Anatomy 2 - Equine Neck

drraythe's version from 2015-06-05 22:56


Question Answer
vertebral formula?C7, T18, L6, S5, Ca15-21
what portions of the vert. have the best mvt?cervical and caudal
least amt of mvt region of vert?thoraco-lumbar region
how is the mvt between each vert?poor, however collective movement is fine
vert colum main mvts are?mainly dorsal, ventral and lateral flexion. A little rotation occurs.
why such poor mvt in thoracolumbar region? (3)(1) interspinous ligs (2) intertransverse ligs (3) only in horse synovial joints in some lumbar xverse processes
intertransverse ligs link what?LUMBAR xverse processes
lumbar transverse process synovial joints usually where?4th and 5th and between the 6th lumbar and the sacrum, but often involves other lumbar transverse processes.
what is the most important part of casting a horse?make sure thoracolumb. region doesnt have violent mvt b/c of all its specialized structures
most mobile joint of verts?lumbosacral joint (think kicking)
for what reason is the lumbosacral joint so mobile?Essential for transmission of propulsion from the pelvic limbs to the cranial part of the body (AND KICKING)
what bears the weight of the ab. organs?the vert column
the lumbar area of the horse is ____ and ____. Why?short and immobile. It's because the intervert discs are VERY THIN
how much of the vert length is lumbar? (%) (vs. carnivore and human?)10% (carnivores=16% and humans=25%)
where is the center of gravity in the horse? why?nearer forelimbs due to weight of head and neck.
ratio of weight bearing in forelimb vs hindlimb?55:45 (fore:hind) (dog is 60:40)
in relation of center of gravity, fxn of forelimb vs hindlimb?fore= POSTURAL mostly. Hind= PROPULSION mostly
why does a lame forefoot cause the horse's head to jerk back? other example of when something similar happens?center of gravity can be moved by mvt of head (same applies for lifting of foot for hoofwork, head must be lifted opposite of side lifted)
what is the dorsoscapular lig formed by?Formed by the thoracolumbar fascia (deep fascia) in the interscapular region (withers)
what kind of tissue is the dorsalscapular lig?fibroelastic connective tissue
where does the dorsoscap. lig extend from (along the length of the horse), to, and attach to?extending from T2 to T5, and attaching to the spinous processes, transverse processes, scapula and ribs in this region
so dorsoscapular lig is over what region of the horse?the WITHERS---region of scapulae (NOT NECK)
where is the thoracolumbar fascia in relation to the supraspinous lig?thoraco is under supra
where is the withers in relation to vert column? (measure in terms of verts)T1-T4(up to T6)
where does the dorsoscap fuse to its fellow? fuses with its fellow over the spinous processes of T2 and T3
where does the dorsoscap lig place in relation to the lig nuchae? the rhomboideus m?arises ventral to the ligamentum nuchae and medial to the rhomboideus (thoracis) muscle.
what does the supraspinous lig turn into in the neck?lig. nuchae
how many/what are the layers of the dorsoscap lig?(3) superficial, middle, and deep layer
all three layers of dorsocap lig originate where?thoracolumbar fascia over the spinous process
why do we care so much about the dorsoscap lig?b/c of fibroelastic nature, used as CONCUSSION ABSORPTION MECHANISM (shock) of forelimb.
what is casting a horse?when a horse is on its side (for sx usually)
where does the SUPERFICIAL layer of the dorsoscap lig attach dorsally? Ventrally?dorsally=thoracolumbar fascia under the lig nuchae. Ventrally=attaches to ribs laterally.
what muscles are associated with the SUPERFICIAL layer of the dorsoscap lig?medial part of serratus ventralis and rhomboideus thorasis. (interdigitating with the fascicles of both mm, and fibers extened laterally beyond serratus ventralis mm)
where does the MIDDLE layer of the dorsoscap lig attach dorsally? Ventrally?dorsal= thoracolumbar fascia under the lig nuchae. Ventrally= attach to ribs proximally (as opposed to laterally as in the superficial layer)
what mm does the MIDDLE layer of the dorsoscap lig associate with, and how?runs OVER the the longissimus thoracis and between longissimus and iliocostalis m as it goes down further to finally attach to the proximal ribs
where does the DEEP layer of the dorsoscap lig attach dorsally? ventrally?dorsally=thoracolumbar fascia under the lig nuchae. Ventrally= attach to transverse process of thoracic vert.
what mm does the DEEP layer of dorsoscap lig associate with, and how?medial to splenius and longissimus thorasis and lateral to spinalis thorasis+cervicis and multifidi mm.
what bursa does the dorsoscap. ligament lie close to, and where?close to the supraspinous bursa-- T3. (it goes: spinous process, thoracolumbar fascia, supraspinous bursa, funnicular part of lig. nuchae)
How does the dorsoscapular ligament affect the spread of infection?Both PREVENTS by inhibiting spread to underlying tissues, but PERMTS cr-ca spread along its fascicles
how does the dorsoscap lig act as the CONCUSSION ABSORPTION MECHANISM of the forelimb? (attachments esp.)attach to xverse processes, medial aspect of scapula, and ribs to hold together when there is a shock-force
