anatomy Flashcards
which spinal structure ends at S2
dura
what group of muscles attaches to ischial tuberosity
hamstrings (not short head of biceps)
ischiopubic ramus is the site of attachment for
external genitalia
which foramen is formed by the ischial and pubic rami
obturator foramen
how to differentiate male and female pelvis
pubic arch flares out more in female (wider subpubic angle)
pelvic cavity is shallower in females
pubic arch is thicker in males
list the joints of the pelvis
sacroiliac joint hip joint (synovial) pubic symphysis (secondary cartilaginous)
what makes the SI joint so stable
interosseous ligament
which is more stable; SI joint or pubic symphysis
SI joint because it is fibrous not cartilaginous
why is the pubic symphysis a cartilaginous joint
so it can stretch out in childbirth
PSIS is in line with which vertebral level
S2
the top of the iliac crest is at which vertebral level
L4
where does the inguinal ligament attach
the ASIS and the pubic tubercle
which nerve is associated with the sacrotuberous ligament
pudendal nerve
where is the sacrospinous ligament
sacrum and ischial spine
where is the sacrotuberous ligament
sacrum and ischial tuberosity
function of the macro-tuberous and -spinous ligaments
ensure the inferior part of the sacrum is not pushed superiorly when weight is suddenly transferred vertically through the vertebral column (eg jumping or during late pregnancy)
which two foramina do the pelvic ligaments form
greater and lesser sciatic foramina
what is the pelvic inlet made up of
sacral promontory
ilium
superior pubic ramus
pubic symphysis
what is the pelvic outlet made up of
pubic symphysis ischiopubic ramus ischial tuberosities sacrotuberous ligaments coccyx
which muscle is also known as the pelvic floor
levator ani muscle
functions of bony pelvis
support of body when sitting and standing
transference of weight from spine to legs to allow standing and walking
attachment for muscles of locomotion and abdominal wall
attachment of external genitalia
protection of pelvic organs
passage for childbirth
what is moulding
movement of one bone over another to allow the foetal head to pass through the pelvis during labour
what is the vertex
an area of the foetal skull outline by the anterior and posterior fontanelles and the parietal eminences
which is longer; the occipitofrontal diameter or the biparietal diameter
occipitofrontal
which way should the foetus by facing when it enters the pelvic inlet and why
left or right
the transverse diameter of the pelvic inlet is wider than the AP diameter so the occipitofrontal diameter of the foetal head can fit through easier if it is sideways
what is the station
the distance of the foetal head from the ischial spines
-ve means superior
+ve mean inferior
what should happen to the baby’s head when it reaches the pelvic outlet and why
it should turn so it is in an occipitoanterior position
the AP diameter of the pelvic outlet is wider than the transverse diameter
why is there a further rotation after the baby’s head has been delivered
so the shoulders can fit through
which female reproductive organs are found in the pelvic cavity
ovaries
uterine tubes
uterus
superior part of vagina
which female reproductive organs are found in the perineum
inferior part of vagina perineal muscles Bartholin's glands clitoris labia
which muscle group separates the perineum and pelvic cavity
pelvic diaphragm
which pouches are formed by the peritoneum in the female pelvic cavity
vesicouterine pouch
recto-uterine (pouch of Douglas
which structure forms the floor of the peritoneal cavity and the roof of the pelvic cavity
peritoneum
in which pouch is fluid most likely to collect in the anatomical position
pouch of Douglas
how can fluid in the pouch of Douglas be drained
culdocentesis
fluid drained via a needle passed through the posterior fornix of the vagina
buzzword with regards to uterine ligaments
“double layer of peritoneum’
broad ligament
buzzword with regard to uterine ligaments
“embryological remnant”
round ligament
where is the broad ligament found
extending between the uterus and the lateral walls of the pelvis
function of the broad ligament
maintains the uterus in its correct midline position
what is contained within the broad ligament
uterine tubes
proximal part of the round ligament
where is the round ligament found
attaches to the lateral aspect of the uterus
passes through the deep inguinal ring to attach to the superficial tissue of the female perineum
