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repro Flashcards

1
Q

kidney topographical anatomy

A

RIGHT = level of L1-3 w cranial pole @ level 13th rib, in renal fossa of caudate lobe liver
* caudal vena cava medially

LEFT = level L2-4 w cranial pole more caudal than R
* aorta medially

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2
Q

connecting peritoneum bladder

A
  • median lig -> ventral abdom wall
  • lateral ligs -> pelvic wall
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3
Q

trigone

A

area in bladder where ureters enter + urethra exits
* fuller bladder = ureter more closed + harder for urine to enter

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4
Q

topographical anatomy bladder

A

neck passes -> pelvic canal

empty bladder contracts close to pelvis
full extends cranially into abdom
* ventral to descending colon male/uterus female

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5
Q

gonads

A

repro gland that prods gametes
* ovaries in female, testes in male

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6
Q

gross anatomy female genital sys

A

ovaries sat in pocket of tiss (ovarian bursa) then -> uterus via uterine/fallopian tube
uterus = y-shaped w L + R horn (cornu) joining to form bod, sepped from outside world by cervix -> vagina -> vestibule

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7
Q

catheterising dogs

A

bitch = go in, find urethral opening, then straight
male = hole visible, but then 180deg hairpin loop

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8
Q

ovaries

A
  • paired regular ovals
  • inactive = smooth, active = knobbly w follicles
  • end = funnel-shaped = infundibulum to catch egg -> uterine tube
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9
Q

peritoneal attachments ovary

A
  1. mesovarium = ovarian lig -> lat bod wall @ caudal pole kidney w ovarian artery + vein LIGATE (continuous w mesometrium)
  2. mesosalpinx -> uterine tube (removed w other bits)
  3. suspensory lig -> lat bod wall @ caudal pole kidney (not 1 asw!!!)
  4. proper lig of ovary -> cranial end of uterine horn

all continuous w each other

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10
Q

suspensory lig in bitch

A

v short + must be broken to allow exteriorisation of ovary for spay

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11
Q

ovarian bursa

A

pocket of peritoneum encasing ovary
* bitch = lots fat = obscured = complicates

mesovarium cranial, uterine horn caudal

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12
Q

uterine horns attach where

A

-> ovaries cr., -> uterus bod cd.

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13
Q

uterine attachments

A

mesometrium (broad lig) -> lat bod wall
* round lig of uterus runs in thru inguinal canal = foetal remnant of gubernaculum (gonad, not needed in females bc ovaries no move) – looks like ureter

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14
Q

vagina

A

w/in pelvic canal
* external urethral orifice opens on midline ridge (urethral tubercle) w fossa either side = catheterisation awks)
* glans clitoridis in deep fossa under mucous mem fold

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15
Q

hymen

A

at junction bet vagina + vestibule

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16
Q

vestibule

A

bounded by labia of vulva caudally

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17
Q

female genitals blood supply

A
  1. ovarian artery + vein in arterio-venous complex -> anastomose w uterine art + vein
  2. vaginal art + vein branch caudally -> supp vag + vestibule
    * cranial branch becomes uterine art + vein in mesometrium

need keep vaginal intact bc leaving in animal

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18
Q

where find ovaries

A

dorsal abdom @ caudal poles kidneys (13th rib)
* level of umbilicus ventrally

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19
Q

topographical anatomy uterus

A

uterine horns bet intestinal mass + lateral abdom wall w uterine bod mid-line ventral to descending colon, dorsal to bladder

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20
Q

ovario-hysterectomy anatomy

A
  • stretch/tear suspensory lig
  • ligate ovarian art + vein in mesovarium
  • transect uterine bod @ level of cervix + ligate uterine art/vein
  • 50% of time mesometrium vascular enough need ligate
  • ureters close to ovaries + cervix - don’t ligate
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21
Q

mammary glands

A

5 pairs mammae each w papilla (teat)
* 2 thoracic (scant adipose), 2 abdom, 1 inguinal (lots adipose)

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22
Q

blood supply mammary glands

A

cr. via cranial superficial epigastric
cd. via caudal superficial epigastric

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23
Q

lymph drainage mammary glands

A

cr. 3 pairs via auxillary
cd. 2 pairs via inguinal

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24
Q

perineum

A

area under tail round anus
* either side anus = anal glands

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25
Q

perineal muscs

A

form pelvic diaphragm thru which urino-genital + digestive sys open to outside
1. levator ani lifts anus so poo on floor not down butt
2. coccygeus musc
3. rectococcygeus musc
4. internal anal sphincter = sm musc
5. extenral anal sphincter = sk musc
6. internal obturator musc

weakening = adom contents can protrude = perineal hernia

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26
Q

inguinal canal anatomy

A

potential space bet abdom wall musc layers - comms w external pouch
1. deep inguinal ring = gap in IAO
2. superficial inguinal ring = slit in EAO
3. vaginal ring = opening of peritoneal cavity into inguinal canal

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27
Q

purpose inguinal canal

A

allow testes descend from caudal to kidneys -> scrotum
* bc in abdom too hot for sperm to form

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28
Q

development in inguinal canal

A

peritoneum outpouch (vaginal process) pushes thru -> protrude into scrotum
* females = only bitch has rudimentary vaginal process extending in

abdom structures can pass thru vag ring into ing can = inguinal hernia

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29
Q

who is more at risk of inguinal herniation

A

pigs, rabbits - deep inguinal ring superimposed over superficial inguinal ring

only female can occur in is bitch

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30
Q

what aids testes descent

A

gubernaculum guides them = no get lost in abdom (exact process unknown)

female has one but vestigial - looks like ureter (in mesometrium)

