Anatomy 2 - Equine Pelvis and Male Repro

ktepps's version from 2015-10-24 16:19


Question Answer
5 dimensions used to evaluate the birthcanal are?xverse diameter, conjugate diameter, vertical diameter, pelvic inclination, pelvic axis
what is the transverse diameter?widest horizontal line just above or at acetabula
what is the conjugate diameter?the line extending from pecten (of pubis) to sacral promontory (slanted line)
what is the vertical diameter?from pectin (of pubis) to ventral surface of the sacrum or Cd 1 vertebra. It is usually perpendicular to pelvic floor (straight line)
what is the pelvic inclination?angle subtended at the pecten of the pubis by the conjugate and vertical diameters
what is the pelvic axis?median line drawn between pelvic surface of the sacrum and dorsal surface of pelvic symphysis (baby path)
how does the ischial tuberosity and ischial spine of the horse compare to the ox's?flat
the pelvic entrance is _________ and __in the mare. In the stallion it is _________.mare= wide and round. stallion= triangular
describe the pelvic floor of the the horse? (___ and ___)flat and nearly horizontal
describe the long axis of the pelvic cavity?nearly straight
what ligament of the pelvis in the horse is well developed, and what kinda of tissue is it?broad sacrotuberous ligament (soft tissue)
the features of the pelvis which make birthing easy in the mare (4)(1) wide and almost round entrance (2) lateral walls have more soft tissue (sacrotub. lig) (3) cavity is roomy (4) generally horizontal pelvic axis (no undue curvatures and turns)
shape of the scrotum? describe the neck of it? how tight is it?golbular, no distinct neck, and tightly encloses the testis
how mobile are the testis in the scrotum?relatively immobile
can you see the scrotum of a horse from a caudal view?no, it's high between the thighs
how would you describe the surface of the scrotum?sparse hair, glistens (oily look and feel)
what separates the two halves of the scrotum? (outside)median scrotal raphe
what vessel supplies the scrotum?ext pudendal artery
layers from outside to inside of the scrotum?** and more inwards?Skin-->dartos (tunica dartos) [after this, external spermatic fascia--> cremaster muscle+cremasteric fascia--> internal spermatic fascia--> vaginal tunic (parietal peritoneum)--> mesorchium (visceral peritoneum)
what layer of the scrotum forms the scrotal septum?tunica dartos
what connects the dartos to the spermatic sac (vaginal tunic)?scrotal ligament
what is the spermatic sac also known as?vaginal tunic
what is the tunica dartos composed of?fibroelastic tissue and SMOOTH muscle
what does the ext spermatic fascia loosely attach to?(going outwards) what does the ext. spermatic fascia arise from?to the dartos, it arises from the external abdominal oblique m.
what lays under the ext spermatic fascia? what does it arise from?cremasteric fascia and creamaster m, which arise from the internal abdominal oblique
explain what is done to the layers for the scrotum/testes when there is a CLOSED castration?separate skin and the external spermatic fascia from the creamasteric fascia
what tightly adheres to the vaginal tunic? what is it derived from?internal spermatic fascia, derived from transverse abdominal m
what cavity is directly continuous with the peritoneal cavity?the cavity of the vaginal tunic
nerve supply of the fascial sheaths/layers?L2 and L3 spinal nn, and a little contribution from the preputial and scrotal branch of the pudendal n. (23pps)
which lymph nodes lie around the spermatic cord?the scrotal (superficial inguinal) lymph nodes
what is the shape of the testes?rounded or oval, flattened mediolaterally
what is the long axis of the testis in the horse?horizontal
how does the spermatic cord lie in relation to the long axis of the testis?it is nearly perpendicular to the long axis of the testis
how would you describe the mediasteinum testis?indistinct
where does the epididymus lie in relation to the testis?on the dorsal aspect of the testis
where does the head of the epididymus project? The tail?head= projects only a little beyond the cr pole of testis. Tail**= projects more caudally beyond the pole of the testis ((of course the tail is caudal and sticks out a lot)
what attaches the tail of the epi. to the vaginal tunic?ligament of the tail of the epididymus
what attaches the tail of the epi. to the caudal pole of the testis?proper ligament of the testis
which part of the epi. does the deferent duct leave? where/how does it ascend?leaves the tail and ascends the inguinal canal as part of the spermatic cord
what is the main blood supply to the testis and epididymus?The testicular (spermatic) artery.
