1. PowerPoint Presentation to accompany Hole’s Human Anatomy and Physiology, 9/e Shier, Butler, and Lewis

2. Skeletal System – Repairing Bone

3. Factors Regulating Bone Growth
Ions:
Calcium, phosphate, magnesium, citrate, carbonate, sodium, and potassium
Vitamins:
Vitamins A and C
Vitamin D derivatives

4. Factors Regulating Bone Growth
Parathyroid hormone (PTH) acts to increase overall availability of calcium ions in the blood when calcium levels are low.
Increased osteoclast activity is the direct result of PTH levels.
Calcitonin is the antagonist of PTH.
Increased osteoblast activity to build bone when calcium levels are high
Growth hormone and thyroxine increase osteoblast activity leading to bone growth.
Sex hormones increase bone growth dramatically during puberty.

5. Blood Cell Formation
Blood cell formation (hematologists) occurs in yolk sac in early development.
Later it occurs in the liver and spleen.
In the adult red and white blood cells are formed in the red bone marrow.

6. Blood Cell Formation
Red marrow fills the cavity in the diaphysis of the long bones in infants. In adults it is replaced with yellow marrow (fat).
Adult red marrow is found in spongy bone of the skull, ribs, sternum, vertebrae, pelvis.

7. Fracture Repair
Blood escapes from damaged blood vessels and forms a hematoma.
Spongy bone forms in regions near blood vessels and fibrocartilage forms farther away.
A bony callus replaces the fibrocartilage.
Osteoclasts remove excess bony tissue, restoring new bone much like the original.

8. 1 STEP Immediately after the fracture, extensive bleeding occurs. Over
Bone
fragments
Fracture
hematoma
Dead
bone
Immediately after the fracture,
extensive bleeding occurs. Over
a period of several hours, a large
blood clot, or fracture hematoma,
develops.

9. 1 2 STEP Bone fragments Fracture hematoma Dead bone Spongy bone
of internal
callus
Periosteum
Cartilage
of external
New
An internal callus forms as
a network of spongy bone
unites the inner edges, and
an external callus of cartilage
and bone stabilizes the outer
edges.
Immediately after the fracture,
extensive bleeding occurs. Over
a period of several hours, a large
blood clot, or fracture hematoma,
develops.

10. 1 2 3 STEP Bone fragments Fracture hematoma Dead bone Spongy bone
of internal
callus
Periosteum
Cartilage
of external
New
Internal
External
An internal callus forms as
a network of spongy bone
unites the inner edges, and
an external callus of cartilage
and bone stabilizes the outer
edges.
The cartilage of the external
callus has been replaced by
bone, and struts of spongy
bone now unite the broken
ends. Fragments of dead
bone and the areas of bone
closest to the break have
been removed and replaced.
Immediately after the fracture,
extensive bleeding occurs. Over
a period of several hours, a large
blood clot, or fracture hematoma,
develops.

11. 1 2 3 4 STEP Bone fragments Fracture hematoma Dead bone Spongy bone
of internal
callus
Periosteum
Cartilage
of external
New
Internal
External
An internal callus forms as
a network of spongy bone
unites the inner edges, and
an external callus of cartilage
and bone stabilizes the outer
edges.
A swelling initially
marks the location
of the fracture.
Over time, this
region will be
remodeled, and
little evidence of
the fracture will
remain.
The cartilage of the external
callus has been replaced by
bone, and struts of spongy
bone now unite the broken
ends. Fragments of dead
bone and the areas of bone
closest to the break have
been removed and replaced.
Immediately after the fracture,
extensive bleeding occurs. Over
a period of several hours, a large
blood clot, or fracture hematoma,
develops.

12. Clinical Note – A Classification of Fractures

13. Clinical Note – A Classification of Fractures