Osseous Tissue

Discuss the importance of bone remodeling, making sure to mention Wolff's Law.

>1/5 of the Adult skeleton is recycled and replaced each year. >exercise is essential in maintaining normal bone structure >Wolff's Law of bone- architecture of bone determined by mechanical stresses *action of osteoblast and osteoclasts

Compare and contrast the following in regards to calcitriol, calcitonin, and PTH (Parathyroid Hormone) : How the rise or fall of calcium levels in the blood will affect the release of these hormones. In other words, be able to predict how hypocalcemia and hypercalcemia are corrected,

>Calcitirol- corrects hypo >Calcitonin- corrects hyper >PTH- corrects hypo

Compare and contrast the following in regards to calcitriol, calcitonin, and PTH (Parathyroid Hormone) : What each of these hormones does, including target organs/regions of the body for each hormone.

>Calcitirol- increases intestinal absorption of calcium, promotes urinary re-absorption of calcium ions. >Calcitonin- reduces osteoclast activity up to 70%, increases the number and activity of osteoblasts >PTH- increases osteoblast population, promotes calcium re-absorption by the kidneys, inhibits collagen synthesis and bone deposition by osteoblast

Compare and contrast the following in regards to calcitriol, calcitonin, and PTH (Parathyroid Hormone) : Where each hormone is produced

>Calcitriol- UV radiation, epidermal keratinocytes; liver; kidney >Calcitonin- thyroid gland >PTH- 4 glands on posterior surface of the thyroid

Compare and contrast the following in regards to calcitriol, calcitonin, and PTH (Parathyroid Hormone) : How each hormone is produced (especially if there are multiple steps).

>Calcitriol- when calcium is too low >Calcitonin- when calcium levels rise too high >PTH- when calcium is too low

Compare and contrast the types of bone found in the diaphysis and epiphysis of a long bone,

>Diaphysis- Shaft; contains compact bone >Epiphysis- ends of long bone; contains mostly spongy bone

Discuss some treatments for osteoporosis and why these treatments may be contradicted in some patients.

>ERT- increase risk of breast cancer, stroke, and heart disease.

What is the function of Haversian Canal and Volkmann's canal? What are other names for each of these canals?

>Haversian Canal- conatin blood vessels that run vertically >Volkmann's Canal- perpendicular to Haversian canal- carry blood vessels into bone and marrow

What does it mean that compact bone is homogeneous and spongy bone is heterogeneous?

>Homogeneous- strength in one direction >Heterogeneous- strength in multiple directions

Compare and contrast hypocalcemia and hypercalcemia, focusing on how each of these imbalances might present clinically

>Hypocalcemia- deficiency of blood calcium *causes excitability of nerves (suffocation) >Hypercalcemia- is an excess of calcium *sluggish reflexes (cardiac arrests)

Compare and contrast the roles of oesteocytes, osteoblasts, osteoclasts, and osteoprogenitor cells.

>Osteocytes- live in lacunae, do not divide, maintain the protein and mineral content of the matrix. >Osteoblasts- perform osteogenesis *make and release the proteins and other parts of the bone matrix *blasts=build >Osteoclasts- cells that break down bone matrix, large cells with approx 50 nuclei >Osteoprogenitor- stem cells that undergo mitosis, producing daughter cells that differentiate into osteoblasts *aid in the repair bone fractures *located in the endosteum (which lines marrow cavities)

Compare and contrast the process of osteogenesis and ossification

>Osteogenesis- bone formation >Ossification- the process of replacing other tissues with bone

Explain the importance of calcium and phosphate in the human body

>Phosphate- is a component of DNA, RNA, ATP, phospholipids, and PH buffers >Calcium- is needed in nervous, muscle contraction, blood clotting, and exocytosis

Identify common bone markings, using the proper anatomical terminology.

>Projections and processes- grown out from the bone surface >Depressions or cavities- indentation

List and describe the six functions of the bone.

