Title: Bones, Joints, and the Architecture of Movement: Exploring the Skeletal System Introduction: Welcome to our engaging SlideShare presentation on the Skeletal System & Joints, where we embark on a fascinating exploration of the framework that supports our bodies and facilitates movement. Join us as we delve into the intricate world of bones, joints, and the dynamic interplay that shapes our mobility and stability. The skeletal system serves as the foundation of our anatomy, providing structural support, protection for vital organs, and a framework for locomotion. Comprised of bones, cartilage, ligaments, and tendons, this complex system forms the structural scaffold upon which our bodies are built. In this presentation, we'll take a closer look at the anatomy of bones, from their composition and classification to their roles in mineral storage and blood cell production. Through detailed illustrations and interactive diagrams, we'll explore the dynamic nature of bone remodeling and the factors that influence bone health and density. But bones alone do not account for the versatility of human movement. Joints, the articulations where two or more bones meet, play a crucial role in facilitating motion and absorbing impact. From synovial joints like the knee and shoulder to fibrous and cartilaginous joints, we'll unravel the mechanics of joint structure and function. Together, the skeletal system and joints form a complex network that enables us to walk, run, jump, and perform a myriad of daily activities. Whether you're a student studying anatomy, a fitness enthusiast seeking to optimize performance, or simply curious about the mechanics of the human body, our presentation offers valuable insights into the wonders of the skeletal system and joints. Join us as we embark on a journey through the bony landmarks and articulations that define our physical form and discover the intricate architecture of movement hidden beneath our skin.

1. THE
SKELETAL
SYSTEM
&
JOINTS

2. INTRODUCTION
The Skeleton is the name given to the collection of
bones that holds the rest of our body up.
* Human skeleton initially cartilages and fibrous membranes.
* Hyaline cartilage is the most abundant cartilage.
* By age 25 the skeleton is completely hardened.
* 206 bones make up the adult skeleton (20% of body mass).
- 80 bones of the axial skeleton
- 126 bones of the appendicular skeleton
* Parts of the skeletal system include:
- Bones (skeleton)
- Joints
- Cartilages
- Ligaments
* Divided into two divisions:
- Axial skeleton (skull, ribs and vertebra)
- Appendicular skeleton (pelvis, extremities- Upper or Lower)

4. Bones
 Highly vascular mineralized connective tissue.
 Consists of cells and dense intercellular organic matrix impregnated with inorganic
salts
 Organic material- collagen fibers. Provides tensile strength.
 Inorganic – calcium phosphate, traces of other salts. Provides hardness & rigidity
Bones Functions
 PROTECTION : It protects our vital organs such as brain, heart, lungs etc...
 SUPPORT & SHAPE : It gives us our shape that we have. Without our skeleton,
we would just be a blob of blood and tissue on the floor.
 MOVEMENT : It allows us to move. Because our muscles are attached to our
bones, when our muscles move, they move the bones, and we move.
 HEMOPOIESIS (IN RED BONE MARROW) : It makes blood cells so the rest of the
body can use them.
 MINERAL HOMEOSTASIS (STORAGE AND RELEASE) : Calcium, and other
minerals.
 TRIGLYCERIDE STORAGE (IN YELLOW BONE MARROW) : It is a warehouse for
fat cells.

5. Composition of bone
SOLID WATER (10%)
Organic Inorganic
Substance (25%) Substance (65%)
Bone Cells Protein Ca2+ (99% of total body Ca2+
is present in bones),
Po 4
2- , Na+ , Cl- ,
Co3
- , K+ etc…
Osteoprogenitor cells
(Bone-forming stem cells)
Osteoblast
(Bone-forming cells)
Osteocytes
(Mature bone cells)
Osteoclast
(Bone-destroying / remodeling cells)
Glycoprotein
Collagen fiber type-I

7. Classification of bone
 According to shape :
Long Bones - Metacarples, Metatarsals, Phelangies,
Humerus, Femur, Ulna, Radius, Tibia, Fibula
Short Bones - Carpals, Tarsals
Flat Bones - Ribs, Scapula, Skull, Sternum
Irregular Bones - Vertebrae, Some facial bones
Sesamoid Bone – Patella
 Long bones
 Typically longer than wide
 Have a shaft with heads at both ends
 Contain mostly compact bone

8. (e) Sesamoid Bone
(e.g., patella)

9.  Examples: Femur, humerus
 Short bones
 Generally cube-shape
 Contain mostly spongy bone
 Examples: Carpals, Tarsals etc...
 Flat bones
 Thin and flattened
 Usually curved
 Thin layers of compact bone around
a layer of spongy bone
 Examples: Skull, ribs, sternum etc…

10.  Irregular bones
 Irregular shape
 Do not fit into other bone classification
categories
 Example: Vertebrae and hip
 Sesamoid bone
 Sort bones within tendones
 Example: Patella

11.  According to structure :
Macroscopically - Compact Bone, Cancellous (Spongy
Bone)
Microscopically- Woven, lamellar etc….
• Compact bone
 Outer layer of bone, very hard and dense.
 Organized in structural unit called Haversian systems.
 Matrix is composed of Ca salts (Ca carbonate and Ca
phosphate)
 Osteocytes – living bone cells that live in matrix.

