1. Skeletal System
Provides body with rigid framework of support and structure
Bones are living organs. Can change and help body respond to changing environment
Specialized cells allow bone to grow in size and shape as we grow

2. Functions Support: supporting framework for body
Protection: skull protects brain, breastbone and ribs protect vital organs (heart, lungs), vital tissue (red bone marrow- blood cell forming tissue
Movement: muscles anchored to bone, contract and shorten, pull on bones and move
Storage: Maintain homeostasis of blood Calcium (bones store extra calcium in blood, when blood calcium low, bone releases calcium (can lead to osteoporosis)
Hemo (blood) poiesis (to make): blood cell formation in red marrow- found in spongy bone located in ends of long bones
Infant: (cartilage skeleton turns to bone as cartilage is replaced with bone) . Increased red marrow turns into yellow marrow (inactive fatty tissue)

3. Microscopic structure of bone and cartilage
2 major types of Connective Tissue
Bone
Cartilage

4. BONE Different appearance and texture depending on location
Outer bone layer: (hard & dense) Dense or Compact bone
Porous bone in end of long bones: Spongy bone (contains many spaces that can be filled with marrow)
Trabeculae (in spongy bone- threads
surround network of spaces)
( text 89)

5. Compact or Dense Bone No network of open spaces
Matrix of Haversian Systems (multiple layers of calcified matrix in rings called concentric lamella that surround Haversian canal which contains blood vessels
Bone cells: osteocytes, found between hard layers of lamella, in little spaces called lacunae.
Tiny passageways-canals: canaliculi connect lacunae with each other and the central canal in Haversian system
(text 90, 91, overheads A9, A10)

7. Nutrients pass from blood vessels in Haversian canal through canaliculi to osteocytes (in lacunae that are in concentric lamella)
Many blood vessels from outer periosteum enter bone -> Haversian canals (with blood vessel)

8. Osteoclasts: bone absorbing cells allow bone tissue present to be absorbed/removed
Osteocytes and osteoclasts required for bones to grow and heal.
Osteoblasts: bone forming cells

9. Cartilage Like bone consists of intercellular substances and cells
Collagenous fibers reinforce matrix of both tissues
In cartilage: fibers are embedded in firm gel matrix
gives flexibility
In bone: hard, calcified matrix gives rigidity

10. Chondrocytes: cartilage cells (like osteocytes in bone)
are located in lacunae, but lacunae
suspended in cartilage (gel) matrix
(compared to bones concentric lamella)
No blood vessels in cartilage.
Nutrients must diffuse through matrix to reach cells
(text 92, A11) Study guide part 1

11. Structure of Long Bones
Diaphysis: (Shaft) Hollow tube made of hard compact bone- rigid, strong, structure. Light weight, easy movement
Medullary cavity: Hollow area inside diaphysis of bone contains soft yellow marrow (fatty)
Epiphysis: Ends of bone where red marrow fills in small spaces in spongy bone (trabeculae) that composes epiphysis
Articular cartilage: Thin layer of cartilage covering each epiphysis- functions like rubber cushion around joint
Periosteum: Strong fibrous membrane covering long bone, except at joint surfaces (where it’s covered by articular cartilage)
(text 93, 94, overhead A9, A11)

13. Epiphyseal fracture Young children susceptible to fracture
Epiphyseal plate (growth plate) can be separated from diaphysis or epiphysis.
As soon as plate replaced with calcified matrix, growth is complete
(text 94, 95, overhead A11)

15. Bone formation and growth
Skeleton of baby before birth- cartilage & fibrous structures shaped like bone
Transforms into bone when cartilage replaced with calcified matrix deposited by osteoblasts, (bone forming cells)
Combined action of : Bone forming osteoblasts and
bone absorbing osteoclasts
sculpts bone into adult shapes.
Laying down of calcium salts in matrix  calcification makes bones hard. (XS Ca from blood stored in bone, low Ca in blood, Ca removed from bone osteoporosis
Vitamin D (made in dermis with UV exposure) aids is Ca absorption. (milk w/ vitamins A and D added)
(text 94, overhead A11)

16. Bone growth cont’d
Diaphysis: grows in both directions toward both epiphyses, and both epiphysis grow toward diaphysis
Continues until all epiphyseal cartilage has been transformed to bone
IF epiphyseal cartilage still present, growth still occurring.
If epiphyseal cartilage absent, adult growth attained.
Ossification: cartilage undergoes ossification and becomes bone. Occurs in shaft of diaphysis and then in epiphyses.
(overhead A11) study guide part 2 and diagram 1
structure of human bone and diagram ws
Skeletal Lab with Chicken Bones

17. Types of bones

18. flat bone Thin bones that protect certain organs, including most
of the bones of the skull as well as the scapula.