which part of the brachiocephalicus is present in the horse?ONLY CLEIDOMASTOIDEUS
which part of the sternocephalicus is present in the horse? where does it attach?ONLY STERNOMANDIBULARIS attaches to angle of mandible
parts of the splenius2 parts-- SPLENIUS CERVICIS and SPLENIUS CAPITIS
what are the 7 mm of the neck?brachiocephalicus (cleidomastoideus), sternocephalicus (sternomandibularis), splenius (cervicis and capitis), sternohyoid, sternothyroideus, longus capitis, longus coli
what is the yes joint? no joint?yes=atlanto-occipital. No=atlanto-axial
what are the muscles of the occipito-atlanto-axial joints? ( 6)rectus capitis dorsalis major. rectus capitis dorsalis minor. rectus capitis ventralis. rectus capitis lateralis. obliquus capitis cranialis. obliquus capitis caudalis. (two rect capitals, two oblique capitals. and 1 ladders/1 vent)
what must be pierced in order to get into the subarachnoid space for collection of CSF?ATLANTO-OCCIPITAL MEMBRANE, dura mater, and arachnoid mater
how is the horses' occipito-atlanto-axial Joints different from the dogs?have horse HAS longitudinal lig of the dens and the lig of the apex of the dens
how devoloped is the lig nuchae in the horse?well devoloped
how would you describe the lig nuchae in two words? what does it support? what are its two parts?median, elastic. supports head and neck. has a funniculus nuchae and a lamina nuchae portion
what is the funnicular portion of the nuc lig continuous with, and where? is it paired?continuous with supraspinous lig at T3. IS paired
origin of funicular lig nuc? how does it run, what does it NOT attach to?originates at external occipital protruberance, runs caudally, and doesnt attach to C1 or C2.
where does the funnicular part of the lig nuc sig. widen?withers
is the laminar portion of the lig. nuch. paired? what is different from its structure than that of the funnicular part?it IS paired. It is FENESTRATED (fun=/=fen)
where does the laminar portion of the lig nuch move-- from where to where? where else does it attach?spinous processes of C2 to C7....also attaches to spinous processes of T1 to T4
where does laminar and funnicular lig nuchae parts fused?fuses at about C3 and continue together caudally.
does the LIG NUCHAE impede infection in the neck? how does it determine the route of infection?lig nuch+dorsoscap lig impede infection in neck. However it also determines spread of infecion b/o fenestrations, (abscess can move to medial aspect due to fenestrations), and also infection can move along it, cranio-caudally
what are the bursa associated with the nuchal lig? which is aquired/genetically determined?cr and ca nuchal bursa. BOTH are aquired, but the cr. is relatively constantly present. Supraspinous bursa also, IS GENETICALLY determined.
where does the cr nuchal bursa lie? what is the name of its inflammation/necrosis?between funnicular part and dorsal tubercle of ATLAS. POLL EVIL.
where does the ca nuchal bursa lie? is it more or less constant than the cr one? dz associated w/it?lies between funicular part and spinous processes of the AXIS. Less constant than cr. NO DZ NAME.
how important is the supraspinous bursa clinically? where does it lie? is it aquired or genetically determined?very important. lies between funnicular part and summit of the spinous process of T3**. (between ligs according to the diagram tho?) GENETICALLY DETERMINED.
how big is the supraspinous bursa? what is the name of the dz associated with it? how do you tx the dz?~40mm. FISTULOUS WITHERS. surgical intervention @ level of vertical line thorugh tuber spinae of the scap.
where does the external jug. vein lie in the horse?in the jugular groove
what are the boundaries of the jugular groove (dorsal, ventral, medial)?dorsally- cleidomastoideus, ventrally- sternocephalicus (sternomandibularis), medially- omohyoideus (Jugular has mms that have specific divisions and omohyoideus. OR, raise the homomandible mast on the jugular rancher)
where do you venipuncture the jugular, and why?in the CRANIAL PART OF VEIN because the jugular is covered by the THICK CUTANEOUS COLLI M
what are the boundaries of the visceral space? (ventral, lateral, dorsal)V= strap mm (sternohyoideus, sternothyroideus) L= omohyoideus + sternocephalicus. D= longus coli, longus capitis (what strapping viscera that stern 'omo has, I bet hes DOUBLE long)
content of the visceral space of the neck? (6)(1) cervical trachea (2)cervical esophagus (3) cervical thymus (4) carotid sheath (5) recurrent laryngeal n. (6) tracheal duct
where would you perform a tracheotomy?@ level of 4th or 5th tracheal cartilage
what is in the carotid sheath in horse? donkey?common carotid, vagosymp trunk and recurrent laryngeal nerve. (donkey is just carotoid and vagosymp)
what ISNT in the carotid sheath?internal jug vein NOT IN SHEATH BECAUSE IT DOESNT EXIST
deep cervical lymph nodes drain what? efferents go where?head, neck, larynx, esophagus, thyroid. Efferents to the tracheal trunk/cr mediasteinal LNs

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