Skeletal system

Question 1

How many bones are in the a) appendicular skeleton b) axial skeleton?

Answer 1

appendicular skeleton - 134

axial skeleton - 80

Question 2

How can bone be classified?

Answer 2

Shape/Morphology
Function
Development

Question 3

What are the 5 shapes of bones? Give atleast 3 examples for each case.

Answer 3

.Long bones - femur, metatarsals, phalanges
Short bones - tarsals (calcaneus, talus, cuneiforms), carpals
Flat bones - cranial (occipital, parietal, lacrimal), coxae(pelvis;ilium, ischium, pubis), thoracic cage (sternum + ribs), scapula
Irregular - vertebra, facial bones, sacrum, coccyx
Sesamoid - patella, others in hands and feet

Question 4

State the functions of flat bones

Answer 4

1. protection of internal organs

2. site for muscle attachment

Question 5

What is the longest bone in the body?

Answer 5

Femur

Question 6

What the functions of long bones?

Answer 6

1. Facilitate movement

2. Provide support for body weight

Question 7

2 functions of the short bones are…

Answer 7

1. provide stability

2. support movement

Question 8

What is a function of irregular bones?

Answer 8

Protect internal organs

Question 9

What is the purpose of sesamoid bones?

Answer 9

Re-enforce tendons

Question 10

In which bone is the highest number of red blood cells produced?

Answer 10

Flat bones

Question 11

What is the difference between a nutrient artery and a periosteal artery?

Answer 11

Nutrient artery supplies both compact and spongy bone including bone marrow. Periosteal artery only supplies the compact bone.

Question 12

State a difference between a condyle and an epicondyle?

Answer 12

Condyle is covered in hyaline cartilage. Epicondyle is more prominent and NOT covered in hyaline cartilage.

Question 13

What is the difference between a tuberosity and a tubercle?

Answer 13

A tubercle is a rounded eminence (ex: quadrate tubercle, adductor tubercle) that’s smaller and for attachment of smaller structures. Tuberosities are generally larger and attachment site for larger structures (ex: ischial tuberosity, tibial tuberosity). But there is overlap. Ex: gluteal tuberosity is smaller than the quadrate tubercle.

Question 14

Define a meatus.

Answer 14

a canal in a bone

Question 15

Differentiate a meatus from a foramen

Answer 15

A foramen is a hole through which structures and blood vessels pass. A meatus is an opening into a canal.

Question 16

Which bones form from intramembranous ossification?

Answer 16

Flat bones

Question 17

True or False: Bone ossification and calcification are the same.

Answer 17

False; calcification is only a part of bone ossification.

Question 18

Which bones develop by endochondral ossification?

Answer 18

Long bones, irregular bones, ends of flat bones

Question 19

Which bone develops by both endochondral and intramembranous ossification?

Answer 19

Flat bones

Question 20

True or False: Intramembranous ossification is the only type of ossification involved in bone healing

Answer 20

False. Endochondral ossification is also involved

Question 21

In which bones does red bone marrow persist?

Answer 21

Flat bones and Epiphysis of long bones

Question 22

What is the difference between yellow and red bone marrow?

Answer 22

Red bone marrow; 
-produces red blood cells, white blood cells, bone marrow, 
-is red in color from haemoglobin, 
-highly vascular 
Yellow bone marrow
-produces fat, cartilage, and bone 
-yellow color from fats 
-not highly vascularized

Question 23

How does composition of bone marrow change in bones as we age?

Answer 23

In infants, almost all bones have red bone marrow.
In children, it’s only long bones with red bone marrow.
In adults, only flat bones have red bone marrow
Red bone marrow replaced by yellow bone marrow

Question 24

Name the four descriptive regions of long bones.

Answer 24

Epiphysis
Epiphyseal plate
Metaphysis
Diaphysis

Question 25

Give the sequence of events in endochondral ossification.

Answer 25

1. Bone collar formation
   - development of primary ossification center containing osteoblasts
   - osteoblasts secrete osteoid against diaphysis walls encasing diaphysis in compact bone (bone collar)
2. Cavitation
   - chondrocytes hypertrophy
   - hyaline cartilage calcifies into bone
   - chondrocytes die and leave cavities for blood vessels to pass through
3. Periostial bud invasion
   - blood vessels and nerves enter bone
   - now osteoclasts and osteoblasts can enter cavities left by dead chondrocytes
4. Diaphysis elongation
   - medullary is the cavity containing red bone marrow
5. Epiphyseal ossification
   - epiphyses develop secondary centers of ossification
   - undergo steps 1-3
   * Pnemonic: Boys Can’t Pee During Erections

Question 26

What are the 3 types of joints?

Answer 26

SAD Feelings Can Sink you.
Synarthroses; Fibrous
Amphiarthroses; Cartilaginous
Diarthroses; Synovial

Question 27

What is a difference and a similarity between synchondrosis and symphisis?

Answer 27

1. Both are a type of cartilaginous/amphiarthrotic joint.

2. Symphisis shows presence of fibrocartilaginous disc, but synchondrosis doesn’t.

Question 28

Where are symphisis joints found?

Answer 28

Midline of the skeleton (vertebrae, pubic symphysis, sacrococcygeal symphysis

Question 29

Where are synchondrosis joints found?

Answer 29

Ossification centers of developing bones; absent in mature bone

Question 30

Classify the synovial joints based on their shape.

*Hint; there are 6

Answer 30

Hinge (ankle)
Saddle (thumb) 
Pivot (wrist, neck and vertebrae) 
Condyloid (condyles of femur and tibia)
Plane (tarsal bones of foot, vertebrae)
Ball and socket (hip joint)

Question 31

What descriptive regions are long bones divided into?

Answer 31

Epiphysis (the ends)
Diaphysis (shaft)
Metaphysis (junction where epiphysis meets diaphysis)
Epiphyseal growth plate (part of the metaphysis)

Question 32

What kind of growth is it when a bone grows in length?

Answer 32

Interstitial growth

Question 33

What is appositional growth?

Answer 33

Growth in thickness/width of bone as new layers are added.

*Apposition=Addition