Module 7 Wk 2 Flashcards
what produces the matix in cartlidge?
chrondroblasts
what maintains matrix in cartilidge?
chrondrocytes
what does ECM consist of in cartilidge?
fibres for rigidty
ground substances for resiliencyw
what does the fibre depends on within cartilidge?
what type of cartilidge
what does avascular mean?
no blood supply
what are the 3 types of cartilidge
- hyaline
- fibrocartilidge
-elastic cartilidge
what is the most commen type of cartilidge?
hyaline
what does hyaline cartilidge form?
temp skeleton in embryo which is gradually replaced by bone (long bones)
what is hyaline cartilidge made from?
u- abundent ground substance plus a few type 2 collogen fibres
where would you find hyaline cartilidge in adults?
articulating surface of moveable joints, walls of resp passages , costal cartilidge
T/F hyaline cartilidge goes underboth appositional and interstitial growth
True
what is elasatic cartilidge characterised by?
The precence of abundanct elastic fibres and is quite cellular
Where other than the ear pinna is elastic cartilidge found?
epiglottis
What is Fibro-cartilidge distinguished by?
It’s high content and orderly arrangement of type 1 collagen fibers.
Where is Fibro-cartilage typically found?
Regions where tendons attach to bones, the invertrbral discs and the symphysis between certain bones.
T/F there is lots of ground substance in Fibro-cartilage?
False - Limited
How are the cells arranaged in Fibro cartilage?
Chondricytes and Chondroblasts arranged in colums between bundles of collagen fibres.
What 2 types of cartlidge have appositional growth?
- hyaline
- elastic
Describe appositional growth?
New cartilidge forms at the edges
- Fibroblasts differentiate to chondroblasts and synthesise artilidge ECM
- Chondrocytes maintain the ECM
Describe Intersitial growth?
Growth within existing cartilage
- Chondrocytes become reactivated to blast form
- Then undergo cellular division to form isogenous groups that produce additional ECM
What is the function of synovial fluid apart from nurtrition?
Lubrication - provides film on cartilidge seeping in via mechanical action. Once seeped in it can go into spongey bit where it will dampen the effect of imapction
What is a sign using synovail fluid that there is problem in or around the joint?
- cloudy fluid
- blood in it
In cartilage, what is the main cell type involved in the formation of the extracellular matrix?
Chondro blasts
In cartilage which type of growth gives rise to the formation of isogenous groups?
Intersitail growth
Which type of cartilage is present at articulating bony surfaces?
Hyaline
Where would you expect to find perichondrium and what is its functional role?
surface of cartilage
What is Bone?
Cells and fibres embedded in a hard unbending calcified matrix
What are 2 functions of bone
Rigid and hard support (cf. cartilage)
Protects vital organs
Contains the bone marrow (hematopoiesis) origens of blood cells
Reservoir for calcium, phosphate and other ions released when needed
Transforms forces of skeletal muscle contraction into bodily movements
Why is bone a dynamic tissue?
capable of remodelling and repairing itself
What type of bone forms outer wall?
compact bone
What type of bone stenthens bone internally?
trabecular
What is the diaphysis?
hollow cylinder consisting of compact bone
What is the metaphysis?
where Growth plate originates - border between epi and diaphysis
Whats the difference in fibers when comparing lamellar and woven bone?
Lamellar bone has specific orientation of collagen fibres and woven bone has a randome one.
T/F woven bone is replaved by lamellar bone
True
what is the function of an osteoblast?
To form the osteoid
What is the function of the osteocyte?
maintan the bony matrix
how do the osteocytes communicate with one another?
via specail cellular extentions called canaliculi
What is the function of osteoclasts?
enzymatic digestion of ECM
Where are osteoclasts located?
On the external and internal surfaces of bony surfaces
What do osteoprogenitors cells become?
Osteoblasts and produce osteoid
What does osteoprogenitors cells give rise too?
Outer and inner circumferentail lamellae of bone
Describe volkman and haversian canals
- volkman canals come in at right angles to the parallel surface to the bone
- from volksman canals there are internal perpendicular canal called haversian
where does haversain systems develop?
