Chapter 7 Lecture!
Put the cycle of intramembranous ossification in order.
trabeculae formed, which spread out from primary ossification center and angiogenesis occurs
developing of crystal occurs, and developing of primary ossification in cutaneous membrane
calcium and phosphate deposit in osteiod
spongy bone will be inside with blood supply, compact bone on outside, and outside of that we have our periosteum with osteoblasts, osteoblasts, osteoprogenitors (form around bone)
1. developing of crystal occurs, and developing of primary ossification in cutaneous membrane
2. calcium and phosphate deposit in osteoid
3. trabeculae formed, which spread out from primary ossification center and angiogenesis occurs
4. spongy bone will be inside with blood supply, compact bone on outside, and outside of that we have our periosteum with osteoblasts, osteoblasts, osteoprogenitors (form around bone)
Which type of growth involves having new undifferentiated stem cells and having new chondroblasts formed?
appositional growth, which is most of our bone growth in the future
Where is the hormone calcitonin released from?
They are released from parafollicular cells of the thyroid, released in response to high Ca++ levels in the blood and inhibits resorption of bone.
Which leg bone doesn't participate in our knee joint?
The fibula (has lateral malleous), and it's on the lateral side.
1. Lubricant, which has slippery hyaluronic acid and provides our nutrients to articular cartilage (remember cartilage doesn't have a strong blood supply)
2. Vehicle for nutrients/wastes, which its circulation is driven by joint movement (apply that we either use/lose it principle since no movement can lead to stiffness/degeneration)
3. Shock absorption (especially at knee since we get a lot of compression)
Significance of phosphate and calcium?
Phosphate is used to make ATP and phospholipids in the plasma membrane.
Calcium is used for muscle contraction, blood clotting and nerve impulse transmission.
What are the zones of growth pertaining to our epiphyseal plate?
zone of resting cartilage: anchors plate growth to bone, which is where some mitotic division will occur
zone of proliferating cartilage: cartilage pushes from bone and we get rapid cell division
zone of hypertrophic cartilage: maturing of cartilage, and enlarged cells
zone of calcified cartilage: matrix calcifies and cells die; osteoclasts are on surface and we have osteoblasts create bone over calcified cartilage model
What is a key feature on the os coxae that allows transfer of mechanical stress to femur?
The bony conduit, also known as the arcuate line (can be seen on the medial side of innominate), and that transfers the weight of the body to the acetabulum and femur.
What is considered our weakest synovial joint and why?
The glenohumeral joint because it is also considered our most moveable joint. The principle of the greater the mobility of the joint is, the weaker it will be.
What is an example of our atlanto-axial joint?
our "no joint", done through our C2 axis vertebra
What's significant about our epiphyseal line?
It stems from our epiphyseal plate, which is critical to our bone growth, and that thin compact bone line is a remnant of the plate which appears as we stop growing.
What is required for bone formation to occur?
Calcium, Phosphate, Trace Ions, Vitamin A, Vitamin C, Calcitriol (Vitamin D)
Regulatory Hormones like Calcitonin and PTH (controls Ca++ levels in blood)
Other hormones: growth hormone, thyroxine, estrogen, testosterone, glucocorticoids (more about these in 67B)
What are the hormones involved with concentration levels of Ca++ in blood?
PTH, also known as parathyroid hormone, and it will respond to low levels of Ca++ in blood; stimulates osteoclast and osteoblast activity
Calcitonin, which responds to high levels of Ca++ in the blood; inhibits osteoclast activity
This special movement type is described as moving a body part anteriorly. What type of movement is this?
Protraction, like protracting your jaw when you pout
What type of joint movement is considered "immovable"?
synarthroses; in our sutures (skull bones) and gomphosis which is a joint between the teeth and aveoli/ maxilla/ mandible
What type of bones utilize intramembranous ossification?
flat bones in skull, mandible, some facial bones, central clavicle
State the order of our bone remodeling cycle.
Activation, Reabsorption, Inversion/Reversal, Formation, Quiescence
Which type of growth involves angiogenesis (blood vessels entering cavity) occurring in periosteum and osteoblasts migrate to cavity, becoming the primary ossification center?
What types of movement are allowed by our ball and socket gleno humeral joint?
allows flexion, extension, abduction, adduction, medial and lateral rotation, circumduction of the arm
What are factors that influence mobility of our joints?
- shapes of articulating surfaces
- the presence/ absence of other bones, muscles, fat pads around joint
- accessory ligaments/ fibers of joint capsule
- tension of muscles (tendons), insertions and origins at joint
What components are in our bone matrix and why is it important to have that balance?
The organic part is comprised of osteoid, our uncalcified bone matrix, produced by osteoblasts. This gives us our bone strength, allows resistance of stretching, and flexibility.
The inorganic part includes mainly hydroxyapatite and other salt crystals, which provides stiffness.
Having the proper balance of our organic and inorganic components allow proper functioning when it comes to strength, flexibility, and stability.
How do we heal bones from a fracture?
1. Bone is vascular, and has a hetatoma (swelling of clotting blood in tissues) which forms between the 2 fragments
2. Bone will use both endochondral and intramembranous ossification
3. Hormone signals and new formation of blood vessels leads to an external callus of fibrocartilage and internal callus of spongy bone
4. External callus gets replaced by spongy bone and trabeculae come together to join ends of fracture
What type of joint allows opposition?
The saddle joint, (which is the movement of the thumb against other fingertips of the palm) between the trapezium and metacarpal bone 1, the pollex.
What are the rotator cuff muscles that hold the head of humerus into the glenoid cavity of our scapula?
supraspinatus, infraspinatus, teres minor, subscapularis
Give an example of a hinge joint and the movement involved.
knee and elbow, movement in 1 plane occurs. flexion/ extension in elbow and knee