Week 2 - Shape of Bones

Question 1

what is the morphology of bones? Name all 6

Answer 1

1. ) long
2. ) short
3. ) flat
4. ) accessory
5. ) irregular
6. ) sesamoid

Question 2

true or false:

the description of bones by shape is NOT fixed terminology

Answer 2

true

Example: some would consider innominates flat bones, while others would consider them as irregular

Question 3

long bones are found in the ____ skeleton which provide support for the _____ skeleton

Answer 3

appendicular; axial

Question 4

each long bone consist of the tubular part, known as the ____ or the ______. Each long bone also consist of 2 extremities, the ______.

Answer 4

shaft; diaphysis; epiphysis

Question 5

The outside layer of the long bone is called _____, which surrounds spongy bone and medullary (marrow) cavity

Answer 5

cortical bone

Question 6

what are examples of long bones?

Answer 6

upper limb: humerus, radius, ulna

lower limb: tibia, fibula,

Question 7

long bones are preformed in ______

Answer 7

cartilage

Question 8

true or false: short bones do not have a shaft or epiphysis

Answer 8

false: long bones have a shaft and 2 extremities

Question 9

what are examples of short bones?

Answer 9

metatarsals, metacarpals, phalanges

Question 10

“long bones in miniature”

Answer 10

short bones

Question 11

“a bone sandwich”

Answer 11

flat bones

Question 12

flat bones

Answer 12

“a bone sandwich” 2 layers of cortical (dense, compact) bone, with a layer of trabecular (spongy, cancellous), bone in between
eg. many skull bones, innominates, sternum, scapulae

Question 13

why do flat bones have relatively extensive surfaces?

Answer 13

1) protection for internal organs (most form the walls of rounded cavities (eg., skull thorax, pelvis) and are curved
2) mm attachments

Question 14

true or false: at birth, there are no trabecular bone in flat bones

Answer 14

true; at birth, flat bone is a single layer of bone

Question 15

define ectocranial surface of skull

Answer 15

outer surface of skull

Question 16

true or false: skulls are dilaminar

Answer 16

false; skulls are trilaminar: cortical bone, trabecular bone, cortical bone

Question 17

what are examples of irregular bones?

Answer 17

vertebrae, maxilla, sphenoid bone, and many other cranial bones. Carpal bones, tarsal bones,

Question 18

_____ relates to function

Answer 18

shape relates to function

Question 19

what bones begin to ossify before birth?

Answer 19

3 irregular bones - calcaneus, talus, cuboid

epiphysis of 3 long bones (knee end of femur and tibia, and shoulder end of humerus)

Question 20

the pisiform bone is an example of a ____ bone

Answer 20

sesamoid bone

Question 21

what is the largest sesamoid bone

Answer 21

patella (in tendon of quadriceps femoris)

Question 22

sesamoid bone

Answer 22

• found within certain tendons where they pass over convex bony surfaces
• free surface of bony sesamoid nodule is covered with articular joint cartilage; remainder is within tendon ( no periosteum)

Question 23

each sesamoid bone acts as a _____ to increase the ____ of muscle

Answer 23

fulcrum; leverage

Question 24

there are ___ sesamoid on plantar surface of head of 1st metatarsal

Answer 24

2

Question 25

there are ____ sesamoid found on head of 1st metacarpal in tendons of ______ and _____

Answer 25

2; adductor pollicis; flexor pollicis brevis

Question 26

pisiform bone of wrist is an example of _____ bone

Answer 26

sesamoid bone within tendon of flexor carpi ulnaris

Question 27

examples of other sesamoid bone location

Answer 27

lateral head of gastrocs, peroneus longus, tibialis posterior, heads of MC 2, 4 in palmar plates (slide 50)

Question 28

where are accessory bones mainly found

Answer 28

1) skull

2) where there is a failure of epiphyseal fusion

Question 29

In the skull, accessory bones are collectively known as ______

Answer 29

Wormian bones or ossa suturarum ( sutural or extrasutural bones)

Question 30

what are examples of accessory bones?

Answer 30

1. ) metopic suture
2. ) superior region of occiput (Inca bone)
3. ) zygomatic bone
4. ) Sutural(Wormian bone)
5. ) epiphysis of acromion
6. ) lumbar (5th vertebrate) may be biparte
7. ) patella may be biparte or triparte

Question 31

where are sesamoid bones usually found?

Answer 31

within tendons where they pass over bony convex surfaces (so mm aren’t just sliding past bones directly)

Question 32

where are accessory bones mainly found?

Answer 32

1) skull

2) where there is failure of epiphyseal fusion