Thoracic Limb Flashcards
what is considered the ‘sling’ muscle?
serratus ventralis
Midline → cranial to caudal, what plane is this?
Median/
mid-sagittal plane
If you were to cut a dog in half like Houdini, what type of plane would that be?
Transverse plane
What are the extensors of the shoulder?
infraspinatous
supraspinatous
subscapularis
coracobrachialis
biceps brachii
What are the Flexors of the shoulder?
Deltoideous
Teres major
Teres minor
Latissimis Dorsi
Tricep- Long Head
Infraspinatous
What are the Extensors of the elbow?
Triceps (all heads)
Tensor fascia antebrachii
anconeous
What are the Flexors of the elbow? hint:2
Biceps Brachii
Brachialis
What are the Extensors of the carpus? hint:3
Extensor carpi radialis
Common digital extensor
Lateral digital extensor
What are the Flexors of the carpus? hint:5
flexor carpi radialis
superficial digital flexor
deep digital flexor
flexor carpi ulnaris
ulnaris lateralis
What are the Extensors of the digits? hint:2
lateral digital extensor
common digital extensor
What are the Flexors of the digits?
superficial digital flexor
deep digital flexor
What is innervated by the Accessory nerve?
brachiocephalicus
sternocephalicus
omotransversarious
trapezius
What is innervated by the Axillary nerve?
Deltoideous
teres major
teres minor
what is innervated by the median nerve?
pronator teres
pronator quadratus
flexor carpi radialis
superficial digital flexor
deep digital flexor (also innervated by ulnar nerve)
what is innervated by the Musculocutaneous nerve?
coracobrachialis
biceps brachii
brachialis
what is innervated by the suprascapular nerve?
supraspinatous
infraspinatous
subscapularis
What is innervated by the radial nerve?
tensor fascia antebrachii
triceps brachii (all heads)
anconeous
extensor carpi radialis
common digital extensor
lateral digital extensor
ulnaris lateralis
abductor digiti 1 longus
supinator
what is innervated by the ulnar nerve?
flexor carpi ulnaris
deep digital flexor (also innervated by median nerve)
What is the digging muscle?
latissimis dorsi
What are the components of the “v” muscles?
Sternocecephalicus->
sternomastoideous (mastoid process)
and sternooccipitalus (nuchal crest)
what are the components of the “Y” muscles?
Brachiocecephalicus->
cleidocephalicus
->cleidomastoideus
->cleidocervicalis
(cleidobrachialis is a part of this set of muscles but not considered a part of the ‘y’ since it is further down the arm)
which is closer to the trachea/ more medial: sternohyoideus or sternothyroideous?
*jordyn double check with ta’s
sternothyroideous
What digit(s) does the common digital extensor affect?
extends 2-5
what digit(s) does the lateral digital extensor affect?
extends 3-5
what digit(s) does the superficial digital flexor affect?
Flexes 2-5
what digit(s) does the abductor digiti 1 longus affect?
abducts the 1st digit
what direction is pronation: turn palmar surface up or down?
palmar surface down
what direction is supination: palmar surface up or down?
palmar surface up
(as if holding soup)
Where does the deltoideus originate and insert?
origin: spine, acromion of scapula
Insertion: deltoid tuberosity
Where does the infraspinatous originate and insert?
origin: infraspinatous fossa
insertion: infraspinatous tuberosity
Where does the supraspinatous originate and insert?
origin: supraspinatous fossa
insertion: greater tubercle
Where does teres minor originate and insert?
origin: caudal border of scapula (infraglenoid tubercle)
insertion: teres minor tuberosity of humerus
Where does teres major originate and insert?
origin: caudal border of scapula (infraglenoid tubercle)
insertion: teres major tuberosity of humerus
Where does the subscapularis originate and insert?
origin: subscapular fossa
insertion: lesser tubercle
Where does the coracobrachialis originate and insert?
origin: coracoid process
insertion: medial humerus
Where does the tensor fascia antebrachii originate and insert?
origin: latissimus dorsi (in fascia)
insertion: olecranon
Where does the triceps brachii LONG head originate and insert?