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31
Q

scrotum

A

sac of skin enclosing testes + coverings
* median septum seps testes w/in it
* lots sebaceous + sweat glands = incisions thru scrotal skin no heal well
* blood supply = branch external pudendal art/vein

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32
Q

testis layers

A
  1. skin
  2. tunica dartos - lots sm musc to move to/from bod maintain temp
  3. spermatic fascia
  4. parietal peritoneum (vaginal tunic)
  5. visceral peritoneum

outside to inside

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33
Q

spermatic fascia layers

A
  1. external spermatic fascia
  2. cremasteric fascia cont cremaster musc (sk musc, attaches spermatic sac)
  3. internal spermatic fascia

extensions of lat abdom wall muscs

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34
Q

testis structures

A
  1. epididymis w head, bod, tail (where sperm stored) - ductus deferens = sperm from tail -> urethra
  2. testis covered visceral peritoneum - gland that prods sperm + male hormones
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35
Q

spermatic cord

A

cont ductus deferens, testicular vein/art in peritoneal fold (= mesorchium) (continuous w vaginal tunic)

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36
Q

testis blood supply

A
  1. test art coveys blood -> testis
  2. test vein arranged in mesh encasing art = pampiniform plexus = can cool art blood via heat exchange w venous blood
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37
Q

spermatic sac

A

vaginal tunic + internal spermatic fascia + cremasteric fascia
* attached scrotum via scrotal lig - break to free testis in closed castrate

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38
Q

diff types castration

A

== orchidectomy
* open/closed depending whether abdom cavity opened or not
* open has potential risk peritonitis (infection back up into abdom) + herniation

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39
Q

open orchidectomy

A
  1. scrotum incised to remove testes (break lig of tail of epididymis) + left open to drain bc of glands + inflamm fluid
  2. haemostasis of art/vein via press => clotting (5 mins)
  3. herniation unlikely unless superimposition (= suture inguinal canal)

inflammatory fluid passing out prevents contamination peritoneal cavity (usually)

most bc closed needs ligature + hard keep suture mat sterile

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40
Q

which type castration when in dog

A

> 25kg = open
< 25kg = either
inexperiences surgeon = open

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41
Q

layers incised in open castration

A
  1. skin if testes pushed out scrotum -> inguinal area = normal skin cut = can suture (dog so no inflamm fluid in living room)
  2. all spermatic fascia
  3. vaginal tunic (= ‘opened perit cav)

remove visceral peritoneum w testes

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42
Q

closed castration

A
  1. incise inguinal skin + ESF
  2. free spermatic sac from scrotum by breaking scrotal lig
  3. neck of spermatic fascia inc cord ligated

haven’t cut thru vaginal tunic

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43
Q

penis structure

A
  • shaft cont erectile tiss + urethra
  • free part lies w/in prepuce (skin protective covering w enlarged tip = glans penis)

root attached ischium

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44
Q

penile erectile tiss

A
  1. corpus spongiosum penis
  2. corpus cavernosum penis
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45
Q

corpus spongiosum penis

A

encloses urethra from pelvis to penis tip
* expansion near pelvis = bulb of penis/urethral bulb
* expansion at tip = glans penis

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46
Q

how get erection

A

fill penis w blood + prevent exit

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47
Q

penis arterial blood supply

A

branch of internal pudendal round ischiatic arch then -> erectile tiss at penis root
* conts along dorsal penis surface outside tunica albuginea

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48
Q

penis venous blood supply

A

erectile tiss drained at root via internal pudendal
* horse also massive drainage from penis bod -> external pudendal

no vasc connections bet corpus spong + cavern

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49
Q

muscles of penis

A
  1. retractor penis
  2. ischiocavernous
  3. bulbospongiosus
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50
Q

bulbospongiosus musc

A

circular, thick, covering bulb (= cd. enlargement corp spong)
prevent venous drain in erec as rhythmic contracts incr press in corp spong

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51
Q

retractor penis musc

A
  • slender musc connected internal/external anal sphincters + cocygeus
  • passes ventral to penis midline + attaches 1/2way
  • sm musc to retract penis back into sheath
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52
Q

ischiocavernous musc

A

ischiatic arch -> tunica albuginea of corpus cavernosum
prevent venous drainage in erection + rhythmic contractions incr press in corp cav during erection

covers L + R crura

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53
Q

mitosis

A
  1. chromosomes replicate + divide -> 2 new nuclei
  2. cell division => geneticaly identical daughter cells maintaining no. chromosomes
  3. prophase, metaphase, anaphase, telophase stages
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54
Q

meiosis

A

specialised division in germ cells
* 2 rounds division => 4 cells w 1 copy each chromosome

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55
Q

ovarian cycle w hormones etc

A

follicular phase = before ovulation
luteal phase = after

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56
Q

menstrual cycle of women w hormones etc

A
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57
Q

compare menstrual + oestrus cycle

A

menstrual: primates, renewed start follic phase (bleed)
* 2wk follic phase
* 4wk cycle
* day 0 = start follic phase, low oestrogen

oestrus:
* others, no bleed but spot when high oestrog (weak bvs)
* * 1wk follic phase
* 3wk cycle - follicles develop throughout luteal phase
* day 0 = start oestrus, end follic, high oestrog

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58
Q

oogenesis

A

== development of female gamete (ova) for release from ovary
1. primordial germ cells migrate -> gonadal ridge in early gestation
2. gonad develops medial to embryonic kidney
3. diploid oogonia divide by mitosis in foetal life
4. birth = oogonia stopped in meiotic division (= have all eggs, finite no.) = primary oocytes
5. after puberty: 1st meiotic division at ovulation -> secondary oocyte (haploid) + 1st polar bod
6. 2nd meiotic division after fertilisation

