Classification Of Bones

Question 1

Typical long bones

Answer 1

Humerus radius ulna femur tibia and fibula with two secondary epiphyses

Question 2

Miniature or short long bones

Answer 2

Have one epiphysis like metacarpals metatarsals phalanges

Question 3

Modified long bones

Answer 3

Have no medullary cavity like clavicle

Transmits weight from appendicular skeleton to axial skeleton

Question 4

Short bones

Answer 4

Cuboid
Scaphoid
Eg tarsal and carpal bones

Question 5

Flat bones

Answer 5

Shallow plates
Sternum ribs scapula
Bones in vault of skull

Question 6

Irregular bones

Answer 6

Hip bone, bones in the base of the skull eg sphenoid and first and second cervical vertebrae

Question 7

Pneumatic bones

Answer 7

Large spaces lined by epithelium 
Maxilla sphenoid ethmoid
Make the skull light in weight
Help in resonance of voice 
Air conditioning chambers for inspired air
Improves timbre of voice

Question 8

Sesamoid bones

Answer 8

Bony nodules embedded in joint capsules or tendons
Have no periosteum, medullary cavity and haversian system and ossify after birth
Related to an articular or non articular surface
Surfaces of contact are covered with hyaline cartilage and lubricated by a synovial membrane
Patella in the tendon of quadriceps femoris
Pisiform in tendon of flexor carpi ulnaris

Question 9

Function of sesamoid bones

Answer 9

To resist pressure
To minimise friction
To alter the direction of pull of the muscle
To maintain local circulation, protect the vessels and nerves

Question 10

Accessory bones

Answer 10

Are not always present
Ununited epiphyses from extra centres of ossification
Eg sutural bones of skull
Cervical ribs lumbar ribs

Question 11

Compact bone is present in the ——- of Long bones

Answer 11

Shaft / diaphysis

Question 12

Wolfs law

Answer 12

Bone formation is directly proportional to stress and strain

Question 13

Cancellous or spongy bone is found in

Answer 13

Epiphyses of long bone

Question 14

Lamellae of compact bone

Answer 14

Arranged to form Haversian system

Question 15

Lamellae of compact bone

Answer 15

Arranged to form haversian system

Question 16

Bone marrow of compact bone

Answer 16

Yellow

Stores fat after puberty

Question 17

Bone marrow of cancellous bone

Answer 17

Red

Produces RBCs granular WBCs and platelets

Question 18

Periosteum

Answer 18

thick fibrous membrane
Outer fibrous layer
Inner cellular layer-osteogenic
Periosteum united to bone by sharpeys fibres- strong over tendons and ligaments

Question 19

According to number of epiphsyis

Answer 19

Simple: ends of long bones develop form many epiphyses-these fuse independently eg femur
Compound ends of bones develop from many centres which unite to form a single epiphysis which fuses with the shaft eg humerus

Question 20

Based on function

Answer 20

Pressure epiphysis
Atavistic Ephiphysis
Traction ephiphysis
Aberrant epiphysis
Compound epiphysis

Question 21

Pressure epiphysis

Answer 21

Articular and takes part in transmission Of weight
Eg head of humerus
Lower end of radius

Question 22

Traction epiphysis

Answer 22

Non Articular
Does not take part in transmission of weight
Provides attachent to tendons which exert a traction on the epiphysis
Ossify later than pressure epiphyses
Eg trochanter of femur and tubercles of humerus

Question 23

Atavistic epiphysis

Answer 23

Phylogenetically an independent bone
Becomes fused to another bone
Eg coracoid process of scapula
Os trigonum of talus

Question 24

Aberrant epiphysis

Answer 24

Not always present

Eg epiphysis at the head of the first metacarpal and the bases of other metacarpal bones

Question 25

Compound epiphysis

Answer 25

2-3 smaller epiphysis join to form a compound epiphysis
Joins the shaft
Eg epiphysis of head greater and lesser tubercle of humerus join to form a compound epiphysis which joins that shaft

Question 26

Traction epiphysis

Answer 26

Non Articular
Does not take part in transmission of weight
Provides attachent to tendons which exert a traction on the epiphysis
Ossify later than pressure epiphyses
Eg trochanter of femur and tubercles of humerus

Question 27

Atavistic epiphysis

Answer 27

Phylogenetically an independent bone
Becomes fused to another bone
Eg coracoid process of scapula
Os trigonum of talus

Question 28

Aberrant epiphysis

Answer 28

Not always present

Eg epiphysis at the head of the first metacarpal and the bases of other metacarpal bones

Question 29

Compound epiphysis

Answer 29

2-3 smaller epiphysis join to form a compound epiphysis
Joins the shaft
Eg epiphysis of head greater and lesser tubercle of humerus join to form a compound epiphysis which joins that shaft

Question 30

Diaphysis

Answer 30

Elongated shaft of the bone
Develops from primary centre of ossification
Receives blood supply from nutrient artery

Question 31

Diaphysis

Answer 31

Elongated shaft of the bone
Develops from primary centre of ossification
Receives blood supply from nutrient artery

Question 32

Metaphysis

Answer 32

Epiphyseal ends of diaphysis are called métaphyses
Zone of active growth
Before epiphyseal fusion, metaphysis is richly supplied with blood through end arteries forming hair pin bends
Common site of osteomyelitis because bacteria/emboli are trapped In hair pin bends causing infarction
After epiphysis fusion, vascular communications are established between metaphysical and epiphysial arteries

Question 33

Intracapsular metaphysis

Answer 33

Both ends of humerus

Question 34

Extracapsular Metaphysis

Answer 34

Upper and lower ends of radius and ulna

Question 35

Epiphyseal plate of cartilage

Answer 35

Separates epiphysis from metaphysis
Proliferation of cells in cartilaginous plate- lengthwise growth of bone
Nourished by epiphysial and metaphysial arteries

Question 36

The nutrient artery enters through the ———- runs through cortex and divides into ascending and descending branches which turn down to form

Answer 36

Nutrient foremen

Hair pin bends