Topics Covered 1. Classification of Skeleton 2. Bone Structure 3. Axial skeleton - Cranium, Face, Vertebral Column, Ribs 4. Appendicular Skeleton - Arms, Legs 5. Joints - Classification 6. Muscular System 7. Classification of Muscle 8. Functions of Muscles 9. Muscle Miscro-structure 10. Muscle Contraction and Fatigue

1. The Musculo-skeletal
System
Chapter 2

2. The Skeletal System
 Human adult has 206 bones
 Babies have >300 bones that fuse during
developemnt
 Function
 Support and Shape
 Protection
 Blood Cell Formation (hematopoiesis)
 Leverage for locomotion (along with muscles)
 Inorganic salt storage (Ca, PO4, Mg, Na, K)
 The study of bones “osteology”

3. Classification
 Classification of the Skeletal system
 Axial Skeleton
 Head
 Neck
 Trunk
 Appendicular Skeleton
 Upper Limbs
 Lower Limbs
 Pectoral Girdle
 Pelvic Girdle

4. Classification
Classification of Bones
Based on density
Spongy Bone
Compact Bone
Based on Shape
a. Long Bone
b. Short Bone
c. Flat Bone
d. Irregular Bone
e. Sesamoid (Round) Bone

5. Bone Structure
Microstructure of the bone Parts of a long bone

6. Bone Development

7. Factors affecting bone development,
growth and repair
 Vitamin A Deficiency – retards bone
development
 Vitamin C deficiency – fragile bones
 Vitamin D Deficiency – Rickets, osteomalcia
 Growth hormone imbalance – dwarfism /
gigantism
 Hypothyroidism – delay in bone growth
 Sex Hormones - promotes bone formation
early ossification
 Physical stress – stimulates bone growth

8. The Axial Skeleton
 Groups of Bones
 Skull
 Cranial bones
 Facial bones
 Vertebral Column
 Cervical
 Thoracic
 Lumbar
 Pelvic
 Thoracic Cage
 True Ribs
 False ribs
 Sternum

9. THE SKULL

10. The Skull
 Bones of CRANIUM
encloses and protects the
brain
 8 cranial bones
 Unmovable joints (sutures)
 Contain holes (foramen)
for VAN
 Bones of the FACE holds
eyes and shape of the
face
 14 facial bones
 One movable joint
 Foramen for VAN

11. The Bones of the Cranium
 Frontal (1)
forms forehead
 Parietal
superior and lateral walls (paired)
 Temporal
inferior to parietal, at temples (paired)
 Occipital
posterior wall of the orbit
 Sphenoid
deep to the anterior of skull, forms floor
of cranial cavity
 Ethmoid
forms roof of nasal cavity, medial walls
of orbits

12. The Bones of the Cranium
 Frontal (1)
forms forehead
 Parietal (2)
superior and lateral walls (paired)
 Temporal
inferior to parietal, at temples (paired)
 Occipital
posterior wall of the orbit
 Sphenoid
deep to the anterior of skull, forms floor
of cranial cavity
 Ethmoid
forms roof of nasal cavity, medial walls
of orbits

13. The Bones of the Cranium
 Frontal (1)
forms forehead
 Parietal (2)
superior and lateral walls (paired)
 Temporal (2)
inferior to parietal, at temples (paired)
 Occipital
posterior wall of the orbit
 Sphenoid
deep to the anterior of skull, forms floor
of cranial cavity
 Ethmoid
forms roof of nasal cavity, medial walls
of orbits

14. The Bones of the Cranium
 Frontal (1)
forms forehead
 Parietal (2)
superior and lateral walls (paired)
 Temporal (2)
inferior to parietal, at temples (paired)
 Occipital (1)
posterior wall of the orbit
 Sphenoid
deep to the anterior of skull, forms floor
of cranial cavity
 Ethmoid
forms roof of nasal cavity, medial walls
of orbits

