forelimb Flashcards

1
Q

what is the locomotor system

A

musculoskeletal system that allows a wide range of animal movement

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2
Q

what are the three components of the musculoskeletal system

A

1) bones = act as rigid support/framework
2) joints = allows movement between bones
3) muscles = produces movement between bones

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3
Q

what are cursors

A

vertebrates that run on ground + are modified to enhance speed+ endurance. mostly predators or medium to large herbivores (common domestic species)

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4
Q

what are the cursorial adaptation of locomotor system

A

1) reduced pectoral skeleton (allows more cranial/caudal movement)
2) elongation at proximal end of limb (scapula lies laterally)
3) elongation at distal end of limb (lon metacarpals, walk on toes/hooves)

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5
Q

Describe how the pectoral skeleton is reduced in cursors

A

Clavicle is absent or vestigial.
No skeletal component attaching the forlimb to the trunk
Joint is purely muscular = synsarcosis
joint is called the omothoracic junction

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6
Q

Decribe how the proximal end of the limb is enlongated in cursors

A

scapula lies laterally
this allows increased stride length as the leg length is increase.
At the proximal end of the forelimb the scapula moves from lying flat across the back of a broad chest (humans) to lying flat agaisnt the sides of a deep narrow chest.

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7
Q

How is the distal end of the limb elongated

A

to increase leg length = increases stride length
as they have long metacarpals and walk on their toes or their hooves

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8
Q

What is flexion

A

folding limb (decreasing angle around the joint)

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9
Q

what is extension

A

stretching limb (increasing angle around the joint)

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10
Q

what is protraction

A

moving limbs forward

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11
Q

what is retraction

A

moving limbs backwards or fixing limb + moving trunk forwards towards the limb

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12
Q

How does trunk affect the locomotion of the species

A

locomotion + diet are linked in evolution
-herbivores with roughage diets and bulky abdominal viscera have less flexible trunks and rely more on limbs elongation
=cows, rigid = restricted movemnt
in horses they have a rigid vertebral column, propulsion/stride length comes from limbs, have a flexed suspension plate
- carnivores with small volume, run fast have flexible trunks with multipurpose limbs
e.g. cats = have flexible vertebral column allow limbs to swing more, acts like bow to increase propulsion/stride length from limbs and have flexed + extended suspension phase

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13
Q

what is a gait

A

sequence of limb movements

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14
Q

in equine what is a walk

A

4 beat gait
each limb move forward individually sequentially + hit ground separately (slow)

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15
Q

what is a trot

A

diagonal gait = 2 beat gate
two limb hit ground simultaneously
pairs are opposite diagonal limbs

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16
Q

what is a canter

A

3 beat gait
with one period of suspension
left lead = RH LH+Rf LF
right lead LH RH+LF RF
still diagonal pairing

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17
Q

what is a gallop

A

4 beat
left lead - RH LH RFLF
right lead - LH RH LF RF
fast

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18
Q

what is the axial skeleton

A

bones of vertebral column, skull and ribcage

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19
Q

what is the appendicular skeleton

A

all bones of fore and hind limbs

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20
Q

what are the 4 types of bones

A

1) flat (scapula/pelvis)
large surface area for muscle attachment and protects underlying structures
2) long (humerus/femur)
support and leverage in limbs , hole inside = blood cell production
3) short (carpus/tarsus)
large range of movement , anti-concussive , cluster
4() sesamoid bones(e.g. kneecap)
embedded in tendons, change in angle over bony surfaces, can redirect forces and reduce friction to prevent damage

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21
Q

3 bone general features

A

1) smooth surface areas
for passge of structures/tendons
articular surfaces : hyaline cartilage at weight bearing surfaces, resistant to deformation, no blood vessels or nerves, no periosteum
2) specific bony contours
tuberosities/tubers/tubercles/processes
provide site for attachment of important structures
3) rough surface areas
for general muscle attachment

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22
Q

in x-ray/radiographs what are the visible features of long bones

A

-diaphysis = shaft
- cortex = wall
- medullary cavity = hollow centre
- epiphysis = end (incorporated articular surfaces)
- metaphysis = transition zone
appear white as they reflect the x-rays (radio opaque)

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23
Q

where is the insertion of the muscle

A

distal
or where it is not fixed ( joint)

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24
Q

how can muscles be attached

A

1) directly to bone
size of area depends on muscle, rough surface, bony tuber
2) by tendons
condensation of deep fascia into cords, less bulky across joints. small area of attachment , may have separate centre of ossification
3) via aponeurosis
limited access to bone. Fibrous tissue arranged in thin sheets of tissue. condensation of deep fascia into sheets, long area of attachment, muscles in areas with limited access to bone