origin: caudal border of scapula
insertion: olecranon
Where does the triceps brachii LATERAL head originate and insert?
origin: tricipital line (humerus)
insertion: olecranon
Where does the biceps brachii -accessory and medial heads originate and insert?
origin: proximal humerus
insertion: olecranon
Where does the anconeous originate and insert?
origin: lateral and medial epicondyles
insertion: olecranon
Where does the biceps brachii originate and insert?
origin: supraglenoid tubercle
insertion: radial and ulnar tuberosities
Where does the brachialis originate and insert?
origin: proximal humerus
insertion: radial and ulnar tuberosities
Where does the extensor carpi radialis originate and insert?
origin: lateral supracondylar crest
insertion: dorsal MC 2 and 3
Where does the common digital extensor originate and insert?
origin: lateral epicondyle
insertion: extensor process, distal phalanges of digits 2-5
Where does the lateral digital extensor originate and insert?
origin: lateral epicondyle
insertion: extensor process, distal phalanges of digits 3-5
Where does the ulnaris lateralis originate and insert?
origin: lateral epicondyle
insertion: MC V and accessory carpal bone
Where does the abductor pollicis (digiti 1) longus originate and insert?
origin: ulna
insertion: MC 1
Where does the supinator originate and insert?
origin: lateral epicondyle
insertion: proximal radius
Where does the pronator teres originate and insert?
origin: medial epicondyle
insertion: medial radius
Where does the flexor carpi radialis originate and insert?
origin: medial epicondyle
insertion: palmar MC 2 and 3
Where does the superficial digital flexor originate and insert?
origin: medial epicondyle
insertion: palmar surface, middle phalanges of digits 2-5
Where does the flexor carpi ulnaris originate and insert?
origin: ulnar head- olecranon; humeral head- medial epicondyle
insertion: accessory carpal bone
Where does the deep digital flexor originate and insert?
origin: humoral head- medial epicondyle; radial head- radius; ulnar head- ulna
insertion: palmar surface, digital phalanges of digits 1-5
Where does the pronator quadratus attach?
attachments: opposed surfaces of radius and ulna
Where do the superficial pectoral muscles originate and insert? what is its action?
origin: first 2 sternebrae
insertion: crest of the greater tubercle
action: adduct
Where do the deep pectoral muscles originate and insert?
origin: sternum
insertion: greater and lesser tubercles of the humerus
Where does the trapezius originate and insert?
origin: median raphe of the neck, supraspinous ligament
insertion: spine of scapula
Where does the rhomboidious originate and insert?
origin: median raphe of neck, nuchal crest
insertion: dorsal border of the scapula
Where does the latissimus dorsi originate and insert?
origin: spinous process of thoracic and lumbar vertebrae, thoracolumbar fascia
insertion: teres major tuberosity of the humerus
Where does the serratus ventralis originate and insert?
origin: the transverse process of cervical vertebrae, middle of first 7-8 ribs
insertion: the serrated face of the scapula
What is the definition of a fossa?
a depression
what is the definition of an acromion?
the shoulder
-the tip on the outer end of the spine of the scapula that protects the glenoid cavity forms the outer angle of the shoulder
What is the definition of a glenoid?
a shallow cup
what does coracoid mean?
a bird beak
Does a cat have a supratrochlear foramen?
no
does a cat have a suprachondylar foramen?
yes
What part of a bone can often fail to unite?
the anconeal process
what does ungual refer to?
nail/claw
What does it mean to flex?
to make flexor angle smaller
what does it mean to extend?
to make the flexor angle larger
what does it mean to adduct?
move towards midline
what does it mean to abduct muscle?
move muscle away from midline
How many cervical vertebrae do mammals have?
7
how many thoracic vertebrae do canines have?
13
how many lumbar vertebrae do canines have?
7
how many sacral vetrebrae to canines have?
technically 3 but they may fuse and look like 1
What action does the Atlas vertebrae (C1) do?
Atlanto-occipitaljoint
flexion and extention= ‘yes joint’
What action does the axis vertebrae (C2) do?
atlanto-axialjoint
Rotation/ pivot= ‘no joint’
which cervical vertebrae does not have a transverse foramen?