>Support- supports body and cradles soft organs >Protection- fused bones of skull, vertebrae, rib cage >Leverage- skeletal muscles use bones as levers for movement >Mineral Storage- calcium and phosphate >Storage of Lipids- (yellow marrow)

Explain how a bone lengthens

An ossification spreads from the primary ossification site, the second ossification site begins. When the two connect, the bone can no longer continue to grow and creates epiphysial.

What are the two major divisions of the human skeleton?

Appendicular and axial

What exactly does appositional bone growth refer to?

Appositional bone growth is the compact bone thickening and strengthens a long bone with layers of circumferential lamellae *diameter

Describe the causes and symptoms of osteoporosis

Bones lose mass and become more brittle (loss of organic matrix and minerals)

What is the name given to the region of bone in which osteocytes within nutrition and allow the osteocytes to get rid of passageways?.

Canaliculi, they support the osteocytes with nutrition and allow the osteocytes to get rid of waste

Label the following regions of a long bone: Articular Cartilage

Covers the external surface of the epiphyses, made of hyaline cartilage, decreases friction at joint surfaces

Label the following regions of a long bone: Spongy Bone

Does not have osteons, the matrix forms an open network of trabeculae (have no blood vessels), not in areas of high stress, takes weight off of skeleton.

What is the functional unit of mature compact bone called?

Endochondral ossification

Label the following regions of a long bone: Epiphysis (proximal and distal)

Ends of the bone, composed mostly of spongy bone

List and describe some important factors affecting bone growth

Hormones, vitamins, puberty (boy or girl)

Describe in detail how osteoclasts break down bone. Using this knowledge, describe how braces work.

Hydrogen pumps into the cell membrane secrete hydrogen into space between the osteoclasts to remove bone surface. Braces- create more pressure on the side of tooth, stimulates osteoclasts to remove bone decreased pressure stimulates osteoblasts

What exactly does interstitial bone growth refer to?

Interstitial bone growth is the epiphysial cartilage being replaced by a new bone *length

Label the following regions of a long bone: Compact Bone

Lacunae, osteocytes, and canaliculi, Central Haversian canal (conatin blood vessels that run vertically) and performing Volkmann's (perpendicular to main canal, carry blood vessels to bone and marrow)

Compare and contrast ligaments and tendons.

Ligaments- bone to bone Tendons- muscle to bone

Label the following regions of a long bone: Metaphysis

Middle, where diaphysis and epiphysis meet

Which region(s) of a long bone is periosteum not found?

Periosteum is the thin yet tough outermost layer of bones, It covers the entire surface of every bone in the body, with the exception of the joint-forming ends of bones where cartilage forms the bone's outer layer

What type of marrow is found in the medullary cavity of children?

Red marrow

Label the following regions of a long bone: Sharpy's Fibers

Secure periosteum to underlying bone

Label the following regions of a long bone: Diaphysis

Shaft, compact bone

Label the following regions of a long bone: Epiphyseal Line

The line in long bones where the primary ossification site and the second ossification site meet.

List AND describe the chemical makeup of osseous tissue. Be generally familiar with the abundances of each of the components of bone.

-Dense supportive connective tissue -Contains specialized cells (only make up 2% of bone mass!!!) -Produces solid matrix of calcium salt deposits -Around collagen fibers -Matrix Minerals- 2/3 of bone matrix is calcium phosphate -Matrix Proteins- 1/3 of bone matrix is protein fibers (Type 1 collagen)

describe in words examples of the six classifications of bones.

1> Long bone- shaft and two ends 2> Short bone- cube-like and contain mostly spongy bone 3> Flat bone- thin bone with thin layers of compact bone over a layer of spongey bone 4> Irregular Bone- does not fit into any category (vertebrae, patella, and hips) 5> Sutures- small irregular bones 6> Sesamoid bones- small and flat (develop inside tendons near joints of knees, hands, and feet)

What type of marrow is found in the medullary cavity of adults?

Yellow marrow