12. • Porous (Spongy) bone
 Located in the ends of long bones.
 Many spaces that are filled with red bone marrow which
produces bone cells.
 Trabeculae – needle-like threads of spongy bone that
surround the spaces. Add strength to this
portion of the bone.
 According to development :

13. Femur
Periosteum
Yellow marrow
Medullary cavity
Space containing
red marrow
Spongy bone
Compact bone
Articular cartilage
Epiphyseal plates
Proximal
epiphysis
Distal
epiphysis
Diaphysis
Endosteum
Gross Anatomy of a Long Bone
Parts of a Long Bone
• Epiphysis
• Distal
• Proximal
• Diaphysis
• Metaphysis
• Compact bone
• Spongy bone
• Articular cartilage
• Periosteum
• Endosteum
• Medullary cavity
• Trabeculae
• Bone marrow
• Red marrow and yellow marrow

14. Distal
epiphysis
Proximal
epiphysis
Diaphysis
Yellow marrow
Epiphyseal line
Periosteum
Compact bone
Spongy bone
Endosteum
Hyaline cartilage
Sharpey’s fibers
Distal
epiphysis

15.  Diaphysis
 Shaft
 Composed of
compact bone
 Epiphysis
 Ends of the bone
 Composed mostly of
spongy bone

16.  Periosteum
 Outside covering of the
diaphysis
 Fibrous connective tissue
membrane
 Sharpey’s fibers
 Secure periosteum to
underlying bone
 Arteries
 Supply bone cells with
nutrients

17.  Articular cartilage
 Covers the external surface of the epiphyses
 Made of hyaline cartilage
 Decreases friction at joint surfaces
 Medullary cavity
 Cavity of the shaft
 Contains yellow marrow (mostly fat) in adults
 Contains red marrow (for blood cell formation) in infants

18. Microscopic Structure
• Bone cells are called osteocytes ( in a lacuna )
• Osteocytes transport nutrients and wastes by cellular processes in canaliculi.
• The extracellular matrix of bone is largely collagen and inorganic salts
• Collagen gives bone resilience & strength
• Inorganic salts make bone hard
Compact Bone
• Osteon aka Haversian
System (Structural and
basic unit of compact
bone)
• Central canal
• Perforating canal aka
Volkmann’s canal
• Osteocytes
• Lamellae
• Lacunae
• Bone matrix
• Canaliculi
Nerve
Osteon
Nerve
Nerve
Canaliculus
Osteocyte
Periosteum
Endosteum
Trabeculae
Pores
Bone matrix
Blood
vessels
Compact
bone
Lacuna
(space)
Blood
vessels
Perforating
canal
Central canal
containing blood
vessels and nerves
Central
canal

20.  Osteon (Haversian System) : A unit of bone
 Central (Haversian) canal :
 Opening in the center of an osteon
 Carries blood vessels and nerves
 Perforating (Volkman’s) canal :
 Canal perpendicular to the central canal
 Carries blood vessels and nerves

21.  Lacunae
 Cavities containing bone cells (osteocytes)
 Arranged in concentric rings
 Lamellae
 Rings around the central canal
 Sites of lacunae
 Canaliculi
Tiny canals
Radiate from the central
canal to lacunae
Form a transport system

23. (a)
(c)
Spongy bone
Compact bone
(b)
Spongy
bone
Compact
bone
Remnant of
epiphyseal plate
Spongy Compact
bone
Spongy Bone
• Spongy bone is aka cancellous bone.
• Trabeculae is the basic structural unit of spongy bone.
• There is no calcification in spongy bone so hematopoiesis occur.
• Trabeculae is the tubular shape structure present in spongy bone, it is soft like
honey womb.
• The outer covering of spongy bone is covered by compact bone for its
protection.

25. Bone Development and Growth
 As an infant, most of your skeleton is cartilage.
 Process of bone formation called ossification &
Calcification
 From mesenchyme
 Cartilage is a strong flexible tissue.
 Over time the cartilage is replaced by solid bone,
usually complete by the time you stop growing.
 Not all cartilage is replaced in adults. Many
joints contain cartilage, protecting the ends of
bones (ears and the end of the nose is also
cartilage).
 Epiphyseal plates allow for growth of long bone during
childhood.
New cartilage is continuously formed.
Older cartilage becomes ossified.
 Bone replaces cartilage.

26. Bones are remodeled and lengthened until growth stops

Bones change shape somewhat
Bones grow in width

27. • Parts of the skeletal system begin to develop during the first few weeks
of prenatal development
• Bones replace existing connective tissue in one of two ways:
• As intramembranous bones
• As endchondral bones
Intramembranous Bones
• These bones originate within sheetlike layers of connective tissues
• They are the broad, flat bones
• Skull bones (except mandible)
• Are known as intramembranous bones
Endochondral Bones
• Bones begin as hyaline cartilage
• Form models for future bones
• These are most bones of the skeleton
• Are known as endochondral bones

28. 28
Endochondral Ossification
Hyaline cartilage model
• Primary ossification center
• Secondary ossification centers
• Epiphyseal plate
• Osteoblasts vs. osteoclasts
(b) (c) (d)
(e) (f)
(a)
Cartilaginous
model
Calcified
cartilage
Articular
cartilage
Developing
periosteum Compact bone
developing
Primary
ossification
center
Medullary
cavity
Medullary
cavity
Medullary
cavity
Secondary
ossification
center
Secondary
ossification
center
Blood
vessel
Epiphyseal
plate
Remnant of
epiphyseal
plate
Remnants of
epiphyseal
plates
Epiphyseal
plates
Compact
bone
Spongy
bone
Articular
cartilage
Spongy
bone

29. Types of Bone Cells
Osteogenic cells:
Respond to traumas, such as fractures, by giving rise to
bone-forming cells and bone-destroying cells
Osteoblasts (Bone-forming cells)
Bone forming cells synthesize and secrete unmineralized
ground substance and are found in areas of high
metabolism within the bone
Bone lining cells - made from osteoblasts along the surface of
most bones in an adult. Bone-lining cells are thought to
regulate the movement of calcium and phosphate into and
out of the bone
Osteocytes (Mature bone cells)
Mature bone cells made from osteoblasts that have made
bone tissue around themselves. They maintain healthy
bone tissue by secreting enzymes and controlling the bone
mineral content; they also control the calcium release from
the bone tissue to the blood.

