Anatomy 2 - Equine Forelimb mm-aa-vv-nn

martinezdvm's version from 2015-10-29 22:53

Know the mm, the mm groups, and the nn of the mm groups

Question Answer
extrinsic mm of the forelimb are?trapezius, brachiocephalicus, omotransversarius, latissimus dorsi, pectoral mm, subclavius, serratus ventralis, rhomboideus
where does the trapezius extend to and from?almost from poll to the withers
what does the tapezius do the mvt of the scapula?swing it back and forth, both parts abduct the scapula (cervical and thoracic)
what innervates the trapezius?dorsal branch of the accessory n
what is the prime advancer of the forelimb?brachiocephalicus
what is the prime retractor of the forelimb?latissimus dorsi
what innervates the brachiocephalicus?accessory n, cervial nn, and axillary n
what does the omotransvarsarius do?complements action of the brachiocephalicus
what innervates the latissimus dorsi?thoracodorsal n
what are the superficial pectoral mm?descending pect, transverse pect
what do the superficial pectoral mm do?ADduction of forelimb (desc pec, xverse pec)
what does the deep pectoral do?retractor and ADductor of the forelimb, complements action of serratus ventralis to an extent
what are all of the pectoral mm innervated by?pectoral nn from the brachial plexus
origin of subclavius?just cr to the deep pectoral on the sternum.
what does the subclavius do?complements actions of the deep pectoral (retractor/ADductor of forelimb)
what is the subclavius innervated by?pectoral n
what is the serratus ventralis innervated by?long thoracic n
what are the parts of the serratus ventralis? what does it do?cervical and thoracic parts. *suspends the trunk in between the forelimbs
what are the parts of the rhomboideus m? which is bigger?cervical (bigger) and thoracic
what is the rhomboideus innervated by?the dorsal branches of the caudal cervical nn
how are the shoulder region mm organized? what is their purpose?into lateral and medial groups- surround shoulder joint and stabilize it
what is included in the lateral group of the mm of the shoulder?supraspinatus, infraspinatus, deltoideus
what innervates the supraspinatus?the suprascapular n
what is the fxn/mvt of the supraspinatus m?stabilize shoulder joint, extend shoulder joint
which mm is associated with sweeny?supraspinatus
how is the infraspinatus divided?tendon of insertion splits into two parts, **the superficial possesses a synovial bursa
special to note about the infraspinatus?It has two tendons of insertion & the superficial one possesses a synovial bursa
what is the fxn of the infraspinatus?acts as a collateral lig and stabilizes shoulder (abduction is a secondary fxn)
what innervates the infraspinatus?suprascapular n
what innervates the deltoideus mm?axillary n
what is the fxn of the deltoideus m?primarily a flexor of the shoulder and has a secondary ABductor action
what is included in the medial group of the shoulder mms?subscapularis, teres major, coracobrachialis
what innervates the subscapularis? action?subscapular n. stabalizes shoulder joint, ADducts the arm.
what innervates the teres major? action?axillary n. chiefly a flexor of the shoulder, but also ADducts the arm
what innervates the coracobrachialis? action?musculocutaneous n. ADductor of the arm
what are the flexors of the arm? (elbow/cubital joint)biceps brachii, brachialis
Innervation of the biceps brachii? fxn?musculocutaneous n. important role in fixation of the shoulder joint, and also extends the shoulder joint. PRIMARY= flexor of the elbow.
innervation of the brachialis?musculocutaneous and a little radial n
what are the extensors of the arm? (elbow/cubital joint). what innervates them?tricpes brachii, tensor fascia antebrachii. RADIAL N.
how is the triceps brachii divided?into three HEADS, the long, lateral, and medial
what is the lacertus fibrosis?a think fibrous strand extending along the length of the biceps brachii m to insert on the extensor carpi radialis
why do we care about lacertus fibrosis?it is an important component of the forelimb stay apparatus. Keeps cubital joint from flexing.
explain what is involved in "capped elbow" ?the bursas of the TRIceps brachii of cubital joint- the bursa between the triceps b. and the bone, and then an acquired one between mm and skin
what does tensor fascia antebrachii m do?extensor of the arm
extensors of the forearm (of carpus and digits)?extensor carpi radialis, common digital extensor, lateral digital extensor, extensor carpi obliquuis, ulnaris lateralis<--(it is a flexor but it is innervates by the radial n. weird.)
where do the forearm extensors originate? Run? insert?O= crlateral aspect of distal humerus. Run along the craniolateral part of the forearm. I= on carpus/metacarpus, or digits.
what innervates the extensors of the forearm? action? radial n. They extend carpus AND digits.
where does the extensor carpi obliquuis m originate?NOT on the cr-l aspect of the humerus-- it originates on the shaft of the radius
explain the grouping of ulnaris lateralisit is grouped as an extensor because it is innervated by the Radial n like the rest, even through it is a FLEXOR!
how are the extensors of the forearm secured down?by the extensor retinaculum at the carpus
what are the flexors of the forearm (carpus and digits)?flexor carpi radialis, flexor carpi ulnaris, superficial digital flexor, deep digital flexor
where do the FLEXORS of the carpus and digits arise from? what space do they occupy on the forearm?caudomedial aspect of humerus, occupy the caudal part of the forearm
how are the flexor mm of the carpus and digits secured?by the flexor retinaculum at the caudal aspect of the carpus.
What innervates the flexors of the carpus and digits?mainly the Median and Ulnar nerves

