The ground substance of bones matrix is made up of: A. B. C. D. Chondroitin sulphate Mucopolysaccharides Hyaluronic acid A&C

If a bone has matrix but no mineral , it would be: A. Strong and rigid B. Brittle and easily breakable C. Rubbery and flexible D. None of the above

Hydroxyapatite crystals are precipitated . A. Calcium hydroxide crystals B. Calcium carbonate crystals C. Calcium hydrogen phosphate crystals D. Calcium phosphate crystals

Which of these factors is NOT necessary for normal bone growth and development ? A. PTH B. High fat diet C. Male and female sex hormones D. Vitamin D

In which stage of a females life does the rate of bone formation become equal to that of bone breakdown? A. B. C. D. Childhood Adult life After menopause All of the above

In the Kidneys , 60% of filtered ionized Ca2+ is reabsorbed in A. B. C. D. Bowmans capsule The Proximal tubule The loop of Henle The Distal tubule

If a man has remodeled all his bones thrice, you would expect his age to be approximately: A.60 years B.30 years C.3 years D.You can not estimate age from the number of times that bone has been remodeled

What is one way by which the GIT helps in obtaining calcium? A. Facilitated diffusion B. Active transport through Ca- ATPase pump C. Reabsorption D. Filtration

Oestrogen : A.Stimulates osteoblats B.Stimulates osteocytes C.Stimulates osteoclasts D.Has no affect on bone

Stress leads to : A. An increase in bone formation B. A decrease in bone formation C. An increase in osteocyte activity D. None of the above

All of these hormones help in the formation of bone EXCEPT : A.Calcitonin B.Oestrogen C.Thyroid hormone D.Corticosteroids

...why ?

The GIT : A. Absorbs calcium B. Secretes calcium C. Absorbs and secretes calcium D. Has no relation to calcium

A decrease in PTH would cause: A. decreased reabsorption of calcium from PCT B. decreased osteoclast activity C. increased absorption of calcium D. bone resorption

GH affects which aspect of bone formation? A. Formation of chondroitin sulphate B. Osteoblast activity C. Osteoclast activity D. Formation of hyaluronic acid

The substance that is used to dissolve Ca3(PO4)2 from bone is : A.An acid B.An alkali C.A nutrient solution D.A salt solution

All of the following facilitates nutrition and oxygen supply to osteocytes inside their lacunae EXCEPT: A.Gap junction B.Haversian canal C.Bony canaliculi D.Sharpeys fibers

... then what is the function of Sharpey`s fibers??

Bony canaliculi: A. Connect haversian canals to one another B. Are cytoplasmic extensions of osteoblasts C. Are channel-like structures which houses the cytoplasmic processes of osteocytes D. Are boney trabeculae or spicules

Which of these cells lie in Howships lacunae? A.Osteogenic cells B.Osteocytes C.Osteoclasts D.Osteoblasts

Which of these bone cells is considered as a component of mononuclear phagocytic system? A.Osteoblasts B.Osteoclasts C.Osteocytes D.Osteoprogenitor cells

All of the following structures are found in bone , EXCEPT : A.Hydroxyapatite crystals B.Howships lacunae C.Sharpeys fibers D.Volkmanns canal E.Type II collagen

THANK YOU =)By Zeinab Hassan Ebtesam Alaa Elshennawy