15. The Bones of the Cranium
 Frontal (1)
forms forehead
 Parietal (2)
superior and lateral walls (paired)
 Temporal (2)
inferior to parietal, at temples (paired)
 Occipital (1)
posterior wall of the orbit
 Sphenoid (1)
deep to the anterior of skull, forms floor
of cranial cavity
 Ethmoid
forms roof of nasal cavity, medial walls
of orbits

16. The Bones of the Cranium
 Frontal (1)
forms forehead
 Parietal (2)
superior and lateral walls (paired)
 Temporal (2)
inferior to parietal, at temples (paired)
 Occipital (1)
posterior wall of the orbit
 Sphenoid (2)
deep to the anterior of skull, forms floor
of cranial cavity
 Ethmoid (1)
forms roof of nasal cavity, medial walls
of orbits

17. The Facial Bones
 Maxillae (2)
Forms upper jaw
 Palatine (2)
Posterior to maxillae, between back
 Zygomatic (2)
Cheekbones, lateral walls of orbits
 Lacrimal (2)
Part of medial walls of orbits, between ethmoid
bones and maxillae
 Nasal (2)
Bridge of nose
 Vomer (1)
Median line of nasal cavity
 Inferior conchae (2)
Bone projections from lateral wall of nasal cavity
 Mandible (1)
Lower jaw, connected by only freely movable
joint of face

18. The Facial Bones
 Maxillae (2)
Forms upper jaw
 Palatine (2)
Posterior to maxillae, between back
 Zygomatic (2)
Cheekbones, lateral walls of orbits
 Lacrimal (2)
Part of medial walls of orbits, between ethmoid
bones and maxillae
 Nasal (2)
Bridge of nose
 Vomer (1)
Median line of nasal cavity
 Inferior conchae (2)
Bone projections from lateral wall of nasal cavity
 Mandible (1)
Lower jaw, connected by only freely movable
joint of face

19. The Facial Bones
 Maxillae (2)
Forms upper jaw
 Palatine (2)
Posterior to maxillae, between back
 Zygomatic (2)
Cheekbones, lateral walls of orbits
 Lacrimal (2)
Part of medial walls of orbits, between ethmoid
bones and maxillae
 Nasal (2)
Bridge of nose
 Vomer (1)
Median line of nasal cavity
 Inferior conchae (2)
Bone projections from lateral wall of nasal cavity
 Mandible (1)
Lower jaw, connected by only freely movable
joint of face

20. The Facial Bones
 Maxillae (2)
Forms upper jaw
 Palatine (2)
Posterior to maxillae, between back
 Zygomatic (2)
Cheekbones, lateral walls of orbits
 Lacrimal (2)
Part of medial walls of orbits, between ethmoid
bones and maxillae
 Nasal (2)
Bridge of nose
 Vomer (1)
Median line of nasal cavity
 Inferior conchae (2)
Bone projections from lateral wall of nasal cavity
 Mandible (1)
Lower jaw, connected by only freely movable
joint of face

21. The Facial Bones
 Maxillae (2)
Forms upper jaw
 Palatine (2)
Posterior to maxillae, between back
 Zygomatic (2)
Cheekbones, lateral walls of orbits
 Lacrimal (2)
Part of medial walls of orbits, between ethmoid
bones and maxillae
 Nasal (2)
Bridge of nose
 Vomer (1)
Median line of nasal cavity
 Inferior conchae (2)
Bone projections from lateral wall of nasal cavity
 Mandible (1)
Lower jaw, connected by only freely movable
joint of face

22. The Facial Bones
 Maxillae (2)
Forms upper jaw
 Palatine (2)
Posterior to maxillae, between back
 Zygomatic (2)
Cheekbones, lateral walls of orbits
 Lacrimal (2)
Part of medial walls of orbits, between ethmoid
bones and maxillae
 Nasal (2)
Bridge of nose
 Vomer (1)
Median line of nasal cavity
 Inferior conchae (2)
Bone projections from lateral wall of nasal cavity
 Mandible (1)
Lower jaw, connected by only freely movable
joint of face