==> 1 large complex female gamete + 3 small polar bods

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59
Q

what happens to primary oocytes

A
  1. enter prophase of meiosis 1 in foetal development then nothing until puberty
  2. 1st meiotic division at ovulation => secondary oocyte (haploid) + 1st polar bod
  3. 2nd div after fertilisation

==> 1 large female gamete + 3 small polar bods

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60
Q

what drives ovulation

A

release luteinising hormone (LH) from pituitary gland

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61
Q

primordial follicles

A

several stimmed each month after puberty to nourish developing oocyte + be endocrine glands driving cycles
1. prim oocyte in prim follicle ->
2. prim oocyte in 2ndary follicle ->
3. 2ndary oocyte in Graafian (tertiary) follicle

first FSH dependent for growth then Graaf = LH dependent for ovulation

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62
Q

follicle types

A

cells around oocyte grow to form follicle
primordial = single layer squamous granulosa cells
–> cuboidal granulosa cells = primary follicle = prod oestrog

secondary + tertiary prod oestrogen
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63
Q

phases graph

A
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64
Q

oogonia

A

diploid female gamete mother cells

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65
Q

how is oestrog proded

A

theca interna cell w LH receptor: cholesterol -> testosterone
-> granulosal cell w FSH receptor: testost -> oestrog
–> blood –> brain/repro tract

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66
Q

effect of oestrog in repro tract

A
  • incr blood flow
  • incr oedema of tiss
  • incr mucous secr
  • incr leukocytes
  • incr sm musc motility
  • incr growth uterine glands
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67
Q

effect oestrog on brain

A
  • mating posture
  • incr phonation
  • incr physical activity
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68
Q

when are you fertile

A

egg lasts 24hrs, sperm 5-6days
== fertile 7days up to + inc day of ovulation
* probability of impregnation incr up to ov

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69
Q

what point to we reference oestrus cycle from

A

when animal starts showing signs of being on heat = advertising wants to be served (just before ovulation)

21 day cycle

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70
Q

behavioural oestrus

A

time animal advertises shes fertile
* cow = 18hrs in 21d cycle
* horse = 5d in 21d
* sheep = 30hrs in 17d
* pig = 2d in 21d

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71
Q

pituitary hormones

A

LH + follicle stimulating hormone (FSH)

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72
Q

reg repro hormones

A

hypothalamus releases gonadotropin releasing hormone (GnRH), stims release pit hormones (LH + FSH), stims release inhibin + oestrogen from developing follicles in gonad

neg feedback control

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73
Q

what hormones do follicles release

A

inhibin (inhibits FSH)
oestrogen (inhibits LH + GnRH)

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74
Q

normal neg feedback loop of repro hormones

A
red line = inhibits
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75
Q

how does brain reponse to oestrogen change

A

Changes from neg to pos feedback:
oestrog => surge centre => incr GnRH = incr LH = incr oestrogen… continues until ovulation due LH surge
* ov = Graaf follicle ruptures to release 2ndary oocyte

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76
Q

corpus luteum

A

mature graafian follicle becomes one = temp. structure to establish + maintain pregnancy = prod progesterone after ovulation
* ~14days w/o fertilise 2ndary oocyte = corpus luteum undergoes luteolysis = stops secr progesterone => corpus albicans (fibrous scar tiss)

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77
Q

what does progesterone do

A

inhibits release GnRH = inhib LH = inhib oestrogen + ovulation

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78
Q

role of ovary structures overall

A
  • egg release at specific pt in development ready to fertilise
  • correct endocrine environ at release
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79
Q

other factors to consider for repro

A
  • seasonal/not
  • reflex/spontaneous ovulators
  • mono or polyoestrus
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80
Q

who breeds when

A

mares in spring = long day breeders
ewes in autumn = short day

=> born in spring (12mo vs 5mo gestation)

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81
Q

what controls seasonality in breeding

A

controlled by effect melatonin on release GnRH from hypothal
* mare = low melatonin incr GnRH, ewe = decr

spring = low melatonin, autumn = high (proded in dark)

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82
Q

reflex ovulators

A

GnRH pulse generator not enough for LH surge so w/o mating only have follisuclar phase
* brain inputs + vagina stretch inputs + sensory inputs combine to incr GnRH (via signals to hypothal)…..=> ovulation

skips pos feedback loop shenanigans

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83
Q

oestrus cycle of mare

A

seasonal long day breeders
* 21 day cycle
* oestrus 5day
* ovulate 24-48hrs b4 end oestrus
* 11mo gestation

FSH opposite to oestrogen
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84
Q

oestrus cycle sheep

A

seasonal polyoestrus - short day breeders
* 17day cycle
* oestrus 30hrs
* ovulates 20-25hrs from start oestrus
* 5mo gestation

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85
Q

cow oestrus cycle

A

not seasonal
* 21day cycle
* oestrus 18hrs
* ovulates 20-30hrs from start oestrus
* 9mo gestation

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86
Q

what causes follicles develop

A

FSH

only ovulate if progesterone basal bc inhibitory so you get follicular waves:
from d0 follicles start develop but proges high = no ov = degrade by d10, then start develop again + by time Graaf proges low = oestro incr = LH incr = can ov

in cows (so usually only 1 follicle will ovulate)

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87
Q

why are oestrus cycles shorter than menstrual

A

follicles develop throughout luteal phase = nearer maturity when progesterone decr at luteolysis

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88
Q

what determines length of oestrus

A

lifespan of corpus luteum (bc die = no progest = no inhib = can ovulate)
* prostaglandin F(2alpha) from uterus via uterine vein -> ovarian artery = signals luteolysis

