Unit 10: Skeletal System

Question 1

What are osteons?

Answer 1

Cylindrical structures that make up compact bone

Question 2

Name the following parts of osteons.
1. Concentric circles of matrix?
2. Between (1) (where osteocytes live)?
3. Small channels connecting osteocytes to blood supply and each other?
4. Contains blood vessels and nerves?
5. Perpendicular to (4), carries blood and nerve supply from periosteum?

Answer 2

1. Lamellae
2. Lacunae
3. Canaliculi
4. Central Canal
5. Perforating Canal

Question 3

Instead of osteons, what makes up spongy bone?

Answer 3

Trabeculae (irregularly arranged lamellae)

Question 4

What types of bone is spongy bone found in?

Answer 4

Flat, irregular, and long bones (epiphyses and lining medullary cavity)

Question 5

What makes up the axial skeleton?

Answer 5

The skull, hyoid bone, vertebral column, and thoracic cage

Question 6

What are connections between bones called?

Answer 6

Articulations (e.g. the humerus articulates with the scapula)

Question 7

The palatine bones and maxillae combine to make up the ________.

Answer 7

Hard palate

Question 8

Name the 3 auditory ossicles

Answer 8

2 incus
2 malleus
2 stapes

Question 9

What is the only bone to not articulate with any other bone?

Answer 9

Hyoid bone

Question 10

How do the atlas and axis differ from most vertebrae?

Answer 10

Atlas (C1) has no body or spinous process. It articulates with the occipital epicondyle and allows flexion/extension of the neck
Axis (C2) has the dens, which allows for the head to pivot on the neck

Question 11

Scoliosis, kyphosis, and lordosis are all examples of abnormal spinal curvatures. Which does each specific one mean?

Answer 11

Scoliosis: spinal column curves laterally
Kyphosis: exaggerated thoracic curve
Lordosis: exaggerated lumbar curve

Question 12

What is the difference between the epiphyseal plate and the epiphyseal line?

Answer 12

The epiphyseal plate is hyaline cartilage which is used for bone growth (length) when immature. When growth is completed, it becomes bone called the epiphyseal line

Question 13

What does the medullary cavity contain in long bones?

Answer 13

Red marrow in a child, yellow marrow in an adult

Question 14

The periosteum is the outer layer of a bone that gives it its white appearance and allows for the bone to grow in diameter. What makes up its 2 layers?

Answer 14

Connective tissue:
Outer ~> dense irregular
Inner ~> mainly osteoblasts and osteoclasts

Question 15

What are the 3 types of structural joints?

Answer 15

Fibrous, cartilaginous, synovial

Question 16

What are the physiological functional classifications of functional joints? (Based on degree of movement)

Answer 16

Synoarthrotic: immovable (skull sutures)
Amphiarthrotic: slightly moveable (pubic symphysis)
Diarthrotic: freely moveable (hip joint)