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Objectives 5-7
Fichas del conjunto (42)
- 1Osteogenesis (Ossification)process of bone formation
- 2What is it necessary for?formation, growth, and remodeling of the skeleton
- 3Interstitial growthincrease the number of cells and matrix from within tissue
- 4Appositional growthincrease number of cells and matrix by adding to a surface
- 5Perichondriumdense CT sheath covering cartilage (except articular cartilage)
- 6Alkaline phosphateenzyme produced by osteoblasts and chondroblasts that makes phosphatases available for the mineralization of bone
- 7Woven bonealso called immature or primary bone; lacunae are disordered and the matrix contains large amounts of thick, irregular collagen fibers, will be reorganized into lamellar bone
- 8When does intramembranous ossification begin?around 6th - 8th week of gestation
- 9What membrane model formed during intramembranous ossification?- mesenchymal cells proliferate and generate a fibrous membrane
- mesenchymal differentiate into osteoblasts - 10What bones are formed during intramembranous ossification?flat bones of the skull, clavicles
- 11Stages for Intramembranous Ossification1) Osteoblasts secrete osteoid
2) Osteoid calcifies
3) Osteoblasts become osteocytes
4) Osteoid from adjacent centers fuse and form trabeculae
5) periosteum develops
6) woven bone collar forms deep to periosteum, will become lamellar bone - 12"General plan" of Endochondral Ossification1) Cartilage is formed
2) Cartilage calcifies
3) Cartilage matrix deteriorates
4) Cartilage is replaced by bone tissue - 13Development of the Hyaline Cartilage Model- hyaline cartilage model is generated that has the shape of the future bone
- the model enlarges using interstitial growth - 14Bone collar formation- the diaphyseal perichondrium becomes vascularized and osteoprogenitor cell arise
- periosteal osteoblasts deposit bone around the periphery of the diaphysis forming a "bone collar"
- the "perichondrium" is now a "periosteum" - 15Loss of Cartilage in the Central Diaphysis- chondrocytes in the mid-diaphysis hypertrophy
- chondrocytes secrete alkaline phosphatase
- the cartilage matrix becomes calcified
- chondrocytes are isolated form nutrients so they die
- the cartilage matrix deteriorates - 16Deposition of Bone in the Central Diaphysis- during the 3rd month, a "periosteal bud" invades the mid-diaphysis
- osteoblasts in the periosteal bud deposit bone matrix over the spicules of deteriorating cartilage matrix
- AKA "primary center of ossification" - 17Periosteal budincludes NAVALs, osteoclasts, osteoblasts, and red marrow elements
- 18Formation of the Medullary Cavity- spongy bone forms in the center of the diaphysis
- osteoclasts then degrade the spongy bone
- the resulting space is the "medullary cavity"
- the cartilage model elongates during this period
"ossification" chases "cartilage formation" - 19Ossification of the Epiphysis- at various times after birth, the epiphyses ossify
- AKA "secondary centers of ossification" - 20Steps for ossification of the epiphysis1) Cartilage cells hypertrophy
2) Cartilage matrix becomes calcified
3) Cartilage cells die (lack nourishment)
4) A periosteal bud invades
5) Osteoblasts produce bone matrix
6) Spongy bone forms and persists - 21Hyaline cartilage remains where in two places?1) Articular cartilage
2) Epiphyseal plate - 22Longitudinal growthgrowth of bones in length, interstitial growth at the epiphyseal growth plate
- 23Label each point (zones) and what happens here1) Growth (proliferation) zone: mitosis of cartilage cells
2) Hypertrophic zone: cartilage cells enlarge
3) Calcification zone: cartilage cells die and matrix is calcified
4) Ossification zone: bone formation - 24Growth in diameter is an example of what kind of growth?Appositional growth
- 25What does growth in diameter involve?endosteal osteoclasts and periosteal osteoblasts
- 26What is growth hormone secreted by?secreted by the anterior portion of the pituitary gland.
- 27What is thyroid hormone secreted by?thyroid gland
- 28What is estrogen and testosterone secreted by?the gonads
- 29Thyroid Gland - Anatomy- Anterior neck
- Inferior to the thyroid cartilage
- 2 lateral lobes connected by an isthmus
- 30What secretes hypothalamus, pituitary, and thyroid? What is release regulated by?1) Hypothalamus secretes TRH
2) Pituitary secretes TSH
3) Thyroid secretes T3 & T4
4) Release regulated by a negative feedback mechanism
- 31What are the effects of thyroid hormone on growth?1) Modulates growth hormone activity
2) Stimulates osteoblasts
3) Increases metabolic rate
4) Increases mitochondrial activity
5) Stimulates carbohydrate, protein, and lipid metabolism - 32What are the effects of estrogen/testosterone?1) At puberty, stimulates osteoblasts
2) At the end of growth, stimulates closure of the epiphyseal plate - 33What are the nutritional requirements of skeletal growth?1) Vitamins A, B12, C, & D
2) Minerals calcium, phosphorous, fluoride, magnesium, iron
3) Weight-bearing exercise - 34Bone remodelingRefers to a continuous process of bone resorption (degradation) and bone deposition.
- 35What happens during Bone Resorption?1) osteoclasts secrete lysosomal enzymes which degrade osteoid and acids which demineralize the bone
2) bone resorption is enhanced in acidosis and by excess vitamin A and parathyroid hormone
3) bone resorption is suppressed by estrogen, calcitonin - 36What happens during Bone Deposition?1) osteoblasts osteoid seam
2) calcification occurs if there is enough Calcium & phosphate; also needed are alkaline phosphatase, osteocalcin
3) glucocorticoids (cortisol) inhibit osteoblasts
4) nutritional requirements for bone deposition include proteins, vitamin D, vitamin A, and minerals - 37What does Parathyroid Hormone (PTH) increase?1) Increases osteoclast numbers
2) Increases intestinal calcium absorption (via Vitamin D)
3) Increases resorption of calcium by the kidneys - 38What does Calcitonin secreted by, inhibits, and encourages?secreted by C cells of the thyroid gland, inhibits osteoclasts, and encourages Calcium deposition into bone
- 39What are the targets of PTH (Parathyroid Hormones)?1) Bone (increased osteoclast activity)
2) Kidney (less calcium lost in urine, vitamin D produced)
3) Intestine (increased calcium absorption from diet) - 40What is Wolff's Law?bone tissue grows in response to stress in order to produce a structure that is best able to accommodate the applied forces weight, pull of ligaments and tendons increases bone deposition
- 41What happens in the stretched region?positive charges are generated
- 42What happens in the compressed region?negative charges are generated and osteoblasts produce bone tissue here
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- 203 (Topic 3) Anatomy and Physiology Fichas sobre Objectives 5-7, creado por Cherry Mae el 14/03/2016.
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- Cherry Mae · mar 2016
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