19. short bone Bones shaped somewhat like cubes that facilitate
flexibility of the joints; examples include the bones
of the wrist and ankle.

20. long bone Elongated bone to which powerful muscles,
such as those of the leg and arm, are
attached.

21. irregular bone Bones of varying shapes and sizes, such
as the vertebrae and certain bones of the
skull or pelvis.

22. Divisions of Skeleton Axial: bones of skull, spine, chest, hyoid
Appendicular: bones of upper extremities (shoulder, pectoral girdle, arms, wrists, hands), bones of lower extremities (hip, pelvic girdle, legs, ankles, feet).
(text 96, 97, overhead A12, A13 review parts/terms/location)
Interactive Drag and Drop. Simulations/Virtual surgeries
Articulated/Disarticulated Skeleton and joints

24. Axial Skeleton SKULL: cranium (8 bones) face (14 bones)
middle ear (6 bones)
Sinuses: spaces/cavities inside some of cranial
bones
4 pairs: frontal
maxillary
sphenoid
ethmoid

25. Openings into nose referred to as paranasal sinuses
Inflammation of mucus membrane:
swollen, painful frontal sinusitis
(text 102, 103, overheads A14, A15) study guide diagram 4 and 5

26. Mastoiditis Inflammation of airspaces within mastoid portion of
temporal bone from infection
of middle ear.
Mastoid cells don’t drain into nose like paranasal sinuses.
Infectious material may erode bony partition to brain and spread infection to covering membranes
(text 102, overhead A15)

27. Axial skeleton cont’d SPINE: (Vertebral column)
Consists of series of separate bones (vertebrae),
connected to form flexible rod
7 cervical region
12 thoracic region
5 lumbar region
1 sacrum region
1 coccyx region
(text 104, overhead A16)

28. Axial skeleton cont’d Vertebrae: spinous process
2 transverse processes
vertebral foramen (hole in center)
Tip head forward. Run finger down back of neck to shoulder level. Feel tip of 7th cervical vertebra’s spinous process
7 cervical vertebrae form
supporting framework of
neck
(text 104, 106, overhead A16)

29. Axial skeleton cont’d 4 Curves of the spine:
Neck and small of back curve slightly
inward/forward
Chest area of spine and lower lumbar curve
opposite creating 4 curves
Cervical and lumbar curves: concave (in)
Thoracic and sacral: convex (out)
Cervical: concave (in) develop
Thoracic: convex (out)
Lumbar: concave (in) develop
Sacral: convex (out)
(text 104, overhead A16)
Concave in
Convex out
Concave in
Convex out

30. Axial skeleton cont’d
Newborn: continuous convex curve from top to bottom. Gradually changes
Holding head up: concave neck-cervical (in)
Stand up: concave lumbar (in)
Creates the 4 curves of the spine
Normal curves important: Strength to support body, balance to stand, walk on 2 feet.
Curved structure has increased strength
(text 104, overhead A16)

31. Axial skeleton cont’d
Poor posture/disease can cause curves to become abnormally exaggerated
Swayback or Lordosis: lumbar curve exaggerated
lumbar

32. Kyphosis or Huntchback: thoracic curve exaggerated
Scoliosis: abnormal side to side curvature
(text 105)

33. Axial skeleton cont’d THORAX or CHEST 12 prs of ribs
Sternum (breastbone)
Thoracic vertebrae
All form bony cage/protection
Each of 12 prs of ribs attaches posteriorly to a vertebra
All ribs except lower 2 prs attach to sternum giving them anterior and posterior anchorage
Prs 1-7 true ribs: attach to sternum by costal cartilage
Prs 8, 9, 10 false ribs: attach to cartilage of 7th
Prs 11, 12 floating ribs: don’t attach to any costal cartilage
(text 104, overhead A16)