30. Osteoclasts (Bone-destroying cells)
Break down bone matrix for remodeling and release of
calcium
Bone absorbing cell – large cells that break down bone
tissue – important to growth, healing, remodeling
Bone remodeling is a process by both osteoblasts and
osteoclasts
Homeostasis of Bone Tissue
• Bone Resorption – action of osteoclasts and parathyroid
hormone aka parathormone aka PTH
• Bone Deposition – action of osteoblasts and calcitonin
• Occurs by direction of the thyroid and parathyroid glands
• Calcitonin decreases blood ca++ level by increasing
osteoblastic activity.
• PTH increases blood ca++ level by increasing osteoclastic activity.

31. Factors Affecting Bone Development, Growth and
Repair
• Deficiency of Vitamin A – retards bone development
• Deficiency of Vitamin C – results in fragile bones
• Deficiency of Vitamin D – Rickets, Osteomalacia
• Insufficient Growth Hormone – Dwarfism
• Excessive Growth Hormone – Gigantism, Acromegaly
• Insufficient Thyroid Hormone – delays bone growth
• Sex Hormones – promote bone formation; stimulate
ossification of epiphyseal plates
• Physical Stress – stimulates bone growth

32. Cartilage
 Specialized connective tissue having rigidity with elasticity
 Consists of chondrocytes embedded in gel like matrix
 Provide rigidity & support
 Smooth gliding surface for articulation
 Enables development and growth of long bones
Structure
 Cells- chondrogenic, chondroblasts, chondrocytes
 Fibers- type I collagen, type II collagen, elastic
 Ground substance- proteoglycans in the form of keratan sulphate &
chondroitin sulphate, glycoprotein, water, no mineral component
Features
 Avascular
 No lymphatics
 No nerves
 Surrounded by perichondrium
 Growth by appos. & inter.
 When it calcifies, chondrocytes die
 Articular
cartilage &
fibrocartilage have
no perichondrium

33. Hyaline Cartilages:
Fine collagen fiber matrix- most
abundant type- found in articular
(movable joint) cartilages, costal
cartilages (connect ribs to sternum),
respiratory cartilages (in larynx &
upper respiratory passageways) &
nasal cartilages
Elastic Cartilages:
Similar to hyaline cartilage, more
elastic fibers (very flexible) – found in
external ear & epiglottis (larynx
covering)
Fibrocartilage:
Rows of chondrocytes with thick
collagen fibers; highly compressible
with great tensile strength- found in
menisci of knee, intervertebral discs
& pubic symphysis

35. Bone Fractures & Repair of fracture
A break in the continuity of 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)
Fracture reduction :
Closed reduction ,no surgery is needed
Open reduction ,surgery is needed

36. Repair of fracture
Healing time for simple fracture is 6-8 weeks (longer in elderly
people)
It occurs in FOUR major events
1- Hematoma formation (blood-filled swelling is formed)
2- Fibrocartilage callus formation (Break is splinted by
fibrocartilage to form a callus)
3- Bony callus formation (Fibrocartilage callus is replaced by a
bony callus)
4- Bone remodeling (Bony callus is remodeled to form a
permanent patch)

37. Stages in the Healing of a Bone Fracture

38. Common Types of Fractures

39. Skeletal Organization
Typically there are about 206 bones
Divisions of the Skeletal System
Bones of the skeleton are grouped into two principal
divisions:
Axial skeleton
Consists of the bones that lie
around the longitudinal axis of the
human body
 Skull bones,
 Auditory ossicles (ear bones),
 Hyoid bone,
 Ribs,
 Sternum (breastbone), and
 Bones of the vertebral column
Appendicular skeleton
Consists of the bones of the upper
and lower limbs (extremities), plus
the bones forming the girdles that
connect the limbs to the axial
skeleton.

42. Axial Skeleton

43. A p p e n d i c u l a r S ke l e t o n

44. Bone Surface Markings
 Bones have characteristic surface markings
 Structural features adapted for specific functions
 There are two major types of surface markings:
1) Depressions and openings :
Allow the passage of blood vessels and nerves or form joints
2) Processes
Projections or outgrowths that form joints or serve as attachment
points for ligaments and tendons

46. Axial
Skeleton

47. Skull (Cranium)
 Consists of 22 bones
 Bones of the skull are grouped into two categories:
Cranial bones (8)
Paired bones :
- Parietal bones (2)
-Temporal bones (2)
Unpaired bones :
- Frontal bone (1)
- Occipital bone (1)
- Sphenoid bone (1)
- Ethmoid bone (1)
Facial bones (14)
Paired bones :
- Nasal bones (2)
- Maxilla (2)
- Zygomatic (2)
- Palatine (2)
- Lacrimal (2)
- Inferior nasal
concha (2)
Unpaired bones :
- Mandible (1)
- vomer (1)

56.  The cranial and facial bones protect and support
special sense organs and the brain.
 Besides forming the large cranial cavity, the skull also
forms several smaller cavities :
• Nasal cavity
• Orbits (eye sockets)
• Para - nasal sinuses
• Small cavities which house organs involved in hearing and
equilibrium
 Immovable joints called sutures fuse most of the skull
bones together.
 The skull provides large areas of attachment for muscles
that move various parts of the head & produce facial
expressions.
 The facial bones form the framework of the face and
provide support for the entrances to the digestive and
respiratory systems.