Around the central vanacls which run parallel to the long axis of the bone
Describe the features you see at the haversian system
Cement line (CL)
Lacuna (L)
Osteocyte
Osteo-pogenitor cell (OP)
Osteoblast (OS)
When you see things in middle whihc dont have cental canal histologically what will it be?
Remodelling bone
what bone is there no haversian systems in?
Spongy, Trabecular, Cancellous Bone
what does Spongy, Trabecular, Cancellous Bones consist of?
Consists of Bony spicules/trabeculae covered with endosteum
Where does intra-membranous ossification occur?
in restricted areas only and spoontanously
what does intra-membranous ossification form from?
directly from ostogenic CT
What does it intra-membranous ossification form?
the flat bones of skull, mandible and maxilla
What is the more common ossification?
endochondral ossicication
T/F endochondral ossification starts with cartilidge model that then is replaced by bone?
Trueeee
What is endochondral ossification responsible for?
Growth of long bones
Describe the stages of formation of primary centre of ossification
- Cartilidge will be growing all the time from outside (appositional growth) and swell from withing (intersitial growth)
- Pericondulum will become vascularised chnaging the cells osteoprogenitor cells that then go onto fom the periosteal collar
- At the centre there will be prolifercation of chondrocytes followed by their hyptrophy initaiating the primary ossidication centre in the middle of the shaft
- they secrete vascular endothelial growth factor that induces the sprouting of blood vessels
- then chondrocytes will die off
- the cells that come in this blood supply will disolove in matrix and replace with bone.
what is cacified cartilidge matrix replaced by?
osteoid produced by osteoblasts that come in the blood stream
How does growth of long bones continue?
Via endochondral ossifiction at the epiphyseal growth plate
Describe what happens at the formation of the growth plates, growth and closure of the growth plate
- initail blood vessels (periosteal collar) extends up and down the shaft (diaphysis) where the cartiage has been replaced by bone
- secondary ossicification site starts at one of the epiphysis
- This process starts at other epiphysis
- The Epiphysis growth plates over time close up to form the epiphysis line
With respect to cellular events taking place at the epiphyseal growth plate put the following terms in order (ANS)
- resting zone
- zone of prolificating chondrocytes away from the ossification front which increases the length of the cartlidge
- zone of hypertrophy
- zone of cell death ( osteoclasts do this as chasing them)
- zone of vascular invasion
What type of bones is radius ulna?
both long bones
Out of radius and ulna which is weigth bearing and which provides leverage?
Radius is weight bearing and ulna provides leverage
Where on ulna is the olecranon process?
Large projection proximal to articular surface
Where is the anconeal process located on the ulna?
Fits into olecanon fossa of humerus
What articular surface is the trochlear notch on?
Of elbow joint
What does the radius sit between?
between the medial and lateral coronoid processes of the ulna
what is the site of attachment of the collateral ligaments of carpus
Medial & lateral styloid processes palpable
how many sites of ossification do radius?
3
how many sites of ossification do ulna have?
4
What are the components of the elbow joint?
- Trochlea of humerus at sistal end – subchondral bone goes the way from cranial to caudal - felxibility
- Head of radius +
- Trochlear notch of ulna
T/F does elbow joint have all typical synovail joint features?
yes including all collateral ligaments
what gives elbow joint stability?
- Collateral ligaments – joint stability
- Anconeal process (ulna) - also stability - engaged within, olecranon / ulnar fossa (humerus)
What movement is the elbow joint limited too?
Flexion and extention
what are the conditions that combined caiuse elbow dysplasia?
Osteochondrosis
Ununited anconeal process
Fragmented medial coronoid process
Elbow incongruity
what is the osteochondosis the erosions of?
erosion of articular cartlidge and subcondral bone
what is the origin of the deltoideus muscle?
spine of the scapula
where does the deltoideus muscle insert?
