilage. In some cases, this cartilage may ossify to form a synostosis or bony joint.
Symphysis: Two bones are joined by fibrocartilage, typically found in the midline of the body. Examples include intervertebral discs and the pubic symphysis.

Question 25

What are synovial joints also known as?

Answer 25

Synovial joints are also known as diarthroses.

Question 26

What are the components of a synovial joint?

Answer 26

The components of a synovial joint include:

Fibrous joint capsule and synovial membrane
Joint (articular) cavity, which contains synovial fluid
Articular cartilage, which covers the articulating surfaces
Ligaments that reinforce the joint, both extrinsic and intrinsic to the joint capsule.

Question 27

What is cortical bone?

Answer 27

Cortical bone refers to the outer shell of the bone.

Question 28

What is trabecular or cancellous bone?

Answer 28

Trabecular or cancellous bone refers to the spongy bone that is located underneath the joint surfaces.

Question 29

What is the medullary cavity?

Answer 29

The medullary cavity is the space found in the diaphysis (shaft) of a long bone, and it contains bone marrow.

Question 30

What is endochondral bone development?

Answer 30

bones are formed from a cartilaginous precursor. It involves the replacement of cartilage with bone tissue.

Question 31

What is intramembranous bone development?

Answer 31

Intramembranous bone development refers to the process in which bones are formed directly from mesenchymal (embryonic connective tissue) cells. It does not involve a cartilaginous template and instead occurs within a membrane.

Question 32

What is endochondral ossification?

Answer 32

Endochondral ossification is the process of bone formation where a hyaline cartilage template is gradually replaced by bone. It is the most common method of bone development in the body.

Question 33

What are the characteristics of endochondral ossification?

Answer 33

Endochondral ossification involves the emergence of different ossification centers, with the primary center forming in the diaphysis (shaft) of the bone and secondary centers forming in the epiphysis (ends) of the bone. The growth plate, also known as the epiphyseal plate, exists between the diaphysis and epiphysis, allowing for bone growth and elongation.

Question 34

What is the growth plate?

Answer 34

The growth plate, also known as the epiphyseal plate, is a layer of cartilage located between the diaphysis (shaft) and epiphysis (end) of a long bone. It allows for bone growth and elongation during childhood and adolescence.

Question 35

What happens at the growth plate?

Answer 35

The growth plate is where the process of endochondral ossification takes place. The cartilage in the growth plate gradually converts to bone, resulting in bone elongation and growth in length. This process continues until the growth plate closes and bone growth stops, typically during late adolescence.

Question 36

What is intramembranous ossification?

Answer 36

In intramembranous ossification, bone is formed directly from mesenchymal connective tissue, without the intermediate step of cartilage formation. This process occurs in certain bones of the body.

Question 37

How does intramembranous ossification occur?

Answer 37

In intramembranous ossification, bone growth begins from multiple ossification centers within the mesenchyme. The bone tissue grows radially outward from these centers, gradually replacing the connective tissue and forming flat bones of the face and skull, mandible, and clavicle, among others.

Question 38

What are osteoblasts?

Answer 38

Osteoblasts are bone cells responsible for depositing collagen and bone matrix called osteoid. They are involved in the formation of new bone tissue.

Question 39

What are osteocytes?

Answer 39

Osteocytes are former osteoblasts that have become trapped within the bone matrix. They communicate with each other and other bone cells through small channels called canaliculi. Osteocytes play a role in sensing bone loading and regulating the activity of osteoblasts and osteoclasts.

Question 40

What are osteoclasts?

Answer 40

Osteoclasts are bone cells involved in the resorption of bone tissue. They secrete organic acids and enzymes that dissolve the mineral component of bone and destroy the organic osteoid matrix. Osteoclasts play a crucial role in bone remodeling and the release of calcium into the bloodstream.

Question 41

What is the difference between bone remodeling and modeling?

Answer 41

Bone remodeling refers to the cyclic process of bone resorption and formation, which helps optimize bone structure and maintain bone health. On the other hand, bone modeling involves bone formation without prior resorption, resulting in an increase in bone mass, bone growth, and the maintenance of bone strength.

Question 42

What is osteoporosis?

Answer 42

Osteoporosis is a condition characterized by lower than normal bone mass growth or abnormal bone loss. It can lead to weakened and brittle bones, increasing the risk of fractures.

Question 43

What factors can cause imbalances in bone remodeling?

Answer 43

Imbalances in bone remodeling can be caused by factors such as lack of exercise, hormonal changes (e.g., menopause or acromegaly), and inadequate dietary intake of essential nutrients like vitamin A, vitamin C, and vitamin D.

Question 44

What are some commonly fractured bones?

Answer 44

Some commonly fractured bones include the distal radius (wrist), proximal femur (hip), lateral malleolus of the fibula (ankle), proximal humerus (shoulder), and metacarpals (hand).

Question 45

How does bone fracture healing occur?

Answer 45

Bone fracture healing involves the formation of a blood clot, which encourages the growth of a cartilage bridge. Osteoblasts then lay down new bone, initially in the form of rough or “woven” bone, which is later remodeled into organized lamellar bone. The plentiful blood supply to bone contributes to its quick healing process.