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89
Q

luteolysis in rumis

A
  • corpus luteum secr oxytocin + posterior pituitary
  • oxytocin receptors appear on endometrium in late luteal phase -> stim release PGF(2α) => luteolysis only at right time

prostaglandin has no known role in cats + dogs

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90
Q

how is penis of dog diff

A
  • L + R corp cav don’t fuse w cr. part ossified (= os penis) - ventral groove conts corp spong
  • bulb extra large + glans penis = double structure
  • don’t need full erection for intromission - os penis = can get in, then expansion bulbus glandis + extension pars longa glandis extends => fully erect can’t sep until done (+ blood out)
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91
Q

glans penis dog

A
  1. bulbus glandis covers proximal half os penis
  2. pars longa glandis covers distal half os penis
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92
Q

what is tunica albuginea

A

fibrous envelope covering the corpuses

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93
Q

prepuce gland

A

tubular cutaneous sheath covering free part non-erect penis
* preputial cavity w external lamina (normal skin) + internal lamina (hairless squamous epithelia)
* cont muscs keep preputial orifice closed + retract prepuce

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94
Q

accessory glands

A

to lube duct for + nourish sperm
1. ampulla of ductus deferens (covered by prostate)
2. vesicular
3. prostate dorsally on bladder neck w disseminate parts
4. bulbo-urethral gland empties into distal part pelvic urethra

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95
Q

bitch oestrus cycle

A

monooes w 1-3/yr = prolonged fertile period to make it count
1. prooestrus = 9d, swollen vulva, bloody discharge, v attractive to male, no mate
2. oestrus = 9d, ov d2, accepts male, straw coloured discharge
3. metoestrus/dioestrus = 60d, CL-proges dominant phase
4. anoestrus = ovarian inactivity until next prooestrus (~5mo)

1+2 = follic phase
3 = luteal phase

gestation 9wks

96
Q

bitch adaptations to max conception

A
  • spontaneous ovulators
  • long prooestrus + oestrus
  • LH surge late prooestrus/early oestrus
  • ov over couple days 48-72hrs after surge
  • no luteolytic mech = corp lut lasts 60-70d
97
Q

oestrus cycle graph bitch

A
proges starts incr b4 ov = measure to know when ov for AI
98
Q

fertilisation in bitch

A

ova can’t be fertilised for 48hrs after ov + viable 5d
* so fertilisation period = 2-5d after ov
* sperm viability 9-11d = can mate from start oestrus

== get males ready in prooestrus, then accept for all of oestrus
* once chance gone won’t get preg rest of yr so important

99
Q

label

A
100
Q

where does fertilisation occur

A
  1. sperm stored in isthmus (narrow oviduct next to utero-tubal junction
  2. passage oocyte down oviduct => release of sperm
  3. => fertilisation in ampulla of oviduct (wider part near ovary)
infundibulum funnels egg
101
Q

where is semen deposited diff species

A
  1. vagina - cows, sheep, dogs, cats
  2. cervix - pigs
  3. thru cervical lumen - horse (v projected)
102
Q

what aids transport w/in female tract

A
  • sm musc contractions
  • sperm motility
103
Q

what do sperm have to do for successful fertilisation

A
  1. transverse cervix - select for mobile
  2. be transported thru uterus -> cd oviduct (isthmus) w/o macrophage phagocytosis or ejection back out vag
104
Q

what do sperm do once find egg

A
  1. bind to zona pellucida (lipid capsule round egg) - specific receptor on sperm for specific prot (ZP3)
  2. acrosome reaction = release enzs to digest zon pelluc (exocyt)
  3. fuse w oocyte mem => biochem changes in zon pell/oocyte mem prevent polyspermy (no others can enter)
105
Q

capacitation is?

A

sperm mature in epididymis but not fertile
* have reside in repro tract for min length of timt to reveal receptor prot
* can be reversed by putting sperm back in seminal plasma
* can be induced in vitro

106
Q

why capacitation occur

A

in epididymis surface mols of sperm coated w seminal plasma prots that mask mem prots
* in female tract seminal plasma coating + some surface mols removed, revealing those that can bind zona pell

complete in oviduct + hyperactive motility pattern develops = facilitate sperm-oocyte contact

107
Q

acrosomal reaction

A
  1. acrosome (membranous organelle) swells
  2. mem fuses w over-lying p mem = vesicles form
  3. => exocytosis proteolytic enzs

==> acrosome-reacted sperm can work way thru zon pell

v quick ~15min

108
Q

biology of preventing polyspermy

A
  1. sperm mem fuses oocyte mem
  2. stims Ca release in oocyte
  3. => secr cortical granules
  4. enzs of granules cleave binding site of ZP3 = prevent further attachment/fertilisation

== zona block

109
Q

sperm journey: what occurs where?

