Week 1 Biochemistry, Histology and Physiology Flashcards
what fractures commonly occur in type 1 and 2 osteoporosis?
both - vertebral
1 - colles
2- femoral neck
in osteoporosis, serum phosphorus and Ca are ??
normal
what is desunomab and when is it used?
a monoclonal antibody used in osteoporosis to reduce osteoclast activity (destruction)
treatment for osteoporosis?
biphosphates - effective and innexpenisive
desunomab
calcium and vit d supplements
what is the pathogenesis of osteoporosis?
gradual slowing of osteoblast activity
this is exacerbated after menopause without the protection of oestrogen
try to name 4 things that cause secondary osteoporosis
steroids hypotension cushings ckd RA hyperarathyroidism / hyperthydoism
what can cause low phosphorus levels, and therefore predispose to osteomalacia?
alcohol abuse
genetic factors
renal losses or chronic kidney disease
levels of … in osteomalacia:
- Ca
- Ph serum
- serum ALP
low, low , high
what causes bones moans groans and renal stones?
hyper calcaemia
what is tertiary hyperparathyroidism?
secondary HPThyroid leads to an adenoma (primary normally)
if Ca is low, where does PTH act on in the body to retrieve Ca?
bones - resorption (causing weakness)
GI tract - more absorption into systemic system
kidneys - reabsorption instead of excretion
what causes Pagets?
A. bacterial infection
B. viral infection.
C. Genetic abnormalities
B and C
blood test in pagets…
- serum Ca
- serum ph
- serum ALP
normal
normal
high
remember that pagets is to do with osteoblasts, not the minerals in the bone
Tx of Pagets (2)
biphosphates
calcitonin hormone if extensive lysis
describe the type of bone in the epiphysis vs diaphysis
epi = cancellous diaphysis = dense cortical bone
what is an epimysium?
fibrous tissue around the skeletal muscle as a whole
what is a perimysium?
tissue around a fascicle (collection of fibres)
what is a endomysium?
tissue around a single muscle fibre
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
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
how is cartilage nourished?
through the extracellular matrix diffusing into it. chondrocytes make the ECM and maintain it.
hyaline cartilage
75% —
25% — and —-
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
what type of cartilages are blue / yellow / white ?
blue - hyaline
yellow - elastic
white - fibrocartilage eg pubic symphysis
what is osteoprogenitor bone?
it is an osteoblast reserve space on the bone surface
what bone cells are large and multinucleated A. osteoprogenitor B. osteocytes C. osteoclasts D. Osteoblasts
its C for osteoclasts
what do osteoblasts secrete and how does this become mineralised?
osteoblasts secrete “osteoid secretions” (#organic yahh =- proteoglycans, collagen etc) into the extracellular space where it attracts Ca and phosphate –> mineralised.
describe these here canals for me pls
- volkmanns
- haversian
- canaliculi
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
what collagen is in fibrocartilage and tendons?
type 1
thick linear bundles, unlike type 2 which is a fine 3D mesh structure
what is renal dystrophy and its association with osteomalacia?
in CKD, renal dystrophy leads to reduced phosphate secretion –> secondary hyperparathyroidism causing osteomalacia and also SCLEROSIS AND CALCIFICATINO OF SOFT TISSUES
2 x upper body locations potentially affected by Pagets
skull - remember picture
ear ossicles - can go deaf
3 x lower body locations potentially affected by Pagets
pelvis
femur
tibia
pathogenesis of pagets
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.
what is the name of the muscle fibres that secrete more with increased stretch?
annulospiral fibres at the end of intrafusal fibres. supplied by Gamma motor neurons and don’t contribute to muscle strength.
where do you get WBC (under 200) and polymorphs (under 25) ?
synovial fluid bro
what fibres transmit stabbing prickly pain?
Ag - they are myelinated
C fibres are for slow achy pain, unmyelinated
