Anatomy 2 - Ruminant Mammae

lasiwedu's version from 2017-10-15 00:28


Question Answer
how are the mammae arranged in the embryo?mammary line/ridge from thoracic region to inguinal region.
which animals have thoracic pair of mammae devolop? most of line? inguinals?thoracic= anthropods and elephants. whole line= carnivores and porcine. inguinal= ungulates
where might you find supramammary teats? clinical application? caudo-ventral surface of udder of cow. cranial surface of mammae in ewe/doe. considered undesirable, surgical removal possible.
two parts of mamma? body (corpus mammae) and teat (papilla mammae)
number of mammae in cow? sm. rumi? sow? (bitch/queen/mare?)COW=4(inguinal). Sm.Rumi=2(inguinal). Sow=10-18(thoracoinguinal) [bitch=8-10, queen=8, mare=2inguinal]
shape of mammae in cow? ewe? mare? nanny goat?cow/ewe/mare= hemispherecal. nanny goat= pendulous and sac-like
udder can weigh up to what in cow? why do we care about size?10kg. care about size for breeding selection processes
in cow, how many mammary glands per mammae? how many lactiferous sinuses?one gland per mamma, therefore one lactiferous sinus per mamma.
where is the cow udder located? can extend from where to where?INGUINAL. can extend from umbilicus to labia
where does the cow udder merge dorsally?merges with body wall (inguinal and perineal regions)
what is between the left and right halves of the udder?Median intermammary groove
each half of the udder contains what sections?fore- and hind-quarters
what separates the fore and hind quarters of the cow udder? anything remarkable about it?transverse intermammary groove. it is poorly defined.
how can we tell the difference between the fore and hind quarters of the udder if the transverse intermammary groove is poorly devoloped?their duct systems do NOT connect, even if the glandular tissue intermingles
describe the skin of the cow udderloose, smooth, and hairless (esp. dairy cows-- non dairy might have hair.) teat are hairless.
how many layers are in the wall of the teat? what are they?3 layers-- skin, middle layer, inner tissue
describe skin layer of teat. what does it lack?skin has no cutaneous glands but it is very sensitive
describe middle layer of teat. what does it consist of? what action can it perform?consists of connective tissue and smooth muscle fibers and thick walled veins(venus ring of Furstenberg). Can act as a cavernous tissue that is capable of closing off lactiferous sinus between milkings.
describe the inner layer of the teat?it is the mucosal lining of the lactiferous sinus.
teat/papillary duct exibits what structures? why are they clinically relevant?duct may have LONGITUDINAL FOLDS which radiate into the sinus, and form folds at internal entrance folds called the ROSETTE OF FURSTENBERG. relevant bc exuberant folds may cause 'hard milkers"
what is present at the papillary opening? clinical relevance?papillary sphincter composed of sm. mm. and elastic tissue. if this is too tight it may cause "hard milking"
what are the two parts of the lactiferous sinus? (1)gland sinus/cistern (2)papillary sinus/teat cistern
what separates the lactiferous sinus and the papillary sinus? where?circular mucosal fold composed of a venous plexus in the submucosa, at base of teat.
what is another name for the mucosal fold composed of a venous plexus at the base of the teat?venous ring of Furstenberg
what is clinically relevant about the venous ring of Furstenberg?it is difficult to control bleeding of a teat because of this ring in the middle layer of the teat
what is palpable in a highly lactating mammae, what is their common name?lactiferous ducts comprise alternating dilated and constricted segments-- aka "milk nodes"
the suspensory apparatus of the udder is best developed in what animal?cow
what does the suspensory apparatus of the udder consist of in the cow?LATERAL and MEDIAL laminae (fascial sheets)
how are the lateral and medial laminae of the udder of the cow related?continuous cranially and caudally
what is the composition of the lateral lamina of the udder of the cow? what does it enclose?thick and consists mainly of COLLAGENOUS connective tissue. Encloses BVs, nerves, and the parenchyma.
where does the lateral lamina of the udder of the cow arise from? Arises from deep fascia of abdominal wall (dorsal to the superficial inguinal opening) as well as from symphyseal tendon (caudally)
how does the medial lamina of the udder of the cow compare to the lateral? what is the composition of the medial lamina, which arises from what?better developed and stronger. it is mainly Yellow ELASTIC Tissue arising from linea alba and symphyseal tendon
how is each lamina of the udder separated from its fellow?by loose connective tissue
is amputation of one half of an udder possible? why?it IS possible, because nerves and blood vessels dont pass through the lamina. EACH HALF IS INDEPENDANT
what happens with the teats in heavy udders?the elastic tissue of the medial lamina causes ventral sinking in central part of udder, which causes teats to point ventro-laterally
what happens to the laminas of the udder as it travels from proximal to distal? what does it do as this happens?it progressively thins out, and ENDS BEFORE the base of the teat. Before ending the lamina sends out TEN suspensory LAMELLAE into substance of udder
what do the ten suspensory lamallae of the udder do?provide support and break parenchyma into overlapping lobes and lobules.
how many mammae in the EWE? how many mammary glands/lactiferous sinuses does each mammae have?2 mammae. one mammary gland+lactiferous sinus per mammae.
what is the udder of the EWE like? what is the intermammary groove like? teats shape, and what closes the papillary opening?udder is compact, intermammary groove is distinct. Teats are short and conical, and the papillary opening is closed by elastic fibers
how many mammae on the GOAT? how many mammary glands per mammae? how many lactiferous sinuses/papillary ducts?Goat has 2 mammae. *6-9 mammary glands PER mammae, with same number of lact. sinuses and pap. ducts.
