Skeletal System

Question 1

What are the 6 major functions of the skeletal system?

Answer 1

Support, protection, movement, mineral storage, site of hematopoiesis, and triglyceride storage.

Question 2

What are the 5 classes of bone?

Answer 2

Long bone, sesamoid, short bone, flat, irregular

Question 3

Give an example of a long bone.

Answer 3

Humerus or femur.

Question 4

Give an example of a sesamoid bone.

Answer 4

Patella.

Question 5

Give an example of a short bone.

Answer 5

Trapezoid, carpals.

Question 6

Give an example of a flat bone.

Answer 6

Sternum, ribs, scapula.

Question 7

Give an example of an irregular bone.

Answer 7

Vertebrae, ethmoid.

Question 8

Define diaphysis.

Answer 8

The shaft of a long bone.

Question 9

What is the metaphysis?

Answer 9

The area where the ends of a long bone attach to the shaft, open as a juvenile but fuse in adulthood.

Question 10

What is the epiphysis?

Answer 10

The ends of a long bone that are detached in juveniles but become fused in adulthood.

Question 11

Where does hematopoiesis occur?

Answer 11

In red bone marrow of the pelvis, ribs, sternum, vertebrae, skull, and in the ends of the humeri and femurs.

Question 12

What does an osteogenic cell do?

Answer 12

They develop into osteoblasts.

Question 13

What do osteoblasts do?

Answer 13

They form the bone matrix. OsteoBlasts Build.

Question 14

What do osteocytes do?

Answer 14

They maintain bone tissue.

Question 15

What do osteoclasts do?

Answer 15

They function in resorption and break down the bone matrix.

Question 16

What is a haversian system?

Answer 16

AKA an osteon; a group of concentric lamellae surrounding blood vessels and lymphatic vessels.

Question 17

What are the two basic types of bone tissue?

Answer 17

Compact bone and spongy bone.

Question 18

What special feature of compact bone allows it to have a structural function?

Answer 18

The concentric ring arrangement of the lamellae allow the bone to be dense and strong but still have vessels feeding the tissue.

Question 19

What are other names for spongy bone?

Answer 19

Cancellous or trabecular bone.

Question 20

What percent of bone is water?

Answer 20

20%

Question 21

What cells provide the framework of bone?

Answer 21

A matrix of collagen fibres.

Question 22

What inorganic compounds can be found in bone?

Answer 22

Salts deposited in collagen matrix where they ossify, calcium phosphate and calcium carbonate which form hydroxyapatite crystals.

Question 23

What are the two kinds of bone development.

Answer 23

Intramembranous ossification and endochondral ossification.

Question 24

Describe the steps of intramembranous ossification.

Answer 24

An ossification center develops in the tissue, then the ossification center begins to calcify; next the trabeculae (spongy bone) forms, and lastly the periosteum (vascular connective tissue around the bone) forms.

Question 25

Describe the steps of endochondral ossification.

Answer 25

A cartilage model forms and grows first, next a primary ossification center forms in the middle of the bone, then the medullary (marrow) cavity forms. A secondary ossification center forms in the epiphysis, and lastly articular cartilage and the epiphyseal plate form.

Question 26

When does osteogenesis occur in fetuses?

Answer 26

Begins around 6-7 weeks

Question 27

What is the function of pituitary growth hormone?

Answer 27

Stimulates growth, especially on long bones by stimulating insulin-like growth factors.

Question 28

What is the function of thyroid hormones in bone development?

Answer 28

They stimulate growth.

Question 29

What is the function of androgens and estrogens in bone development?

Answer 29

They are responsible for pre-pubertal growth spurts and estrogen promotes closure of epiphyseal growth plates.

Question 30

Which vitamins and minerals are found in bone.

Answer 30

Vitamins: D, A, B, C Minerals: calcium, phosphorous, and magnesium.

Question 31

Where is parathyroid hormone produced?

Answer 31

In the parathyroid gland.

Question 32

When is parathyroid hormone released?

Answer 32

When blood calcium levels are low.

Question 33

What does parathyroid hormone do?

Answer 33

Stimulates osteoclasts to increase bone resorption (osteoclasts break down bone to release calcium into the blood).

Question 34

Where is calcitonin produced?

Answer 34

In the parafollicular cells of the thyroid gland.

Question 35

When is calcitonin released?

Answer 35

When the blood calcium levels are high.

Question 36

What does calcitonin do?

Answer 36

Stimulates osteoblasts to increase bone formation and lower blood calcium levels (calcitonIN INto bone)

Question 37

Why do we need both parathyroid hormone and calcitonin?

Answer 37

They work together to maintain appropriate calcium levels for nerve and muscle cell activity.

Question 38

What is osteoporosis?

Answer 38

When there is more bone resorption than bone formation, causing weak and brittle bones.

Question 39

What is the most common form of dwarfism?

Answer 39

Achondroplasia which is a defect in long bone development.

Question 40

What are the functional classifications of joints?

Answer 40

Synarthrosis, amphiarthrosis, and diarthrosis.

Question 41

Define synarthrosis.

Answer 41

Immovable joints, such as the sutures of the skull.

Question 42

Define amphiarthrosis.

Answer 42

Slightly movable joints, such as intervertebral joints.

Question 43

Define diarthrosis.

Answer 43

Freely moveable joints.

Question 44

What are the structural classifications of joints?

Answer 44

Fibrous, cartilaginous, and synovial.

Question 45

Define fibrous joints.

Answer 45

Held together with fibrous tissue. Ex. sutures of skull or syndesmosis between tibia and fibula.

Question 46

Define cartilaginous joints.

Answer 46

Held together with cartilage. Ex. Pubic symphysis.

Question 47

Define synovial joint.

Answer 47

When there is a cavity between two articulating bones and the joint is fully moveable, such as between humerus and radius/ulna.

Question 48

What is a bursa?

Answer 48

A fluid filled sac that cushions a gliding surface between tissues.