BONES TEST 2 Flashcards
know the classifications of bones ?
• Flat bone - flattened and bit curved (cranial bones) shoulder blades breeastbone
• Long bones - longer than they r wide. arm forearm fingers palm
• Short bones - cube shaped bones wrist bones
Irregular bones - complex shape (vertebrae , coxal, facial bones
whats the anatomy of skeletal cartilage?
• Perichondrium - wrapping around cartilage
○ 2 layers
§ Fibrous - outer layer
§ Chondrogenic - inner layer (genic means to make)(chondro means cartilage) making cartilage
• Periosteum - wrapping around bone
• 3 types of cartilage all hav chondrocytes trapped in lacunae
○ Hyaline - most abundant Smooth and glossy
§ 4 types
□ Nasal - nose (hav perichondrium)
□ Articular - end of long bones (no perichondrium)
□ Respiratory - Larynx air passage ways (hav perichondrium)
□ Costal - attaches ribs to sternum (hav perichondrium)
○ Elastic - more rare and always hav perichondrium
§ Ear
§ Epiglottis
○ Fibro - Highly compressed for great tensile strength (No perichondrium)
§ Meniscus of the knee
§ Pubic symphysis
§ Intervertebral discs
what the functions of bones ?
- Support - framework of the body
- Movement - providing levers for muscles
- Mineral storage - stores calcium and phosphate
- Protection - organs
- pH balance - buffer
Blood formation - “hematopoiesis
define and describe the dif. types of marrow ?
Red - Red blood cells contain reticular ct and r immature blood cells / fat
Red marrow in children is in all marrow cavities and spongy bone of children
In adults red marrow found in spongy bones toward ends of bones and in some axial skeleton(flat bones, vertebrae, ribs, sternum)
red blood cells degenerate and turn into yellow marrow
Yellow - consists of adipose tissue and in adults for a source of fuel / food for a crisis . Yellow can convert back to red marrow to get passed the crisis
Found in the marrow cavities of adults
what r the organic and inorganic ratios and what r they made of?
○ Organic components: give flexability
§ Osteoblasts - forming bone cells
§ Osteocytes - mature bone cells
§ Osteoclasts - lg cells tht resorb or breakdown bone matrix
§ Osteoid - unmineralized bone matrix composed of proteoglycans, glycoproteins and COLLAGEN
○ Inorganic components: give a hardness strength and resistance to compression
§ Hydroxyapetites , or mineral salts
§ 65% of bone by mass
§ Mainly calcium phosphates
§ Responsible for bone hardness and its resistance for compression
what r the dif. types of bone disease and describe them
- Osteomalacia - Dec. in minerals (in adults)
a. Could b from diet or the lack of ability to absorb it.
b. lack of vitamin d, bones more likely the bow and fracture- Osteoporosis - dec. in bone mass making them easy to break.
a. where the creation of new bone doesnt keep up with the removal of old bone - Rickets - Dec. in minerals (in children)
a. Could b from diet or inability to absorb it. - Osteogenesis imperfecta - Dec. in collagen
a. Brittle Bone Disease
i. Dec. synthesis of collagen
1) Hereditary - Achondroplastic dwarfism (a - not / lack of, chondro - cartilage)
a. Lack of cartilage within the epificiel plate long bones - Pituitary dwarfism (growth hormone deficiency)
a. Tiny but proportioned short legs, ribs, arms,… etc.
- Osteoporosis - dec. in bone mass making them easy to break.
anatomy and function of long bone? pg 21
a
describe the anatomy and where osteons r found ?
• Osteon - structural unit of compact bone
○ Concentric Lamella - weight-bearing column-like matrix tubes composed mainly of collagen.. Circular layers w/ fibers going in perpendicular patterns for strength
○ Central canal - central channel containing blood vessels and nerves to supply the bone
○ Perforating canals - channels lying at right angles to the central canal, connecting blood and nerve supply of the periosternum to tht of the central canal (deep to the bone)
○ Circumferential lamella - surrounds the internal part of bone in ring formation
○ Interstitial lamella - is in between each osteon
○ Lacunae - small cavities in bone tht contain osteocytes
○ Canaliculi - hair like canals tht connect lacunae to each other and the central canal
○ Osteocytes - mature bone cells trapped osteoblasts sense stress in the bone they r located in lacuna insect looking things w/ tentacles. They r connected by gap junctions
○ Canaliculi - hair like tentacles tht connect other lacunae to each other as well as the central canal
basic anatomy of flat bone?