what is the udder of the GOAT like? describe the teats?udder is pendulous, sac-like, inguinal. teats are longer, more voluminous and relatively broader than those of the cow
how many SOW mammae? where? how many mammary glands per mammae (/ teat orifices)up to *14 mammae (5-7 pairs), ventral thoraco-abdominal region. *2-3 mammary glands per mammae (so 2-3 teat orifices)
blood supply of SOW mammae? from (1) lateral and internal thoracic arteries (2) cr and ca superficial epigastric arteries (3) external pudendal arteries
how much blood does the udder need? why? what does this mean for the vascular system?udder has high metabolic rate so needs LOTS of blood (apprx 30-500L per 1L milk). so vascular system must be well developed.
what is the main artery supplying the udder? goes where and branches to what?mainly external pudendal artery, which sends a basal branch caudally to the base of the udder, and divides into 2 large cranial and caudal mammary aa.
what does the cr and ca mammary aa. do after they branch from the external pudendal?they anastomose cr and ca to form ARTERIAL CIRCLE at base of udder
how does the internal pudendal a. supply the udder?a terminal branch of the I.P. (ventral perineal a) runs caudoventrally to join arterial circle. Only small amount of blood supplied.
the superficial caudal epigastric a. (aka?) supplies udder how?aka cranial mammary, part of arterial circle, also anastomoses with sup. cranial epigastric a.
what does the venous drainage of the udder form?form a venous ring following anastomoses between homonymous or satellite veins
what is the milk vein?cranial superficial epigastric vein AKA subcutaneous abdominal vein.
what vein anastomoses with milk vein?caudal superficial epigastric vein (cranial mammary vein)
cranial superficial epigastric vein enters abdominal cavity how and where?(milk vein/subcutaneous abdominal vein) through milk well in rectus abdominus
cr superficial epigastric vein is a tributary of the?internal thoracic vein
what is unique about the caudal superficial epigastric veins?their valves are weak and inefficient (in dairy cow) so blood can flow in either direction
what nerve(s) supply skin and teats of cranial (+base) of udder?iliohypogastric(L1), ilioiguinal(L2), cranial branch of genitofemoral (L3)
what nerve(s) supply skin of middle and caudal part of udder, the teat, and parenchyma? how do/es it/them travel? noteable attribute?genitofemoral n. passes through inguinal canal, **SYMPATHETIC INNERVATION TO PARENCHYMA** (via caudal branch)
what nerve supplies the caudal aspect of skin of udder? possible clinical relevance?mammary branch of PERINEAL nerve (pudendal nerve)... possible milk-let-down reflex arc, maybe hormones involved?
Hey stupid, look at all those aa, vv, nn diagrams.because you know it'll be on there
what are the lymphatics of the udder? how many? where?superficial inguinal (mammary) lymph nodes. (4 per half of udder....2 in doe/nanny goat). located caudolaterally, near superficial inguinal opening
what do the lymphatics of the udder drain? where do efferents go?udder, perineum, medial aspects of thigh. efferents go to deep inguinal ln (iliofemoral ln)
are superficial inguinal (mammary) Lns palapable? clinical sig?palapable, examined in meat inspection
2 types of flank anaesthesia?paravertebral block, paralumbar block
where is the nerve blocked in the paravertebral block? landmark to do so?blocked as it emerges from the intervertebral foramen (before or just after it's divided into dorsal and ventral branches) CLOSE TO BODY OF VERT. caudal borders (not tips) of xverse processes for landmark.
how/where is the needle inserted for paravertebral block? (direction of needle, distance from midline- species diff?)needle inserted vertically. ox= 5cm from midline. sheep/goat=3 cm from midline. *near caudal borders (not tips) of transverse processes (L1,L2,L3)
where are the nerves blocked in the paralumbar block? which nerves?at the tips of the transverse processes (dorsal and ventral to each tip) of L1, L2, and L4 for costoabdominal (T13), iliohypogastric(L1), and ilioinguinal(L2) (respectively.)
two types of epidural anaesthesia?lumbar/high epidural, sacrocaudal/low epidural.
for a lumbar/high epidural, how many injections? which nerves blocked?single injection to block out nerves T13, L1, and L2.
injection area for high/lumbar epidural injection? into the site between L1 and L2 spinous processes, and 1.5-2cm behind a line linking the cranial tips of the transverse processes of L2. No more than 15* from midline, down to floor of spinal canal
in a high epidural, how would you increase the area of influence of the drug? with increased area, what are nerves blocked?inject a greater volume...can block from T13->all lumbar->first two sacral this way.
disadvantage to increasing area of influence of a high epidural block?abdominal/inguinal regions, scrotum/penis/udder, and hindlimb might be blocked. Animal might not be able to stand!
what space is used for a high epidural injection in sheep/goats/pig?lumbosacral space
where is a sacrocaudal/low epidural injection done? how can you locate this area?at the sacrocaudal junction, or between Cd1 and Cd2. You can find these spaces by raising the tail head and locating kink by palpation, sight, or both.
what does a low epidural injection block? what is being anesthetized?last three sacral nerves. blocks the tubular genitalia of the female, the rectum, and the perineal area
prefered width of a udder in a cow?at least 8 inches, with strong ligaments
farmers prefer what kind of teats?should fit into milking machines, be perpendicular to the floor, and have a cylindrical shape.
what kind of distance do farmers want between a cows front and back legs?WIDE distance-- accommodate udder, and front width indicates wide chest which means healthier heart.
what is there a correlation to between mastitis and ___? fertility. This is a big deal.