A
  1. immediate transport = entrance to cervix/uterus - lose to retrograde + phagocytosis
  2. cervix = removal non-motile sperm + abnormalities
  3. uterus = capacitation initiated - loss to phagocytosis
  4. isthmus = capacitation completed, hyperactive motility
  5. ampulla = acrosome reaction, penetration, male + female pronuclei form (fert)
110
Q

syngamy

A

fusion pronuclei to form zygote (after oocyte 2nd meiotic division)

111
Q

fertile period defn

A

period time over which mating might result in preg
* around same length as behavioural oestrus

112
Q

cleavage

A

rapid mitotic division of zygote => blastomeres (pregressively smaller cells proded)
* eventually forms morula = grp lots blastomeres

in embryonic period

113
Q

forming blastocyst

A

granulation as blastomeres of morula line edges zygote =>
* eventually ruptures = hatches => hatched blastocyst

114
Q

attachment

A

extra-embryonic mems (placenta) develop + attach to hatched blastocyst
* allow comm w mum + get nutrients etc
* no attachment for 1st 7 days

= implantation in menstruators

115
Q

progesterone for pregnancy

A

essential + secr by placenta but takes while for it develop enough to secr
=> proges from CL can provide whilst forming if luteolysis prevented

116
Q

how block luteolysis

A

block luteolytic signal (prostaglandin) = maternal recog of preg (MRP)
* bitches no need bc no luteolytic signal = incr chance maintain preg

proges usually determines length cycle

117
Q

zygote

A

fertilised egg

118
Q

stages gestation

A
  1. embryonic period = 20-30% gestation
  2. foetal period = 20/30%-> parturition
119
Q

maternal recog of preg (MRP)

A

process by which early conceptus signals presence to maternal sys preventing luteolysis
* ensures maternal milieu supportive of preg continuation

120
Q

species mechs of MRP

A
  1. inhibit luteolytic factor - pigs, cows, sheep
  2. secretion luteotrophic factor - humans
  3. mechanical - horses
  4. none - dogs + cats
121
Q

inhibition of luteolytic factor

A

block PGF2alpha to inhibit normal regression CL
* cows + sheep = embryo prods interferon to block synth oxytocin receptors = prevent release PGF from endometrium
* pigs = embryo prods oestradiol = PGF released rerouted -> uterine lumen = exocrine secr - no worj w/in lumen uterus (need at least 2 conceptuses per horn to work)

122
Q

secr luteotrophic factor

A

developing blastocyst prods - similar struct to LH = acts LH receptors in CL to prolong life + maintain proges levels

e.g. hCG (human chorionic gonadotropin) b4 attaches myometrium

123
Q

MRP in horses

A

conceptus prods MRP signal but not understood
* mechanical? as equine conceptus migrates over endometrial surface to initiate + complete
* 12-14 times/day on days 12,13,14 to inhibit PGF

hatched blastocyst no spread out like others, stays globular

124
Q

embryonic mems + what form

A
  1. endoderm -> dig sys, lungs, endo sys
  2. mesoderm -> musc, skeleton, CV + repro
  3. ectoderm -> NS, skin, hair
125
Q

foetal mems

A

derived from foetal cells (discarded as stuff see lambing)

== extraembryonic mems that must form b4 attachment to endometrium can occur

126
Q

structures of hatched blastocyst

A

trophoblast = outer ectoderm

ICM = inner cell mass => develops to embryo
127
Q

development from hatched blastocyst

A
  1. primitive endoderm grows downward form lining on inner surface trophoblast
  2. mesoderm begins develop bet primitive endoderm + embryo
  3. primitive endoderm completes growth forming cavity = yolk sac
  4. mesoderm forms sac round yolk sac push against trophectoderm => fold up form amniotic folds round embryo
  5. mesoderm surrounds yolk sac + allantois
  6. mesoderm fuses w trophectoderm form chorion
  7. amniotic folds grow round embryo + fuse => amniotic sac
  8. yolk sac decr, allantois incr
128
Q

allantois

A

diverticulum from primitive gut

129
Q

parts of developing embryo

A

inner sac = trophectoderm + mesoderm => amnion + amniotic cavity (continuous w GI tract)
outer sac = chorion fused w alliontois => allantochorion/chorioallantois = allantoic cavity (continuous w bladder)

  • allantois conts expand + fill cavity

yolk sac conts regress

chorionic villi provide interface w dam
130
Q

allantochorion

A

foetal contrib to placenta = surface for attachment endometrium
* functional part = chorionic villi = exchange apparatus = small protrusions incr SA for exchange

131
Q

micro anatomy least invasive placenta type

A

6 layers:
1. chorionic caps
2. chorionic interstitium
3. chorionic epithelium
4. endometrial epithelium
5. endometrial interstitium
6. endometrial caps

horses, pigs, rumis

132
Q

carnivore placenta

A

5 layers:
1. chorionic caps
2. chorionic interstitium
3. chorionic epithelium
4. endometrial interstitium
5. endometrial caps

bit more invasive

133
Q

primate placenta

A

3 layers (just chorionic ones) as foetus breaks down basement mem + implants self so just pool maternal bood => periods + bleeding out childbirth (v few layers bet foetus + maternal blood

134
Q

cotyledonary placenta

A

numerous cotyledons attached at 1 point (= discrete) - button-like structures of chorionic villi
* attach to maternal caruncles in endometrium (maternal part)

rumis

135
Q

diffuse placenta

A

uniform distribution chorionic villi = pigs

horses = appear same but acc lots tiny ones

136
Q

zonary placenta

A

band-like zone chorionic villi

dog + cat

137
Q

placenta

A
  • interface for metabolic exchange bet dam + foetus
  • endocrine gland prod horms maintain preg, stim mammary gland, promote foetal growth

transient organ = no last

138
Q

timing placental attachment species

A
  1. cow = 18-22d post ov
  2. sheep = 15-18d post ov
  3. mare = 36-38d post ov (migrates = takes longer)
  4. sow = 11-12d post ov
139
Q

occasions for pregnancy loss

A
  • ov = 2% lost (1d)
  • fert = 15% lost (2d)
  • hatching + elongation = 30% lost (8-13d)
  • MRP = 45% lost (2wk)
  • uterus distension = 50% lost (5wk)

most lost by 5/6 wks

% = total lost at the pt (cumulative)

140
Q

development gonads

in foetus

A

primordial cells migrate yolk sac -> gonadal/genital ridge
* primitive germ cells induce local tiss diff into sex cords (gonads bi-potential)