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25
what are intrinsic muscles
origin and insertion with appendicular skeleton (within limbs) movement of limb joints flexion and extension
26
what are extrinsic muscles
origin on axial skeleton insertion in appendicular skeleton movement of limb relative to trunk protaction and retraction of limb
27
in domestic animals is there a join between forelimb and trunk
no muscular attachments oly scapular glide over thorax pivotal point midway down scapula
28
what is the shoulder region called
omo
29
what is the arm region
brachium (region from shoulder to elbow)
30
what is the forearm region
antebrachium (region from elbow to carpus)
31
what is the wrist region
carpus
32
what is the hand region
manus (region distal to carpus)
33
what is the toe regin
digit
34
How does the scapula develop
has 2 centres of ossification primary is in the body secondary in the supraglenoid tubercule open in a young animal potential problem = tendon of orgigin of biceps brachii muscles physis weak point can cause avulsion fracture
35
what bony structures of the scapula can we palpate
dorsal border cranial border cranial angle spine acromion (guide for locating shoulder joint) caudal border is beneath muscle so difficult to palpate
36
what is the brachiocephalic muscle
extrinsic muscle runing from the head to the arm ( down the neck) origin = cervio-thoracic fascia insertion = humerus (aponeurosis) function = protractor (raises arm) what are 3 parts: cleidocervicalis, cleidomastoideus, cleidobrachialis with line of cartilage between brachialis and cervicalis bit = at shoulder (no bone)
37
what is the latissimus dorsi muscle
broadest muscle of the back origin = thoracolumbar fascia insertion = humerus (aponeurosis) crosses shoulder joint caudally function = retractor propulsion (acts on forelimb and across shoulder)
38
what is the serratus ventralis muscle
located between forelimb and trunk origin = thoracis wall (rib) and cervial vertebrae (neck) insertion = proximal scapula (edial aspect) proximal to pivotal point function: cranially = retractor caudally = protractor
39
what are 3 tpes of joints
fibrous cartilagenous synovial
40
what is the omo region
shoulder
41
what is the branchium region
arm from shoulder to elbow
42
what is the antebrachium
forearm elbow to carpus
43
what is the carpus region
wrist
44
what is the manus region
hand (region distal to carpus)
45
what is the digit region
toe
46
where is the scapula
shoulder blade
47
what does the lateral surface of the scapula
facing out has spine running down the middle cranial side is the suprasinous fossa caudal is the infraspinous fossa at end of spine is the acromion process distal area: - cranial side has the supraglenoid tubercle, glenoid cavity and ventral angle scapular notch is above the supraglenoid tubercle
48
what is the glenoid cavity
articular surface (shoulder joint) concave smooth surface
49
where does the biceps brachii muscle attach on the scapula
supraglenoid tubercle
50
what is on the medial surface ofo the scapula
cranial edge is the serrated edge with rough edge has the subsacapula fossa distal caudal aspect has the infraglenoid tubercle beneath the supraglenoid tubercle has the coracoid process dorsal = attachement of the serratus ventralis muscle ventrally = subscapularis muscle
51
what muscles attach to the medial face of the scapula
dorsally is the serratus ventralis ventrally is the subscapularis muscle
52
differences of the cat and dog
more rounded cranial angle than dog in a cat cat has a suprahamate process which is proximal to the acromion process
53
what is the development of the scapula
has 2 centres of ossification : - body - supraglenoid tubercle problem as tendon of origin of biceps brachi attaches to the supraglenoid tubercle but it is a weak point so has avulsion fracture
54
what bony structures of the scapula can we palpate in live animals
- dorsal border -cranial border + angle -spine - acromion (guide to locate shoulder joint) - caudal border is difficult to palapte
55
what are the extrinsic muscles of the shoulder
- brachiocephalic muscle - omotransversarius - serratusventralis muscle
56
describe the brachiocephalic muscle
origin : cervico - thoracic fascia insertion = humerus (aponeurosis) function: acts as a protractor has 3 parts: cleidocervicalis thick bit on neck, clediomastoidues thin bit on neck both make up the cleidocephalicus cleidobrachialis - bit along the arm
57
describe the omotransversarius muscle
goes underneath the brachiocephalic muscle along the neck origin : transverse wing of the atlas C! insertion: acromion process of the scapula function: protracts forelimb
58
describe the latissimus dorsi muscle
'broadest muscle of the back' origin: thorcolumbar fascia insertion: humerus (aponeurosis) function: retraction propulsion (also acts across the shoulder)
59
describe the serratus ventralis muscle
muscle located between the forelimb and trunk, runs under the medial aspect of the scapula origin: - thoracic wall (rib) and the cervical vertebrae (neck) insertion: proximal scapula (medial aspect, proximal to pivotal point) function: cranial portion - retractor caudal portion - protractor think of the way it moves the scapula + what that results for the rest of the limb
