Anatomy 2 - Equine Thorax

drraythe's version from 2015-06-05 22:53


Question Answer
how many ribs does the horse have? what does this mean for the thorax? what does this mean for the lumbar region18. that it is long. that it is short looking.
how would you describe the shape of their chest? why is it this way?laterally compressed, because the ribs progressively slope caudally.
how would you describe the horse ICSs? why are they this way?WIDE ICSs b/c ribs are slender
what does rib one usually act as? what are its properities that allow this?because it is short and relatively immobile, it is a platform for resp mvts of mobile ca ribs
how does the sternum tilt? how is this good? bad?tilts cranio-dorsally (like an "s" tilted to the left). good= streamline thoracic cage. bad= diminishes area/vol of cr thoracic cage
when horse is standing, where is the caudal angle of the scapula?7th rib (Scapula Seven- you can see Seven's Scapula)
when horse is standing, where is the point of the elbow?lower part of 5th rib/5th ICS
why is the cr part of the thorax not accessible to us?1st 5 ribs + scapula + part of humerus covered by TRICEPS BRACHII
how would you describe the slope of the diaphragm? which part is the vertex and where is it?slope is gentle cr-ventral slope. vertex is cr most part (the tip of it "<") at lower part of 6th ICS or 7th rib (just like the heart!)
which ribs does the diaphragm attach to the cartilages of?8/9/10th ribs (and thereafter more steeply to succeeding ribs) (8-9-10 da-a-phrem)
what does the R crus of the diaphragm attach to? how?LUMBAR1-4(maybe5) (aka first 4 or 5) via the ventral longitudinal ligament.
what does the L crus of the diaphragm attach to?L1+L2 (the letter L can be made with 1 or 2 lines)
what does the sternal part of the diaphragm attach to?xiphoid cartilage
why does the diaphragm curve so gently?because the thorax is so long
what is it called where the parietal pleura reflects from thoracic wall to cr surface of diaphragm? is it important?costodiaphragmatic line of pleural reflection. clinically important.
how does the diaphragm attach to the costal wall relative to the costodiaphragmatic line of pleural reflection? clinical relevance of this?diaphragm attaches CAUDAL to this wline of pleural reflection-- in this way, the peritoneal cavity can be punctured behind the line without entering the pleural cavity.
how often does the lung reach the costodiaphragmatic line of pleural reflection?not often.
where would you conduct thoracocentesis?lower/middle portion of 7th intercostal space (just BEFORE line of reflection)
which ribs does the costodiaphragmatic line of pleural reflection run to and from?caudally from 8th costal cartilage--> crosses 9th costocondral jxn--> follows gentle curve with gradually inc distance from costocondral junctions--> reaches prox end of 18th rib (look at pic) (costodiag has two o's which together make an 8)
where does the cupula pleurae extend cr?beyond first rib ONLY ON RIGHT
how many portions of cupula pleurae are there? how deep?two sacs! dorsal is 30mm and ventral 25mm
what is the costodiaphragmatic recess?narrow space bordered immediately by the diaphragm and thoracic wall. is within the thoracic cage, narrow and extensive
how would you describe horse mediasteinum? why is it this way? how many zones?thin and delicate- POORLY SUPPORTED by subpleural CT, ca zone is fenestrated. 3 zones.
weakest part of mediasteinum in hose?Ca part--- it is usually fenestrated
are there fenestrations in the donkey? mule?we dont know about donkey, mule has them though
what would horse thoracic sx require due to weak mediasteinum?needs ARTIFICIAL RESPIRATION
lobation of horse lung? lobulation of horse lung?NON-LOBATED. Lobulation is indistinct.
how is the cr portion of each lung separated ventrally from rest of lung?BY CARDIAC NOTCH (but not divided)
what are the two gross lobes of the left lung?apex (cr lobe) and base (ca lobe)
right lung is bigger or smaller? what lobes does it have? what lobes does it LACK?R lung bigger, has cr/ca "lobes" and accessory lobe. NO R MIDDLE LOBE!!!
where is cardiac notch in L lung? R?L= 3-6th ICS, R=3-4th ICS
three boundaries of lung field?basal border, tricipital line, epaxial mm
what is the caudoventral border of the lung field? what defines this border? describe it. (from where to where, ventral limit?)BASAL border. defined by BASE OF LUNG. extends gently from 5th costocondral jxn to the dorsal end of the 17th rib/ICS. Ventral limit of this border is the olecranon process (5th ICS) (from 5th to 17th 5 and 7 struggle to breathe)
basal border in horse Vs ox is what shape?horse is gently curved, straight in ox.
boundaries of cr border of lung field?ca edge of triceps (tricpital line)
dorsal border of lung field?lateral edge of epaxial mm
where does the heart lie in the mediasteinum?in ventral part of middle mediasteinum
describe long axis of heart in horse?its nearly VERTICAL
what is heart directly cr to?ventral part of diaphragm
what is heart held in place by?held by great BVs at base and STERNOPERICARDIAC LIG
how much vertical space does horse heart take up in thoracic cavity?2/3 of height of cavity