57. Cranial Bones
Frontal Bone (1) :
• Forehead
• Roof of nasal cavity
• Roofs of orbits
• Frontal sinuses
• Supraorbital foramen
• Coronal suture
• Supraorbital ridge/
margin

58. Parietal Bones (2) :
• Side walls of cranium
• Roof of cranium
• Sagittal suture
Temporal Bones (2) :
• Side walls of cranium
• Floor of cranium
• Floors and sides of orbits
• Squamous suture
• External acoustic meatus
• Mandibular fossa
• Mastoid process
• Styloid process
• Zygomatic process

59. Occipital Bone (1) :
• Forms the posterior part
and most of the base of
the cranium
• Back of skull
• Base of cranium
• Foramen magnum
• Occipital condyles
• Lambdoidal suture

61. Sphenoid Bone (1) :
• Lies at the middle part of
the base of the skull
• Base of cranium
• Sides of skull
Transverse section
Lesser wing Optic canal
Greater
wing
Sella turcica
Foramen ovale
Foramen spinosum
Foramen rotundum
Lesser wing
Greater wing
Superior
orbital fissure
Foramen
rotundum
Lateral
pterygoid
plate
Medial pterygoid plate
(b)
(a)
• Floors and sides
of orbits
• Sella turcica
• Sphenoid sinuses

64. Ethmoid Bone (1)
• Located on the midline in the
anterior part of the cranial
floor medial to the orbits
• Roof and walls of nasal cavity
• Floor of cranium
• Wall of orbits
Transverse section
Crista galli
Orbital
surface
Ethmoidal
sinuses
Cribriform
plate
Crista galli
Perpendicular
plate
Superior
nasal concha
Middle nasal
concha
Perpendicular
plate
(a) (b)
• Cribiform plates
• Perpendicular plate
• Superior and middle
nasal concha
• Ethmoid sinuses
• Crista galli

66. Facial Bones (14) :
Zygomatic Bones (2) :
• Commonly called
cheekbones
• Prominences of cheeks
• Lateral walls of orbits
• Floors of orbits
• Temporal process
Nasal Bones (2) :
• Form the bridge of the nose

67. Maxilla (2) :
• Form the upper
jawbone
• Form most of the hard
palate
• Separates the nasal
cavity from the oral
cavity
• Anterior roof of mouth
• Floors of orbits
• Sides of nasal cavity
• Floors of nasal cavity
• Alveolar processes
• Maxillary sinuses
• Palatine process

69. Palatine Bones (2) :
• Form the posterior
portion of the hard palate
• ‘L’ shaped bones located
behind the maxillae
• Posterior section of hard
palate
• Floor of nasal cavity
• Lateral walls of nasal
cavity
Coronal section
Perpendicular
portion
Horizontal portion

70. Lacrimal Bones (2) :
• Medial walls of orbits
• Groove from orbit to
nasal
cavity
Vomer Bone (1) :
• Inferior portion of
nasal septum

71. Inferior Nasal Conchae (2) :
• Form a part of the inferior lateral wall of the nasal
cavity.

72. Mandible (1) :
• Lower jawbone
• The largest,
strongest facial bone
• The only movable
skull bone
• Lower jaw
• Body
• Ramus
• Mandibular condyle
• Coronoid process
• Alveolar process
• Mandibular foramen
• Mental foramen

74. Sutures
An immovable joint that holds most
skull bones together
 Coronal Suture : Between frontal
and parietal bone
 Saggital Suture : Between both
parietal bones
 Lambdoid Suture : Between
occipital and
parietal bones
 Squamous Suture : Between
temporal and
parietal bones
Unique Features of the Skull
Sutures, Paranasal sinuses, Fontanels

75. Paranasal Sinuses
 Cavities within cranial
and facial bones near the
nasal cavity.
 Secretions produced by
the mucous membranes
which line the sinuses,
drain into the nasal
cavity.
 Serve as resonating
chambers that intensify
and prolong sounds
 Frontal sinuses
 Sphenoid sinuses
 Ethmoid sinuses
 Maxillary sinuses

77. Frontal Sinus
Ethmoid Sinus
Sphenoid Sinus
Maxillary Sinus
Functions of paranasal sinuses :
 Lighten the skull
 Give resonance and amplification to voice

78. Fontanels
The fetal skull is large
compared to the infants total
body length.
Fontanel's are fibrous
Membranes connecting the
Cranial bones.
Allow the brain to grow
Convert to bone within 24
months after birth.
(a) Anterior fontanel (Bregma)
(b) Posterior fontanel
(Lambdoid)

80. Hyoid Bone (1)
The only bone that does not
articulate with another bone.
 Supports the tongue,
providing attachment sites
for some tongue muscles and
for muscles of the neck and
pharynx.
The hyoid bone also helps to
keep the larynx (voice box)
open at all times