60
describe abductors
muscles are located proximal to the pivotal point and limn ( dorsal aspect?) move limb away from midline
61
describe adductors
move limb towards midline located distal and medial to limb (ventral aspect) kimited movement (more possible in small than large species)
62
describe the trapezius muscle
origin : cervicothoracic fascia insertion = proximal scapular spine by aponeurosis has 2 parts cranial and caudal superficial, can be felt triangle shape causes abduction of scapula ? no effect on shoulder
63
describe the rhomboideus muscle
lies deep to the trapezius origing : cervicothoracis fascia insertion: dorsal border of scapula abductor of scapula no effect on shoulder
64
describe the pectoral muscles
origin: sternum insertion: humerus ( proximal ) has 2 heads , deep and superficial causes adduction of the limb
65
what are intrinsic muscles
both origin and insertion are within appendicular skeleton (on limb) no effect on limb relative to trunk = move joints within limb causing flexion and extension
66
what type of bone is the humerus
type of long bone s-shaped
67
describe the proximal aspect of the humerus
head contains the greater tubercle laterally and the lesser tubercle is on the medial aspect neck head is the articular surface, convex and smooth surface articulates with glenoid cavity of scapula at shoulder joint coming down from the greater tubercle on the cranial side is the tricipital line (raised) and then the deltoid tuberosity (small tubercles) intertubercle groove is where tendon of the bicep brachii passes through
68
describe the distal aspect of the humerus
contains the musculospiral groove and at the bottom tuburcle is called the condyle medial hald is larger than the lateral it is the articular surface for the radius and ulna and is divided into 2 areas: - trochlea , on the medial side, pulley like structure which is larger with a central depression and articulates with radius and ulna - capitulum : located laterally and is smaller, articulates with the radius in middle of the caudal aspect is the olecranon/ulnar fossa in middle of the cranial aspect is the radial fossa dogs contains the supratrochlear foramen beneath the fossas which has no function and may not be present in shortlegged dogs
69
what does the distal end of the humerus contain in a cat
the supracondyloid foramen not the supratrochlear foramen allows the brachial artery and the median nerve to pass through is vulnerable in fractures
70
what are the centres of ossification of the humerus
has 5 one in the proximal epiphyses (tubercle) one in the body 3 in the condyle: -medial epicondyle -medial half of the condyle -lateral half of the condyle
71
what are the palpation landmarks of the humerus
- greater tubercle, guide for locating shoulder joint - lateral epicondyle - medial epicondyle
72
how is the nerve supply to the muscles developed in the embryo
somites in the embryo (paired blocks of mesochyme) develop alon spinal cord groups combine to form each forelimb and drag nerves with them nerve supply reflects origin
73
which nerves supply the forelimb
C6 C7 C8 T1 and T2 ventral branches form brachial plexus, located in the axillary region emerging nerves supply forelimb
74
what sections of the forelimb does the brachial plexus nerve supply
ulnar nerve radial nerve median nerve axillary nerve musculo-cutaneous nerve
75
what does the ulnar nerve affect
flexor carpii ulnaris muscle deep digital flexor muscle
76
what does the radial nerve affect
tensor fasciae antebrachii muscle triceps brachiim anconeus muscle extensor carpi radialis muscle common digital extensor muscle lateral digital extensor muscle ulnaris lateralis muscle abductor digitis longus
77
what does the median nerve affect
pronator teres muscle flexor carpi radialis superficial digital flexor muscle deep digital flexor muscle pronator quadratus
78
what does the axillary nerve affect
deltoideus msucle teres minor muscle subscapularis muscle teres major muscle
79
what does the musculo-cutaneous nerve affect
coracobrachialis muscle brachiialis muscle
80
what are mixed nerves
consist of both motor and sensory fibres , transmit messages in both directions at once cause spinal reflexes
81
what is proprioception
location of limb in space
82
what muscles does the brachial plexus supply
all intrinsic muscles some extrinisc: - latissimus dorsi (retractor) - serratus ventralis (protractor and retractor) -pectorals (adductor) doesn't supply - brachiocephalicus (protractor) - trapezius and rhomboides (abductors)
83
what are the 3 types of joints
- fibrous -cartilagenous - synovial
84
what is a fibrous joint
allows little movement e.g. skull sutures sydesmosis of the radius and ulna and equine metacarpal bones
85
what is a cartilagenous joint
allows little movement - synchondrosis/synarthrosis pelvic / mandibular symphysis epiphysis/diaphysis in young
86
what does a synovial joint contain
