1. The Skeletal System
Chapter 6

2. Click on the following link for “Flipped class notes” part 1 and click on the Pugs for flipped class part 2 of Chapter 6 notes.

3. Skeletal System
Consists of 206 bones and associated connective tissues including…..
Cartilage
Tendons
Ligaments

4. Support Bones bear weight Cartilage is firm yet flexible
5 Functions of Bones
Support
Bones bear weight
Cartilage is firm yet flexible
Ligaments are bands of fibrous collagen tissue that hold bones together.

5. Ex: rib cage around heart Ex: skull around brain
Bones Function #2
2. Protection
Surrounds organs
Ex: rib cage around heart
Ex: skull around brain

6. 3. Movement Bone Function #3 Tendons: muscle to bone
Ligaments: allow limited movement between bones.
Joints allow movement between bones
Tendons and Ligaments mainly composed of collagen fibers.

7. Bone Function #4 4. Storage Store calcium and phosphorus
as calcium phosphate crystals – hydroxyapatite.
Stores fat in bone cavities – yellow marrow
Stores are released into blood when needed

8. Bone Function #5 5. Blood cell production
Red bone marrow forms blood cells and platelets.
Mostly in spongy bone (epiphyses of long bone.)

9. Connective Tissue
The skeletal system is made of connective tissue which contains extracellular matrices of:
Collagen- a tough ropelike protein
Proteoglycans- a large molecule with branches like pine branches
Hydroxyapatite = calcium phosphate crystals

12. 4 Types Based on Shape
1. Long Bones
Most of the upper and lower limbs

13. 2. Short Bones Ex: bones of the wrist and ankle 4 Types Based on Shape
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14. 3.Flat Bones Ex: skull bones, ribs, scapulae, sternum
4 Types Based on Shape
3.Flat Bones
Ex: skull bones, ribs, scapulae, sternum

15. 4 Types Based on Shape
4. Irregular Bones
Ex: Vertebrae,
facial bones

16. Long Bone Structure
Diaphysis
central shaft

17. Long Bone Structure Epiphyses Each end is called an epiphysis.
Two ends
Each end is
called an
epiphysis.

18. Long Bone Structure Articular Cartilage –
Covers ends of epiphyses where bone moves with other bone.
Made up of what type of cartilage?
Hyaline!

19. Long Bone Structure
Epiphyseal line- Replaces cartilage of the epiphyseal growth plate

20. Long Bone Structure Medullary cavity large cavity in the diaphysis
contains
marrow

21. Long Bone Structure Yellow marrow consists mostly of fat
replaces red marrow in adults

22. Page 198 Review Questions:
Which of these is not a function of bone?
a. internal support and protection b. attachment for the muscles
c. Calcium and phosphate storage d. blood cell production
e. vitamin D storage
“E.” is not a function of bone.
2. Chondrocytes are mature cartilage cells within the ________, and they
are derived from _______.
a. perichondrium, fibroblasts b. perichondrium, chondroblasts
c. lacunae, fibroblasts d. lacunae, chondroblasts
d. lacunae, chondroblasts
3. Which of these statements concerning cartilage is correct?
a. Cartilage often occurs in thin plates or sheets.
b. Chondrocytes receive nutrients & oxygen from blood vessels in the matrix.
c. Articular cartilage has a thick perichondrium layer.
d. The perichondrium contains both chondrocytes and osteocytes.
e. Appositional growth of cartilage occurs when chondrocytes within the
tissue add more matric from the inside.
A. cartilage occurs in thin sheets as put on by chondroblasts.