81. Ear Ossicles
The middle ear contains the three smallest bones in the body,
and these are called the ossicles.
 Malleus (hammer)
 Incus (anvil)
 Stapes (stirrup)
The malleus
 Malleus (hammer) is
attached to the eardrum.
 Largest ear ossicles
 Parts : Manubrium
Neck
Head
Lateral process

83. The incus
 Incus (anvil) is bound by
ligaments to the malleus
and to the stapes.
 Parts : Short process
Long process
Lenticular process
Incudostapedial
joint
The stapes
 Stapes (stirrup) is bound to
and strikes against the oval
window, like a bass drum
pedal.
 Smallest bone of the body
 Parts :* Head
* Neck
* Footplate
*Anterior crus
*Posterior cru

85. Also called the spine, backbone,
or spinal column
 Functions to:
 Protect the spinal cord
 Support the head
 Serve as a point of
attachment for the ribs,
pelvic girdle, and muscles
 The vertebral column is curved to
varying degrees in different
locations.
 Curves increase the column strength.
 Help maintain balance in the upright
position, Absorb shocks during
walking, and help protect the
vertebrae from fracture.
Vertebral Column

86.  Primary curvatures  Secondary curvatures

87. Primary Curvatures
 The vertebral curvatures provide a flexible support
(shock-absorbing resilience) for the body.
 The thoracic and sacral (pelvic) curvatures are
concave anteriorly and are referred to as kyphoses
(singular: kyposis).
 They appear during the fetal period of embryonic
development, hence they are also termed primary or
developmental curvatures.
Secondary Curvatures
 The cervical and lumbar curvatures are concave
posteriorly and convex anteriorly, being referred to
as lordoses (singular: lordosis).
 They appear later (although before birth) and are
accentuated in infancy by support of the head and
by the adoption of an upright or erect human
posture. As a result, they are termed secondary or

88.  Various conditions may exaggerate the normal curves
of the vertebral column
*Scoliosis * Kyphosis * Lordosis
 Composed of a series of bones called vertebrae (Adult=26)
 7 cervical (neck region)
 12 thoracic (posterior to the thoracic cavity)
 5 lumbar (lower back)
 1 sacrum (five fused sacral vertebrae)
 1 coccyx (four fused coccygeal vertebrae)

90. Includes the following parts:
• Vertebral body
• Pedicles
• Lamina
• Spinous process
• Transverse processes
• Vertebral foramen
• Facets
Typical Vertebrae

91. Vertebral Column (Regions)
Cervical Region (Neck Region)
 Cervical vertebrae (C1–C7)
 The atlas (C1) is the first cervical vertebra
 The axis (C2) is the second cervical vertebra
 Atlas – 1st; supports head
 Axis – 2nd; dens pivots
to turn head
 Transverse foramina
 Bifid spinous processes
 Vertebral prominence –
useful landmark

93. Thoracic Region
 Thoracic vertebrae
(T1–T12)
 Articulate with the ribs
 Long spinous processes
 Rib facets

94. Lumbar Region
 Lumbar vertebrae (L1–L5)
 Provide for the attachment of the large back
muscles
 Large bodies
 Thick, short spinous processes

95. Sacrum
 The sacrum is a triangular bone formed by the
union of five sacral vertebrae (S1–S5)
 Serves as a strong foundation for the pelvic girdle
 Median sacral crest
 Posterior sacral foramina
 Posterior wall of pelvic cavity
 Sacral promontory aka base
 Area toward coccyx is the apex
Coccyx
 The coccyx, like the sacrum, is triangular in shape
 It is formed by the fusion of usually four coccygeal
vertebrae
 Aka tailbone
 3-4 fused segments

98. Intervertebral Discs
Found between the bodies of adjacent vertebrae

101. Functions to:
 Form strong joints
 Permit various movements of the vertebral column
 Absorb vertical shock

102. Thoracic Cage
 Forms the framework of the chest
 Components of the bony thorax
• Thoracic vertebrae –
posteriorly
• Ribs – laterally
• Sternum and costal
cartilage – anteriorly
Functions to:
 Enclose and protect the organs in the thoracic and
abdominal cavities
 Provide support for the bones of the upper limbs
 Play a role in breathing
 Provides attachment sites for muscles
 Role in breathing

104. Sternum (Breastbone)
 Located in the center & anterior of the thoracic wall
 Three (3) parts of the sternum :
Manubrium : * Superior part
* Articulates with medial end of
clavicles
Body : * Bulk of sternum
* Sides are articulate for costal
cartilage of ribs 2–7
Xiphoid process : * Inferior end of sternum
* Ossifies around age 40

106. Ribs
Humans have 12 pairs of ribs:
• True ribs (7)
• False ribs (5), of which:
• Floating (2)
Rib Structure
• Shaft
• Head – posterior end;
articulates with
vertebrae
• Tubercle – articulates with
vertebrae
• Costal cartilage – hyaline
cartilage
Anterior end
(sternal end)
Shaft
Facet
Head
Neck
Tubercle
Facet
Spinous process
Costal groove
Shaft
Anterior end
Head
Tubercle
Neck
(a)
(b)

108. Appendicular
Skeleton

109. APPENDICULAR SKELETON
 It includes bones of the upper and lower limbs
 Girdles attach the limbs to the axial skeleton
 The primary function is movement
• Limbs (Upper & Lower)
• Pectoral girdle
• Pelvic girdle
 Skeleton of the Upper Limb
 Each upper limb has 32 bones
 Two separate regions
1. The pectoral (shoulder) girdle (2 bones)
2. The free part (30 bones)