23. The Facial Bones
 Maxillae (2)
Forms upper jaw
 Palatine (2)
Posterior to maxillae, between back
 Zygomatic (2)
Cheekbones, lateral walls of orbits
 Lacrimal (2)
Part of medial walls of orbits, between ethmoid
bones and maxillae
 Nasal (2)
Bridge of nose
 Vomer (1)
Median line of nasal cavity
 Inferior conchae (2)
Bone projections from lateral wall of nasal cavity
 Mandible (1)
Lower jaw, connected by only freely movable
joint of face

24. The Facial Bones
 Maxillae (2)
Forms upper jaw
 Palatine (2)
Posterior to maxillae, between back
 Zygomatic (2)
Cheekbones, lateral walls of orbits
 Lacrimal (2)
Part of medial walls of orbits, between ethmoid
bones and maxillae
 Nasal (2)
Bridge of nose
 Vomer (1)
Median line of nasal cavity
 Inferior conchae (2)
Bone projections from lateral wall of nasal cavity
 Mandible (1)
Lower jaw, connected by only freely movable
joint of face

25. Additional Bones
 Hyoid Bone (1)
 Not technically part of skull
 Does not articulate directly with any other
bone
 Anchored to temporal bones by ligaments
 Movable base for tongue
 Attachment point for neck muscles

26. Bone Markings
Meatus – Canal like Passageway
Process – bony prominence
Foramen – opening through bone
Condyle – rounded articular
projections (involved with joints)
Sinuses – cavities in bone filled with air

27. Bone Markings - Examples
Meatus Process Foramen Condyle Sinuses
External Styloid Process – inferior Jugular Magnum – at Occipital Paranasal Sinuses –
Auditory Meatus to auditory meatus junction of occipital & Condyles – rest on found in different
– canal leads to (temporal) temporal bones, opening for the first vertebra bones surrounding
eardrum and jugular vein (temporal) of the spinal nasal cavity
middle ear Zygomatic Process – column (occipital) (frontal, ethmoid,
(temporal) anterior to cheek bone Carotid Canal – anterior to sphenoid,
(temporal) jugular foramen, opening for maxillae)
carotid artery (temporal)
Mastoid Process –
posterior and inferior to Foramen Magnum –
auditory meatus opening for spinal cord to
(temporal) connect to brain (occipital)
Palatine Processes – Foramen Ovale – opening
extensions of maxillae for nerve fibers to pass to
that form the anterior jaw muscles (sphenoid)
part of the mouth
(maxillae)

28. THE VERTEBRAL COLUMN

29. The Vertebral Column
 Length is 60 - 70cm
 Intervertebral discs contribute (1/5)th of length.
 Made up of 33 vertebrae.
 Five(5) different regions are identified:
 Cervical vertebrae - 7
 Thoracic vertebrae - 12
 Lumber vertebrae - 5
 Sacral vertebrae - 5
 Coccygeal vertebrae - 4
 Vertebrae in sacrum and coccyx are fused together
(false vertebrae), while others are discrete (true
vertebrae).

30. Functions of the spine
 Protection – cord , internal organs
 Flexibility & locomotion – 6 degrees of
movement
 Posture & support – upright, balance
 Attributes to achieve function
(resistance & elasticity)
 Curvature
 Progressive ↑ vertebral mass
 Motion segments

31. Features of the backbone
Curvature Elasticity
[Convex
1 (Lordosis),
Concave
Resistance
Dynamic Center of
(Kyphosis)] gravity
Increased vertebral Primary Secondary
mass from C1 to S1
Forms a firm base
Mass
2
Functional unit
3 Motion
Segments
2 vertebrae +
intervertebral discs +
connecting ligaments

32. Regions of the spine
Cervical (7) Upper Cervical (C1-C2)
Lower Cervical (C3-C7)
Thoracic (12) (T1-T12)
Lumbar (5) (L1-L5)
Coccygeal (9)

33. The Vertebral Column
Vertebral Bones
Lumbar Thoracic Cervical
Vertebral Body
Transverse Process
Vertebral foramen
Superior Articular Process Facet Joint
Spinous Process

