Namibia HP Campus 2017

1. H
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2. THE SKELETON

3. 1. SKELETAL SYSTEM
3 Types of skeletons:
• Hydrostatic skeleton: Consists of fluid held under pressure
Offer no protection of support for large land animals
Can control their form and movement with muscles in
body wall
Eg. Cnidarians (Jellyfish), Annelids (earthworm)
• Exo-skeleton: Found outside the body
Composed of chitin or calcium carbonate , can
be in form of shell
Cannot grow with animal, has to be shed from
time to time to form larger exoskeleton = molting
Eg. Arthropods, insects, crustaceans
• Endo-skeleton: forms internal supporting system
muscles attached to surface of skeleton
2 types of material: bone and cartilage
Continuous growth – no need for molting

4. Functions of bone
1. Supports body and gives shape
2.Protects delicate
internal organs
3. Provides attachment for muscles to
enable movement
4. Storage of minerals eg. Calcium, magnesium
5. Produce red blood cells in bone marrow

5. TYPES OF BONES - SHAPE
Typically longer than wide
Have a shaft with heads at both
ends
Contain mostly compact bone
Generally cube-shape
Contain mostly spongy bone
Thin and flattened
Usually curved
Thin layers of compact bone
around a layer of spongy
bone
Irregular shape

6. Anatomy of a Long Bone
1. Diaphysis
Shaft
Composed of compact bone
Cavity of the shaft:
Contains yellow marrow (mostly fat) in adults
Contains red marrow (for blood cell formation)
in infants
 Periosteum - Outside covering of the diaphysis
Arteries - Supply bone cells with nutrients
2. Epiphysis
Ends of the bone
Composed mostly of spongy bone with red bone
marrow
 Cartilage covers external surface of the epiphyses
- Decreases friction at joint surfaces

7. Structure of human skeleton
• 2 parts:
Axial skeleton: skull and vertebral column + ribcage
Appendicular skeleton: Pectoral girdle with arms
Pelvic girdle with legs
• Baby has 305 bones and an adult has 206 bones. This
is because as we grow some of our bones join
together to form one bone (especially skull).
• The longest bone in our bodies is the femur (thigh
bone).
• The smallest bone is the stirrup bone inside the ear.

8. 206 BONES OF THE HUMAN SKELETON

9. A. AXIAL SKELETON:
1. SKULL: 22 bones (+6)
2 parts: Cranium
Facial bones
Frontal Bone
Parietal Bone
Temporal
Bone Occipital
Bone
Nasal Bone
Maxilla Bone
Mandible
Bone
3 bones in each
middle ear:
Functions?? Malleus Incus Stapes
(Hammer) (Anvil) (Stirrup)

10. 2. Vertebrae:
• 28 bones S-shaped, forming
SPINE
• Provides a strong and flexible
support for the body
• Keep the body upright
• Point of attachment for the
muscles of the back.
• Protect the spinal cord and
nerves
• Absorbs shock through
intervertebral cartilage discs
7 Cerviacal vertebrae
(Neck)
12 Thoracic vertebrae
(Chest)
5 Lumbar vertebrae
(Lower back)
1 sacrum (5 bones fused)
(top part of buttocks))
1 coccyx (4/5 bones fused)
(Tail bone)

11. 3. RIBS / STERNUM
Sternum
(breast bone)
• Thin, flat, curved bones
• Form a protective cage around
organs in upper body.
• Assist with breathing
• Comprised 24 bones
arranged in 12 pairs
attached in the back to thoracic
vertebrae.
 First seven pairs of ribs
attach in the front to the
sternum with cartilage –
true ribs
 Next three pairs are held on
with cartilage to the ribs above
them – false ribs
 Last two sets of not connected
to the sternum or the ribs –
floating ribs
• Sternum: breast bone
clavicles and ribs 1-7
articulate with sternum

12. • Every time you breath, twenty-four ribs,
twelve vertebrae, and a breast bone move.
(37 BONES!)
• These bones move over five-million times a
year.
• Which means you breath about five million
times a year!
DID YOU KNOW??

13. b. Appendicular SKELETON
1. Pectoral girdle: (shoulder)
Allows upper limbs to move freely
(a) Scapula: shoulder blade
• large triangular bone on upper back
corner of each side of the ribcage.
clavicle
scapula
(B) CLAVICLE: collarbone
• S-shaped bone - connects the upper arm to the trunk of
the body
•holds the shoulder joint away from the body to allow for
greater freedom of movement.
•One end of the clavicle connected to the sternum and
one end connected to scapula.
• Most frequently fractured bone in human body! WHY?

