Week 1 Biochemistry, Histology and Physiology

Question 1

what fractures commonly occur in type 1 and 2 osteoporosis?

Answer 1

both - vertebral
1 - colles
2- femoral neck

Question 2

in osteoporosis, serum phosphorus and Ca are ??

Answer 2

normal

Question 3

what is desunomab and when is it used?

Answer 3

a monoclonal antibody used in osteoporosis to reduce osteoclast activity (destruction)

Question 4

treatment for osteoporosis?

Answer 4

biphosphates - effective and innexpenisive
desunomab
calcium and vit d supplements

Question 5

what is the pathogenesis of osteoporosis?

Answer 5

gradual slowing of osteoblast activity

this is exacerbated after menopause without the protection of oestrogen

Question 6

try to name 4 things that cause secondary osteoporosis

Answer 6

steroids
hypotension
cushings
ckd
RA
hyperarathyroidism / hyperthydoism

Question 7

what can cause low phosphorus levels, and therefore predispose to osteomalacia?

Answer 7

alcohol abuse
genetic factors
renal losses or chronic kidney disease

Question 8

levels of … in osteomalacia:

• Ca
• Ph serum
• serum ALP

Answer 8

low, low , high

Question 9

what causes bones moans groans and renal stones?

Answer 9

hyper calcaemia

Question 10

what is tertiary hyperparathyroidism?

Answer 10

secondary HPThyroid leads to an adenoma (primary normally)

Question 11

if Ca is low, where does PTH act on in the body to retrieve Ca?

Answer 11

bones - resorption (causing weakness)
GI tract - more absorption into systemic system
kidneys - reabsorption instead of excretion

Question 12

what causes Pagets?
A. bacterial infection
B. viral infection.
C. Genetic abnormalities

Answer 12

B and C

Question 13

blood test in pagets…

• serum Ca
• serum ph
• serum ALP

Answer 13

normal
normal
high

remember that pagets is to do with osteoblasts, not the minerals in the bone

Question 14

Tx of Pagets (2)

Answer 14

biphosphates

calcitonin hormone if extensive lysis

Question 15

describe the type of bone in the epiphysis vs diaphysis

Answer 15

epi = cancellous
diaphysis = dense cortical bone

Question 16

what is an epimysium?

Answer 16

fibrous tissue around the skeletal muscle as a whole

Question 17

what is a perimysium?

Answer 17

tissue around a fascicle (collection of fibres)

Question 18

what is a endomysium?

Answer 18

tissue around a single muscle fibre

Question 19

the … line is the centre of the … zone in the middle of the … are of the sarcomere, with .. lines at each end. these end lines are the middle of the … zone

Answer 19

M line in the middle of the H zone as part of the crossing lines of the A. There are Z lines at the end of the sarcomere as part of the I zone

Question 20

how is cartilage nourished?

Answer 20

through the extracellular matrix diffusing into it. chondrocytes make the ECM and maintain it.

Question 21

hyaline cartilage
75% —

25% — and —-

Answer 21

75% water
25% type 2 collagen and proteoglycans

type 2 collagen is fine and makes a fibrous 3D mesh. it can help to make the ECM too woo hoo

Question 22

what type of cartilages are blue / yellow / white ?

Answer 22

blue - hyaline
yellow - elastic
white - fibrocartilage eg pubic symphysis

Question 23

what is osteoprogenitor bone?

Answer 23

it is an osteoblast reserve space on the bone surface

Question 24

what bone cells are large and multinucleated 
A. osteoprogenitor
B. osteocytes
C. osteoclasts
D. Osteoblasts

Answer 24

its C for osteoclasts

Question 25

what do osteoblasts secrete and how does this become mineralised?

Answer 25

osteoblasts secrete “osteoid secretions” (#organic yahh =- proteoglycans, collagen etc) into the extracellular space where it attracts Ca and phosphate –> mineralised.

Question 26

describe these here canals for me pls

• volkmanns
• haversian
• canaliculi

Answer 26

v = horizontal and long. interconnect the haversian canals with each other and the periosteum. 
h = vertical, microscopic sized in cortical bone - stretch to the surface vertically. Not in trabecular bone.
c = thin and connect osteophytes to each other

Question 27

what collagen is in fibrocartilage and tendons?

Answer 27

type 1

thick linear bundles, unlike type 2 which is a fine 3D mesh structure

Question 28

what is renal dystrophy and its association with osteomalacia?

Answer 28

in CKD, renal dystrophy leads to reduced phosphate secretion –> secondary hyperparathyroidism causing osteomalacia and also SCLEROSIS AND CALCIFICATINO OF SOFT TISSUES

Question 29

2 x upper body locations potentially affected by Pagets

Answer 29

skull - remember picture

ear ossicles - can go deaf

Question 30

3 x lower body locations potentially affected by Pagets

Answer 30

pelvis
femur
tibia

Question 31

pathogenesis of pagets

Answer 31

genetic / viral triggering of increased osteoclast activity. there is too much turnover and too much resorption –> a mix of sclerosis and lysis. outcome is thick brittle misshapen bone with thick cortices.

Question 32

what is the name of the muscle fibres that secrete more with increased stretch?

Answer 32

annulospiral fibres at the end of intrafusal fibres. supplied by Gamma motor neurons and don’t contribute to muscle strength.

Question 33

where do you get WBC (under 200) and polymorphs (under 25) ?

Answer 33

synovial fluid bro

Question 34

what fibres transmit stabbing prickly pain?

Answer 34

Ag - they are myelinated

C fibres are for slow achy pain, unmyelinated