APII: Skeletal System

Question 1

What are the main components of the skeletal system?

Answer 1

Bones, cartilage, ligaments

The skeletal system accounts for 20% of body weight.

Question 2

What is the primary function of the skeletal system related to support?

Answer 2

Framework supports against gravity

Question 3

Which parts of the body are involved in the protection function of the skeletal system?

Answer 3

Cranium, vertebral column, rib cage

Question 4

How does the skeletal system facilitate movement?

Answer 4

Site for muscle attachment, origin and insertion

Question 5

In the skeletal system, what does the rigid bar represent in the mechanical lever system?

Answer 5

Bone

Question 6

What does the pivot or fulcrum represent in the skeletal system’s mechanical lever system?

Answer 6

Joint

Question 7

In the context of the skeletal system’s mechanical lever system, what does the object moved or resistance represent?

Answer 7

Weight of body part

Question 8

What represents the mechanical force or effort in the skeletal system’s lever system?

Answer 8

Muscle contraction

Question 9

What is stored in the matrix of the skeletal system?

Answer 9

Minerals

Question 10

What is the most abundant mineral stored in the skeletal system?

Answer 10

Calcium phosphate

Question 11

What happens when blood calcium levels drop?

Answer 11

Calcium is released

Question 12

What processes is calcium used for in the body?

Answer 12

Many processes

Question 13

Is the storage and release of calcium a static or dynamic process?

Answer 13

Continuous dynamic process

Question 14

What does yellow marrow in the skeletal system store?

Answer 14

Fat

Question 15

What is the process of blood cell formation called?

Answer 15

Hematopoiesis

Question 16

What are the formed elements produced during hematopoiesis?

Answer 16

Red blood cells, all white blood cells, platelets

Question 17

Where does hematopoiesis take place?

Answer 17

In red marrow of bones

Question 18

In infants, where does most hematopoiesis occur?

Answer 18

Most bones

Question 19

In adults, where does hematopoiesis primarily occur?

Answer 19

Spongy bone in skull, ribs, sternum, clavicles, vertebrae, pelvis, ends of long bones

Question 20

What are the two types of bone tissue?

Answer 20

Compact bone, spongy bone

Question 21

What are the three types of bone cells?

Answer 21

Osteoblasts, osteoclasts, osteocytes

Question 22

What is the function of osteoblasts?

Answer 22

Build bone tissue

Question 23

What is the function of osteoclasts?

Answer 23

Break down bone tissue

Question 24

What do osteocytes do?

Answer 24

Maintain existing bone tissue

Question 26

What is the basic functional unit of compact bone?

Answer 26

The basic functional unit of compact bone is the osteon.

Question 27

What do central Haversian canals contain?

Answer 27

Central Haversian canals contain blood vessels that supply the osteon.

Question 28

What surrounds the central canal in an osteon?

Answer 28

The central canal is surrounded by concentric rings called lamellae.

Question 29

Where are osteocytes located?

Answer 29

Osteocytes are located in lacunae, which are spaces between lamellae.

Question 30

How do osteocytes communicate?

Answer 30

Osteocytes communicate and nutrients & wastes diffuse through tiny canals called canaliculi.

Question 31

What is spongy bone also known as?

Answer 31

Spongy bone is also known as cancellous bone.

Question 32

How does spongy bone compare to compact bone?

Answer 32

Spongy bone is lighter and less dense than compact bone.

Question 33

What are the interconnected plates and bars of bone in spongy bone called?

Answer 33

The interconnected plates and bars of bone in spongy bone are called trabeculae.

Question 34

What do the spaces between trabeculae contain?

Answer 34

The spaces between trabeculae contain red bone marrow.

Question 35

How are trabeculae arranged?

Answer 35

Trabeculae appear random but are arranged to give maximum support and reorganize in response to changes in stress patterns.

Question 36

What are long bones characterized by?

Answer 36

Long bones have a shaft called the diaphysis and two ends called epiphyses.

Question 37

What is the central cavity of long bones called?

Answer 37

The central cavity of long bones is called the medullary cavity, which is filled with yellow marrow.

Question 38

What covers the outer surface of long bones?

Answer 38

The outer connective tissue covering is called the periosteum, which contains osteoblasts.

Question 39

What fuses with the periosteum?

Answer 39

Tendons and ligaments fuse with the periosteum to attach to the bone.

Question 40

What is the inner connective tissue lining of the medullary cavity called?

Answer 40

The inner connective tissue lining of the medullary cavity is called the endosteum, which contains osteoclasts.

Question 41

What is the epiphyseal plate?

Answer 41

The epiphyseal plate is a cartilaginous plate between epiphyses and diaphysis where long bones grow in length.

Question 42

What happens to the epiphyseal plate as bones mature?

Answer 42

The epiphyseal plate ossifies to become the epiphyseal line, and bones no longer grow in length.

Question 43

What is appositional growth?

Answer 43

Appositional growth is when bones grow in diameter.

Question 44

How do osteoblasts and osteoclasts contribute to bone growth?

Answer 44

Osteoblasts build bone on the outside, while osteoclasts remove bone on the inside.

Question 45

How do bones grow in diameter without becoming too heavy?

Answer 45

Bones grow in diameter without becoming too heavy through the actions of osteoblasts and osteoclasts.

Question 47

What are short bones?

Answer 47

Roughly cube shaped, spongy bone covered by a thin layer of compact bone ## Footnote Examples include carpals and tarsals.

Question 48

Characteristics of flat bones?

Answer 48

Flattened and usually curved, sandwich of spongy bone in the middle called the diploe with inner and outer layers of compact bone ## Footnote Examples include the cranium, sternum, ribs, and ilium.

Question 49

What are irregular bones?

Answer 49

Bones that do not fit other categories ## Footnote Examples include vertebrae and some bones of the skull.

Question 50

What is ossification?

Answer 50

Bone growth.

Question 51

What are the two types of developmental growth in ossification?

Answer 51

* Intramembranous ossification * Endochondral ossification

Question 52

Define intramembranous ossification.

Answer 52

Replacement of connective tissue sheets with bone; osteoblasts migrate to membrane and put down bone tissue.

Question 53

What happens to osteoblasts during intramembranous ossification?

Answer 53

Once surrounded by bone tissue, they are called osteocytes.

Question 54

Define endochondral ossification.

Answer 54

Most bones are formed in this manner; hyaline cartilage model is replaced by bone tissue.