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