The skeletal system document describes the structure and functions of bones and the skeletal system. It discusses how bones provide support, protection, allow for movement, store minerals, and help form blood cells. It also outlines common bone diseases like arthritis, osteoporosis, fractures, and cancers that affect the skeletal system.

1. The Skeletal
System
Structure, Function, and Diseases

2. Functions
1. Support
Framework that supports body and cradles
its soft organs
Without the skeleton your body would collapse like jelly.

3. Functions
2. Protection
Protects internal organs
and fragile body parts:
heart, lungs, brain,
lungs, spinal cord, etc.

4. Functions
3. Movement
bones act as levers
for muscles

5. Functions
4. Mineral storage
calcium & phosphate

6. Functions
5. Blood cell formation- “hematopoiesis”

7.  Diaphysis
Shaft
Composed of
compact bone
 Epiphysis
Ends of the bone
Composed mostly of
spongy bone
Gross Anatomy of a Long Bone
CHAguilar 2011

8. Types of Bone Cells
 Osteocytes
 Mature bone cells
 Osteoblasts
 Bone-forming cells
 Osteoclasts
 Bone-destroying cells
 Break down bone matrix for remodeling and
release of calcium
 Bone remodeling is a process by both
osteoblasts and osteoclasts

9. Osteoblast
Osteocyte
Osteoclast
Eats bone
Builds new bone
Mature bone cel

11. Changes in the Human Skeleton
 In embryos, the skeleton is primarily hyaline
cartilage
 During development, much of this cartilage
is replaced by bone
 Cartilage remains in isolated areas
 Bridge of the nose
 Parts of ribs
 Joints

12. I. ENDOCHONDRAL OSSIFICATION- cartilage
to bone
a. Circumference
- deposition of osteoblasts beneath periosteum
forming new bone on the surface and
increasing girth
- osteoclasts dissolve bony tissue in interior to
give way to marrow cavity
b. Length- 4 regions in epiphyseal plate ( between
epiphysis and diaphysis)
1. “resting” cartilage cells
2. zone of proliferation
3. zone of hypertrophy
4. zone of calcification

13. II. INTRAMEMBRANOUS OSSIFICATION
•Membranous tissue to bone
•In flat bones of the skull
•Done through appositional growth ( addition on
sides of osseous tissue)
•Cannot grow by interior expansion
BONE GROWTH AND RESORPTION
•Childhood- faster ossification, slower resorption=
inc in size of the bone
•Adulthood- ossification=resorption-constant size
•Late adulthood(35-40 onwards)- faster
resorption, slower ossification- osteoporosis in
older women

14. cartilage
calcified
cartilage
bone
epiphyse
al plate
epiphyseal
line
Endochondral Ossification
2o
ossification
center
Fetus: 1st
2 months
AdultChildhood
Just before
birth

19. Bone Fractures
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
 A break in a bone
 Types of bone fractures
 Closed (simple) fracture – break that does not
penetrate the skin
 Open (compound) fracture – broken bone
penetrates through the skin
 Bone fractures are treated by reduction
and immobilization
 Realignment of the bone

20. Common Types of Fractures

21. Stages in the Healing of a Bone
Fracture

22. Bone Repair:
1. Electrical stimulation of the fracture site:
• Increases speed and completeness of healing
• The e- stimulation inhibits PTH and slow
osteoclasts down from reabsorbing bone
2. Ultrasound treatment:
• Daily treatments reduce healing time of broken
bones by 25-35%
3. Free vascular fibular graft technique:
• Transplant fibula in arm
• Gives good blood supply not available in other
treatments
4. Bone substitutes:
• Crushed bone from cadaver- but risk of HIV and
hepatitis
• Sea bone- coral
• Artificial bone- ceramic

23. Paranasal Sinuses
SlideCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
 Hollow portions of bones surrounding
the nasal cavity
Figure 5.10

24. • Warm and moisten air
• Lighten the skull
• Enhance voice resonance
Frontal Sinus
Ethmoid Sinus
Sphenoid Sinus
Maxillary Sinus

25. EFFECTS OF HORMONES ON BONES
1. Growth hormone
• hyposecretion/removal of pituitary gland
- results in premature cessation of transformation of
chondrocytes to bones in epiphysis
• Hypersecretion- giantism/acromegaly
2. Parathormone- overactivity
- bones become unduly fragile and fracture
spontaneously and cysts form ( osteitis fibrosa cystica)
3.Thyroxine- deficiency in young- delayed/inc ossification=
softer bones
4. estrogen- stimulate osteoblastic activity
-def during post-menopausal stage- osteoporosis

26. Head shape and delivery method
•Method of delivery determined thru diameter of
female pelvis and size of fetal skull
•Small pelvic measurements- cesarean operation
no molding( different shape of head)
•Average pelvic measurements-natural delivery
head is molded during its passage through
birth canal
•Instrumental delivery- placing forceps on head
and pulling
very delicate job and could cause damage to
motor cortex of brain – spastic child

29. Diseases and Conditions
of the Skeletal System

30. Arthritis

34. Bursitis
• Inflammation of the Bursa (fluid
filled sac surrounding the joint).
• bursa can become inflamed from
injury, infection or due to an
underlying rheumatic condition.
• typically identified by localized pain
or swelling, tenderness, and pain
with motion of the tissues in the
affected area.

