lectures 3 Flashcards

Question

Bone growth in children

Answer 1

``` High velocity (cm/year) in children Varies depending on age Puberty = fastest rate of growth ```

Answer 2

osteoblastic activity In lab - use enzyme ALKLAINE PHOSPHATASE as a marker of osteoblastic activity Highest levels of ALP at birth and puberty

Answer 3

Mid-diaphyseal, bone is bent such as to damage the CONVEX surface, fracture is INCOMPLETE

Answer 4

Bone buckles but the integrity of the surface of the bone on convex side is maintained Eg like bending a piece of cardboard Fractures don’t usually need treatment and bone will remodel over time

Answer 5

``` Fractures including the growth plate S- seperated growth plate A= above grwoth plate L= below growth plate T= through grwoth plate ER= erasure of grwoth plate ```

Answer 6

``` Osteomalacia in adults Prematurity Nutrition Maternal vit D deficiency Lack of sunlight ``` Features worst where growth is GREATEST e.g. long bones

Answer 7

Inevitable loss of muscle mass and strength that occurs in ageing muscle Gradual loss Muscle replaced by fat ``` Loose motor neurones Fewer motor units with more muscle fibers causing loss of coordiantion Slow muscle reflex Bad coordination Higher chance of fall ```

Answer 8

REDUCED physical activity Nutritional, hormonal, metabolic and immunologic factors Decreased motor units and muscle fibers – muscle fiber atrophy

Answer 9

begins as you lose bone mass and your bones get weaker. This happens when the inside of your bones become brittle from a loss of calcium. It's very common as you age BONE LOSS, reduced bone mineral density ( BMD), micro architecture deterioration Bones become more fragile Vertebrae wrist and hip are most at risk Previous fracture increases risk of future fracture

Answer 10

Stimulate bone formation Hormone levels decrease with age Menopause: bone loss becomes twice as fast in women = loss of hormones Effect is systemic ( so other factors operate) Hormone replacement therapy ( hrt) reverses some of effects of menopause Hormones also affect bone via muscle – increased muscle = increased bone

Answer 11

Inadequate dietary calcium is a problem Vitamin and sunlight help Alcohol and smoking can decrease bone mass Low body weight increases risk of low BMD Diet has less effect than genes, hormones and exercise

Answer 12

Cell content/morphology changes Collagen cross links increase and mature – become non reducible – brittle Non enzymic glycation ( NEG) makes tissue yellow and stiffer Microdamage accumulated and makes tissue weaker Cells become less responsive to mechanical stimuli Ligaments get stiffer

Answer 13

fibrous connective tissue which attaches muscle to bone. Tendons may also attach muscles to structures such as the eyeball.

Answer 14

fibrous connective tissue which attaches bone to bone, and usually serves to hold structures together and keep them stable

Answer 15

Elongated cells with long processes

Answer 16

Tenoblasts/fibroblasts - fat

Answer 17

tenocytes/ fibrocytes - thin

Answer 18

Collagen is main component of connective tissue Cross links increase tissue strength and stiffness Non enzymatic glaycation( NEG ) makes tissues brittle and yellow NEG uncontrolled by cells – problem In tissues with LOW turnover Cross links are REDUCIBLE in young tissue and NON REDUCIBLE in mature tissue

Answer 19

Decreased proteoglycan content Decreased aggregation of PGs Increased collagen content and cross linking Increased levels of non enzymatic glycation Increased apopotosis Increased stiffness and decreased flexibility

Answer 20

Produce and maintain Cartlidge Cartlidge cell density decreases with age Chondrocytes stop dividing at skeletal maturity

Answer 21

LOSS OF HYDRATON Leak out Damaged Degraded

Answer 22

Anterior region of traceulae most affected Porous Less connected Leads to kyphotic deformity

Answer 23

look WHITE absorb alot of rays