C7
which cervical vertebrae has an expanded ventral lamina of the transverse process?
C6
Where does the first cervical spinal nerve (and artery and vein) pass through?
The lateral vertebral lamina of C1
what cervicalvertebrae has the tallest spinous process?
C7
what passes through the transverse foramen?
the vertebral artery and vein
What reflex does the cutaneus trunci cause?
the panniculus reflex
What veins do not have partner arteries in the thoracic limb?
cephalic vein
axillobrachial
omobrachial
what does the word condyle mean?
looks like a knuckle
What passes through the supracondylar foramen in cats?
brachial artery and median nerve
( does not exist in dogs)
what passes through the supratrochlear foramen in dogs?
nothing
what does the word trochlea mean?
a pulley
what muscle has a vistigial sesamoid bone? it may be mistaken as a fracture on radiographs
the abductor digiti 1 longus
What would happen if the radial nerve lost function?
total loss would cause the animal to stand with the joint uncharacteristically flexed
What will happen if the musculocutaneous nerve lost full function?
will affect the ability to flex the elbow joint
does not affect the gate or animal’s ability to stand
*rare case
what will happen if the axillary nerve lost function?
Does not impair the animal’s gate since other muscles are potentially able to flex shoulder
what will happen if the subscapular nerve lost function?
lateral deviation of the shoulder and, with time, noticeable atrophy of muscles in shoulder
will the loss of either the median or ulnar nerve (singularly) affect an animal’s gate?
No, because the overlap of the nerves and their motor distribution makes it unlikely
what rib does the subclavian artery wrap around as it leaves the thoracic cavity?
first rib.
name changes from the subclavian to the axillary artery
what does DCDA stand for?
dorsal common digital artery
(will be the more superficial artery in the paw)
what does DMCV stand for?
dorsal metacarpal vein
(deep veins in paw)
What does DPDN stand for?
Dorsal proper digital nerve
(in paw)
what does the direction axial mean?
on the side facing the central axis
(usually used to describe digits)
what does the direction abaxial mean?
on the side facing away from the central axis
(used to describe digits)
A dog holding a bone in its paws would be pronation or supination?
Pronation, because the dog is holding the bone by applying the pressure downward
What are the components of the axial skeleton?
Skull
Hyoid process
Vertebral column
Ribs
sternum
What are the components of the appendicular skeleton?
Thoracic and pelvic limbs
What is the order of regions within a long bone from proximal tip to mid-bone?
Epiphysis
Epiphysis plate
Metaphysics
Diaphysis
What is the average number of coccygeal/caudal vertebrae? outliers may occur
20-25
Key features of C1
Transverse and lateral foramina
Key features of C2
Dens and spinous process
Key feature of C3-C5
Spinous process increase in height from cranial to caudal
Key feature of C6
Expanded ventral lamina of the transverse process
Key features of C7
No transverse foramen and has the tallest spinous process of the cervical vertebrae
What goes through the transverse foramina?
Vertebral artery and vein
What goes through the lateral vertebral foramen on C1?
C1 cervical nerve
What is considered the brachial plexus?
Last 3, first 2= C6,C7,C8,T1,T2
Define fibrous joints. What is an example?
Bones united by dense connective tissue
Example: suture of skull
Define cartilaginous joints. What’s an example?
Bones united by cartilage.
Ex: intervertebral discs, between skull and hyoid apparatus
Define synovial joints
A fluid filled cavity that envelopes union of bones
Name a few examples of synovial joints
Atlanta-occipital joint: flexion and extension (the YES joint)
Atlanta-axial joint: pivot joint and rotates (the NO joint)
The rest of the cervical joints: plane joints that slide
Distal scapula, attachment point of the biceps brachii, and originating area for tendinitis. What am I?
Supraglenoid tubercle
Distal scapula, insertion of the deltoideus
Acromion
Proximal ulna, attachment of the anconeus
Anconeal process
Proximal humerus, insertion of supraspinatus and infraspinatus
Greater tubercle
Flexors of digits attach where?