36. Bunion
• Swelling of bursa of great toe due to
pressure or friction from badly fitting
shoes

37. Tendonitis
• literally means inflammation of
the tendon
• If normal smooth gliding motion
of tendon is impaired, the
tendon will become inflamed
and movement will become
painful.
• The most common cause of
tendonitis is overuse.

39. Carpal Tunnel Syndrome
• Due to any condition that causes
swelling or a change in position of
the tissue within the carpal tunnel
• can squeeze and irritate the median
nerve.
• This causes tingling and numbness
of the thumb, index, and the middle
fingers, a condition known as
"carpal tunnel syndrome."

42. Osteoporosis
• means "porous bones.“
Risk Factors:
• Being female:decreased estrogen after
menopause
• Small frame
• Caucasian or Asian ethnicity
• Little weight-bearing exercise
• diet poor in Ca++ and protein
• abnormal vitamin D receptors
• Smoking
• Drinking alcohol

46. Scoliosis
• Scoliosis is an abnormal curvature of the
spine.
• Scoliosis runs in families, but doctors
often don't know the cause.
• More girls than boys have severe
scoliosis.
• Adult scoliosis may be a worsening of a
condition that began in childhood
• scoliosis may also result from a
degenerative joint condition in the spine.

50. Kyphosis
• With kyphosis, your spine may look normal or
you may develop a hump.
• Kyphosis can occur as a result of
developmental problems; degenerative
diseases, such as arthritis of the spine;
osteoporosis with compression fractures of
the vertebrae; or trauma to the spine.
• It can affect children, adolescents and adults.

53. Lordosis
• A spine affected by
lordosis shows
evidence of a
curvature of the
back bones
(vertebrae) in the
lower back area,
giving the child a
"swayback"
appearance.

55. Tuberculosis of the Spine-
(Pott’s Disease)
• A form of extrapulmonary tuberculosis that
impacts the spine,
• Aka arthritis for the vertebrae
• More properly known as tuberculosis
spondylitis,
• Pott’s disease is often experienced as a local
phenomenon that begins in the thoracic section
of the spinal column.
• Early signs of the presence of Pott’s disease
generally begin with a simple back pain that in
short order,will begin to multiply.

59. 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.

60. Knock knees
Bow legs

62. Beaded ribs

63. Scurvy
• Consumption of fruits and
vegetables or diets fortified with
vitamin C are essential to avoid
ascorbic acid deficiency.
• Even though scurvy is uncommon, it
still occurs and can affect adults and
children who have chronic dietary
vitamin C deficiency.

66. Gout
• results from an overload of uric acid in
the body which leads to the formation of
tiny crystals of urate that deposit in 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

69. Acromegaly
• occurs when the pituitary gland
produces too much growth
• 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.

73. Poliomyelitis
• a highly infectious disease caused by a virus which invades the
nervous system causing total paralysis in a matter of hours.
• can strike at any age, but affects mainly children under three
(over 50% of all cases).
• The virus enters the body through the mouth and multiplies in
the intestine. Initial symptoms are fever, fatigue, headache,
vomiting, stiffness in the neck and pain in the limbs.
• One in 200 infections leads to irreversible paralysis (usually in
the legs). Amongst those paralysed, 5%-10% die when their
breathing muscles become immobilized.
• As most people infected with poliovirus have no signs of illness,
poliovirus can spread widely
• After initial infection with poliovirus, the virus is shed
intermittently in faeces (excrement) for several weeks. During
that time, polio can spread rapidly through the community.

77. Herniated Disk
• Soft inner central portion of intervertebral
disk protrudes into vertebral canal and
exerts pressure on spinal cord
• Laminectomy-operation to correct
condition

78. Spina Bifida
• birth defect that involves the incomplete
development of the spinal cord or its
coverings.
• The term spina bifida comes from Latin and
literally means "split" or "open" spine.
• Spina bifida occurs at the end of the first
month of pregnancy when the two sides of the
ﾊembryo's spine fail to join together, leaving
an open area.
• In some cases, the spinal cord or other
membranes may push through this opening in
the back. The condition usually isﾊdetected
before a baby is born and treated right away.

82. Talipes Equinovarus-
“Clubfoot”
• A deformity of the whole foot that is present at
birth.
• Aka as 'talipes', as the deformity is mostly in
the talus (a bone in the ankle).
• The most common of the talipes is what is
known as "talipes equino varus“
• In talipes equino varus, the child is born with
the foot pointing down and twisted inwards at
the ankle.

85. Sarcoma
• Osteosarcoma-The most common
type of bone cancer.
• arises in bone and is most commonly
found in children and adolescents
• A rare form occurs in adults,
particularly in patients who have
been cured of other cancers with
radiation therapy.

89. Myeloma
• a cancer in which abnormal
cells collect in the bone
marrow and form tumors.
• Sometimes these abnormal
cells (called myeloma cells)
collect in only one bone and
form a single tumor known
as a plasmacytoma.
• However, in most cases,
the myeloma cells collect in
many bones, forming
several tumors and causing
other problems ( multiple
myeloma).

91. Bone Marrow Biopsy