- lateral aspect of humerus
- intrinsic muscle
where is the deltoidues muscle loacted?
caudallateral aspect of limb
what is the function of the deltoidues muscle?
crosses caudal to shoulder joint - shoulder flexor
wwhat is the origin point of the Teres Major muscle?
caudal border of scapula
what is the insertion point of Teres Major muscle?
medial humerus
What is the loaction of Teres Major muscle?
caudomedial aspect of limb
what is the function of the Teres Major muscle?
crosses caudal to the shoulder joint and is a shoulder flexor
how many heads does the triceps brachii muscle have?
4
where does the long head originate from?
The caudal border of the scapula
where is the other heads origin?
shaft of the humerus
where do all the heads of the trachi brachii muscle insert?
olecron process of the ulna
Functions of the triceps brachii muscle?
Crosses caudal to shoulder- Shoulder FLEXOR
Crosses caudal to elbow- Elbow EXTENSOR
where is the origin of the biceps Brachii muscle?
supraglenoid tubercle
what is the insert point of the biceps brachii muscle?
proximal radius intrinsic muscles
what are the functions of the biceps brachii muscle?
Crosses cranial to shoulder - Shoulder EXTENSOR
Crosses cranial to elbow - Elbow FLEXOR
nerve supply that supplies biceps brachii is?
the Musculocutaneous nerve
where is the tendon origin of the biceps brachii muscle?
Intertubular groove of humerus
what is the biceps brachii tendon held in by?
transverse liagments
Whats is the lacertus fibrosis in the horse?
Fiberous extention that inserts into metacarpal 3 and acts as a carpal extensor?
what is the function of the brachialis muscle?
crosses the cranial to elbow joint actuing as an elbow flexor
what is the nerve supply to the brachialis muscle?
musculocutanous nerve
what are the componenents of the carpus in the dog?
Proximal row (PR):
- Radial carpal bone/ Intermediate carpal bone (fused, RCB)
- Ulnar carpal bone (UCB)
- Accessory carpal bone (ACB) - Palpable on palmar aspect
Distal row:
1st , 2nd, 3rd and 4th carpal bones
how many cenetres of ossification does the carpal bone have?
1
What are the 3 joints in the carpus?
- Antebrachio-carpal joint
- middle carpal joint
- carpo-metacarpal joint
where are the Antebrachio-carpal joint located?
between antebrachium and proximal row of carpal bones
where is the middle carpal joint located?
proximal and distal rows of carpal bones
where is the middle carpal joint located?
Proximal + distal rows of carpal bones
where is the carpo-metacarpal joint located?
distal row and metacarpal bones
where would you take carpal hoint fluid sample?
in the joint space
in the standing position what movement does carpus provide?
extension
how afre the carpal bones when in extension?
stacked on top of each other
what carpus joint has most movement?
antebrachio-carpal joint
what does the Acessory carpal bone act as?
level for the distal limb
Any forces applied to accessory carpal bone are conteracted by what?
the palmer ligament
T/F carpus joint have typical synovial joints?
yaaaa
what 3 things give carpal joint stability?
- Collateral ligaments
Lateral: ulna (lat. Styloid process) to 5th metacarpal
Medial: radius (medial styloid process) to 2nd metacarpal - Cartilage plate on palmar aspect of joint capsule – reinforcement of capsule prociding a little more stability when limb is in extention
- Retinaculum – sleeve that imcompases the wholw of the carpus
What does artyrodactyla means and what kind of animals does it refer too?
- even number weight bearing digets
- 3rd and 4th remain
- ruminents
Whats does perissodactyla means and what animal does it refer too?
- uneven number weight bearing digits
- 3rd digit remains
- equines
what do plantigrades weight bare on?
digits and metatarsals and tarsal bones
what do digitigrades weight bear on?
digets and phalanges
what do uguligrads weight bare on?
bear weight on distal phalanx only
what bone does not have 2 centres of ossification in the carpus?
distal phalanx
what is another name for the 3rd metacarpal bone in the horse?
cannon bone
what is the second and forth metacarpal bones names in the euine?
splint bones
what kind of jionts between equine metacarpal bones?
fiberous
T/F all soecaies have proximal sesamoid bones?
True
what are the proximal sesamoid bones imbedded in?
suspensory ligament
what do the proximal sesamoid bones protect?
