This document provides an overview of the musculoskeletal system, including the skeletal and muscular systems. It describes the main bone types and classifications, joints, movements, and muscle contractions. Key terms are defined such as anatomical directions, bone functions, and the differences between skeletal muscle fiber types.

1. VCE Physical Education
Unit 1
The Musculoskeletal System
Traralgon College

2. Anatomical Terms
 To avoid confusion when describing various body
movements and positions of the musculoskeletal
system, standard anatomical terminology is used.
 Medial Direction – toward the midline of the body
 Lateral Direction – toward the side of the body.

3. Anatomical Terms
 Superficial Direction – close to the surface of the
body.
 Deep Position – any feature that is further away
from the surface of the body. Example – the ribs are
“Superficial” and the heart is “deep”.
 Proximal and Distal Positions – refers to the limbs.
Proximal means “closer” to where the limb is
attached. Distal means further from the point of
attachment – the fingers are distal to the shoulder.
 Superior – a position towards the head.
 Inferior – a position away from the head.

5. Skeletal System Overview
 A newborn baby has 305 bones.
 As a human develops to the age of 25, some
bones fuse together to obtain maximum strength.
 The average human skeleton has 206 bones.
 Largest bones – Thigh (Femur) and the Upper
Arm (Humerus).
 Smallest bones – Middle Ear (Maleus, Incus and
Stapes).
 All bones are living organs, which contain living
(cells) and non-living (mineral) materials.

6. Functions of Bones
 Bones have 5 major functions:
Support – Provide support for tendons and ligaments
and the framework for body shape.
Protection – The cranium protects your brain, the ribs
and sternum protect your internal organs such as heart
and lungs.
Movement – Bones work with muscles to produce
movement. Muscles are attached to the skeleton and
work by contracting (shortening) and pulling on bones.
Storage – Bones are the site for storage and release of
excess minerals. These are released as the body
requires.
Blood production – Some bones (ribs, vertebrae,
humerus and femur) contain red bone marrow. This
makes red cells, white cells and platelets for blood.

7. Cranium
Mandible
Scapula
Clavicle
Sternum
Humerus
Ribs
Vertebrae
Radius
Pelvis
Ulna
Carpals
Metacarpals
Phalanges
Femur
Patella
Fibula
Tibia
Metatarsals Tarsals
Phalanges

8. Bone Classifications – Long
Bones
 Long bones consist of a long shaft covered by
hard bone around a hollow centre which contains
yellow marrow.
 The two ends contain spongy bone and red
marrow.
 These bones are light but very strong, and are
major weight-bearing bones of the body.

9. Long Bone - Femur

10. Bone Classifications – Short
Bones
 Short bones are chunky, compact bones that are
strong and reinforced by thickening of the bone
tissue.
 They contain spongy bone and allow a variety of
movements at joints.

11. Short Bone - Carpals

12. Bone Classifications – Flat
Bones
 Flat bones are made up of two strong layers of
compact bone, joined by a layer of spongy bone.
 These bones give protection to organs beneath
them and allow for large areas of muscle
attachment.

13. Flat Bone - Scapula

14. Bone Classifications – Irregular Bones
 Irregular bones are made up of a thin layer of
compact bone containing a mass of spongy bone.
 Irregular bones are reinforced where extra
strength is needed.

15. Irregular Bone - Vertebra

16. Division of the Skeleton
 The skeleton has two main parts:
◦ Axial Skeleton and the Appendicular Skeleton.
 The Axial Skeleton includes the skull, the vertebral
column (spine, sacrum, and coccyx), the sternum,
and the ribs. Its components are aligned along the
long axis of the body.
 The Appendicular Skeleton includes the bones of
the upper extremities (arms, forearms, and
hands), the pectoral (shoulder) girdle, the pelvic
(hip) girdle, and the bones of the lower extremities
(thigh, knee, leg, and foot). Its components are
outside the body main axis.

17. Axial and Appendicular
Skeleton

18. The vertebral column
 Involved in more than 95% of movement
 Comprised of 33 bones (9 fused and 24 unfused)
 Cervical vertebra
◦ 7 unfused bones
◦ Make up the neck and are responsible for supporting the
head
 Thoracic vertebra
◦ 12 unfused bones
◦ Connect the rib cage to the spinal column and form a
protective shield for the heart and lungs
 Lumbar vertebra
◦ 5 unfused bones
◦ Largest and have high weight carrying capacity
 Sacrum
◦ 5 fused bones which fuses to the pelvis
◦ Together they distribute weight of the upper body
 Coccyx
◦ 4 fused bones forms the base of the vertebral column
◦ Provides site for muscle attachment

19. Types of Joints
 Joints occur when 2 or more bones meet. They are
held by ligaments (thick cords of stringy tissue).
 Joints are essential for movement, as muscles need
to pass over them for contraction to occur.
 The type of joint will determine how moveable the
bones are. There are three main types of joints:
 Fibrous – immovable.
 Cartilaginous – partially moveable.
 Synovial – freely moveable.