110. Humerus
Ulna
Radius
8 Carpals
14 Phalanges
5 Metacarpals

111. Upper Limb
 The pectoral girdle consists of two bones, the scapula
and the clavicle
 The free part has 30 bones
 1 Humerus (arm)
 1 Ulna (forearm)
 1 Radius (forearm)
 8 Carpals (wrist)
 5 Metacarpal and
 14 Phalanges (hand)

112. The Pectoral (Shoulder) Girdle
Composed of two bones
Clavicle – collarbone
Scapula – shoulder blade
These bones allow the upper limb to have exceptionally free
movement.
Clavicle (Collarbone / Beauty bone)
 The clavicle is “S” shaped.
 Only horizontal bone of the body.
 The medial end articulates with the manubrium of the
sternum forming the sternoclavicular joint.
 The lateral end articulates with the acromion process
(process of scapula bone) forming the acromioclavicular
joint.

114.  The clavicle is convex in shape anteriorly near the
sternal junction.
 The clavicle is concave anteriorly on its lateral edge
near the acromion.

115. Clinical Connection - Fractured Clavicle
 A fall on an outstretched arm (F.O.O.S.H.) injury can
lead to a fractured clavicle.
 The clavicle is weakest at the junction of the two
curves.
 Forces are generated through the upper limb to the
trunk during a fall.
 Therefore, most breaks occur approximately in the
middle of the clavicle.

116. Scapula (Shoulder blade)
 Also called the shoulder blade.
 Triangular in shape.
 Most notable features include the spine, acromion,
coracoid process and the glenoid cavity.
 Spine - A large process on the posterior of the scapula
that ends laterally as the acromion.
 Acromion - The flattened lateral portion of the spine
of the scapula.
 Coracoid process - A protruding projection on the
anterior surface just inferior to the
lateral aspect of the clavicle.
 Glenoid cavity - Shallow concavity that articulates
with the head of the humerus.
The medial (vertebral) border -Closest to the vertebral spine
 Lateral border - Closest to the arm.

117.  Superior border - Superior edge
 Inferior angle - Where medial and lateral borders
meet inferiorly
 Superior angle - Uppermost aspect of scapula where
medial border meets superior border
 Subscapular fossa - Anterior concavity where the
subscapularis muscle attaches
 Supraspinous fossa - Posterior concavity superior to
the scapular spine, attachment
site for supraspinatus muscle
 Infraspinous fossa - Posterior concavity inferior to the
scapular spine, site of
infraspinatus muscle

120. Humerus
 Longest and largest bone of the free part of the upper
limb.
 The proximal ball-shaped end articulates with the
glenoid cavity of the scapula.
 The distal end articulates at the elbow with the radius
and ulna.
 The head of the humerus has two unequal-sized
projections.
 The greater tubercle lies more laterally.
 The lesser tubercle lies more anteriorly.
 Between the tubercles lies the intertubercular groove
or sulcus (bicipital groove) where the long head of the
biceps brachii tendon is located.

121.  Just distal to the head is the
anatomical neck.
 The surgical neck is where
the tubular shaft begins
and is a common area of
fracture.
 About mid-shaft on the
lateral aspect is a
roughened area, the
deltoid tuberosity where
the deltoid tendon attaches.
 Capitulum - A round knob-
like process on the lateral
distal humerus.
 Trochlea - Medial to the
capitulum, is a spool-
shaped projection on the
distal humerus

122.  Coronoid fossa - Anterior depression that receives the
coronoid process of the ulna during forearm flexion.
 Olecranon fossa - Posterior depression that receives
the olecranon of the ulna during forearm extension.
 The medial and lateral epicondyles are bony
projections to which the forearm muscles attach.

123.  Also called the antebrachium
 Consists of 2 long bones:
 Ulna (Medial)
 Radius (Lateral)
Skeleton of the Forearm –
Ulna
 The longer of the two forearm bones
 Located medial to the radius.
 Olecranon - The large, prominent proximal end, the
“tip of your elbow”.
 Coronoid process - The anterior “lip” of the proximal
ulna.
 Trochlear notch - The deep fossa that receives the
trochlea of the humerus during elbow flexion.
 Styloid process - The thin cylindrical projection on
the posterior side of the ulna’s head

124.  Head –
The head of ulna at
distal end.
 Ulnar tuberosity –
A tuberosity at
proximal end inferior
to radial notch of
ulna.
 Radial notch -
Notch lateral to
coronoid process for
radial bone at
proximal end of ulna

126. Radius
 Lies lateral to the ulna (thumb side of the forearm).
 The head (disc-shaped) and neck are at the proximal
end.
 The head articulates with the capitulum of the
humerus and the radial notch of the ulna.
 Radial tuberosity - Medial and inferior to neck,
attachment site for biceps brachii muscle.
 Styloid process - Large distal projection on lateral
side of radius.
 Ulnar notch - Notch medial to distal end of ulna for
ulnar head.