Superficial Digital Flexor Tendons (SDFT)
Deep Digital Flexor Tendon (DDFT)
In the dog where would you find the dorsal sesamoid bones?
at the dorsal aspect of every metacarpal and metatarsal joint
what is the P1 bone an insertion point for?
oblique distal sesamoidean ligament
what are the components of the metacarpophalangeal joint in the horse?
- 3rd metacarpal / metatarsal bone
- Proximal phalanx
- Proximal sesamoid bones -Typical synovial joint - Large palmar pouch - incorporates proximal sesamoids - Large dorsal pouch - cushions extensor tendons
what provies stability to the MCP joint in the horse
- collarteral ligaments
- sagital ridge that fits into the s groove
what is the movement like at the MCP joint in the horse?
- It is limited to flexion and extension
- referred to a hight motion joint
where does the suspendory ligamant attacht to in distal limb in the horse?
abaxial aspect of proximal sesamoids
what is the function of the suspenosry ligament in the distal limb
acts like a sling - returns joint to resting position and relies on stabilty of proximal sesamoids
what are the 3 sesamoidean ligaments in the horse?
- inter-seasamoidean ligaments
- collarteral sesamoidean ligaments
- distal sesamoidean ligments
what do the sesamoidean ligaments give stability to?
the proximal sesamoids
what is the sagital ridge with P2 proximal with?
P1
what is the components of the middle phalanx?
proximal and middle phalanges
at the distal phalanx ahat is the bone called?
P3
what is the extensor process for P3?
attachment common digital extensor tendon (CDE)
what is the palmer process for P3?
support lateral cartlidges
what is on the solar surface of the distal phalanx?
attachment of DDFT
what is on the dorsal surface of the distal phalanx?
straitions for hoof attachment
vascular channals for blood vessels
where is distal interphanlangeal joint?
buried within hood
what are the components that make up DIP joint?
- Middle & distal phalanges
- Distal sesamoid & distal phalanx
- Distal sesamoid & middle phalanx
what gives the DIP joint stability?
collateral ligaments
whats the other word for diatal sesamoid in horse?
navicular bone
what is the navicular bursa?
fluid filled pocket between distal sesamoid and DDFT
what does it provide to DDFT?
a cushion
what are the 3 hoof outer surface features?
- walls - toe, quarters, heel
- coronary band
- periople
what are the 3 parts of the heel of the walls of hoof?
- angles
- bars
- bulb
what is the function of the frog in the hoof?
shock absorber
describe the makeup of the frog?
central sulcus with collateral sucli either side
should the sole of the hoof come into contacl with ground?
NO
what is the white line in hoof?
boundary between wall and sole
where is the digital cushion in comparison to frog?
deep to it
what is the digital cushion?
wet spounge
when weight bears all blood squeezed out and up though limb and when stop bearing go back down whihc provides circulation
describe the lateral catrilidges in hoof?
- supported by palmer processes of DP
- they are medial and lateral ones
they project above level of hoof - their function is shock absorbtion
what is the significance of a penetrating injury dependent on?
- location
- depth - how long it is
What can you feel for to helo located where an abces in the foot?
digital pulses as you usually cant feel them but when there is infection it will increase pressure and inflammation you will feel so much more
what is the dermis fused to in hoof and what does it cover?
- fused to dorsal surface DP
- covers digital cushion
what is the laminae on hoof?
ridges on the surface of the dermis
Describe the what and the relationship between primary and scondary laminae
Primary ridges are vertical which have a secondary laminea which are horizontal
what does the dermis supply?
the germinal layer
what does the dermis produce?
the epidermis
where on the hoof does the epidermis have activity?
- coronary band
- solar surface
what does the coronary band produce?
epidermis in form of tuber of keratin
what are the gaps between thrown up tubes of keratin filled by?
intertubular horn which is less well organised ketitin
what is the hoof capsule interdigited with?
dermal laminae
what suspends distal phanlanx within hoof capsule?
white line
what producuces the sole of the hoof?
keritinised flakes created by germ layer
what is more soft and elastic, the sole or the frog?
frog
what is the sequence in events of weight bearing in terms of horses?