21. Types of Movement
 Flexion – the angle of the joint is decreased.
 Extension – the angle of the joint is increased.
 Adduction – a body part is moved towards the
middle of the body.
 Abduction – a body part is moved from the midline of
the body.
 Rotation – a body part is moved either outwards or
inwards around its long axis.
 Circumduction – a body part is moved in a cone
shape.

22. Types of Movement
 Supination – a rotation of the forearm which causes
the palm of the hand to face upwards.
 Pronation – a rotation of the forearm which causes
the palm of the hand to face downwards.
 Eversion – a rotation of the sole of the foot outwards.
 Inversion – a rotation of the sole of the foot inwards.
 Refer to Figure 11.22 to 11.26 on page 270 and 271.

23. Muscular System Overview
 There are over 600 muscles in the human body.
 There size ranges from one that make the hairs
on your arms stand up to the large muscles in
your upper leg.
 Without muscles our hearts wouldn’t beat, we
couldn’t breathe, digest food, walk, talk or
reproduce.

24. Functions of Muscles
 Muscles have 3 major functions:
Movement – Most of our muscles are under
voluntary control such as skeletal muscles
responsible for moving our bones. Some
muscles we do not consciously control such as
muscles of the eye and heart.
Posture – Muscles make continuous changes to
our posture allowing for the constant pull
(gravity) placed on our body.
Body Heat – The energy muscles require to
contract produces movement and releases heat
that helps maintain body temperature.

25. Types of Muscles
 There are 3 types of muscles tissue in our body:
Skeletal Muscle – Muscles attached to our
bones under voluntary control.
Smooth Muscle – Muscles found internally in
blood vessels and walls of the intestine and
stomach under involuntary control.
Cardiac Muscle – Muscles that make up the
walls of the heart which are under involuntary
control.

26. Sternomastoid
Trapezius
Deltoid
Deltoid
Rhomboids Pectorals
Triceps
Biceps
Latissimus Dorsi
Rectus Abdominis
Gluteus Maximus
Biceps Femoris
Sartorius
Quadriceps
Gastrocnemius
Soleus

27. The Muscular System Table
Letter Colour Common Name Scientific Name Location Action
(Where it is on the body) (What is does)
A Delts Deltoid Shoulder Lifts arm
B Pecs Pectorals Chest Pulls shoulders forward
C Traps Trapezius Between neck and shoulder Lifts (shrugs) shoulders
D Biceps Biceps Front of upper arm Bends elbow
E Triceps Triceps Back of upper arm Straighten elbow
F Rhomboids Rhomboids Between shoulders Pulls shoulders back
G Abs Rectus Abdominis Stomach Bends trunk forward
H Glutes Gluteus Maximus Buttocks Straightens hip
I Sartorius Sartorius Thigh Rotate leg
J Hamstrings Biceps Femoris Back of thigh Bends knee
K Soleus Soleus Front of leg Flexes ankle
L Lats Latissimus Dorsi Underarms Pulls shoulders down
M Quads Quadriceps Front of thigh Straightens knee
N Calf Gastrocnemius Behind shin Straightens ankle
O Sternomastoid Sternomastoid Neck Turns head

28. Types of Muscle Fibres
 Skeletal muscle is made up of two basic fibre
types:
 Slow-twitch Fibres (Type 1) and
 Fast-twitch Fibres (Type 2).

29. Slow-twitch Muscle Fibres
 Colour = Red
 Contract slowly over a longer period of time.
 Best suited to aerobic and endurance activities.
 Exerts less force and can contract repeatedly.

30. Fast-twitch Muscle Fibres
 Colour = White
 Contract rapidly over a shorter period of time.
 Best suited to anaerobic and high intensity
activities.
 Exerts great force in bursts of power and speed.

31. Athletic Comparisons
Sport % slow twitch % fast twitch
Distance runners 60-90 10-40
Track sprinters 25-45 55-75
Weight lifters 45-55 45-55
Shot putters 25-40 60-75
Non-athletes 47-53 47-53
Figure 11.31 and 11.32 on Page 274 and 275

32. Muscle Structure

33. Types of Muscle Contractions
 There are three types of muscle contractions (listed
in order of most common to least common):
 Isotonic Contraction,
 Isometric Contraction, and
 Isokenitic Contraction.

34. Isotonic Contraction
 Most common muscle contraction.
 Occurs when the muscle length changes as
tension is developed.
 Example – when a shot-putter pick up the shot-put
and raises it to his or her neck.

35. Isometric Contraction
 Occurs when the muscle contracts but do not
produce any movement.
 Example – if you were to hold out your arm, palm
up and a weight is placed on your hand. Your arm
muscles would develop tension but not change in
length.

36. Isokinetic Contraction
 Occur when tension in a muscle is maximal
throughout the range of motion.
 This type of contraction exercises the muscle most
effectively.
 Specialised gym equipment assist with these
contractions.
 The harder you push or pull, the greater the
resistance offered by the machine.

37. Summary
 What you should know – page 1 - 27.
 Test your knowledge – page 29.
 SAC 1 - Preparation Sheet