141
Q

sexual differentiation

flow chart

A

sex chroms w/on spermatozoa determines
* * gene on Y chromosome => SRY prot => reg

all w/in 1st trimester

testes develop b4 ovaries so they're used for sexing in 1st trimester
142
Q

bovine twins

A
  1. placentae (chorion) fuse = share common blood supply
  2. testes of male develop b4 ovaries of female
  3. AMH + testosterone secreted reaches both foetuses
  4. = repro tract female no develop = canalisation no complete = ovaries no continue grow = sterile = ‘freemartin’

tract no continue to cervix

143
Q

vagina + vestibule of freemartin

A

derive from ectoderm = still develop as not sensitive effect AMH
* cr. vagina + uterus from mesoderm = sensitive effect

144
Q

major components male repro sys

A
  • testis = prod sperm + synth, release, store horms
  • excurrent ducts
  • accessory sex glands
  • penis = deliver sperm -> female
145
Q

histology testis

A

sperm prded seminiferous tubules in testis
* total length 500-1000m

146
Q

seminiferous epithelium

A

complex stratified cont:
1. spermatogenic cells = stem cells replicate + diff into mature sperm as migrate -> lumen
2. sertoli = sustentacular = physical + nutritional support + release androgen-binding horms
3. CT w leydig cells to prod + release testost

sertoli = long-lived + permanent
147
Q

spermatogenesis

A

born w un-diffed diploid sperm cells = spermatogonia at basal lamina seminif tubs
starts at puberty:
* develop w/in sertoli cells from basal aspect -> lumen of seminiferous tubule

meiosis:
-> diploid spermatogonia (prim spermatocytes)
-> haploid 2ndary spermatocytes (spermatids = mature sperm)

148
Q

sperm testis barrier

A

physical barrier bet bvs + tubules
== basal + adluminal compartments tubule bc tight juncts bet sertoli cells
* sep haploid cells bc not ‘self’ = foreign = provoke immune reaction

149
Q

diff bet oogonia + spermatogenesis

A
  • s = cont prod, o = cyclic release finite no.
  • concurrent prod sperm + sex steroids but cyclic prod ova + sex steroids
  • lots sperm, few oocytes
  • male = mitosis activated puberty, female = completed by birth -> prim oocytes
  • male = stem cell renewal, infinite no. gametes, fem = no self-renewal, finite no.
  • 1 prim spermatocyte -> 4 secondary, 1 prim oocyte -> 1 mature ovum
  • spermatogenesis cont thruout life, gametogenesis in humans ends at menopause
150
Q

route sperm take

A

seminiferous tubules -> rete testis -> efferent ducts -> head, bod, tail epididymis -> ductus deferens -> pelvic urethra

151
Q

epididymus

A

30-60m tube surrounded sm musc
* sperm mature as pass thru duct + concd in tail
* no. fertile breedings male can perform limited by sperm stored tail

152
Q

ductus deferens

A

connects tail epididymis -> pelvic urethra

153
Q

maturisation of sperm

A

leave sertoli = non-motile + DNA in head no condensed = non-fertile
* takes 8-15d to mature whilst passing thru epididymis

154
Q

spermatogensis general

A
  • 5-9wks depend species
  • no. sperm proded each day independent amount ejaculated
  • released continually from seminiferous tubules
  • requires testosterone
155
Q

leydig cell

A

respond LH to secr testosterone
* equiv theca interna cells

in seminiferous tubules

156
Q

sertoli cell

A

respond FSH
-> secr inhibin
-> convert testosterone -> dihydrotestosterone + oestrodiol

male equiv follicular granulosa cells

in seminiferous tubule

157
Q

reg LH + FSH + effects

A

release controlled GnRH hypothal
* GnRH on leydig stims testost = stim sertoli = initiate spermatogensis
* FSH on sertoli stim prot synth, testost receptor expression, testicular fluid prod, inhib secr

neg feedback

158
Q

testosterone actions

A
  • stim growth internal + external genitalia
  • stim 2ndary sex characteristics - behaviour + sex drive
  • enhance growth sk musc + bone
159
Q

what is required for testis function

A
  • pulsatile GnRH secr (every3-6hrs)
  • adequate LH receptors in leydig cells
  • high concs testost in seminiferous tubules
  • correct temp
160
Q

homeostatic control scrotal temp

rams

A

thermosens neurons in scrotum -> spinal cord -> hypothal -> motor neurons -> pant, sweat glands on scrotum

161
Q

specific scrotum temp control

A
  • lots sweat glands
  • tunica dartos = sm musc under sndrogen control contract -> body wall for warm/opp
  • cremaster musc = sk musc draw testis -> bod fast for protect or pull in to warm short period
  • testi arts + veins close contact = counter-current heat exchange = cool art blood
162
Q

what do accessory glands secr

A
  • fructose as E source
  • horms + enzs

struct + funct dependent on testost

non-cellular = seminal plasma

prostate only visible accessory gland dog
163
Q

copulation

A
  1. mounting
  2. intromission + friction movements
  3. emission = seminal fluids acc glands -> pelvic urethra = mix w sperm
  4. ejaculation - symp NS due sensory (temp, press) stim penis head - sperm + seminal plasma out repro tract
164
Q

erection

A
  • elevated art blood flow
  • dilation corporal sinusoids
  • restrict venous outflow
  • incr intra-penile press
  • relax retractor penis musc

non-adrenergic non-cholinergic (NANC) parasymp neurons dominate

165
Q

how ejaculate

A

symp NS due sensory stim = ischiocavernous, bulbospongiosus + urethralis musc contract together to squeeze semen out