- Frog contacts ground
- Digital cushion compressed
Acts like wet sponge
Forces blood back up leg - Lateral cartilages
Expand laterally
Dissipate forces - Hoof wall contacts ground
- Weight transferred to DP
- Weight transferred to hoof wall - via interdigitation of laminae
what are the 4 parts at the distal phalanx in the carnivore?
- ungual process
- ungual crest
- extensor process
- palmer process
what is the function of the ugul process?
support the claw
What is the ugual crest?
The vascular root of claw
What is the extensor process?
Where the extensor tendons attach
what is the the palmer process of the distal phalanx?
Where flexor tendons attach
how many digit pads are there is dogs and cats?
4
what is the other pad seen in cats and dogs?
the metacarpal pad
what does the carpal pad protect?
Accesory carpal bone
what are the functions of footpads?
- Allow weightbearing over entire digit
- Support digit & metacarpo / metatarso -phalangeal joints
- Protect deep structures
- Anti-concussion / shock absorption
- Resistance to trauma / wear & tear
- Traction – prevent slipping
What doe sthe surface consist of in foot pads?
- modified skin so dermis, germitive layer, epidermis, sweat glands, varous pigmentation
What tissue is the digital cushion made from in carnivore footpads?
- elastic and fiberous with fat too
what rae the components of the carnivore claw?
Dermis
Fused to periosteum of ungual process
Sensitive and bleeds
(No laminae!)
Germinative layer -active in 2 areas (same as horse)
- Recess at ungual crest - Forms dorsal & lateral surface of claw
- Palmar surface ungual process
Forms underside of claw
Epidermis
heavily keratinised = horn +/- pigment
What is the actions of a normal claw in the dog?
- balanced forces (dorsal elasltic ligament, CDE, DDFT)
- tip touches ground when walking
- continous growth wears naturally on ground
If there is reduced wear of the claw what might be the reasons for this?
- not walking enough
- walking on soft ground
- dew claw - as it dosent touch the ground
- DDFT damage like a stubbed toe
Whats is the normal actions of a claw in the cat?
claw not normally visibles
- very stronf dorsal elastic ligamentis
- so neutral position is distal interphalangeal joint hyperextention
- clwas rest in skin folds between phalanges
what happens when cats want to expose their claws?
- DDFT flexes the joint
- mannual pressure of distal pad
T/F in the rumanant the metacarpals 3 and 4 are fused together?
True
With the metacarpals 3 and 4 being together is there 1 or 2 pairs of promical sesamoids?
2
what digits in the rumanant are present and weight bear?
3 and 4
what happens to digits 2 and 5 in ruminanat?
become dew claw
what are the components of the ruminant hoof?
Cloven hoof – half hoof covering 2 phalanges
- Medial and lateral claws
- Interdigital cleft
Sole (1)
Heel (2)
- No frog
Wall:
- Lateral - convex - Continuous with heel when runs down dorsal bends onto clet
- Medial - vertical - Stops at parapedal groove - Transition hard to soft horn = prone to damage
White line – space between hoof wall and sole
what is the origin of the extensor carpi radialis muscle?
the lateral epicondyle of the humerus
what is the insertion point of the extensor carpi radialis muscle?
The metacarpal bones
where is the extensor carpi radialis muscle located?
The cranail aspect of the anterbrachium
What is the function of the extensor carpi radialis muscle?
It crosses over the dorsal aspect of the carpus acting as a carpal extensor
T/F the axilary nerve supplies the extensor carpi radialis muscle
False the radial nerve does
what is the origin of the Common digital extensor muscle?
The lateral epicondycle of the humerus
what is the isertion point for the Common digital extensor muscle?
All the digits
what is the location of the Common digital extensor muscle?
The Cranio-lateral aspect of the antebrachium
what is the functions of the Common digital extensor muscle?