Medial epicondyle
Extensors of digits attach where?
Lateral epicondyles
Insertion location of the triceps and anconeus
Olecranon
What attaches to the accessory carpal bone?
Ulnaris lateralis and flexor carpi ulnaris
Where does the nuchal ligament attach to in a dog?
C2
Where does the supraspinous ligament attach?
T1-2 to S1
What is the purpose of the intercapital ligament?
Cover and protect intervertebral discs, the goal is to prevent herniation
What about intervertebral discs makes them susceptible to herniation?
Intervertebral discs are thinner on the dorsal side
Where is the vertebral longitudinal ligament located?
Along ventral vertebral bodies
Where is the dorsal longitudinal ligament?
Inside vertebral canal along dorsal vertebral bodies
What path would need to be taken for in laminectomy for a dorsal approach?
The transversospinalis group will be reflected
What path would need to be taken for an intervertebral disc surgery from a ventral approach?
Reflect the longus colli muscle
What are the muscles of respiration?
Scalenus
Serratus dorsalis (cranialis and caudalis)
External and internal intercostals
Clinical signs of damage for the thoracodorsal nerve
Digging action impaired
Clinical signs of damage of the axillary nerve
Reduced flexion of the shoulder
(Can still flex the shoulder because of the long head of the triceps and the latissimus dorsi)
Clinical signs of damage to the suprascapular nerve
Atrophy to muscles (supraspinatus and infraspinatus)
Reduced extension
Migration of the limb away from the body
Clinical signs of damage to the subscapular nerve
Nothing
Can still extend shoulder because of the supraspinatus and infraspinatus
Clinical signs of damage to the musculocutaneous nerve
Cannot flex elbow
(Can still extend shoulder because of the infraspinatus , supraspinatus, and subscapularis muscles)
Clinical signs of damage to the radial nerve (proximal and/or distal)
Proximal: cannot extend elbow, cannot bear weight
Distal: cannot extend carpus or digits -> knuckling
Clinical signs of damage to the median nerve
Reduced flexion of the digits -> plantigrade stance
= cannot stand on digits so stands on metacarpals
Clinical signs of damage to the ulnar nerve
Cannot stand on digits, stands on metacarpals
Blood supply to the head
Internal carotid and vertebral arteries
Blood flow in a dog (order of arteries)
Subclavian-> axillary -> brachial -> median -> manus
Order of arteries for blood flow in a cat
Subclavian -> axillary -> brachial -> median -> radial -> manus
Boundaries of the carpal canal
Lateral: accessory bone
Ventral: flexor retinaculum
Dorsal: palmar carpal ligament
Structures within the carpal canal
Median and ulnar nerves
Differences in the acromion between dogs and cats
Dogs: rounded acromion
Cats: larger acromion and cats have a metacromion which functions as an insertion of the trapezius and the origin of the omotransversarius
Difference in coracoid process between dogs and cats
Dogs: small coracoid process
Cats: better developed coracoid process
What is the difference between long bones in dogs and cats?
Cats have straighter long bones and dogs’ are more curved
Declawing in cats, what is removed?
The distal phalanx is removed, cutting off the insertion of the deep digital flexors
What artery provides blood to the head?
common corotid artery
What vein runs from the head?
Jugular vein
what type of joint is the atlanto-axial joint?
a synovial pivot joint
What muscles attach to the accessory carpal bone?
ulnaris lateralis and flexor carpi ulnaris
(Dr. Holliday Q)
A dog has presented to you that can extend its elbow joint and bear weight, however, only on the dorsal aspect of its manus. When you test the dorsal manus for sensation, the dog is clearly feeling it in his skin. What specific nerve damage might explain this presentation?
deep branch of radial nerve on surface of brachialis muscle
What is the carpus trunci innervated by? Is that nerve a part of the brachial plexus?
lateral thoracic nerve and yes, so if the brachial plexus is severed there will no longer be a penniculus response
What is a common issue for the ancconeal process and what does it result in?
Ununited annconeal process -> non-weight bearing lameness
