The Skeleton: Glossary

Question 1

Abduction

Answer 1

moving a limb away from the midline of the body, the opposite of adduction

Question 2

Acetabulum

Answer 2

rounded cavity on the external surface of the hipbone that receives the head of the femur

Question 3

Adduction

Answer 3

moving a limb towards the midline of the body, the opposite of abduction

Question 4

Anterior

Answer 4

nearer to the front of the body

Question 5

Articular cartilage

Answer 5

a layer of smooth, fibrous cartilage covering freely moveable joints and acting to prevent the bones rubbing against each other, and to absorb shocks

Question 6

Articulate

Answer 6

form a joint

Question 7

Atlas

Answer 7

the top vertebra of the spinal column

Question 8

Axis

Answer 8

the second to top vertebra of the spinal column

Question 9

Ball-and-socket joint a

Answer 9

a joint that permits free movement in all directions, consisting of a ball-shaped bone fitting into a concave socket

Question 10

Blood cells

Answer 10

also called corpuscles, these microscopic units transport oxygen from the lungs to the body cells (red blood cells) or fight bacteria (white blood cells)

Question 11

Bone

Answer 11

rigid connective tissue that supports the body’s soft tissues. Bones protect vital organs, enable locomotion, are the source of the body’s red and white blood cells and blood platelets, and play a vital role in keeping the calcium balance in the body. Bone exists in either dense form (known as compact bone) or spongy form (known as cancellous bone)

Question 12

Bone marrow

Answer 12

(also known as myeloid tissue.) A network of soft tissue found at the centre of many bones. Yellow bone marrow is mainly fat; red bone marrow provides the body with red and white blood cells and blood platelets

Question 13

Calcaneus

Answer 13

the bone forming the heel of the foot

Question 14

Calcium

Answer 14

a soft grey metallic element occurring naturally in limestone, marble, chalk and so on. Calcium is essential for normal growth in living organisms, and is a constituent of bones

Question 15

Cancellous bone

Answer 15

bone tissue that consists of an irregular latticework of thin plates of bone called trabeculae

Question 16

Cartilage

Answer 16

a firm flexible connective tissue consisting of a dense network of collagen fibres and elastic fibres

Question 17

Cartilaginous joints

Answer 17

slightly moveable joints held together by elastic cartilage

Question 18

Circumduction

Answer 18

the circular or cone-like movement of a body segment, as in arm-circling, a combination of flexion, extension, abduction and adduction

Question 19

Collagen

Answer 19

a protein found in connective tissue that produces gelatin on boiling. Collagen makes up bone, skin, tendons, and cartilage, is the most abundant protein found in the body

Question 20

Compact bone

Answer 20

same as cortical bone

Question 21

Condyle

Answer 21

arounded prominence found at the end of some bones, helping to form an articulation with another bone in a condyloid joint

Question 22

Condyloid joint

Answer 22

a joint in which an oval-shaped head (condyle) of one bone fits into a shallow cavity in the another bone – like a shallow ball-and-socket joint. Examples are the joints of the metacarpals and phalanges of the hand (but not the thumb)

Question 23

Contralateral

Answer 23

on the opposite side of the body

Question 24

Cortical bone

Answer 24

very dense and strong bone material that forms an outer layer (beneath the peristeum) and in long bones is thickest in the middle of the shaft. (‘Cortical’ is the adjective from the noun ‘cortex’, which means ‘outer layer’)

Question 25

Cranium

Answer 25

the skull

Question 26

Depression

Answer 26

dropping of the shoulder girdle

Question 27

Diarthroses

Answer 27

freely moveable joint

Question 28

Distal

Answer 28

located away from the centre or point of attachment. The distal end of a bone is the foot of the bone. See proxima

Question 29

Dorsi flexion

Answer 29

the pointing of the toes upwards towards the knee. The opposite of plantar flexion.

Question 30

Downward rotation

Answer 30

the scapula in the shoulder girdle can be rotated downwards

Question 31

Elevation

Answer 31

lifting up of the shoulder girdle

Question 32

Eversion

Answer 32

turning the sole outwards

Question 33

Extension

Answer 33

increasing the angle between bones at a joint – the opposite of flexion

Question 34

Fascia sheet

Answer 34

a thin sheath of fibrous tissue

Question 35

Flexion

Answer 35

decreasing the angle between bones at a joint. The opposite to extension

Question 36

Force arm

Answer 36

the distance from the fulcrum to the line of the applied effort in a lever

Question 37

Freely moveable joint

Answer 37

joint in which the articulating bones are free to move to the extent allowed by the ligaments, muscles and so on

Question 38

Fulcrum

Answer 38

the point on which a lever turns or is supported

Question 39

Gelatin

Answer 39

a transparent water-soluble protein that is almost colourless, and can be derived from collagen

Question 40

Gliding joint

Answer 40

a type of joint found between various bones in the wrist and ankle, in which the surfaces of the bones move a short distance over each other. Gliding surfaces are almost flat, with perhaps one surface being slightly convex and the other slightly concave