It crosses the dorsal aspect of the carpus making it a carpal extensor
It crossies the dorsal aspect of metacarpo-phalangeal joints and interphalangeal joints making ti an digital extensor
what nerve suplies the Common digital extensor muscle?
radial nerve
how many branches of the Common digital extensor muscle
tendons are there in the dog?
4 - onto each digit
how many branches of the Common digital extensor muscle
tendons are there in the horse?
1 - attches to dorsal aspect phalanges
what is the origin of the Extensor carpi ulnaris / Ulnaris lateralis muscle?
The lateral epicondyle of humerus
What is the insertion point of the Extensor carpi ulnaris / Ulnaris lateralis muscle?
Laterally at the proximal end of the metacarpal bone and ACB
what is the location of the Extensor carpi ulnaris / Ulnaris lateralis muscle?
The lateral aspect of the antebrachium close to ulna
what is the function of the Extensor carpi ulnaris / Ulnaris lateralis muscle?
it crosses the lateral aspect of carpus and inserts onto metacrapal 5 and ACB making it an carap extensor and flexor
what is the nereve that supplies the Extensor carpi ulnaris / Ulnaris lateralis muscle?
the radial nerve
what is the origin of the Flexor carpi ulnaris muscle?
The medial epicondyle and the olecaron process of the ulna
what is the insertion point of the Flexor carpi ulnaris muscle?
ACB
what is the location of the Flexor carpi ulnaris muscle?
caudal aspect of the antebrachium
what is the nerve that supplies the Flexor carpi ulnaris muscle?
The median and ulna nerves
what is the origin of the Superficial digital flexor muscle?
The medial epicondyle of the humerus
what is the insertion point of the Superficial digital flexor muscle?
All digits
what is the functions of the flexor carpi ulnaris muscle?
crosses caudal aspect of the carpus making it a carpal flexor
what is the location of the Superficial digital flexor muscle?
The caudal aspect of the limb
what is the function of the Superficial digital flexor muscle?
- crosses palmer aspect of carpus making it a carap flexor
- crossies the plamer aspect of the metacarpo-phalangeal joints am dproximal interphalangeal joints making it a digital flexor
what nerves supply the Superficial digital flexor muscle?
median and ulnar nerves
what is the origin of the Deep digital flexor muscle (DDFT)?
The meadail epicondyle
what is the insertion point for the Deep digital flexor muscle (DDFT)?
All digits
what is the location fo the DDFT muscle ?
The caudal aspect of limb
what is the function of the Deep digital flexor muscle (DDFT)?
It crosses palmer aspect of carpus making it a carpus flexor
what does the Deep digital flexor muscle (DDFT) pass through before inserting on the distal phalanx?
The split in the SDFT
extensor tendosn in the quine distal limb is on what aspect?
dorsal
what are the boundaries of the carpal canal in the horse?
- Dorsal - Palmar aspect of carpal joint capsule
- Lateral – ACB
- Palmar – palmar / flexor retinaculum - Sleeve of fibrous tissue encasing limb
what is the function of the tendon sheath?
to protect tendons where pass through confined spaces
in the dorsal part of the llimb what is the CDE held in by?
retinaculum
in the palmer aspect of the limb what is the SDFT and DDFT held in place by?
The carpal canal
annular ligaments
T/F horses weigth bear on there hind limbs?
false - forelimbs
the spinal nerves have two branches what are these?
dorsal branch - supllies dorsal stuctures
ventral branch from some cervical an dthoracic vert that form the brachial plexus
where is the brachial plexus located?
in axilla (armpit)
what do the emerging nerves from the brachial plexus supply?
forelimb muscles
what is the function of the subscapular nerve?
Provides medial shoulder support to subscapularis muscle
what is the function of the suprascapular nerev?
Provides lateral shoulder support for supraspinatous and infraspinatous muscle
what is the function of the musculocutanous nerve?
Flexion of the elbow via brachials muscle and biceps brachii muscle
cutanous sensation to crania and medial elbow and medial aspect of antebrachium
what is the function of the axillary nerve?
- Shoulder flexors via deltiodeus and teres major muscle
- cutanous sensation to lateral aspect of shoulder and brachium regions
what is the function of the medial and ilnar nerves?
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