127. Ulna and Radius
 The shaft of these bones are connected by an
interosseus membrane
 There is a proximal radioulnar joint and a distal
radioulnar joint
 Proximally, the head of the radius articulates with the
radial notch of the ulna
 Distally, the head of the ulna articulates with the
ulnar notch of the radius

128. Skeleton of the Hand
The hand
Carpals – Wrist
Metacarpals – Palm
Phalanges – Fingers
CARPALS (WRIST BONES)
 The carpus (wrist) consists of 8 small bones (carpals).
 Also called wrist bones.
 Two rows of carpal bones :
 Proximal row - scaphoid, lunate, triquetrum, pisiform
 Distal row - trapezium, trapezoid, capitate, hamate
 Scaphoid - Most commonly fractured.
 Carpal tunnel - Space between carpal bones and flexor
retinaculum.

129. Metacarpals and Phalanges
 Five metacarpals - numbered I-V, lateral to medial
 14 phalanges - two in the thumb (pollex) and three in
each of the other fingers
 Each phalanx has a base, shaft, and head
 Joints - Carpometacarpal,
Metacarpophalangeal,
Interphalangeal .

131. Skeleton of the Lower Limb
Two separate regions:
1. A single pelvic girdle (2 bones)
2. The free part (30 bones)
Pelvic (Hip) Girdle
 Each coxal (hip) bone consists of three bones that fuse
together: ilium, pubis, and ischium.
 The two coxal bones are joined anteriorly by the
pubic symphysis (fibrocartilage).
 Joined posteriorly by the sacrum forming the
sacroiliac joints.
Protects several organs:
 Reproductive organs
 Urinary bladder
 Part of the large intestine

133. The Ilium
 Largest of the three hip bones.
 Ilium is the superior part of the hip bone.
 Consists of a superior ala and inferior body which
forms the acetabulum (the socket for the head of the
femur).
 Superior border - Iliac crest.
 Hip pointer - Anterior superior & inferior iliac spine.
Posterior superior & inferior iliac spine.
 Greater sciatic notch - Allows passage of sciatic nerve
Ischium
 Inferior and posterior part of the hip bone
 Most prominent feature is the ischial tuberosity, it is
the part that meets the chair when you are sitting
 Lesser sciatic notch

135. Pubis
 Inferior and anterior part of the hip bone
 Superior and inferior rami and body
 Obturator foramen
 Symphysis pubis
 Pubic arch
 Pubic tubercle

136. Divisions of the Pelvis
False and True Pelves :
 Pelvic brim - A line from the sacral promontory to the
upper part of the pubic symphysis.
 False pelvis - lies above this line.
 Contains no pelvic organs except urinary bladder
(when full) and uterus during pregnancy.
 True pelvis – The bony pelvis inferior to the pelvic
brim, has an inlet, an outlet and a cavity.
 Pelvic axis - Path of baby during birth.

139. Male and Female Pelves
Males –
• Bone are larger and heavier
• Pelvic inlet is smaller and heart shaped
• Pubic arch is less the 90°
Female –
• Wider and shallower
• Pubic arch is greater than 90°
• More space in the true pelvis

140. Comparing Male and Female Pelves

142. Lower Limb
Bones of the Lower Limbs :
 Femur (Thigh)
 Patella (Kneecap)
 Tibia and fibula (Leg)
 Tarsals (Ankle)
 Metatarsals (Foot)
 Phalanges (Toes & Fingers)

143. Skeleton of the Thigh – Femur
 Longest, heaviest, and strongest bone in the body.
 Proximally, the head articulates with the acetabulum of the
hip bone forming the hip (coxal) joint.
 Neck - distal to head, common site of fracture.
 Distally, the medial and lateral condyles articulate with the
condyles of the tibia forming the knee joint.
 Also articulates with patella.
 Greater and lesser trochanters are projections where large
muscles attach.
 Gluteal tuberosity and linea aspera - attachment sites for
the large hip muscles.
 Intercondylar fossa - depression between the condyles.
 Medial and lateral epicondyles - muscle site attachments
for the knee muscles.

144.  Fovea capitis – Small depression at the center on the head
of the femur (Ligament attach to fovea capitis to acetabulum).

145. Patella
 Largest sesamoid bone in the body.
 Forms the patellofemoral joint.
 Superior surface is the base.
 Inferior, narrower surface is the apex.
 Thick articular cartilage lines the posterior surface.
 Increases the leverage of the quadriceps femoris
muscle.
 Patellofemoral stress syndrome - “runner’s knee”

146. Tibia (shin bone)
 The larger, medial weight-bearing bone of the leg.
 The lateral and medial condyles at the proximal end
articulate with the femur.
 Lateral condyle makes joint with the head of fibula –
Proximal tibiofibular joint.
 It articulates distally with the talus and fibula.
 Tibial tuberosity - attachment site for the patellar
ligament.
 Medial malleolus - medial surface of distal end
(medial surface of ankle joint).
 Anterior crest – A line / border on the anterior surface
of tibia.
 3 borders – Anterior, medial & lateral.
 3 Surfaces – Lateral, medial & posterior.

147. Fibula
 The smaller, laterally placed bone of the leg.
 Non-weight bearing.
 The head forms the proximal tibiofibular joint.
 Facet for tibia – articular surface for lateral condyle of tibia.
 Lateral malleolus - distal end, articulates with the tibia and
the talus at the ankle.
Tibia & Fibula
 The shaft of these bones are connected by an interosseus
membrane.
 There is a proximal tibiofibular joint and a distal tibiofibular
joint.
 Proximally, the head of the fibula articulates with the tibia
at lateral condyle.
 Distally, the fibula (distal end) articulates with the fibular
notch of the tibia (medial surface of distal end).