34. Appendicular Skeleton
126 of 206 bones appendicular
Bones in shoulder & pectoral girdle attach the bones of arm, forearm, wrist and hands to axial skeleton of thorax
Bones in hip and pelvic girdle attach the bones of thigh, leg, ankle and feet to axial skeleton of pelvis

36. Upper Extremity Pectoral girdle
Scapula (shoulder blade) and clavicle (collar bone) compose
shoulder (pectoral girdle) which functions to attach
upper extremity to axial skeleton (in thorax)

37. Sternoclavicular joint: Only direct point of attachment
between clavicle & sternum
(breastbone)- very small attachment-
 provides wide range of motion
but susceptible to injury b/c ↑ pressure
can occur at joint
(text 96, 97, overheads A12, A13)

38. Upper Extremity cont’d
Humerus: long bone of arm, 2nd longest in body
Attaches to scapula at its proximal end and articulates with 2 bones of forearm, the radius (thumb side) and ulna
Elbow: Ex of structure that determines function
Long bony process of ulna (olecranon process), fits into large depression on posterior surface of humerus (olecranon fossa) makes joint movement
Radius and ulna of forearm articulate with each other and distal end of humerus at elbow joint.
Radius and ulna touch each other distally for articulation with wrist bones
(text 106, 107 overhead A17)

40. Upper Extremity cont’d
Anatomical position: ulna medial (inside)
radius lateral (outside-thumbside)
Wrist and hands: many bones
8 carpal (wrist bones) (vs 7 tarsals/ankle)
5 metacarpal (form support structure for palm)
14 phalanges (finger bones) (distal, middle, proximal)
27 total many bones, joints,
=  increased dexterity
but more bones to break
(text 108, 109, overheads A18)

42. Lower Extremity Hip (pelvic girdle) attaches legs to trunk
Consists of 2 large innominate bones, 1 located on each side of pelvis
2 innominate bones, sacrum, coccyx: provides strong base of support for torso- serves to attach lower extremities to axial skeleton
Infant: Innominate bone consists of 3 bones: ilium, ischium and pubis
that grow to become
1 innominate bone in adult
(text 119 review parts/location)

43. Lower Extremity cont’d
Femur: thigh bone, longest bone in body
articulates proximally (toward hip) with innominate bone in deep cup shaped socket (acetabulum)
Articulation of acetabulum more stable than articulation of head of humerus with scapula in upper extremity
Hip dislocation less common than shoulder
Distally, femur articulates with knee cap (patella) and tibia (shin bone).
Fibula: slender outer (lateral) border of lower leg
(text 112, 113, overhead A17)

45. Lower Extremity cont’d
Toe bones: (phalanges) same # (14) as finger bones:
(proximal, middle, distal)
Foot bones: 5 metatarsals (similar to hand/palm metacarpals) and 7 tarsals (vs 8 carpals in hand)
Feet: standing features for support
Big toe: more solid vs thumb, but less mobile
Foot bones, held together to form springy arches
increase support, strength stable base
Fallen arches: (flat feet) foot ligaments/tendons weaken
3 arches: medial longitudinal arch (inside)
lateral longitudinal arch (outer edge)
transverse or metatarsal arch (extends across
ball of foot)
(text 114, 118, overheads A19) study guide part 3 and diagram 2 and 3
axial/appendicular diagram ws LAB

46. Male vs Female Skeleton
Size: male skeleton larger vs female
(no functional importance)
Hip bone structural differences: (functional importance)
Female pelvis made so baby can be cradled before birth and pass through at birh
Male: Innominate (hip) bones larger and narrower Funnel Shaped
Female: pelvis broader, shallow basin shape, and pelvic inlet wider
(text 119 review parts, location) study guide part 4 and with pgs part 5
Male vs Female Pelvis Activity
Bone Development and Osteoporosis worksheet
Sports Injuries worksheet

48. Osteoporosis
Osteoporosis: bone disease characterized by xs loss of calcified matrix and collagenous fibers from bone.
(xs calcium stored in bone, when calcium levels low, calcium removed from bone leaves bones brittle, degeneration increased fractures and curvature of spine
Sex hormones important role in stimulating osteoblast activity after puberty. Decreased hormone levels in elderly reduces new bone growth and maintenance.
Treat with hormone therapy, dietary supplements (calcium and vitamin D to help absorb calcium.
***Dermis cells exposed to UV rays make vitamin D (remember) to help absorption of calcium also vitamins A and D added to milk! Drink your milk!

