C37: The Skeleton and
muscles
Mr. E Murphy
Objectives
 Functions
of the skeleton
 Structure of human skeleton
 Parts of the axial skeleton
 Parts of the appendicular skeleton
 Bones: types, growth and development
 Joints
 Musculoskeletal disorder
 Muscles
Functions of the skeleton
 Support
 Shape
 Protection
 Movement
 Manufacture
components
of blood
Skeleton
Structure
12
1
13
2
14
15
3
4
16
17
5
6
18
7
8
19
20
21
9
11
10
22
Regions of the spine
1
2
3
4
5
Structure of the human skeleton
 213
bones in the human
skeleton
 Divided into the axial
and the appendicular
skeleton
Parts of the axial skeleton
Skull
•Skull consists of 22 bones
•Most are fused together except for the jaw
Spine
•Made of 33 bones called
vertebrate
•Top 24 vertebrate are held together
by ligaments
•They are separated by discs of
cartilage
•Last 9 are fused together and there
are no discs between them
•No movement between them
TS of Vertebra
Activity
 Complete
diagram of the spine fig 45.2
p365
 TS of vertebra into your notes copy fig
45.4 p365
Parts of the axial skeleton
Rib cage





Consists of the sternum
(breastbone) and 12 pairs of ribs
All ribs are attached to the
vertebra of the spine
Top 7 ribs are attached to the
breastbone at the front (True ribs)
Next 3 ribs (8, 9 and 10) are
attached to each other at the front
of the chest by cartilage (false
ribs)
Bottom two ribs (floating ribs) only
attached to the spine
Parts of the appendicular skeleton
Pectoral girdle
 Collarbone
(clavicle) and
the shoulder blade
(scapula)
 Forms a connection with
the vertebral column and
with the arms
Parts of the appendicular skeleton
Pelvic girdle





Composed of two halves joined at
the front by a band of flexible
cartilage
Each half consists of 3 fused bones
Pelvic girdle is fused to the spine
Hip bones attach to the sacrum is
called the pelvis
Pelvic girdle consists of the hip
bones, the sacrum and the legs
Parts of the appendicular skeleton
Limbs
 Arms
and legs have a
similar design pattern
 Each limb ends in 5 digits
 Pentadactyl limb
 The phlanges are the
individual bones of the
fingers and toes
 Opposable thumbs
The thumb can be pushed against all the other four digits
Parts of the appendicular skeleton
Structure of long bone
 Long
bones are enclosed
by a membrane called the
periosteum
 Membrane contains blood
vessels and nerves
 Long shaft of the bone is
the diaphysis, head of the
bone is the epiphysis
Replacement of cartilage by bone in early life is
called ossification
Parts of the appendicular skeleton
Cartilage
Cartilage contains a firm but flexible fibrous protein called collagen

The collagen fibres are
embedded in a matrix of
calcium and phosphorous salts
 Lacks in blood vessels and
nerves
 Transport occurs through
diffusion
•Cartilage
also found in the pinna of the ear, the nose,
trachea
and discs is
in between
 Cartilage
slowerthe
totrachea.
heal than
•Cartilage
bonecovers the end of bones, protects them and allows
movement without friction
Types of Bone
•Compact bone
•Spongy bone
•Bone marrow
Compact bone

Made in bone cells, a
mixture of 70% inorganic
salts and 30% protein
 Blood vessels supply
•Calcium salts give bones their strength
bones with nutrients
•Protein gives bone its flexibility
 Nerve fibres run through
•Location: Compact bone is mostly found in
the bone
the diaphysis of a bone
•Also located as a layer around the end of
bone
Types of Bone
Spongy bone



Like compact bone but contains numerous hollows
Spaces in spongy bone are filled with red bone marrow
that produces blood cells
Location: Mainly at the end (epiphyses) of bones
Bone marrow


Soft fatty substance found in the medullary cavity and
within spongy bone
Red marrow makes blood components
Bone growth
The increase in the length of a bone is due to a
growth plate made of cartilage

Begins around 8 weeks into
development in the uterus
 Bone forming cells called
osteoblasts produce the
protein collagen
 Hard compound forms around
the collagen fibres
 Osteoblasts become trapped
in this hard compound and
become dormant bone cells
Bone development
Bone material is removed from the interior of the medullary cavity and
extra bone is deposited on the outside of the bone
 Throughout
life bone is dissolved and
replaced
 Catabolic cells digest bone cells
depositing calcium into the bloodstream
 Osteoblasts form new bone to replace the
Osteoporosis
is theisloss
of protein (collagen) material from the bone.
bone
that
destroyed
Causes bone to become brittle and easily broken
Joints
A joint is two or more bones meet
Joints are classified according to the degree of movement
they allow
 Immovable
E.g. Skull and pelvic girdle
 Slightly movable
E.g. Joints between vertebrae in the upper
spinal column
Joints

