1. MUSCULOSKETAL SYSTEM Windsor University School of Medicine
Premed Biology
September 2014

2. Pre Med – Biology Chapter 13 Musculoskeletal System
There is more to lectures than the power point slides!
Engage your mind

3. SKELETON
Animals have a framework similar to the framework of a home. The framework in animals is called the skeleton. In animals or man, the framework has muscles attached to it instead of walls or roof.
“Endoskeleton”
Protection, support, and movement of the body

4. ENDOSKELETON
EXOSKELETON

5. Bones serve the following functions: -
Protect the vital organs inside the body
Provide anchor or support to the muscles
Produce blood cells

6. The Skeletal System Gives form to the body Protects vital organs
Consists of 206 bones
Acts as a framework for attachment of muscles
Designed to permit motion of the body

7. Bone cells are living, they can reproduce resulting in the hardening of the bones called “ossification” and bone growth
Not only does bone size change, their number also changes. As you grow the number of your bones increases although some bones fuse

9. Skeletal system includes the bones, cartilage, ligaments, and tendons
Skeletal system includes the bones, cartilage, ligaments, and tendons. These are tissues that make up the skeleton.
A bone is a hard, living tissue and contains blood vessels, nerves and dividing cells
Bones are hollow or spongy inside
Hollow portion of the bone is made of “Marrow”
The marrow produces red and white blood cells and stores some of the body’s excess fat

10. Cartilage – Tough, flexible tissue that functions as cusioning
Found in lower nose, earlobes, trachea, voicebox
Ligaments – Tough, connective tissue that connect one bone to another
E.g. Hurt when sprain an ankle
Tendons – Connect a bone to a muscle

11. Skeletal System Bone types Bone structure Bone function
Bone growth and metabolism affected by calcium and phosphorous, calcitonin, vitamin D, parathyroid, growth hormone, glucocorticoids, estrogens and androgens, thyroxine, and insulin.

13. There are 3 main parts of the AXIAL skeleton –
Skull
Rib cage
Back bone or spinal cord
Appendages which includes the hands, arms, shoulders and collar bone and the back appendages composed of the feet, legs, knees and hip bone.

14. VERTEBRAE
BACKBONE is made up of thirty-three small bones called vertebrae
Neck to tailbone
33 bones Total:
1. Cervical = 7
2. Thoracic = 12
3. Lumbar = 5
4. Sacral = 5
5. Coccyx = 4

15. Musculoskeletal Anatomy and Physiology
Flat, Short, Long, Irregular bones
Muscles – visceral, cardiac, skeletal
Joints – freely & slight moveable, synovial fluid
Cartilage,Ligaments, Tendons, Fascia, Bursae
Physiology
Structure, shape, movement, protection, support, hematopoiesis

16. Joints Types include synarthrodial, amphiarthrodial, diarthrodial
Structure and function of the diarthrodial or synovial joint
Subtyped by anatomic structure
Ball-and-socket
Hinge
Condylar
Biaxial
Pivot

17. Functions of the Musculoskeletal System
Gives the body shape
Protects internal organs
Provides for movement
Consists of more than 600 muscles

18. Anatomy Muscles - provide movement & generate heat.
Ligaments - connect bone to bone
injury = sprain
Tendons - connect bone to muscle
injury = strain
Bones - protection & shape

19. The Skull
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20. The Neck

21. The Spinal Column
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22. The Thorax
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23. The Pelvis
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24. The Lower Extremity Hip Thigh Knee Leg Ankle Foot
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25. The Upper Extremity Shoulder girdle Arm Elbow Forearm Wrist Hand
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26. Joints
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27. Types of Muscle (1 of 2) Skeletal (voluntary) muscle
Attached to the bones of the body
Smooth (involuntary) muscle
Carry out the automatic muscular functions of the body

28. Types of Muscle (2 of 2) Cardiac muscle Involuntary muscle
Has own blood supply and electrical system
Can tolerate interruptions of blood supply for only very short periods

29. THE MUSCULOSKELETAL SYSTEM
The musculoskeletal system includes all of the bones in a body and the muscles that make them move. It supports the body and protects delicate organs.

30. THE MUSCULOSKELETAL SYSTEM
The skeleton consists of bones, ligaments, and cartilage, which are three types of connective tissue.

31. THE MUSCULOSKELETAL SYSTEM
The other component of the musculoskeletal system is muscles. Muscle tissue consists of bundles of long cells called muscle fibres, which contain specialized proteins. These proteins cause muscles to contract when signalled by nerve cells.

32. THE MUSCULOSKELETAL SYSTEM
Skeletal muscles are attached to the bone by tendons. The other muscle types include smooth muscles (generally located in the intestines) and cardiac muscles in the heart.

33. THE MUSCULOSKELETAL SYSTEM
Similar to other organ systems, the musculoskeletal system is susceptible to disease. Osteoporosis is a common disease that involves the loss of bone tissue, which makes bones weak and brittle. It is common among older women. As well, extreme movements can fracture bones and damage muscles, ligaments, and cartilage.
Some invertebrates have no rigid frame to give them structure, while others have their skeletal system on the outside (exoskeleton).

