:L Flashcards
what is the main mineral in the mineralised ECM in bones? [1]
what other subtstance is mostly found in the bone matrix [1]?
what is the main mineral in the mineralised ECM in bones? [1]
calcium phosphate
what other subtstance is mostly found in the bone matrix [1]?
type 1 collagen - 90% of bone
bone classification:
- outside, dense part of bone is called?
- inside, less dense is called?
bone classification:
- outside, dense part of bone is called: compact
- inside, less dense is called: spongy (trabeculae)
when are bones not covered in periosteum?
Osteoprogenitor cells are located where?
where they articulate with other bones
Osteoprogenitor cells are located on the outside of trabecula eg beside adipocytes in periosteum
what is periosteum?
what is inside it?
Fibrous capsule surrounding bone
Carries blood and neural supply
Periosteal blood vessels penetrate the bone from this layer.
Inner periosteum is liner by osteoprogenitor cells.
These may differentiate into osteoblasts and so are important in bone growth, modelling and repair.
what are canaliculi?
Tiny canals in bone to allow for the passage of blood vessels for nutrient supply.
They appear as fine lines
Extend from capillaries to osteocytes and their matrix.
Osteocytes are interconnected by the canaliculi through processes. Communication through gap junctions.
where do you find osteocytes? [1]
characteristic feature of osteocytes [1]
role of osteocytes? [1]
how do u prepare bone to see ^? [1] 2
where do you find osteocytes? [1]
- osteocytes encolosed in bone matrix, trapped in lacunae
characteristic feature of osteocytes [1]
- osteocyte processes
role of osteocytes? [1]
- respond to redeuced mechanical stress by secreting MMPs: osteocytic remodelling
how do u prepare bone to see osteocyte processes? [1]
- visible on ground sections (no stain, just dried)
- not visible with H&E
(see photo)
osteoclasts
location? [1]
characteristics? [1]
derived from? [1]
function? [1]
osteoclasts
characteristics?
large and multinucleated
location
at sites where bone is removed
derived from? [1]
from the fusion of the granulocytes / macrophage progenitor cells
function [1]
responsible for bone resorption in response to long term calcium requirements and changing mechanical stresses.
what are osteoclasts activated by?
how does it cause bone remodelling?
which other cells can activate them?
osteoclasts express a receptor molecule called RANK (receptor activator of nuclear factor). interaction with RANKL ligand molecule expressed on osteoblasts
dissolves bone matrix: pumps protons out to acidify & enzymes = bone remodelling
also activated by t-lymphocytes (can express RANKL) during inflammation
what are the two methods of bone formation? [2]
endochrondral ossification: cartilage model as precursor
intramembranous ossification: no cartilage model
which bones does the radiocarpal joint connect? [3]
what type of joint is it? [1]
which bones does the radiocarpal joint connect? [3]
- scaphoid & lunate to radius (not the ulna!)
what type of joint is it? [1]
- condyloid joint (extension and flexion and ulnar and radial devaitation (side to side)
which direction is extension and flexion of the thumb?
which direction is adductio and abduction of thumb?
what is oppositon of the thumb?
muscles of the superficial layer of forearm:
names? [4]
where do they run from / to?
muscles of the superficial layer of forearm:
- Pronator teres (pronates the arm)
- Flexor carpi radialis (flexes the wrist)
- Palmaris longus (small muscle)
- Flexor carpi ulnaris (flexes the wrist)
(Pass Fail Pass Fail)
muscles of the superficial layer do not extend into the digits so they act to
- **flex the wrist
- pronate the arm**
which is the muscle of intermediate layer of forearm?
where does it run to from the medial epidcondyle?
what movements does it cause? [3]
which is the muscle of intermediate layer of forearm?
- flexor digitorum superficialis
where does it run to from the medial epidcondyle?
- middle phalanx
what movements does it cause?
- *- flexes the wrtist
- flexes the MCP
- flexes the PIP**
what are deep layer muscles of the forarm? [3] where run to ? what movements?
flexor digitorum profundus:
- makes way to fingers and distal phalanx !
- causes flexion of the wrist, MCP, PIP and DIP joints
flexor pollicis longus
- *- forearm to distal phalanx of thumb**
- thumb flexion
pronator quadratus
- between ulnar and radius
- initiates pronation of the forearm
what are deep layer muscles of the forarm? [3] where run to ? what movements?
flexor digitorum profundus:
- makes way to fingers and distal phalanx !
- causes flexion of the wrist, MCP, PIP and DIP joints
flexor pollicis longus
- *- forearm to distal phalanx of thumb**
- thumb flexion
pronator quadratus
- between ulnar and radius
- initiates pronation of the forearm
what is the carpal tunnel?
what is the layer at the top called?
which nerve runs through?
- At the base of the palm of the hand, there is a groove/tunnel through which 9 flexor tendons pass.
- Across the top is the flexor retinaculum (thickening of the deep fascia)
- median nerve runs through the carpal tunnel
what are the borders of the anatomical snuffbox? [3]
which bone is this?
why is this bone clinically significant? [1]
scaphoid
why is this bone clinically significant
- has a retrograde blood supply (comes in at distal end and moves proximally) - means if fracture at proximal end -> can become avascular -> lead to necrosis
ID B, C, E & F?
B: corocoid process
C: glenoid fossa
E: acromion
F: biciptial groove (inbetween the tubercles) for long head of bicep tendon
which joint permits thumb oppositon in the hand? [1]
carpo-metacarpal
what are the characteristics of power grip?
and subtypes? [3]
- *power grip**
- all fingers flexed around object, thumb curled around to press agaisnt / meet fingers
- all muscles closing hand are active
- wrist extensors are active - stable base
- most primitive (new borns can do)
i) hook or snap
ii) cylindrical grasp
iii) spherical grasp
what are the characteristics of power grip?
and subtypes? [3]
- *power grip**
- all fingers flexed around object, thumb curled around to press agaisnt / meet fingers
- all muscles closing hand are active
- wrist extensors are active - stable base
- most primitive (new borns can do)
i) hook or snap
ii) cylindrical grasp
iii) spherical grasp
what are 4 muscles of thenar emincence? & innervation?
- flexor pollicis brevis - median nerve
- oppenens pollicis - median nerve
- abductor pollicis brevis - median nerve
- adductor pollicis - ulnar nerve