34. The Vertebral column
 Sacral Vertebrae
 5 vertebrae fused together
 Joins to the pelvic bones on either side
 Forms the posterior of the pelvic girdle
 Coccygeal Vertebrae
 4 vertebrae fused together
 Vestigial in humans

35. The Intervertebral Discs
 Annulus Fibrosis
 Outer portion of the disc
 Made of lamellae
 Great tensile strength
 Nucleus Pulposus
 Inner structure
 Gelatinous
 High water content
 Resists axial forces
* Slip Disc

36. THE RIB CAGE

37. Thoracic Cage
Functions
 Supports pectoral girdle
 Protects Viscera
 Helps Breathing
Components
 Thoracic Vertebrae
 Ribs – 24 ribs
 True – 7 pairs
 False – 5 pairs
 Sternum
 Costal cartilages

38. Rib Anatomy
Common Features
 Head, Neck and Tubercle articulate with the
vertebral bone
 Long curved shaft
 Ends with costal cartilage
 Contains groove for VAN
True Ribs – 7 pairs
 Connect to vertebrae and sternum directly
False Ribs – 5 pairs
 3 connect to sternum with 7th costal cartilage
 Last 2 „float‟ without connection to sternum

39. Sternum
 Also called Breast bone
 Shaped like a shield
 Attaches costal cartilages
 Three parts
 Manubrium
 Articulates with pectoral girdle
 Body
 Attaches costal cartilages
 Xiphoid Process

40. The Appendicular Skeleton
 Groups of Bones
 Upper Limbs
 Pectoral Girdle
 Arm
 Hand
 Lower Limbs
 Pelvic Giidle
 Leg
 Foot

41. Upper Limbs
 Shoulder Joint – Pectoral Girdle – 3 bones
 Collar bone – Clavicle
 Shoulder Blade – Scapula
 Humerus
 Arm – 3 bones
 Humerus
 Radius - outer
 Ulna – inner
 Hand – 27 bones
 Carpels - 8
 Metacarpels - 5
 Phalanges - 14

42. Lower Limbs
 Hip Joint – Pelvic Girdle – 2 bones
 Pelvic Bones
 Leg – 4 bones
 Femur – Longest Bone
 Tibia
 Fibula – Shin
 Patella – Knee cap
 Foot – 26 bones
 Tarsals - 7
 Metatarsals - 5
 Phalanges - 14

43. Joints

44. Classification of Joints
Structural Functional
Synoarthr Amphi- Di-
Cartilagin
Fibrous Joints Synovial Joints otic arthrotic arthrotic
ous Joints
Joints Joints Joints
Hyaline or
Between
Dense fibro
close Most Allow free Slightly Freely
connective cartilage Immovable
contact complex movement movable Movable
tissue connects
bones
bones

45. Classification of Joints
Fibrous
Fibula
 Sheet bundle of fibres
Tibia
 Parallel bones
 Syndesmosis
Margin of
 Very thin layer of connective tissue suture
 Cranial plates
 Suture
 Cony Process of connective tissue
 tooth and jaw
Periodontal
 Gomphosis ligament

46. Costal cartilage
Classification of Joints
Cartilaginous
 Bands of hyaline cartilage unite
bones
 Ribs and sternum
 Synchondrosis
Intervertebral
discs
 Pad of fibrocartilage between bones
Symphysis pubis
 Vertebrae, pubic bones
 Symphasis

47. Classification of Joints Spongy Bone
Synovial
 Freely Movable Synovial membrane
 Complex structure enables free movement Joint Cavity
Synovial Fluid
 6 types of joints - based on movement
Articular Cartilage
Uni-axial Bi-axial Multi-axial
Joint capsule
Ball
Hinge Pivot Saddle Condylar Gliding
Socket

48. Synovial Joints - Examples

49. Lifespan Changes
 Joint stiffness is an early sign of aging
 Fibrous joints first to change; can strengthen however over a lifetime
 Changes in joints of vertebral column diminish flexibility and decrease height
 Synovial joints lose elasticity
 Disuse hampers the blood supply
 Activity and exercise can keep joints functional longer

