1. Module 1- Skeletal Physiology

Question 1

What are bones used for?

Answer 1

Protection

Standing/support

Movement

Regualtion of calcium and phosphurus

Blood cell production

Defends against acidosis

Conducts sound in inener ear

Question 2

How are bones classified

Answer 2

Long bones (e.g. humerues)

Flat bones (e.g. sternum)

Flat bones (e.g. carpal bones)

Irregular bones (e.g. vertebrea)

Sesamoid bones (e.g. patella)

Question 3

What is the periosteum?

Answer 3

Fibrocarltilage layer of bone

Question 4

Where is articualr cartilage found?

Answer 4

At either end of bone, allows for smooth gliding of bones

Question 5

Where is yellow bone marrow found?

What is its function?

Answer 5

Diaphysis (middle)

Mainly contains fat cells

Question 6

Where is red bone marrow found?

What is its function

Answer 6

Metaphysis (top)

Production of red blood cells

Question 7

What are the anatomicla regions of bone

Answer 7

Epihysis- outer region of bone

Diaphysis- middle region of bone

Metaphyis- area between epiphysis and diaphysis

Question 8

What is cortical bone?

Answer 8

Hard outer shell

Question 9

What is trabecular bone?

Answer 9

lightweight network of bone foudn in the inner region

Question 10

How are flat bones formed?

Answer 10

Begins as a fibrous plate and then differntiates fro, fibroblasts and haemopoietic precursors

There is no cartilaginous phase

Question 11

Describe the formaiton of long bones

Answer 11

Forms as cartilage

Blood vessels invade cartilage (through osteogenic cells)

Cartilage remains in growth plate (only have epiphysis and diaphysis)

Growth plate fuses and turn into bone

Question 12

What are bones made of?

Answer 12

48% mineral
31% organic
21% water

(roughly)

Question 13

What is meant by bone minereal?

Answer 13

Hydroxyapatite

Provides ridgitity

Question 14

How does minerealization occur?

Answer 14

Old bone is laid down from the edge and minerlized in the center

Question 15

What is the organic section of bone made of?

Answer 15

Type 1 collagen

Triple helxi protein with two alpha 1 and one alpha 2 chains

Combine to make fibrils and fibrils make fibres

Question 16

How is water stored within the bone?

Answer 16

May be foudn in pores between haversian canals

May be found loosely bound (elasticity with collagen)

Might be found tightly bound

Question 17

How does the water contnet of bone change as you get older?

Answer 17

More loosely bound water when youre young

More tightly bound water when youre old

Question 18

What are the three key cells that maintain and repair bones?

Answer 18

Osteoclasts- multinuclear bones. Cut bone

Osteblasts- build new bone. Works together

Osteocytes-Sensors of mechanical load. Influence osteoblasts and clasts

Question 19

Where do the repair cells come from

Answer 19

Osteblasts and osteocytes come from mesenchymal stem cells

Osteoclasts come from haemopoietic stem cells

Question 20

Describe how osteoblasts build bone

Answer 20

Lay down osteoid (uncalcified bone matrix)

Calcifies after around 10 days

Question 21

How do osteoblasts function help with their biosynthetic function?

Answer 21

Rich in endoplasmic reticulum and golgi apparatus (protein synthesis)

Question 22

How do osteoclasts cut bone?

Answer 22

Form an F actin ring within the cell to seal off the area

Use acid and enzymes to degrade the bone (dentine)

Question 23

How long does the bone remodelling cycle take?

Should you know it for exams

Answer 23

3 months

if you know nothign else know this - Jenny G

Question 24

Describe the bone remodelling cycle

Answer 24

Starts in stage of quiescence (bone linign cells)

State of resorbtion (osteoclasts)

Reversal stage (osteblasts recruited)

Formation (New bone synthesised) and then mineralised

Question 25

Discuss bone formation throughout life

Answer 25

0-25- bone mass gains

25-40- bone stays stable

Old age- bone is lost

Question 26

What factors impact bone mass?

Answer 26

Genes

exercsie

Nutrition

Calcium and vitamin D

Smoking

Oestrogen

Question 27

What changes occur to bone in osteoperosis?

Answer 27

Reduced bone mass

Same amount of minereals and organic tissue

Question 28

What bone changes occur in osteoarthritis?

Answer 28

Increased bone mass

Reduced minerals

Increased organic material

Question 29

In osteopetrosis what changes occur in bone

Answer 29

Decreased resorption (increased mass)

Question 30

During paget’s disease, what changes occur to bone

Answer 30

Increased resorption (bendy bones)