150. Foot
• Tarsal Bones (14)
• Calcaneus (the heel bone,
the largest and strongest),
• Talus
• Navicular
• Cuboid
• Lateral (3rd) cuneiform
• Intermediate (2nd) cuneiform
• Medial (1st) cuneiform
• Metatarsal Bones (10)
• Phalanges (28)
• Proximal
• Middle
• Distal

152. Arches of the Foot
Bones of the foot are arranged to form three strong arches
• Two longitudinal
• One transverse
 Two arches support the weight of the body
 Provide spring and leverage to the foot when walking
 The arches flex when body weight applied
 Flatfoot - the arches decrease or “fall”
 Clawfoot - too much arch occurs due to various
pathologies

154. ARTICULATORY
SYSTEM
(ARTHROLOGY)

155. With the exception of the hyoid bone, every bone in the
body is connected to or forms a joint.
 A joint is a point of contact between:
 Two or more bones
 Cartilage and bone
 Teeth and bone
Functions of joints
 Hold bones together
 Allow for mobility
Joint ( Articulation)
The junction between two or
more bones or cartilages.

156. Ways joints are classified
 Functionally
 Structurally
 Arthrology : study of joints

157. Structural Classification of Joints
Fibrous Joint
 Sutures – dense
fibrous CT
Ex. Suture
 Syndesmoses –
more dense fibrous
CT than a suture
Ex. Gomphosis
 Interosseous
membranes – a
broad sheet of
dense fibrous CT
Ex. Between radius and
ulna
Cartilaginous
 Synchondrosis
– hyaline
cartilage; no
movement
Ex. Epiphyseal
plate
 Symphysis –
fibrocartilage;
some
movement
Ex. Pubic
symphysis
Synovial Joint
 Articular
cartilage on
ends of long
bones and a
synovial cavity
between
articulating
bones
surrounded by
accessory
ligaments; freely
moveable
Ex. Hip, knee,
shoulder,elbow

158. FUNCTIONAL CLASSIFICATION OF JOINTS
Synarthroses
 Allow no
movement
Ex. Suture,
gomphosis,
Syndesmosis
Amphiarthroses
 Allow little
movement
Ex. Epiphyseal plate
(synchondrosis),
Pubic symphysis,
intervertebral
discs
(symphysis)
Diarthroses
 Freely
moveable
Ex. Hip, knee,
shoulder, elbow

162. What is a Ligament?
Group of dense connective
tissues connects bone to
bone.
What is a Tendon?
Group of dense connective
tissues or ends of muscles
which connects muscle to
bone.

163. Fibrous Joints
 Lack a synovial cavity.
 Articulating bones are held together with dense
 fibrous connective tissue.
 Permit little or no movement.
 Types:
Sutures
Gomphosis
Syndesmoses

164. EXAMPLES OF FIBROUS JOINTS

165. EXAMPLES OF FIBROUS JOINTS

166.  Lack a synovial cavity.
 Articulating bones are held together with cartilage
 connective tissue.
 Permit little movement.
 Types:
 Synchondroses (Primary cartilaginous joint)
 Symphyses (Secondary cartilaginous joint)
CARTILAGINOUS JOINTS
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.

167. EXAMPLES OF CARTILAGINOUS JOINTS

168.  Have a synovial cavity
 Articulating bones are covered with articular
cartilage, held together by ligaments, contain
synovial fluid, have a nerve and blood supply, and
are surrounded by an articular capsule
 Permit a large range of movement
SYNOVIAL JOINTS

169. GENERAL STRUCTURE -
 Articular cartilage
 Articular ligaments (Capsule)
 Synovial membrane
 Joint (synovial) cavity
 Synovial fluid
 Reinforcing ligaments
 Articular discs
 Menisci
 Bursae and Tendon Sheaths

170. STRUCTURE OF A SYNOVIAL JOINT

171. ARTICULAR CARTILAGE
 Hyaline
cartilage
covering the
bone surfaces
171

172. CAPSULE
 Fibrous
capsule lined
by synovial
membrane
 Continuous
with
periosteum
172

173. SYNOVIAL CAVITY
 Joint cavity is
synovial cavity
 Surrounded by
synovial
membrane
173

174. SYNOVIAL MEMBRANE
Lines the cavity of
joint except over
the articular
cartilage.
174

175. SYNOVIAL FLUID
 Viscous slippery
fluid rich in
albumin &
hyaluronic acid &
similar to raw egg
white
175

176. ARTICULAR DISC
 Circular rim of
fibrous
cartilage
between
articular
surfaces of two
bones 176

177. MENISCUS
 Meniscus is an incomplete
rim of white fibrous
cartilage between
articular cartilages.
 Shock absorber
 Enhancement of
congruence
 Protection of edges
 Weight distribution
 Facilitation of movement
177

178. BURSA
Lubricating device
consist of a closed
fibrous sac.
Present wherever
tendon rub against
bones,ligaments or
other tendons
178

179. Bursae and tendon sheaths can be found at many
synovial joints.
Bursae – flattened, fibrous sacs lined with synovial
membranes and containing synovial fluid
Tendon sheath – elongated (tubelike) bursa that
wraps completely around tendons subject to a
great deal of friction
BURSAE AND TENDON SHEATHS
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.

180. Synovial Joints: Range of Motion
1. Nonaxial – Gliding movements only
2. Uniaxial – Movement in one plane
3. Biaxial – Movement in two planes
4. Multiaxial – Movement in or around all three
planes

181. Types of Movement at Synovial Joints

192. Types of Synovial Joints