where does the testicular (spermatic) artery lie? how would you describe it?on cr border of the spermatic cord.It is TORTUOUS as it approaches the testis
what happens as the testicular (spermatic) artery leaves the spermatic cord?it sends branches to the testis and epididymus
what is an equine peculiarity of the testis?the torturous branches of the testicular artery on the surface of the testis
what surrounds the testicular artery? where did this structure come from?panpiniform plexus, formed from the vessels leaving the testis


Question Answer
when is the testicular VEIN free from the panpiniform plexus?high up in the inguinal canal
what are the vessels running alongside the ductus deferens?the cremasteric or deferent a and v
where do the lymphatic vessels of the testis run? how big are they? where do they go?large, accompany the vv, and go to the medial iliac Ln
what is incised in the open castration?scrotal skin through to the vaginal process incised (so in open, ALSO cut through the creamaster m/fascia and internal spermatic fascia (and vaginal tunic i think)
what is incised in the closed castration?only SCROTAL SKIN (+tunica dartos) and EXTERNAL SPERMATIC FASCIA are incised, transect distal to a ligature, or emasculate-- testis is removed.
what is the difference between castration and sterilization?steralization RETAINS THE LIBIDO because the testis are RETAINED.
how do you do a sterilization?open vaginal process (indicative of a open castration) and put a ligature between the tail of the epididymus and body and the ductus deferens. Then remove intervening tail tissue
which accessory sex glands does the horse have?all of them (minus pars disseminata)
how developed is the ampulla of the ductus deferens in the horse? duct(s)?BEST developed. common duct (ejaculatory duct) with duct of the ipsilateral vesicular gland
how long is the ejaculatory duct? where does it open?its quite short, opens on the side of the SEMINAL COLLICULUS, a dorsal mound-like feature of the initial part of the urethra
what is the seminal colliculus?a dorsal mound-like feature of the initial part of the urethra
Look at sex gland picsyay
what is the genital fold?from the pic, looks like a membrane between the ampullas of the ductus deferens. vesicular gland lies within it
what is the muscle which is between the prostate and the bulbourethral gland?urethralis
what is special about the horses vesicular gland?it is actually a TRUE vesicle (being sac like)
what is the shape of the vesicular gland? where does it lie?pear shaped, lies on DORSAL side of the UB within the genial fold.
where does the neck of the vesicular gland dip?beneath the prostate
duct(s) of the vesicular gland?common duct, ejaculatory duct with the ductus deferens
which part(s) of the prostate are present? where does it lie/relate to other things?only the body. lies across neck of UB and beginning of pelvic urethra, also overlies terminal parts of vesicular glands and ducti deferentia
how are the L and R lobes of the prostate associated with each other?connected by an isthmus
what does the prostate look like?discrete, compact, and there is obvious lobulation
duct(s) of the prostate?up to 20 ducts opening separately on either side of the seminal colliculus
shape of the bulbourethral gland? where is it?oval and small. It is on dorsal end of pelvic urethra (as it turns around the ischial arch)
what covers the bulbourethral gland?the bulboglandularis m
duct(s) of the bulbourethral gland? (how many and open where?)6 to 8 ducts opening into dorsal part of urethra (6 and 8 look like bubblebutt)
what are the two parts of the urethra?pelvic and extrapelvic (spongiose)
how do you differentiate the pelvic urethra from the bladder?cant really, it's a direct and non-demarcated continuation of the neck of the UB.
what is related to the pelvic urethra?dorsal surface is largely covered by accessory sex glands and is invested, except at origin, by urethralis m
what are the unique things about the internal surface of the urethra? (2)(1) there is a median and dorsal hillock, the colliculus seminalis, on the sides of which the ejac. ducts open. (2) uterus masculinus may be seen to open centrally through the seminal colliculus
what structures line the sides of the ejac ducts?prostatic orifices (up to 20)
where do the ducts of the bulbo. glands lie? in relation to the prostatic orifices?on either side of the median plane of the ejac duct, more caudal than the prostatic orifices.
where do the ducts of the lateral urethral glands lie? type of gland?(tubuloalveolar glands) in ejac duct, dorso-laterally in the same region as the ducts of the bulbo gland (on either side of the median plane of the ejac duct, more caudal than the prostatic orifices.)