50. The Muscular System
Specialized tissue that enable the body and its parts to move.

51. Overview of Muscular System

52. The Muscular System
 Consists of 640 Muscle (40% body  Functions of Muscles
mass)
 Movement
 The Sartorious – The longest muscle in
the body
 Posture and muscle tone
 The Stapedius – Shortest muscle in the  Heat production
body
 Protection of bones and organs
 Gluteus Maximus – Biggest muscle in
the body

53. Classification of Muscles
 Functional
 Voluntary – can be moved at will
 Involuntary – cant‟ be moved
intentionally
Striated Smooth
 Structural
 Striated – have stripes
 Non-Straited – no striations
Cardiac

54. Straited Cardiac Smooth
 Fibers are long and  Cells branched and  Fibers are thin and
cylindrical appear fused with one spindle shaped.
another
 Has many nuclei  No striations
 Has striations
 Has striations  Single nuclei
 One central nuclei/cell
 Have alternating dark  Slow contractions
and light bands  Contractions pump
 Muscles fatigue very
blood through body
 Attached to bones by slowly
tendons  Muscles never fatigue
 Lining of tube inside
 Muscles fatigue body

55. Classification of muscles
Voluntary Involuntary
Skeletal Cardiac Smooth
Limbs Heart Viscera
Striated Non-Striated

56. Muscle Control
Type of Muscle Nervous control Type of Control Example
Skeletal CNS controlled Voluntary Lifting a glass
Cardiac ANS Regulated Involuntary Heart Beating
Smooth ANS Controlled Involuntary Peristalsis

57. Movement
 Muscle moves bones always by pulling and never by pushing
 Synergy – Movement always due to more than one muscle working together
 All muscles responsible – Synergists
 Prime Muscle – One muscle most important for movement
 Most important muscle – agonist
 Paired functionality – every agonists must have an antagonist
 Prime Mover opposite to agonist – antagonist
 When one contract, the other has to relax

58. Posture
 Maintaining body position - tonic
contractions
 Don‟t produce movement but hold
up position
Heat Production
 Muscles contraction produces heat
 Maintains / Increases Body
temperature

59. Muscle
Muscle Fibre
Microstructure
Skeletal Muscle
Myofibril
Sarcomere
Filament Organization
Thin Filament
Thin Filament

60. Skeletal Muscle Microstructure

61. Smooth Muscle
 Blood vessel Lining - Helps blood
Circulation
 Esophagus, stomach, intestine -
Controls digestion
 Respiratory system - Controls
breathing
 Urinary bladder - Controls urination
 Two Distinct Layers
 Longitudinal
 Circular
 Helps Peristalsis

62. Smooth Muscle
 Cells have dense bodies that anchor fibrin
 Contracts on ANS stimulus
 Causes wave like movement along the tube

63. Cardiac Muscle
 Forms the chambers of the heart
 Atrial and Ventricular Contractions
 Signal by ANS through cardiac nerves
and Sino-atrial nodes
 Left ventricle has strongest cardiac
muscles
 Microstructure similar to striated
muscle

64. Muscle Contraction
• Electrical impulse travels down a motor neuron. When it reaches
the end, acetylcholine (chemical) is released into the synapse
• Acetylcholine bind to special receptors on the muscle cell and
causes an electrical impulse to spread over the cell
• The sarcomeres shorten and the muscle cell contracts

65. Muscle Fatigue
 Nervous Fatigue
 Nerves responsible for muscle contraction
 sequence and force
 Number of muscles
 Regular movements require far less force than maximum
 During weight training – maximum nerve signal
 Diminishes in time – muscle stop listening – returns to original
state
 Strength training – sustained signal – sustained threshold signal
results in hypertrophy
 Metabolic Fatigue
 Energy used for contraction – buildup of waste products
(metabolites) cause fatigue/cramps
 Metabolites include ADP, Chloride, K, Lactic Acid