Freely movable
(synovial)
E.g. Ball and socket joints
(shoulder and hip)
Hinge joints (elbow and
knee)
•Ends of the bones are covered with
cartilage
•Bones are separated by a cavity
•Held in place by ligaments
•Joint is enclosed in a synovial membrane
•Membrane secretes synovial fluid which
lubricates the joint and reduces friction
Homework 16/12
 Complete
diagram p 371 diagram 45.10,
typical synovial joint
Joints
Ligaments
•Strong, fibrous, slightly elastic
tissues
•Connect bone to bone
Tendons
•Strong, flexible, inelastic fibres
that connect muscle to bone
•Composed of collagen and
contain some blood vessels
Musculoskeletal Disorder
Arthritis
Cause
Arthritis is a skeletal disorder resulting from inflammation (swelling) of
joint
•Most common arthritis is osteoarthritis
•Caused by the cartilage in synovial joints
wearing down
•The underlying bones enlarge and more
synovial fluid forms
•Joint becomes sore and stiff
Musculoskeletal Disorder
Arthritis
Cause


Rheumatoid arthritis is the most severe form of joint
inflammation
Caused by the body’s immune system turning on itself
Prevention
•Reduce damage to joints
•Wear proper footwear when
running, avoid running on
hard ground
Treatment
•No cure for either form or
arthritis
•Treatments include rest,
exercises, weight loss and
possibly surgery to replace the
joint
Muscles
Three types of muscle
•Skeletal e.g. body movements
•Smooth e.g. involuntary muscle
•Cardiac e.g. heart
Skeletal muscle
 Concerned
with body movements
 Can contract quickly, but tires very
easily
 Under voluntary or conscious control
Muscles
Smooth muscle

Involuntary muscle
 Found in the digestive system, blood vessels,
bladder and uterus
 Contracts slowly, slow to tire
 Involuntary or unconscious control
Cardiac muscle
•Found in the heart
•Involuntary
Antagonistic Pairs
Muscles
Muscles are connected to bones by tendons. When the muscle
contracts, the tendons pull on the bone, causing it to move
 Muscles
can only pull (by contracting)
 They cant push
Forearm
•Biceps contract to pull the lower
arm up
•The triceps contracts to straighten
the arm
Muscles
•A pair of muscles that
have opposite effects to
each other is called an
antagonistic pair
•Biceps are called flexors
•Triceps is called an
extensor
•Generally flexors are
stronger than extensors
Key Words









Endoskeleton
Exoskeleton
Axial and appendicular skeleton
Bone growth
Osteoblasts
Joints
Musculoskeletal disorder
Arthritis
Muscles
Homework 14/12
Q
4 2009 exam papers
 Diagram of the internal and external
structure of a long bone p368
Q4 2009
Corrections
Homework 15/12
Q
15 a 2008
 Q 15 a 2006
Exam Questions 2010 Q15 c
Exam Questions 2008 Q15 c
Exam Questions 2007 Q14 b
Exam Questions 2006 Q15 b
Exam Questions 2005 Q15 b
Solutions
skeleton, muscular, nervous
2. A) support, protection, movement and
shape
b) framework, inner organs muscles can
move skeleton, features
3. A) skull, ribs, spine and sternum
b) arms, legs, pectoral girdle and pelvic
girdle
1.
Solutions
A-neural spine, b_ transverse process, cneural canal, d- centrum
b) Muscular attachment
c) Spinal chord
d) Contact with next vertebrae
5. a) true- attached breast bone, false –
attached to each other, floating- only to
the spine
4.
Solutions
b) pectoral-collar bone and shoulder
blade pelvic- spine and hip
c) compact- hard and strong, bone cells in
salt and protein, spongy- hollow spaces
containing bone marrow
d) ligament- bone to bone, tendon – muscle
to bone
e) red- makes blood cells yellow- does not
5.
Solutions
a) bones in the spine
b) cervical-7, thoracic-12, lumbar- 5, sacrum- 5,
coccyx-4 (33 in total)
c) Inter vertebral disc
d) Prevents friction (offers lubrication)
7. a) A- scapula, B- humerus, C- radius, D-carpel
b) Ball and socket, hinge
d) Radius and scapula
e) Closes the joint
6.