Bone, Cartilage, Joints

Front 1

Functions of Bone (6)

Back 1

1. framework, support, protection
2. blood cell production
3. mineral homeostasis
4. attachment for muscles (movement)
5. fat cell storage
6. plasticity

Front 2

responsible for lengthening of bone

Back 2

epiphyseal plate

Front 3

spongy bone

Back 3

cancellous
- lines of stress, trabecule

Front 4

Cell Types

Back 4

osteoprogenitor
osteoblasts
osteocytes
osteoclasts

Front 5

Bone Matrix

Back 5

matrix- water 25%, protein (collagen) 25%, mineral 50%

mineral - mostly Ca salts, hydroxyapatite

Organic (osteiod) - collagen fibers embedded in amorphous ground substance (proteoglycans, glycoproteins) - not full minerlized --> flexible

inorganic bone w/o collagen --> brittle

Front 6

bone development

Back 6

1. intramembranous ossification - no cartilage used

2. endochondrial ossification - cartilage model is used

Front 7

intramembranous ossification - no cartilage used

Back 7

1. very loose well vascularized tissue bed
2. osteoprogenitor cells
3. differentiate into osteoblasts
3. deposition of bone, osteoblasts become osteocytes
4. white part (osteiod) not fully calcified

Front 8

Osteiod

Back 8

fresh deposition of bone in well vascularized connective tissue bed by osteoblast, not fully calcified

Front 9

Endochondrial Ossification - hyaline cartilage model is used

Back 9

1. Cartilage is produced by chondrocytes, surrounded by perichondrium except where joints will form
2. the perichondrium of the diaphysis becomes the periosteum and a bone collar is produced
- internally, chondrocytes hypertrophy (intestitial growth) and calcified cartilage is formed
4. primary ossification center forms as blood vessels and osteoblasts invade the calcified cartilage
5. process of bone collar formation, cartilage calcification, and cancellous bone production continues - calcified cartilage forms epiphysis, medullary cavity forms in center of diaphyses
6. secondary ossification center begins to form in epiphysis of long bones
7. original cartilage model is almost completely ossified - except epiphyseal plate and articular cartilage
8. in mature bone, epiphyseal plate becomes the epiphyseal line - only articular cartilage left

Front 10

Osteon - histology of compact bone

Back 10

- central canal (haversion) - blood supply to osteocytes and nutrients to reach cells by diffusion within canaliculi
- osteocytes - in lacuna
- canaliculi - canals in matrix, extends to where blood supply is (tissue fluid, gas exchange, osteocytes not isolated)
- concentric lamellae

Front 11

Cartilage composition

Back 11

- chondrocytes in lacuna
- matrix of water, collagen fibers, and ground substance (3 GAGs - hylauronic acid, chondroitin sulfate, keratin sulfate) - squishy
- lacks calcified inorganic component
- interstitial growth via daughter cells (isogenous groups)
- hyaline cartilage
- perichondrium

Front 12

Cartilage Functions (5)

Back 12

1. flexibility and support
2. reduces friction and absorbs shock at joints
3. provides strength and elasticity
4. maintains shape of certain organs
5. essential for growth of long bones

Front 13

Bone vs Cartilage

Back 13

1. basic cells
2. blood supply
3. ability to repair
4. blast cells
5. remodeling

Front 14

what disorder of abnormal bone formation caused by inherited disorder of connective tissue

Back 14

fibrodysplasia ossifican progressiva
- ectopic bone present
- excess production of morphogenetic protein 4

Front 15

abnormal bone formation caused by defect in mineralization of bone matrix

Back 15

Rickets
- lack of vit D (necessary for absorption of calcium)
- bone remodeling is defective, bulgy of bent long bones

Front 16

Osteoporosis

Back 16

- loss of bone mass, increased bone porosity, leading to fragility and susceptibility to hip and spinal fractures - deterioration of vetebral support
- due to deficiency of estrogen noted in postmenopausal females
- balance between bone formation and resoprtion is disturbed - increased osteoclast

Front 17

Osteoarthritis

Back 17

- age related deterioration of cartilage and joint, bone against bone
- non inflammatory, degenerative wear and tear
- osteophytes (bone spurs)
- just pain, no swelling

Front 18

Rheumatoid Arthritis

Back 18

Autoimmune, inflammatory response in synovial fluid
- pannus (synovial membrane) inflammation
- red, swollen, painful
- ankylosis - joint stiffness

Front 19

Joint types

Back 19

- ball and socket
- gliding
- suture
- hinge

Front 20

Bone types

Back 20

- long
- short
- irregular
- flat

Front 21

Joint functions

Back 21

1. allow for varying degree of motion between 2 or more bones
- united by cartilage, CT, or synovial fluid
- major motions: flexion, extension, abduction, adduction, rotation

Front 22

Synovial Fluid

Back 22

- encapsulated by CT = joint capsule - synovial membrane (Pannus) and fibrous capsule
- lubricant - synovial fluid formed as an ultrafiltrate from blood - thick viscous material lubricates synovial joints, reducing friction between articular cartilage and cushioning joints
- supply oxygen and nutrients to chondrocytes of articular cartilage and removes CO2 and waste products
- added to filtrate by cells in membrane are - hylauronic acid, lubricin, prpteinases, collagenases

Front 23

Bursitis

Back 23

Bursae - more lubrication for joints, fluid filled sac to allow tendons to slide over bones

Bursitis - inflammation of bursae

Front 24

Gout

Back 24

- deposit of uric acid crystals in joints (usually big toe)
- acute inflammation and articular cartilage damage plus swelling and pain

Front 25

Cretinism

Back 25

congenital hypothyroidism
- iodine deficiency, nonfunctional or absent thyroid
- severe impairment of all aspects of growth

Front 26

Gigantism

Back 26

abnormally high secretion of growth hormone from pituitary gland at any age prior to closure of growth plate (epiphyseal plate)
- pituitary tumor or increased secretion of hypothalamic GHRH
- very tall

Front 27

Acromegaly

Back 27

disorder of excess GH in adults
- hands, feet, face enlarge
- lower jaw protrudes
- arthritis

Front 28

Dwarfism

Back 28

- abnormally short stature
- can arise from genetic or other conditions
- GH deficiency, not bioactive GH, hypothalamus inactivity to not signal pituitary to release GH properly
- bony deformities common