• Compact bone spongy bone compact bone • Periosteum then compact spongy(diploe) compact • Periosteum contains 2 layers ○ Osteogenic ○ Fibrous layers § Dense irregular ct § Protects bone § Anchors blood vessels and nerves § Attachment for ligaments Inner layer consists of osteoprogenitor cells osteoclasts / blasts
compare appositional / interstitial growth.?
Appositional growth - is an inc. in width along the cartilages outsice edge or periphery
- undifferentiated stem cells at the internal edge of perichondrium begin to divide
- new undifferentiated stem cells and committed cells tht differentiate into chondroblasts are formed . these chondroblasts are located at the periphery of the old cartilage where theu begin to produce and secrete new cartilage matrix
- the chondroblasts as a result of matrix formation push apart and become chondrocytes . with each occupying its own lacuna . the cartilage continues to grow at the periphery as chondrocytes continue to produce more matrix
interstitial growth occurs within the internal regions of cartilage through the following series of steps
- chondrocytes housed within lacunae are stimulated to undergo mitotic division
- following cell division two cells occupy a single lacuna ; they now r called chondroblasts
- as chondoblasts begin to synthesize and secrete new cartilage matrix , they r pushed apart . these cells now reside in their own lacuna and are called chondrocytes
- the cartilage continues to grow in the internal regions as chondrocytes continute to produce more matrix
describe the steps of Endochondral and intramembranous
Intramembraneous ossification - makes flat bones / clavicles
1. Ossification centers form within thickened regions of mesenchyme
2. Osteiods undergoes calcification
3. Woven bone and its surrounding periosteum form
4. Lamellar bone replaces woven bone as compact bone and spongy bone form and red marrow form
Endochondral ossification- makes long bones
1. hyaline cartilage model developes
2. Cartilage calcifies and periosteal bone collar forms
3. Primary ossification center forms in the diaphysis
4. Secondary ossification centers form in the epiphyses
5. Bone replaces almost all cartilage except the articular cartilage and epiphyseal cartilage
6. Lengthwise growth continues until the epiphyseal plates ossify and form epiphyseal lines.
explain the following in bone growth , maintenance and calcium homeostasis?
- Epiphyseal plates . Grows bone lengthwise until theres no more cartilage. Turns into epiphyseal line. Uses calcium to build up bone
- Osteoblasts - use calcium to build up bone
- Osteoclasts - break down bone and release calcium into the blood stream
- Calcitonin - Dec. calcium in blood by:
a. Comes from thyroid gland or parathyroid gland
b. Stimulating osteoblasts and Inhibiting osteoclasts
c. Weak effect in adults - Parathyroid - Inc blood calcium
a. Stimulates osteoclasts
b. Works w/ calcitriol help kidneys to not secrete via urinary
describe the process in bone deposition and bone resorption?
• Deposition
○ Osteoblasts lay down collagen in a helical pattern, hydroxyapatite crystals from on the collagen only if calcium and phosphate lvl solubility product
§ U need enuf calcium and phosphate and hav the solubility product must b met for this to work..
○ Calcium and phosphate form hydroxyapetite seed crystals which cause more minerals to deposit forming more hydro.. Making more come out of solution etc.positive feed back it pushes further away from homeostasis
○ This happens wen bones r stressed or for storage
• Resorption
○ Wen we don’t stress the bones or the dietary rqment met.
○ This happens wen osteoclasts use lysosmal enzymes and acidic secretions
○ Negative feedback
y is calcium so important in the body? hypo / hyper calcemia
• Calcium allows for the strength of a bone the inorganic compund • Hypocalcemia - too low muscle spasms • Hypercalcemia - too high sluggish muscle • • Calcium is necessary for ○ Transmission of nerve impulses ○ Muscle contraction ○ Blood coagulation ○ Secretion by glands and nerve cells ○ Cell division
explain how bone fractures heal
4 stages
1. Hematoma formation
○ Torn blood vessels hemorrhage
○ A Mass of clotted blood forms at the fracture site
○ Site becomes swollen, painful and inflamed
2. Fibrocartilaging callus forms
a. Granulatuion tissue (soft callus) forms a few days after the fracture
i. Fibroblasrs secrerte collagen fibers tht connect the bone
ii. Osteoblasts begin forming spongy bone and collagenous matrix tht later calcifies
b. Capollaries grow into the tissue and phagocutic cells begin cleanig debris
3. Bony callus formation
a. Osteoblasts and calsts
b. New bone trabeculae appear in the fibrocatilaginous callus
c. Fibrocartilaginous callus converts into a bony callus
d. Bone callus begin 3-4 weeks after injury and continues until firm union is formed 2-3 months later
4. Bone remodeling
a. Osteoblasts and calsts
b. Excess material on the bone shaft exterior and in the medullary canal is removed
c. Compact bone is laid down to reconstruct shaft walls