explain the relation of the corpus spongiosum penis (dont forget to write penis) and the corpora cavernosum penis?they fuse to form a single corpus which is the dorsal part of the penis, extending to the tip of the organ
what does the corpus spongiosum penis surround?urethra
where do the corpora cavernosum penis' arise from?the L and R tubera ischiadica
what type of penis does the horse have?musculocavernous
describe the corpora cavernosa of the horse penis (consists of what where in what, with what spaces?)consists largely of SMOOTH MUSCLE oriented longitudinally in the trabeculae, with large cavernous spaces
what do the smooth muscles of the corpora cavernosum of the penis do? with what innervationthey stay in a state of tonic contraction to hold the penis within the prepuce (this is sympathetic innervation (keeping it within prepuce) b/c parasympathetic is "point")
where do the corpus spong. and urethra lie in relation to the corpora cav.?ventral
which parts of the horse penis are in the tunica albuginea?only the corpora cavernosum are in the tunica albuginea (urethra and sponio. are outside of it)
what covers the corpus spongiosum?bulbospongiosus muscle (transverse fibers bridging urethral groove)
how does the retractor penis mm run? paired, they course the entire ventral part of the body of the penis (dip between the transverse fibers of the bulbospongiosus m to lie dorsal to the latter, close to the terminal part of the penis)
what is the glans penis an extension of? what does it cap?the corpus spongiosum PENIS. caps the distal end of the corpus cavernosum penis
what are the three main parts of the glans penis?(1) corona glandis (raised margin-(flare) ) and linked with the (2) dorsal process of the glans by the (3) collum (neck) glandis
how would you describe the free part of the penis?blunt, not pointed
look at penis pictureshot


Question Answer
how does the urethra end in the horse? (what is it, shape, what surrounds it?)ends as the cylindrical urethral process that is surrounded by the fossa glandis
does the urethra process project beyond the glans penis?only a little
where is the urethral diverticulum? what might it contain?the fossa glandis (fossa around urethral process) it might contain smegma, which if it hardens up, is called THE BEAN
how many folds does the equine penis have? how do they relate?two, one telescopes the other
what is the name of the inner fold of the prepuce, what is the name of its orifice? (the extra fold only in horses)the preputial fold, with the preputial ring as its orifice
the outer/external part of the prepuce or sheath has which opening?the main opening, the Preputial orifice
what protracts/retracts the prepuce? absent and present in who?cr and ca preputial mm, respectively. ABSENT IN THE STALLION, best developed in the bull.
what is the main blood supply of the penis and prepuce? what is the artery it comes from?Main= artery of the penis, continuation of the internal pudendal artery (penis inside you)
main vessel of the penis (name it) supplies how many areas? name themartery of the penis branches three times to supply the base(for erectile tissues), dorsal surface, and bulb
what does the deep artery of the penis supply?the erectile tissue (corpora spongiosum and cavernosum) at root of the penis
what does the dorsal artery of the penis supply?the dorsal surface of the penis
what does the artery of the bulb supply?the bulb of the penis
in order from top to bottom (D to V) of the penis, name the branches of the artery of the penisdorsal--> deep--> bulb
what 2 vessels suppliment the artery of the penis? which is more prox?(1) obturator (more prox, but distal to a of penis) (2) external pudendal (most distal)
what is the blood vessel config that is unique to equine?(supply for penis)the fact the external pudendal artery helps supply the artery of the penis
what does the external pudendal artery provide (turn into)the cranial artery of the penis
why do we care about penis veins?responsible for turgidity or flaccidity
what is the venous drainage of the penis?** (3)usually at the root of the penis ONLY, through the (1) internal pudendal v (2) ** MAJOR VEIN of the external pudendal v (3) obturator vein
explain the drainage of the internal pudendal vein (what,where, passage?)drains the ROOT of the penis, which then drains into the internal iliac v (inguinal canal)
explain the drainage of the external pudendal vein (what,where, passage?)****MAJOR VEIN drains body of penis into external iliac V. Passes through the ORIGIN OF THE GRACILIS M AND PECTINUS M-- only a SMALL DIVISION goes through inguinal canal
explain the drainage of the obturator vein (drains what, to where, passage?)drains penis, into internal iliac v (inguinal canal)
which vein does not pass through the inguinal canal?ext pudendal v
explain the mechanism of erection in the horseexternal pudendal v Passes through the ORIGIN OF THE GRACILIS M AND PECTINUS M, not the inguinal canal. When the horse abducts its legs to mount it stretches these muscles which occludes the vein (hence erection is kept up)
what are the vessels of the prepuce?dorsal a and v of the penis and also by branches/tributaries of the ca superficial epigastric vessels on each side
lymph nodes of the penis? efferents go where?deep inguinal Lns, send efferents to medial iliac LNs