which hemithorax is the heart more in?displaced a little more to the left than the right
where is heart located (regards to ICSs)2-6th intercostal spaces
describe cr border(side) of heart? ca border(side)? (shape)CR IS CONVEX. CA IS CONCAVE
what type of heart skele does the horse have?FIBROUS
the part of the annulus fibrosus that surrounds aorta contains two irreg shaped cartilages, the ___cartilago cordis
which coronary artery is dominant in the horse?RIGHT is dominant
what does the R coronary a supply? runs in what?interventricular septum in the subsinuosoidal groove and also part of the L ventricle
which coronary a is dom in dog/sheep/ox?LEFT coronary (lefties are such sods)
what does the L coronary a supply? in what animals?supplies subsinusoidal interventricular septum and part of R ventricle (in dog, sheep and ox b/c L is dom in these)
how do coronary aa arise? from where? when does blood flow in them?arise in a retrograde manner from aortic bulb. blood flows in them CONTINUOUSLY (systole or diastole)
where does the L subclavian a derive from?brachiocephalic trunk
what is the major vein of the heart?great coronary vein
where does the great coronary vein open into? through what?open into the right atrium though ORIFICE OF THE CORONARY SINUS.
where do minor coronary veins open into?directly into all four chambers of the heart
which azygous vein does the horse have? can it have the other?HAS the RIGHT azygous vein . NO LEFT.
branches of aorta?brachiocephalic trunk splits off into R + L subclavian (it doesnt come off of the aorta itself), then the R subclavian gives off bicarotid trunk
Look at pictures of heartsknow them
what is the apex beat?point of max ascultation.
when is apex beat felt in horse?not normally felt except in pathological circumstances
where do you do percussion of the heart? what is percieved?done where heart makes contact with the thoracic wall, a dullness is percieved (area of cardiac dullness)
what area is used to ascult the heart in a horse?the cardiac notch region
location of ascult of valves of heart?PAM-T= ICS-- 3,4,5 --4( M and T aka L AV and R AV)
what might happen to which valves in aged horses? does this affect efficiency?AORTIC vaves might show nodular outgrowths and maybe fenestrations. DOESNT AFFECT EFFICIENCY
how does the esophagus run from thoracic inlet up?leaves left of inlet, attains DORSAL position over trachea, and then median position
describe the musculature of the esophagus of horse?striated to heart, then rest is sm mm
describe course/location of trachea? where does it bifurcate? Which bronchi is larger?occupies median position in course, bifurcates over base of heart into larger R and smaller left bronchi (just like the R coronary artery, the R bronchi is larger. also the R lung is larger so makes sense the bronchi would be larger)
which bronchi is larger in the horse?R is larger
in young horses, where does the thymus lie?from close to thyroid gland to heart
where does the thymus lie in older horses?restricted to ventral part of cr mediastinum
what nerve is thought to be associated with laryngeal hemiplagia (roaring)?LEFT recurrent laryngeal n (Left Larynx)
how do lymph nodes appear in horses?clusters of lymph nodules
what are the lymph nodes of the thorax? (6)intercostal nodes, cr mediastinal nodes, middle mediastinal nodes, pulmonary nodes, tracheobronchial nodes, ca mediastinal nodes
where do the intercostal nodes lie?dorsal aspect of some ICSs
where do cr mediastinal nodes lie?along length of esophagus, trachea at thoracic inlet region
where do middle mediastinal nodes lie?at base of heart
where do pulmonary nodes lie?usually embedded into lung, but drain into TRACHEOBRONCHIAL NODES
where do the tracheobronchial nodes lie?along trachea and primary bronchi
where do the ca mediastinal nodes lie?associated with esophagus and aorta
which lymph nodes are poorly developed or absent in the horse?the caudal mediasteinal nodes (everything to do with the caudal mediasteinum is shitty apparently)
how do you perform thoracocentesis? (horse position, location for puncture, landmarks for this)in standing position, middle and lower part of 7th intercostal space, 5cm dorsal to olecranon OR just dorsal to superficial thoracic vein
where do you perform pericardiocentesis?4th intercostal space, level of costochondral junction (needle FOUR your heart)
which lymph node might be involved in "roaring" ?L tracheobronchial ln. which may enlarge and put pressure on L recurrent laryngeal n. which would cause degeneration of nerve and lead to paralysis of most intrinsic mm of larynx
what is the caudal half of the jugular vein covered by?THICK cutaneous coli mm
( jugular vein and relationships) where does omohyoideus lie? how would you describe it?medial in cranial half of neck. it is THIN
where might injections accidentally be infused if the jugular is missed? results?into common carotid a, may be fatal
how might a misplaced jugular injection cause nerve damage? what problem might it cause?might hit the vagosympathetic trunk---> horners syndrome (lack of symp. innervation to the head)
what might laryngeal hemiplegia be caused by?damage to recurrent laryngeal n

Recent badges