23. 4. Which of these substances makes up the major portion of bone?
a. collagen b. proteoglycan aggregates
c. hydroxyapatite d. osteoblasts e. osteocytes
hydroxyapatite
5. The flexible strength of bones occurs because of:
Collagen
6. The primary function of osteoclasts is to:
a. prevent osteoblasts from forming.
b. become osteocytes
c. break down bone.
d. secrete calcium salts and collagen fibers.
e. form the periosteum
C. Break down bone

24. 7. Central canals: A. connect perforating canals to canaliculi
B. connect spongy bone to compact bone.
C. are where blood cells are produced
D. are found only in spongy bones.
E. are lined with periosteum.
7 = A. connects blood to canaliculi
8. The lamellae found in osteons are _________lamellae.
a. circumferential b. concentric c. interstitial
Concentric rings of lamellae
9. Spongy bones consists of interconnecting rods or plates of bone called:
a. osteosns b. canaliculi c. circumferential lamellae
d. haversian system e. trabeculae
Trabeculae!
10. A fracture in the shaft of a bone is a break in the:
a. epiphysis b. perichondrium c. diaphysis
d. articular cartilage e. sacroiliac
C. Diaphysis = shaft

25. 11. Yellow marrow is:
A. found mostly in children’s bones.
B. found in the epiphyseal plate.
C. Important for blood cell production.
D. mostly adipose tissue.
E. where blood cells are mainly produced.
D. Fat = adipose tissue
12. The periosteum:
A. is an epithelial tissue membrane.
B. covers the outer and internal surfaces of bone.
C. contains only osteoblasts.
D. becomes continuous with collagen fibers of tendons
or ligaments.
E. has a single fibrous layer
Tendons and ligaments are an extension of periosteum.

26. Perform case study with a partner, prepare to discuss
Critical Thinking #3
Astronauts can experience a dramatic decrease in bone density while in a weightless environment. Explain how this happens and suggest a way to slow the loss of bone tissue.
Perform case study with a
partner, prepare to discuss
as a class in 20 minutes.

27. Case Study link to compare with your group answers:
It is good to understand and follow the questions associated with this case study, especially question #6.

28. Periosteum Long Bone Structure covers outer surface of bone.
dense connective tissue.
contains blood vessels, nerves, osteoclasts, & osteoblasts.

29. Long Bone Structure Endosteum lines surface of medullary cavity
thin connective tissue membrane
contains osteoblasts

31. Compound Fracture

33. 2 types of bone based on structure:
Compact bone
Cancellous bone C

34. Osteon or (haversian system) – basic unit of structure of compact bone

35. Osteon or (haversian system) – basic unit of structure of compact bone.

36. Osteon
Consists of rings of lamellae

37. Lamellae – thin sheets of extracellular matrix

38. Osteocytes – bone cells located between the lamellae in spaces called lacunae

40. osteocyte

41. Practice labeling 1. Periosteum 2. Medullary cavity 3. Compact bone
4. Cancellous bone
5. Epiphyseal plate
6. Epiphysis
7. Osteon
8. Perforating canal
9. Endosteum
10. Canaliculi
11. Osteocyte
Diaphysis
Lacuna
Practice
labeling

42. Canaliculi – channels running within the lamellae between the osteocytes

43. Caniculi

44. Canaliculi
Pathway for nutrients from blood vessels of central canals to ostocytes
Looks like cracks in the lamellae
Waste products diffuse through them

45. Cancellous bone
Spongy bone
Located in epiphyses of long bone and interior of other bones
Consists of trabeculae

46. Trabeculae Interconnecting rods or plates of bone Add strength
Spaces filled with marrow
Consists of lamellae with osteocytes

48. Six Bone Features to know:
1. Foramen -
“Hole” in a bone.

49. 2. Fossa - A “depression” or dip in a bone. 3. Condyle -
Smooth, rounded end of
a bone where it
articulates with
another bone,
or bones.

50. Xiphoid process of sternum <------- 4. Process -
A “projection” from a
bone.
Xiphoid
process of
sternum
<

51. 5. Tubercle (tuberosity) -
A “lump” or bump on a bone.

52. 6. Canal or Meatus -
Tunnel or canal through the bone.

53. Read and Chapter 6 and your CLA packet, as well as these notes.