166
Q

cryptorchid horses

== rigs

A

== 1/both testis retained in ingional canal/abdom
* don’t just test testost bc if retained may not prod much
* inject LH + test blood b4 + after + if testicular tiss will get incr in testost

167
Q

general progest pattern during preg

A

remains high thruout gestation, rapidly decr just b4 parturition

species variation in specifics

168
Q

horse progest in preg

A

embryo prods pregnant mare serum gonadotropin (PMSG)
=> stims FSH + LH receptors on ovarian follicles to initiate ov 2nd oocyte
=> prod accessory corp lut
=> augment progest prod

progest obligatory to maintain preg - luteolysis early = abortion

169
Q

progest sources diff species

A
  • horse = PMSG
  • cow = 6-80mo using corp lut
  • bitch = progest from corp lut thru whole preg
170
Q

luteal phase preg vs not bitch

A

prolactin in preg luteotrophic = plateau progest prolonged then sidden decline for parturition
not preg = more gradual decline

pretty similar

171
Q

terminating preg

A

give exogenous prostaglandin whilst relying on progest from CL = induce luteolysis = terminate preg

also to induce cow just b4 parturition

172
Q

what does placenta prod

A

progest + then oestrogen peaking HIGH just before partur (as progest declines)

173
Q

why does progest decline before partur

A

removes block to oestrog + promotes myometrial contractions

174
Q

what initiates partur

A
  1. end gestation = foetal mass approaching space limitation uterus + exchange limitation of placenta
  2. = foetus stressed = secr stress hormones cortisol from adrenal, ACTH from ant pit

majority foetal growth in last 1/3 gestation

remove/add stress hormones = prevent/induce partur

175
Q

result of foetal cortisol

A
  • progesterone convert -> oestrogen = contractions can begin
  • placenta synth prostaglandin = luteolysis
176
Q

relaxin

A

synth in CL/placenta stimmed prostaglandin
=> softening soft tiss of cervix + incr elasticity pelvic ligs

177
Q

oestradiol effects

A
  • incr secr mucous -> wash out cervical seal + lube vaginal + cervical canal
  • incr myometrial contractions
178
Q

stages partur

A
  1. initiation myometrial contractions + cervical dilation
  2. expulsion foetus
  3. expulsion foetal mems
179
Q

expelling foetus

A

uterine contraction push foetus + allantois into vagina =>
1. neuroendocrine reflex to release oxytocin
2. spinal reflex to stim abdom straining

180
Q

when do sacs rupture

A
  • allantois ruptures in vagina
  • amnion can burst at vulva or can cover head of offspring (mares + bitches partic)

amnion = water bag

181
Q

stim + role of oxytocin

A

stretch sensitive cells in cervix activated by descending foetus => neuroendo reflex => secr oxytocin from post pit
== incr strength + frequency uterine contractions

doesn’t initiate partur, but later big pos feedback loop until delivery

182
Q

mammary gland is

A

modified sweat gland - ectoderm
* arises from lat lines on ventral surface developing conceptus = mammary ridges
* vary in no, location + teat no.

183
Q

mammary tiss development

A

terminal alveoli (prod milk) grow into lobules = grape-like structures empty common duct
* 90% mass mammary gland

184
Q

growth mammary gland post puberty

A

induced cyclical ovarian activity
1. oestrogen = ducts branch + incr in diameter
2. progest = terminal portions branch form alveoli

prolactin + GH incr during puberty + needed complete + rapid development ducts

faster than normal body growth, development only so far if not preg

185
Q

mammary alveoli epithelial cells

A

metab active on basement mem surrounded collagenous ECM
* incr rough ER for prot synth
* incr smooth ER for phospholipid + triglyceride synth
* milk synthed across apical surface
* tight junctions bet cells = impermeable barrier

186
Q

composition milk

A

prot, fat, lactose
Na+, K+, Cl-, Ca2+ prot-bound (lots more than plasma)

similar osmolarity to ECF

187
Q

formation colostrum

A

gland plasma cells prod immunoglobulins = passive immunity (animals w/o passive placental transfer)
* high in fats, prots, vit A, low lactose

188
Q

lactogenesis

A

onset milk secr
1. acquisition secretory capability pre-partum
2. onset copious secr at partur (horms ensure right time)

189
Q

hormonal control lactogenesis

A
  1. low progest at end preg allows synth prolactin receptors
  2. prolactin binds receptor + upregs α-lactalbumin + enzs involved synth lactose

incr cortisol, prolactin, oestrogen, placental lactogen in late preg

190
Q

galactopoesis

A

== maintenance milk secr, requiring:
1. horms
2. removal of milk as alveolar cells secr prot Feedback Inhibitor of Lactation (FIL) - builds up + inhibits secr unless removed

191
Q

horms for galactopoesis

A
  1. prolactin maintains alveolar cell metabl + secr α-lactalbumin
  2. oxytocin stims myoepithelial cells to help remove milk
  3. rumis = GH helps uphold secr
  4. GH, insulin, thyroid + cortisol required indirectly
192
Q

factors affecting milk yield

A
  • no. secretory cells in mammary gland
  • blood supply to mammary gland
  • water intake (milk mostly water)
  • incr blood gluc = decr lactose = decr vol (most important factor)
  • milk removal - sucking frequency to remove FIL
193
Q

where is milk secreted

A
  1. mammary epithelial cells of alveoli secr milk -> alveolar lumen
  2. milk in alveoli + fine ducts = small diameter = big resistance = hard suck
194
Q

milk ejection

A

milk pushed out mammary gland -> larger ducts + cisterns as myoepithelial cells contract
* stimuli = tactile stim teat, smell, vision, sound
* = oxytocin secr = contraction reflex

milk pushed not sucked out - eject reflex easily conditioned for parlour

195
Q

tunica albuginea

A

thick CT capsule around testis w CT septa sepping testis into lobules cont seminiferous tubule + interstitial tiss