49. Joint Articulations
Every bone in body connects to another bone via joints- except hyoid bone in neck (tongue attaches to)
Joints perform 2 functions:
1. Holds bones together securely
2. Makes movement possible between bones
Type of joint determines type and range of movement
3 kinds of joints based on degree of movement
1. Synarthroses
2. Amphiarthroses
3. Diarthroses
(text 120, 121 overheads A20 and binder)

50. Types of Joints cont’d
Synarthroses: joint where fibrous connective tissue grows
between articulating (joining) bones, holding
them close together sutures Ex. Cranial
bones

51. Types of Joints cont’d Amphiarthroses: joint where cartilage connects
articulating bones
Ex. Symphysis pubis (joint between pubic bones)
joints between bodies of vertebrae
Allows flexing of trunk forward, sideways, circumduct (rotate)
Strong ligaments connect bodies of vertebrae & fibrous disks lay between them
Central core of invertebral disks pulpy/elastic- ↓ resiliency w age
Can be compressed by sudden exertion/injury w/ fragments protruding into spinal canal- pressing on nerve root of spinal cordsevere pain herniated/slipped disk
(text 120, 121, 122 overhead A20 and binder)

54. Types of Joints cont’d
Diarthroses: most joints, allow considerable movement
in 1, 2 or many directions.
Structure of Diarthroses joints: All have joint capsule, joint
cavity, and layer of cartilage
over ends of 2 adjoining bones
(text 122, overhead A21 and binder)
Display joints and skeleton

55. Structure of Diarthroses joints cont’d
Joint capsule: made of strong fibrous connective tissue,
lined with smooth, slippery synovial membrane
capsule fits over ends of 2 bones like sleeve
Joint capsule attaches firmly to shaft to form
covering (periosteum) around bone. It holds
bones together securely, but permits
movement at joint
Structure of joint capsule helps make possible joint function
(text 122, overhead A21 and binder)

57. Structure of Diarthroses joints cont’d
Ligament: cords or bands made of same strong connective
tissue as joint capsule grow out of periosteum &
connect bone to bone firmly
Articular cartilage layer: over joint ends, acts like rubber
cushion- absorbs jolts
Synovial Membrane: Secretes lubricating synovial fluid, allows
easier movement, ↓ friction
(text 122, overhead A21 and binder) study guide diagram 6

60. Types of Diarthroses Joints
Ball and Socket
Hinge
Pivot
Saddle
Others
Differences in structure 
differences in type and range of motion
(text 122, overhead A21 and binder)

61. Types of Diarthroses Joints
Ball and Socket: ball shaped head of 1 bone fits into concave socket of another. Permit widest range of motion
Ex. Shoulder and hip
Forward (text 121, overheads A20 and binder)
Backward
Abduct (away from side)
Adduct (towards side)
Circuduct in circle)

62. Types of Diarthroses Joints cont’d
Hinge Joints: Allows movement in 2 directions (door)
Flexion (bending)
Extension (straightening)
Ex. Elbow, knee, fingers

63. Types of Diarthroses Joints cont’d
Pivot Joints: Small projection of bone pivots in arch of
another bone
Ex. Projection of axis (C2) pivots in arch of atlas (C1)
 rotates head that rests on atlas
(text 121, overheads A20 and binder)

64. Types of Diarthroses Joints cont’d
Gliding Joint:  opposed surfaces are flat or only slightly curved,
so that the bones slide against each other in a
simple and limited way.
bones of the wrist and ankle meet in gliding joints
 gliding movement.

65. Types of Diarthroses Joints cont’d
Saddle Joints: only 1 pr between metacarpal (of thumb) and
carpal (trapezium) of wrist
Articulating surfaces of these bones-
saddle shaped, allow thumb great range of movement
mobility/dexterity: flex, extend, abduct, adduct, circumduct
Without saddle joint- No grasping, picking up, or holding utensil
(text 121, overheads A20 and binder)
study guide part 6, 7, 8 and 9
Diarthroses- synovial joint ws
M&L study guide

66. You should have the following completed
Skeletal System
You should have the following completed
Study guide including all diagrams
Lab
All worksheets, diagrams and additional study guide(s)
End of chapter test