AA of the distal thoracic limb

Question Answer
what are the 3 major blood vessels of the forelimb?axillary, brachial, and median a
where does the median a run? when does it divide?courses caudally to palmar surface of limb. divides at apprx the carpus
what two branches does the median a give off? what does it continue as, then?the palmar branch of the median a (L) and the radial a (M). Median a then continues as the medial palmar artery
what is the main artery of the manus (forefoot)?the medial palmar a (a continuation of the median a after it gives off the palmar branch of the median a and the radial a)
where/what does the medial palmar a divide into?above the fetlock, the medial and lateral palmar proper digital aa
where do the medial and lateral palmar proper digital aa run?course on abaxial surfaces of the prox. sesamoid bones then on the borders of the deep digital flexor tendon to gain entry to the hoof
what do the (proper) digital arteries give off?dorsal branches to the dorsal surfaces of the prox and middle phalanges (medial and lateral dorsal branches anastomose to form an arterial circle around the phalanx)
how do the arteries of the manus end?in the terminal arches
how is the terminal arch formed?the proper digital aa pass through the sole foramina into the sole canal, and the anastomose to form the arch
explain what happens to the palmar branch of the median a and a branch from the radial a? (the two original branches of the median a)they join together, give off the MEDIAL AND LATERAL PALMAR METACARPAL AA, then join the medial palmar artery.
which limbs are most likely to have laminitis happen in first?the forelimbs
how can you try to diagnose laminitis?feeling a strong pulse in the digital arteries (fore and hind limbs)
Look at two charts for aa of the forelimbsi want to die

VV of the thoracic limb

Question Answer
how does the venous drainage of the forelimb start? (describe position also)starts as 3 interconnected, valveless venous plexuses in the foot: (1) dorsal venous plexus (deep in the laminar dermis) (2) the palmar (and plantar) venous plexus (deep in the sole dermis and on the axial surfaces of the cartilages of the distal phalanx) (3) The coronary venous plexus (in the coronary cushion overlying the common (or long) digital extensor tendon, and abaxial surfaces of the cartilages of the distal phalanx)
what is formed from the three venous plexuses of the foot?the digital (medial and lateral) veins
what do the digital (medial and lateral) veins turn into? followed by?then the palmar vv, then the cephalic v
how do you order the vessels and nerves of the thoracic limb?from cr(dorsal) to ca(palmar)= VAN (vein, artery, nerve)

NN of the manus

Question Answer
the nn of the manus come from the what? (2)median and ulnar nn
what provides the MAIN innervation to structures of the manus?the median n
where does the median n divide, and into what? How does it run after that?into M and L palmar nerves above the carpus. then runs in the metacarpal grooves on both sides
as the medial palmar n descends the forefoot, it lies between what two things? it then sends out what, at that point?between the interosseus mm and the deep flexor tendon. At mid metacarpus it sends a communicating branch obliquely and ventrolaterally to the lateral palmar n
just above the fetlock, what does the medial palmar nerve become?the medial palmar proper digital n, which runs with the digital vessels on the abaxial aspect of the prox. sesamoid bone
which nerve does the ulnar n contribute to?the lateral palmar nerve
how do the M and L palmar metacarpal nn arise?lateral palmar breaks off the deep branch of the lateral palmar n, which divides in the M and L palmar metacarpal nn
what is the dorsal aspect of the distal forelimb innervated by? (3)(1) dorsal branch of the ulnar n. (2) medial cutaneous antebrachial nerve (branch of the musculocutaneous n) (3) dorsal branches from medial and lateral (palmar proper) digital nn.
what do both medial and lateral (palmar proper) digital nn give off?dorsal branches (one or two each)
Draw out all the flow diagrams in this packet.Srsly.
*medial and lateral palmar nn are branches of what?the median nn
*medial and lateral palmar metacarpal nn are the branches ofdeep branch of the lateral palmar n
*major/main nerves supplying the PALMAR aspect the distal forelimb/manus are?median and ulnar n
*nerves supplying the DORSAL aspect of the distal forelimb/ manus are? (3)(1) dorsal branch of of the ulnar n. (2) medial cutaneous antebrachial nerve (branch of the musculocutaneous n) (3) dorsal branches from medial and lateral (palmar proper) digital nn.