196
Q

where is urethra in penis

A

extending down centre corpus spongiosa

197
Q

Uterus layers

A
  1. Endometrium lining = simple columnar w uterine glands + bvs
  2. Myometrium = layers sm musc (inner circ, outer longi) w large bvs bet - responsive horms esp oxytocin
  3. perimetrium = loose ct w lymphatic vessels
198
Q

cervix struct

A

fibromuscular plug at opening uterus
* lining = simple columnar
* secr mucous

199
Q

function cervix

A
  • seal off uterus during preg
  • maintain sterile stable internal environ for embryonic development
200
Q

vagina histo

A
  • non-keratinised stratified squamous epithelium
  • secr prod acidic environ
  • then lamina propria
  • then double layer sm musc (inner circ, outer longi)
201
Q

label

A

testis

202
Q

label

A

ductus deferens

203
Q

label

A

prostate gland = tubulo-alveolar gland

204
Q

label

A

seminal vesicle = coiled tubular gland that enters ductus deferens

205
Q

label

A

penis

206
Q

label

A

ovary w follicles in diff stages development

207
Q

glands in uterine horn

A

acinar glands lined cuboidal epithelium

208
Q

label

A

epididymis

209
Q

journey sperm

A

seminiferous tubules -> rete testis (channs in mediastinum testis) -> efferent ducts -> epididymis -> ductus deference -> urethra lumen

210
Q

umbilical cord vessels

A
  • 2 umbilical arts from internal iliac art
  • 1 umbilical vein
  • urachus = allantoic duct -> allantoic art (drains bladder)

art + vein oxygenation wrong way round

211
Q

what do umbilical arts connect

A

L + R internal iliac art -> foetal-maternal blood exchange at chorionic villi

212
Q

what do umbilical vein connect

A

foetal-maternal blood exchange at chorionic villi -> ductus venosus

213
Q

what happens at birth

A
  • amniotic mem of cord broken
  • umbilical arts retract
  • umbilical vein + urachus close (temporarily remain outside bod)
214
Q

what does umbilical art become

A

round/lateral ligaments of bladder

215
Q

what does umbilical vein become

A

round lig of liver = falciform lig

216
Q

what does urachus become

A

median lig of bladder

217
Q

what happens in postpartum period

A
  1. myometrial contraction to return uterus to size + expel lochia (normal remnants)
  2. endometrial repair
  3. resumption ovarian function
  4. elimination bac contamination from repro tract
218
Q

uterine involution

A

== return pre-preg status so myometrium conts contract after birth so decr in size
2. = sm musc cells decr in size
3. glands in endometrium degraded
4. granulocytes invade lumen + decomp tiss remnants + kill microorgs

219
Q

lochia

A

normal remnants foetal tiss expelled out vagina (brown discharge)

220
Q

species variation in uterine involution

A

rapid in animals w diffuse placenta
* mare oestrus + ov can occur 1-2wks after foaling (= foal heat)

221
Q

effect of suckling on uterine involution

A

suckling = oxytocin for milk let down but uterus still has oxytocin receptors for few days after parturition so also incr speed uterine involution

222
Q

GnRH pulse generator

A

drives repro function bc incr frequency pulses of GnRH drives LH + FSH which drive gonadal function

too low frequency = no repro function

223
Q

what controls GnRH release

A
  • sex-steroids (feedback)
  • inflamm
  • stress
  • drugs
  • metabolism
224
Q

synth of GnRH

A

peptide neuro-hormone made neural cell in preoptic area of hypothal + released at terminal end

225
Q

puberty =

A

acquisition of repro competence

226
Q

what controls puberty

A

hypothal
* GnRH v low in young animals
* sexual maturity signalled by incr in GnRH pulsatility

GnRH hard to measure so LH often used as marker

227
Q

factors in onset puberty

A
  • size + fatness (more in female) due effects metabolic hormones on GnRH pulsatility, e.g. leptin
  • season of birth + photoperiod - depends E supply, seasonality
  • social cues - large grps + presence of male
  • age
  • metabolic status

all affects GnRH release

228
Q

defn puberty in males

A

age when ejaculate contains sufficient sperm to fert
also:
* when behavioural traits expressed
* at first ejaculation
* when sperm 1st appear in ejaculate

229
Q

defn puberty in females

A

age when female can support preg w/o deleterious effects
also:
* at 1st oestrus
* at 1st ov

230
Q

normal reasons supress GnRH pulsatility + ovarian cycles stop

A
  1. lactation
  2. preg
  3. photoperiod
  4. starvation
231
Q

lactation + preg

A

lactation amennhorea (LAM) = avoid preg based natural postpart infertility associated fully breastfeeding
* suckling reduces = ov returns

232
Q

lactation on GnRH

A
  1. lactation = lots inhib GnRH pulse generator
  2. plasma FSH insufficient for follicle development but GnRH too low for ov

suckling frequency incr inhib

233
Q

what controls seasonality in breeding

A

effect melatonin on GnRH pulse generator

234
Q

who goes back into oestrus faster dairy or beef

A

beef bc calf suckling more times a day than milked = more oxytocin = more contraction uterus = returns back faster = oestrus starts sooner

235
Q

newly calved dairy heifer + cycle

A

2yrs old = still growing + new calf + bred for loads milk + stress of bullying = inhib GnRH pulse generator

NSF (22 decks)

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