14. (C) Upper limb (arm):
 Humerus: upper arm bone
 shoulder to elbow
 Radius and Ulna: forearm bones
– elbow to wrist
– Radius: located on the thumb side of hand
– Ulna: obvious on little finger side of hand
– When you pronate the forearm, the radius is
actually crossing over the ulna yourself
 Carpals: 8 wrist bones
 Metacarpals: palm of hand
– 5 bones, one aligned with each of the fingers
– numbered I to V starting with the thumb
– heads of the metacarpals form the knuckles of
a clenched fist.
 PHALANGES: finger bones
– 14 bones: 3 in each finger; thumb only 2
– A single finger bone is called a phalanx.
8 carpals (wrist)
5 metacarpals
(palm of hand )
14 phalanges
(fingers)

15. • Pelvic girdle: (hips)
(a) Hip bone
 Composed of three pair of
fused bones
o Ilium (hip)
o Ischium (sit)
o Pubic bone (pelvis)
 Total weight of upper body rests on the pelvis
 Protects several organs
 Allows articulation of hind limbs
 3 bones form cup-shaped socket – ACETABULUM for femur to rotate

16. b) lower limb (leg):
 Femur: thigh bone
– Longest bone in body
– Rounded head where it articulates with the
acetabulum
 Tibia: shin bone
– Large flat area at the knee to articulate with
the femur
– End of the tibia forms the ankle joint
 Fibula: calf bone
– Much smaller than the tibia
– Larger at the ankle and narrows to a small
head near the knee
 Patella: Kneecap
– triangular-shaped bone that protects the
knee joint.

17.  Tarsals (7)
• ankle bones
• calcaneus (heel bone) largest tarsal bone
 Metatarsals (5)
• 5 bones of the foot
• unite with the toes
 Phalanges (14)
• toe bones
• three per toe except the big toe
TOTAL = 205 BONES ??

18.  The hyoid bone (Lingual Bone)
• Bone in the human neck
• Only bone in the skeleton not articulated
to any other bone.
- Supported by the muscles of the neck
• Supports the root of the tongue.
• The hyoid bone is shaped like a horseshoe
• Involved in the production of human speech. It allows a wider
range of tongue movements

19. Types of joints
• Immovable: bones firmly fitted
together for no movement - skull
• Ball and socket: ball of one bone
fits into socket of another - movement
in all directions – shoulder, hips
• Hinge: movement in one direction
only – elbow, knee
• Gliding: bone only slide over one
another – wrist bones
• Pivot: one bone rotates around
another – atlas/axis (“NO!”)

20. Identify following joints:

21. Structure of a synovial joint
(Synovial membrane)

22. Diseases and Conditions
of the Skeletal System

23. Gout
• Disease that results from
overload of uric acid in the body.
This overload of uric acid leads to
formation of tiny crystals of urate
that deposit in tissues of the
body, especially the joints.
• When crystals form in the joints it
causes recurring attacks of joint
inflammation (arthritis).
• Chronic gout can also lead to
deposits of hard lumps of uric
acid in and around the joints and
may cause joint destruction,
decreased kidney function, and
kidney stones.

24. Arthritis

25. Tendonitis• Sometimes the tendons
become inflamed for a
variety of reasons, and the
action of pulling the muscle
becomes irritating. If the
normal smooth gliding
motion of your tendon is
impaired, the tendon will
become inflamed and
movement will become
painful. This is called
tendonitis, and literally
means inflammation of the
tendon.
• The most common cause
of tendonitis is overuse.

26. Osteoporosis
• Osteoporosis is a term that
means "porous bones." It is a
skeletal disease affecting
women and men.
Osteoporosis is a condition in
which bones have lost
minerals especially calcium,
making them weaker, more
brittle, and susceptible to
fractures (broken bones). Any
bone in the body can be
affected by osteoporosis, but
the most common places
where fractures occur are the
back (spine), hips, and wrists.

27. Scoliosis• Scoliosis is an abnormal
curvature of the spine. If
your child has scoliosis, the
view from behind may
reveal one or more
abnormal curves.
• More girls than boys have
severe scoliosis. Adult
scoliosis may be a
worsening of a condition
that began in childhood,
but wasn't diagnosed or
treated. In other cases,
scoliosis may result from a
degenerative joint condition
in the spine.

28. Rickets
• Rickets is the softening
and weakening of bones
in children, usually
because of an extreme
and prolonged vitamin D
deficiency.
• Some skeletal deformities
caused by rickets may
need corrective surgery.

29. Acromegaly
• Acromegaly is a serious condition
that occurs when the body
produces too much of the growth
hormones that control growth. It is
produced by the pituitary gland, a
tiny organ at the base of the brain.
• Growth hormone promotes growth
of bone, cartilage, muscle,
organs, and other tissues.
• When there is too much growth
hormone in the body, these
tissues grow larger than normal.
This excessive growth can cause
serious disease and even
premature death.

30. Talipes Equinovarus- “Clubfoot”
• Clubfoot is a deformity
of the whole foot that is
present at birth.
• There are several types
of clubfoot that are
jointly known as
'talipes', as the
deformity is mostly in
the talus (a bone in the
ankle).