APP 7 Flashcards
What is the difference between an osteoblast and an osteocyte? (1)
Immature/mature bone cell
Draw a long bone and label the following on it: epiphysis, diaphysis, metaphysis, epiphysis, compact bone, spongy bone, medullary cavity, periosteum (8)
Epiphysis - End of Bone / Diaphysis - Middle of Bone
Metaphysis - Between Middle and End
Epiphyseal line- Growth line at end of bone
Compact bone - Around the Medullary cavity / Medullary cavity - ‘hollow’ center
Spongy bone - In the end / Periosteum - ‘skin’ surrounding
What is the matrix made of in bone – material and % ? (3)
25% protein fibres
25% water
50% crystallised mineral salts
What’s the difference between an osteoblast and an osteocyte? (2)
Blast lays down bone, Cyte maintains it
What is an osteoclast? (1)
A cell that dissolves bone
What are the 2 main minerals in bone? (2)
Calcium sulphate and calcium phosphate
Where does the hardness come from in bone and where does the strength & flexibility come from? (2)
Mineral salts and protein fibres
What is the epiphyseal (growth) plate? (1)
A line of hyaline cartilage in the bone from which the bone grows
Why do we stop growing at adolescence ? (1)
The epiphyseal plate ossifies
What causes the epiphyseal plate to ossify? (1)
Hormones, particularly oestrogens
What are the 4 main types of cells in red bone marrow? (4)
Rbc’s
Wbc’s
Adipocytes
Fibroblasts
Give 2 possible causes of giantism (2)
Oversecretion of human growth hormone (pituitary),
Lack of oestrogen/receptors so plate doesn’t close
Give 3 possible cause of shorter stature (3)
Under secretion of human growth hormone (pituitary), or thyroid hormone, or genetic
In 10 words or less, what happens in bone remodelling? (2)
Osteoclasts dissolve bone and osteoblasts simultaneously rebuild it
What is an open fracture? (1)
Bone protrudes
What is a comminuted fracture? (1)
Splinters
What is a greenstick fracture?(1)
One side broken, other side bends
What is an impacted fracture? (1)
One side driven into other side
What is a Pott’s fracture? (1)
Fracture of far end of fibula
What is a Colles’ fracture? (1)
Fracture of far end of radius and displaced posteriorly
What is a stress fracture ? (1)
Microscopic fissures in bone due to repeated stress eg jumping or osteoporosis
Where is 99% of the body’s calcium stored? (1)
In bone
Which hormone causes osteoclast activity to increase resulting in less calcium in bone and more in blood ? (1)
Parathyroid
Which hormone causes osteoclast activity to decrease resulting in more calcium in bone and less in blood ? (1)
Calcitonin
What is the effect of mechanical stress on bone? (1)
It makes it lay down more bone
Why is bone resorption more marked in women? (1)
Because of the reduction in sex hormones after the menopause
What is the condition called in which bone resorption is greater than bone deposition? (1)
Osteoporosis