AOS 1: skeletal system

Question 1

The skeletal system

Answer 1

Supportive and protective structure - 206 bones

Question 2

5 Main functions

Answer 2

• Body movement
• Framework
• Protection
• Mineral storage
• Red blood cell production

Question 3

Body movement

Answer 3

Bones work together with skeletal muscle to help produce movement
- A muscle contracts and pulls on the bone it is attached to
- The muscle contraction creates movement at the joint it acts upon

Question 4

Body movement example

Answer 4

The bicep brachii acts on the elbow allowing it to flex and extend

Question 5

Framework

Answer 5

Skeleton provides support
- Suitable attachment sites for muscles
- Allows upright posture
- Helps battle the forces of gravity

Question 6

Protection

Answer 6

Protects vital internal organs and tissues

Question 7

Mineral storage

Answer 7

Bone tissue effectively stores a number on minerals that are important for health
- Calcium, phosphorus, sodium and potassium all contribute to the health and maintenance of bone tissue

Question 8

Red blood cell production

Answer 8

New blood cells are produced within the cavity of long bones (red bone marrow)
- RBC are essential for oxygen transport around the body
- EPO released by the kidneys stimulates erthropoiesis by the bone marrow

Question 9

Division of the skeleton

Answer 9

Axial skeleton and appendicular skeleton

Question 10

Axial skeleton

Answer 10

Consists of bones located centrally within the body, including:
- Cranium
- Rib cage
- Vertebral column

Plays a supportive role to all other bones in the human body

Question 11

Vertebral column

Answer 11

Involved in more than 95% of movement

Comprises of 33 bones and divided into 5 sections:
~ Cervical- 7 vertebrae
~ Thoracic- 12 vertebrae
~ Lumbar- 5 vertebrae
~ Sacrum- 5 fused vertebrae
~ Coccyx- 4 fused vertebrae

Question 12

Appendicular skeleton

Answer 12

Refers to the appendages that are attached to the axial skeleton
- Vital for human movement

• Joined to the axial skeleton by 2 limb girdles:
  ~ Pectoral
  ~ Pelvic

Question 13

Name the bones

Answer 13

Cranium, mandible, clavicle, scapula, sternum, rib cage, vertebral column, humerus, ulna, radius, carpals, metacarpals, phalanges, pelvis, femur, patella, tibia, fibula, tarsals, metatarsals

Question 14

Types of bones

Answer 14

• Short
• Long
• Sesamoid
• Flat
• Irregular

Question 15

Short bone

Answer 15

Equal length, width and height

e.g. carpals, tarsals

Question 16

Long bones

Answer 16

Longer than they are wide

e.g. femur, humerus

Question 17

Sesamoid

Answer 17

Small bones embedded within a tendon to increase the ROM at a joint

e.g. patella

Question 18

Flat bones

Answer 18

Broad, flat plates that provide protection & a site for muscle attachment attachment

Question 19

Irregular bone

Answer 19

Have no particular size or shape

Question 20

Joint classification

Answer 20

• Fibrous joint
• Cartilaginous joint
• Synovial joint

Question 21

Fibrous joints

Answer 21

Offer no movement, also known as immovable joints

• Bones joined by fibrous tissue, no joint cavity present

e.g. pelvis, sacrum, sternum

Question 22

Cartilaginous joints

Answer 22

Slightly movable joints joined by cartilage
Lack a joint cavity

e.g. intervertebral joint, sternocostal joint

Question 23

Synovial joints

Answer 23

Freely movable joint
- Offer movement in at least one direction

e.g. knee joint, shoulder joint

Question 24

Synovial joints

Answer 24

• Pivot
• Gliding
• Ball & socket
• Hinge
• Saddle
• Condyloid

Question 25

Pivot joint

Answer 25

Unaixial joint that only allows rotation

Movement, atlas & axis

Question 26

Gliding

Answer 26

Occurs where flat bones glide past each other

Gliding movements , carpals, tarsals

Question 27

Ball & socket

Answer 27

Occurs where a rounded bone head articulates with a cup-shaped cavity

Flexion/extension, adduction/abduction, internal/ external rotation

e.g shoulder, hip

Question 28

Hinge

Answer 28

A unaxial joint

flexion/extension

e.g. knee, elbow

Question 29

Saddle

Answer 29

Occurs where concave & convex bone surfaces align

Flexion/extension, adduction/ abduction, circumduction

e.g. base of thumb joint

Question 30

Condyloid

Answer 30

Very similar to a hinge joint but allows slight rotation

Flexion/extension, adduction/abduction, circumduction

e.g. wrist