A1 - skeletal system

Question 1

Cranium

Answer 1

• box like cavity (space)
• interlinking bones (these are not fused when born)
• contains and protects the brain

Question 2

Ribs

Answer 2

• 12 pairs of ribs (forming the ‘thoracic cage’)
• first 7 are attached to the sternum
• bottom 5 are not attached to the sternum

Question 3

Carpals

Answer 3

• 8 small bones that make up the wrist
• arranged in 2 rows of 4
• held in place by ligaments

Question 4

Metacarpals

Answer 4

• 5 long bones in the palm of the hand (one corresponding to each finger)

Question 5

Pelvis

Answer 5

• made up of 2 hip bones
• each hip bones has 3 sections (illium, ischium and pubis)
• these fuse together during puberty

Question 6

Femur

Answer 6

• longest and strongest bone in the body

Question 7

Vertebral column

Answer 7

• made up of 5 different sections
• cervical, thoracic, lumbar, sacral and coccygeal

Question 8

What are the 5 classifications?

Answer 8

• short bones
• irregular bones
• long bones
• flat bones
• seasamoid bones

Question 9

Long bones

Answer 9

• bones found in the limbs
• used in movement
• they have two distinct parts ( diaphysis and epiphysis )
• femur, clavical, carpals, metatarsals

Question 10

Short bones

Answer 10

• small, light, strong and cube shaped
• they are a ‘cancellous bone’ = light and porous bone material that has a honeycomb or spongy appearance
• used for weight bearing
• tarsals and carpals

Question 11

Flat bones

Answer 11

• used for protection
• thin, flattened and slightly curved bones
• large surface area
• sternum, scapulae and cranium

Question 12

Irregular bones

Answer 12

• complex shapes (that fit into no other bone categories)
• vertebrae
• used for protection and movement

Question 13

Sesamoid bones

Answer 13

• these have a specialised function (usually found within a tendon)
• these provide a ‘smooth’ surface for the tendon to slide over
• used to reduce friction and protect inner parts of a joint
• patella

Question 14

Appendicular skeleton

Answer 14

• consists of the bones attached to the axial skeleton
• there are 4 main sections of the appendicular skeleton (upper limbs, lower limbs, shoulder girdle and pelvis girdle)

Question 14

What are the two parts of the skeleton?

Answer 14

Axial skeleton - 80 bones forming the ‘long’ axis of the body (middle-midriff-spine-main bit)
Appendicular skeleton - 126 bones forming the bones attached to the axial skeleton (extremities/appendages-arms-legs)

Question 15

Upper limbs (appendicular skeleton)

Answer 15

• consists of 60 bones (30 in each arm)
• humerus-radius-ulna-carpels-metacarpals-phalanges

Question 16

Lower limbs (appendicular skeleton)

Answer 16

• consists of 60 bones (30 in each leg)
• femur-patella-tibia-fibula-tarsals-metatarsals-phalanges

Question 17

Shoulder girdle (appendicular skeleton)

Answer 17

• consists of 4 bones
• clavical-scapula-ribs-humerus

Question 18

Pelvic girdle (appendicular skeleton)

Answer 18

• consists of 3 bones
• illium, ischium and pubis
• vertebrae-femur-coccyx

Question 19

Axial skeleton

Answer 19

The axial skeleton (main core) of the body consists of …
- the skull (including cranium and facial bones)
- the thoracic cage (sternum and facial bones)
- the vertebral column (cervical, thoracic, lumbar, sacrum, coccyx)

Question 20

vertebral column/ spine (axial skeleton)

Answer 20

• between each vertebrae is an ‘inter vertebral disc’ and they act as shock absorbers, spongy tissue material
• main roles are to protect the spinal cord and support the rib-cage
• made of 33 irregular bones called vertebrae
• the vertebral column accounts for around 40% of a persons height
• the vertebrae held together by powerful ligaments, theses allow a little movement between the vertebrae, but a considerable amount of flexibility along the spine

Question 21

What the 5 classified sections of the vertebral column and how many vertebrae do they have?

Answer 21

• cervical vertebrae (7)
• thoracic vertebrae (12)
• lumbar vertebrae (5)
• sacral vertebrae (fused 5)
• coccygeal vertebrae (fused 4)

Question 22

Cervical vertebrae

Answer 22

• 7 vertebrae of the neck (C1 known as the ‘atlas’ and C2 known as the ‘axis’
• theses form a pivot joint that allows the head and neck to move freely
• these are the most vulnerable vertebrae of the column

Question 23

Thoracic vertebrae

Answer 23

• the ‘mid spine’ made of 12 vertebrae
• these articulate (connect) with the ribs
• they lie in the ‘thorax’ a dome shaped structure that protects the heart and lungs

Question 24

Lumbar vertebrae

Answer 24

• the 5 largest (and most vulnerable) vertebrae
• situated into the lower back
• they support more weight than any other vertebrae, and provide a base for muscle attachment
• these create a ‘concave’ curve in the back

Question 25

Sacral vertebrae

Answer 25

• made of 5 vertebrae fused together to form the ‘sacrum’
• this forms the back wall of the pelvic girdle, sitting between two hip bones
• the upper of the 5 bones connects to the bottom lumbar vertebrae, and the bottom of the 5 connects to the coccyx
• needed for protection

Question 26

Coccygeal vertebrae

Answer 26

• found at the very bottom of the vertebral column
• made of 4 coccygeal vertebrae which are fused together to form the coccyx (tail bone)

Question 27

What are the effects of a pelvic tilt and hip/knee hyper-extension on the lower posture?

Answer 27

• anterior pelvic tilt (lordotic back)
• posterior pelvic tilt (flat back)
• forward shifted pelvis (sway back)
• neutral pelvic tilt (balanced posture)

Question 28

What are postural deviations?

Answer 28

• these are disorders which can cause the natural curves of the spine to deviate

Question 29

Kyphosis

Answer 29

• excessive outward curve of the thoracic region of the spine, resulting in a ‘hunchback’ appearance
• often caused by poor posture or deformities in the vertebrae

Question 30

Scoliosis

Answer 30

• abnormal curvature to the left or right (lateral curvature)
• most likely in the thoracic region and mostly in children
• not caused by posture, actual cause unknown, but it is inherited

Question 31

What is bone?

Answer 31

• a living organism that is constantly being replaced/ strengthened/ replenished
• it is constantly being reshaped through a process called ‘remodelling’

Question 32

What is ossification?

Answer 32

• the process in which bones are formed
• throughout the process parts of the bone are reabsorbed so that unnecessary calcium is removed (via cells called osteoclasts) while new layers of bone are created

Question 33

How is calcium used in cells?

Answer 33

• osteoclasts = take away/ remove calcium
• osteoblats = bring calcium and create bone matter
• osteoblats activity increases after exercise (therefore PA makes bones denser and stronger)
• calcium stores are increased so that there is less chance of developing osteoporosis in later life (covered in depth layer)

Question 34

What happens in osteoporosis?

Answer 34

• bone mineral density and bone mass decrease

Question 35

What is bone growth and how does it work?

Answer 35

• the ends of each long bone contain ‘growth plates’ which allow the bone to grow longer
• this continues throughout childhood until they reach full maturity
• these are specifically known as ‘epiphyseal plates’
• once the bone has finished growing the plates fuse to the main shaft (diaphysis) to create the ‘epiphyseal line’