REGISTRY REVIEW- ANATOMY OF UTERUS, CERVIX & VAGINA
body of the uterus
1. AKA corpus 2. mid-section of uterus 3. great flexibility to expand with pregnancy
basal layer of endometrium
1. AKA deep layer 2. not influenced by menstrual cycle
internal iliac artery
1. AKA hypogastric artery 2. non-pregnant patient- internal iliac artery = smaller in caliber than external iliac artery 3. divides into anterior/posterior segments 4. uterine artery = anterior segment branch
functional layer of endometrium
1. AKA superficial layer 2. thickens & sloughs off with menses
vagina anatomy
1. anterior to rectum, posterior to bladder/urethra 2. b/w right & left levator ani muscles 3. connects to cervix 4. lower segment of cervix extends slightly into vaginal canal forming vaginal fornices 5. vaginal walls = not exceeding 1 cm thickness or measured together = no greater than 2 cm 6. average cuff measurement = 1.4 cm
uterine artery
1. branch of anterior interior iliac artery 2. extend to cervix then goes superiorly along outside of uterus 3. vaginal artery branches from uterine artery & supplies vagina 4. small branches merge with branches of ovarian artery near uterine cornua 5. blood supply of ovaries/tubes = by uterine artery/ovarian artery 6. gives rise to many small arcuate arteries
arcuate arteries
1. encircle periphery of uterus 2. course parallel to long axis of uterus 3. gives rise to smaller branches (radial arteries)
3 layers of the uterine wall
1. endometrium 2. myometrium 3. perimetrium/serosa
correct method to measure uterus length
1. in sagittal plane 2. from uterine fundus to level of external os
endometrium
1. inner most layer 2. composed of 2 layers (functional/basal)
size of nulliparous uterus
1. length = 6-8.5 cm 2. AP = 2-4 cm 3. width = 3-5 cm
size of multiparous uterus
1. length = 8-10.5 2. AP = 3-5 cm 3. width = 4-6 cm
myometrium
1. middle, muscular layer of uterus 2. thickest layer 3. involved in birth
uterine artery flow characteristics
1. moderate velocity 2. high resistance 3. resistance increases with age until diastolic flow = absent (RI = 1.0)
fundus of the uterus
1. most superior portion of uterus 2. above where cornua extend into fallopian tubes
perimetrium
1. outermost layer of uterus 2. AKA serosa 3. composed of fibrous connective tissue
radial arteries
1. penetrate serosa & myometrium 2. branch into spiral & straight arteries
internal iliac veins
1. posterior/medial to internal iliac arteries 2. located lateral & posterior to ovaries 3. non-pregnant patient internal iliac vein = smaller than external iliac vein 4. merges with external iliac vein to form common iliac vein 5. drains pelvic organs
landmarks of the uterus
1. round, cardinal & uterosacral ligaments suspend uterus in pelvic cavity
postmenopausal uterus size
1. segment ratio remains same 2. overall organ atrophy
location of the uterus
1. sits b/w 2 layers of the broad ligament 2. posterior to bladder 3. anterior to rectosigmoid colon 4. segmented into fundus, corpus & cervix
vaginal fornices
1. superior recesses of the vagina 2. caused by the extension of the cervix into the vaginal canal
spiral arteries
1. supply functional layer of endometrium 2. stimulated by menstrual cycle
internal iliac artery branches
1. umbilical artery 2. internal vesicle artery 3. middle rectal artery
anteflexed uterine position
1. uterine body forms sharp angle with cervix 2. folds over sharply on cervix
retroverted uterine position
1. uterine body tips posteriorly w/ small angle b/w body & cervix 2. cervix angles posterior from origin at vaginal cuff
anteverted uterine position
1. uterus forms <90 degree angle with cervix 2. cervix angles anterior from origin at vaginal cuff
adult nulliparous uterus size
1:1 ratio of cervix & body/fundus length
prepubertal uterus size
body half the size of cervix
adult multiparous uterus size
body/fundus at least 2X longer than cervix
neonatal uterus size
cervix more than 2X longer than body/fundus
cervix
connects uterine cavity with vagina
uterine veins
empty into internal iliac veins
levoposition uterine position
entire uterus displaced to left
dextroposition uterine position
entire uterus displaced to right
uterine anatomy
hollow, thick-walled muscular organ
isthmus of the uterus
lower portion of the corpus (body) connected to cervix
external os
opening from cervix to vagina
internal os
opening from uterus into cervix
lower uterine segment
short segment b/w body & cervix in PREGNANT patients
straight arteries
supply basal layer of endometrium
levoflexed uterine position
uterine body flexed to left
dextroflexed uterine position
uterine body flexed to right
retroflexed uterine position
uterine body folds posteriorly @ very sharp angle to cervix