34. Structure and function of bone Organization of the skeleton Joints
The skeletal system
Structure and function of bone
Organization of the skeleton
Joints
Functions of bone (skeleton)
Support and protection
Blood cell formation
Mineral storage (calcium especially)
Site for muscle attachment  body movement

35. Bones classified by shape: long, short, flat,
irregular, round
Bone enclosed in periosteum, which is continuous
with tendons and ligaments
blood vessels in periosteum
Epiphysis- ends
spongy bone contains red marrow
compact bone, articular cartilage
Diaphysis- middle
compact bone
medullary cavity- contains yellow marrow (fat)
lined with endosteum (squamous epithelium)

37. Compact bone
osteocytes within lacunae
arranged in concentric circles called lamellae
This surround a central canal; complex is called
Haversian system
Canaliculi connect osteocytes to central canal and
to each other

39. Prenatal development
skeleton is mostly cartilaginous
Cartilage cells and then osteoblasts start to
deposit minerals
Cartilaginous disk (epiphyseal disk) remains
in epiphysis
Cells eventually stop dividing

41. Adults continually break down and build up bone
Osteoclasts remove damaged cells and release
calcium into blood
Osteoblasts remove calcium from blood and build
new matrix. They become trapped
osteoclasts

42. Types of bone breaks
Simple- skin is not pierced
Compound- skin is pierced
Complete- bone is broken in half
Partial- broken lengthwise but not into two
parts
Greenstick- incomplete break on outer arc
Comminuted- broken into several pieces
Spiral- twisted

43. Fracture repair
Hematoma- blood clot in space between edges
of break
Fibrocartilage callus- begins tissue repair
Bony callus- osteoblasts produce trabeculae
(structural support) of spongy bone and
replace fibrocartilage
Remodeling- osteoblasts build new compact bone,
osteoclasts build new medullary cavity

45. Axial skeleton
skull (cranium and facial bones)
hyoid bone (anchors tongue and muscles
associated with swallowing)
vertebral column (vertebrae and disks)
thoracic cage (ribs and sternum)
Appendicular skeleton
pectoral girdle (clavicles and scapulae)
upper limbs (arms)
pelvic girdle (coxal bones, sacrum, coccyx)
lower limbs (legs)

46. posterior view
p. 135

47. Axial skeleton supports and protects organs
of head, neck and trunk
Appendicular skeleton- bones of limbs and
bones that anchor them to the axial
skeleton
Articulation- where joints are formed

48. 22 bones in skull
6 in middle ears
1 hyoid bone
26 in vertebral column
25 in thoracic cage
4 in pectoral girdle
60 in upper limbs
60 in lower limbs
2 in pelvic girdle
206 bones in all

49. The skull
8 sutured bones in cranium
Facial bones: 13 sutured bones, 1 mandible
Cranium
encases brain
attachments for muscles
sinuses

51. Allows for
growth

52. Vertebral column
7 cervial vertebrae
12 thoracic
5 lumbar
1 sacrum (5 fused
1 coccyx (4 fused)
Vertebrae vary in size and morphology

54. Thoracic cage
ribs
thoracic vertebrae
sternum
costal cartilages
True ribs are directly attached to the sternum
(first seven pairs)
Three false ribs are joined to the 7th rib
Two pairs of floating ribs

56. Clavicles and scapulae
Help brace shoulders
Attachment sites for muscles

58. Bones of upper limb
Humerus (upper arm)
Radius; ulna
Carpals, metacarpals, phalanges
Bones of lower limb
Femur
Patella
Tibia, fibula
Tarsals, metatarslas, phalanges

59. Joints
Immovable (synarthoses) bones sutured together
by connective tissue: skull
Slightly movable (amphiarthoses) connected by
fibrocartilage or hyaline cartilage:
vertebrae, rib/sternum joint, pubic
symphysis
Freely movable (diarthroses)- separated
ligaments- hold bones together
tendons- muscle to bone
lined by synovial membrane

61. Types of freely movable joints
Saddle: carpal and metacarpal bones of thumb
Ball and socket: shoulder and hip joints
Pivot- rotation only: proximal end of radius and ulna
Hinge- up and own movement in one plane:
knee and elbow
Gliding- sliding and twisting: wrist and ankle
Condyloid- movement in different planes but not
rotations: btw metacarpals and phalanges

62. Types of movement and examples (with muscles)
flexion- move lower leg toward upper
extension- straightening the leg
abduction- moving leg away from body
adduction- movong leg toward the body
rotation- around its axis
supination- rotation of arm to palm-up position
pronation- palm down
circumduction- swinging arms in circles
inversion- turning foot so sole is inward
eversion- sole is out

66. Elevation and depression- raising body part up
or down
Aging and bones
both bone and cartilage tend to deteriorate
cartilage: chondrocytes die, cartilage
becomes calcified
osteoporosis; bone is broken down faster
than it can be built
bones get weak and brittle; tend to fracture
easily

67. Risk factors for osteoporosis
Inadequate calcium
Little weight-bearing exercise
Drinking alcohol, smoking
Being female: decreased estrogen secretion
after menopause
Small frame
Caucasian or Asian ethnicity

68. Skeleton and other systems
Skin makes vitamin D which enhances calcium
absorption
Skeleton stores calcium for muscle contraction,
nervous stimulation, blood clot formation
Red marrow- site of blood cell formation
Calcium levels regulated by
parathyroid hormone and calcitonin
kidneys (can help provide vitamin D)
digestive system (can release calcium
into blood

70. Growth hormone regulates skeletal growth
stimulates cell division in epiphyseal disks
in long bones
Growth stops when epiphyseal disks are
converted to bone
When excess growth hormone is produced in
childhoodgigantism
In adulthood- acromegaly. Bones can’t grow
but soft tissue can

72. When muscle contracts, it shortens and causes
movement
Skeletal muscles attached to bones by tendons
Insertion- attachment to more movable bone
Origin- less movable
Flexors and extensors act on the same joint
to produce opposite actions