allows large range of motion found in most limb joints contains: hyaline cartilage which covers articular surface (bones) , reduces friction and contains no blood vessels or nerve endings = no pain, in arthirits nerves are exposed - synovial fluid is in joint cavity to lubricate joint and nourish the cartilage - joint cavity is lined by synovial membrane that produces synovial fluid and is a physical barrier to contain fluid - joint capsule covers it all , is a fibrous layer that is incorporated into the synovial membrane and attaches round the osteochondral junction - ligaments laterally around joint capsule (formed from condensation of fibrous material) run from bone to bone, support joint and restirct movements between bones
87
what bones make up the shoulder joint
scapula and humerus glenoid cavity articulates with the humerus head glenoid cavity is concave , humerus head is convex
88
what can you palpate on the shoulder joint
acromion process of the scapule and the greater tubercle of the humerus
89
what is the bicipital bursa
allows movement of the tendon of the bicep brachii over the humeral tubercles as joint capsule extends into the inter-tubercular grove and wraps around tendon of orgin of biceps brachii (origin is the supraglenoid tubercle of scapula) held in place by the transverse ligament
90
what is the supraspinatus muscle
supports the shoulder laterally on the cranial aspect origin is the supraspinous fossa on the scapula inserts on the greater tubercle of the humerus two heads? allows extension of the shoulder joint
91
what is the infraspinatus muscle
supports the shoulder laterally on the caudal aspect origin is the infraspinous fossa inserts distally to the greater tubercle on the humerus causes abduction of the shoulder supplied by the suprascapular nerve, contains motor fibres only
92
what is the subscapularis muscle
supports the shoulder on the medial aspect origin is the subscapular fossa on the scapula inserts on the lesser tubercle on the humerus causes adduction of the shoulder joint supplied by the subscapular nerve which contains motor fibres only
93
what muscles extends the shoulder joint
shoulder extensors cross cranially to the shoulder joint - brachiocephalicus (extrinisc muscle) nerve supply is not the brachial plexus - biceps brachii muscle (one head in dog)
94
what is the biceps brachii muscle
intrinsice muscle origin is the supraglenoid tubercle insertion is the ulnar and radial tuberosities shoulder extensor and elbow flexor supplied by the musculocutaneous nerve the bicipital bursa in the humerus protects the tendon of origin as it passes through the intertubercular groove
95
what muscles flex the shoulder joint
shoulder flexors cross caudally to the shoulder joint - latissimus dorsi (extrinisc, nerve supply is the brachial plexus) - teres major (intrisins) - teres minor (intrinsic ) - deltoideus muscle (intrinsic) - triceps (intrinsic)
96
what is the teres major muscle
on lateral aspect caudally of the shoulder joint origin is the caudal border of the scapula insertion is the medial humerus nerve supply from the auxillary nerve which contains both motor and sensory fibres shoulder flexor
97
what is the teres minor
lies cranial to the teres minor but still caudal aspect of the scapula and humerus origin is the infraspinous fossa of the scapula,, distal aspect inserts on the medial humerus supplied by the axillary nerve shoulder flexor
98
what is the deltoideus muscle
has 2 heads origins: scapular spine and acromion process inserts: lateral aspect of humerus nerve supply : axillary nerve, mxed type , both motor and sensory fibres shoulder flexor
99
what is the triceps muscle
has 4 heads one is major = 'long head' , most superficial and caudal long head origin is the caudal border of the scapula other heads origin is the humerus lateral and one medial insert on the olecranon of the ulna extends the elbow nerve supple is the radial nerve which contains both motor and sensory fibres
100
what are the four parts of the hoof
- wall (toe, quarter = underneath, heal and bar - periople - sole - frog
101
what is the frog
rubbery wedge shaped strucutre positioned between the bars can expand hole when weight bearing, is very flexible and elastic in nature in centre is the centre sulcus which either side has the sulci where you need to clear dirt out of these before shoeing or examining
102
what are the bars of the heel
there are two bars on each hoof, either side of the frog. they are triangular support that weight bearing so they are a hard structure
103
what is the sole
the sole covers the bottom offoot, (white bit round the front) / is concave so shouldn't touch the ground)
104
what is the white line in the hoof
interconnected lamina between wall and sole contains both sensitive and insensitive
105
what are the walls of the hoof
go round the outside walls are the same basic structure as your finger and toe nails (weight bearing)
106
where are the heel bulbs
back of heel, round bit at the end
107
what is the coronary band
enitre boundary between skin and hoof, contains the periople transition between skn and hoof wall produces hoof wall and marks boundary between skin and hoof
108
what is the periople
within the coronary band the whiteish line round the middle produces waterproof waxy layer that extends 2/3 way down hoof and prevents evaporation, wear and tear
109
what does the inside of the hoof contain
proximal phalanx, ,middle phalanx and distal phalanx DIP and PIP joint navicular one ( sesamoid bone of the phalanx) DDFT ( deep digital flexor tendon) navicular bursa = protects digital cushion
110
what is the digital cushion
- deep to frog (behing the P2 and P3) contains elastic tissue, blood vessels and fat is a shock absorber (is equiv. of dog pad) protects the DDFT, distal phalanx, navicular bursa and navicular bone
111
what is the clinical significance of the hoof contents
penetration injuries , depending on location and depth abcess formation exerts pressure on the structures may need to apply poultice to soften horn can sometime palpate need to know where strucutures are to let out
112
what and where anf the lateral and ungual cartilages
either side of the DIP cartialge plates, palmer processes both medial and lateral aspects for shock absorption mineralise with age ( can be seen in xray if ossified) when they mineralise = called sidebone
113
how is hoof produced
the dermis corium covers the distal phalanx and digital cushion , is the deeper red layer that is senstitve as it contains blood and nerve supply (extensively vascularised) contains lots of curtain like folds, visible by microscopes this supplies the germinative layer germinative layer : produces epidermis layer at the coronary band and solar aspect ( bottom of hoof) hoof wall ontop is keratinised to stop damage and is insensitive
114
how does the coronary band forms
dermisi firmed into conical shaped papillae dermal papillae produces in the form of tubes of keratin which extend distally towards ground which grow 5-6mm per moth gaps are filled by intertubular horn which forms the hoof wall which is weight bearing surface -epidermal horn tubes glide distally internal surface interdigitates with dermal laminae and forms corresponding primary and secondary laminae known as epidermal/insensitive laminae
115
where does the dermis fuse and how does it form under the hoof
dermis is fused to the distal phalanx primary lamina is macroscopic (bands of pink) secondary is protusions into the insensitive lamina, only visible in the microscopic this is the sensitive part below the hoof wall the primary laminae are the folds you can see
116
what is the interdigitation
white line that prevents separation of epidermis from distal phalanx and transfers weight from hoof wall to distal phalanx the solar surface (bottom) is the active germination layer and has a different composition to hoof wa;;
117
what is the sole composition
keratinised flakes and no tubular horns
118
what is the composition of the frog
incomplete keratinisation and soft and elastic
119
what is the clinical significance of the lamina
introducing nail to attach shoe , if in interweaving bit animal wil go lame as nerve are hits
120
how does the weight bearing occur in the hoof
frog contacts ground first and forces are passed to the digital cushion which pushes the blood back up leg and the lateral cartilages when the hof wall contacts ground the weight is transferrred to distal phalanx then via laminae to hoof wall extensive blood supply mean forces travel back up
121
what to be aware of for farriers
foot needs cutting continuously, as horn always grows shoeing protects weight bearing wall, caudal aspect is oepn so shape doesn't restirct heel therapeutic shoes support heel nails need to be careful and aim for only the insensitive laminae , so nails are sledge tipped nails then tips clipped and flattened form clenches. must 'raise clenches' before reomving
122
difference between ruminants hoof and horses hoof
ruminants have a cloven hoof with both medial and lateral claws with an interdigital cleft has no frog and no angles and the bars no lateral cartilages wall of ruminant hood wall is concave inbetween digits lateral wall is convex and is continuous with heel medial part is vertical and stops at parapedal groove, transition hard to soft hors at top is prone to damage
123
how do ruminants absorb the shock
- bulbous heels with digital cushion - digits splay and are supported by interdigital ligaments have no lateral cartilages and no frog
124
clinical consideration with ruminant hoofs
horn is often overgrown if soft ground (forelimb inner claw is overgrown, hindlimb is outer claw) can get solar ulcers especially with parapedal groove , secondary infection can track up deep digital flexor tendon sheath can get interdigital dermatitis white line disease lamininits
125
how are sheep and goat hooves adapted
- goot hooves are well adapted for climbing, hard walls and softer soles for traction on steep inclines same as cattle skin gland is proximal to inter-digital cleft (waxy substances produced by sebaceous and serous gland) overgrowth is a problem a trimmed
126
how are pigs hooves like
- similar to ruminants have no ruminants and no frog no lateral cartilages has 4 digits extra digits that are non-weight bearing and don't touch the ground