what are the three layers of the uterus
permetirum
myometrium
endometrium
which uterine layer is shed during menstruation
endometrium
where does implantation of the zygote occur
body of uterus
what is an ectopic pregnancy
implantation not in the body of the uterus
what are the 3 layers of support holding the uterus in place
strong ligaments (eg uterosacral ligament endopelvic fascia muscles of the pelvic floor
what is a uterine prolapse
movement of the the uterus inferiorly
what is the most common position of the uterus
anteverted (cervix tipped anteriorly relative to the axis of the vagina) ante flexed (uterus ripped anteriorly relative to the axis of the cervix)
what is a normal variation of the position of the vagina
retroverted (cervix tipped posteriorly relative to the axis of the vagina)
retroflexed (uterus tipped posteriorly relative to the axis of the cervix)
where does fertilisation normally occur
in the ampulla of the Fallopian tubes
what is a bilateral salpingo-oophrectomy
removal of both uterine tubes and ovaries
how is there communication between the genital tract and the peritoneal cavity
the fimbriae at the end of the uterine tubes actually open in to the peritoneal cavity
what are the 4 parts of the vaginal fornix
anterior
posterior
2 lateral
where can the ischial spines be palpated
laterally at 4 and 8 o’clock
what is the perineum
shallow space between pelvic diaphragm and the skin
what are the openings of the pelvic floor
passage of distal parts of the alimentary, renal and reproductive tracts
what type of muscle is levator ani
skeletal muscle
nerve supply to levator ani
S3, 4, 5
what is the perineal body
bundle of collagenous and elastic tissue into which the perineal muscles attach
where is the bed of the breast located
from ribs 2-6
lateral border of the sternum to mid-axillary line
what structures lie deep to the breast
deep fascia
pec major and serrates anterior
what is the retromammary space
space between the fascia and breast
how does the breast tissue attach to the skin
suspensory ligaments
where does the majority of the breast lymph drain to
ipsilateral axillary lymph nodes and then to the supraclavicular nodes
where does lymph from the inner breast quadrants drain to
ipsilateral (or contralateral) parasternal lymph nodes and the to the supraclavicular nodes
what clinical implications are there of axillary node clearance and why
lymphedema of the upper limb
upper limb lymph also drains into the axillary lymph nodes
what are the levels used to describe the extent of axillary node clearance
level I - inferior and lateral to pec major
level II - deep to pec major
level III - superior and medial to pec major
blood supply to the breasts
internal thoracic artery
axillary artery
what are the male reproductive organs
testes
what are the male accessory reproductive organs
vas deferens
seminal glands
prostate gland
penis
what are the stages of the male lower urinary tract
bladder internal urethral orifice internal urethral sphincter (involuntary) prostatic urethra external urethral sphincter (voluntary) spongy urethra external urethral orifice
what makes up the trigone
2 ureteric orifices
internal urethral orifice
which muscle forms the bladder wall
detrusor muscle
what is the function of the internal urethral sphincter in males
contracts during ejaculation to prevent retrograde ejaculation
where do the testes originate
on the posterior wall of the abdominal cavity
which structures travel through the spermatic cord
testicular artery testicular vein vas deferens lymphatic vessels autonomic nerves somatic nerves
three layers of fascia covering the spermatic cord
external spermatic fascia
cremastueric fascia
internal spermatic fascia
what is the name of the structure in which the testes sit
tunica vaginalis
what are the two layers of the tunica vaginalis
parietal layer
visceral layer
what is a hydrocele
excess fluid in the tunica vaginalis
where is sperm produced
seminiferous tubules
which muscle helps control the temperature of the testes
dartos muscle
route of sperm out of the testes
rete testis
head of epididymis
vas deferens
average volume of testes
12-25 ml
venous drainage from testes
left testicular vein to left renal vein
right testicular vein to IVC
arterial supply to testes
testicular arteries from lateral aspect of abdominal aorta
what is the function of the seminal glands
produce seminal fluid, rich in fructose
what is the function of the bulbourethral gland
mucus secretion
lubricates urethra
neutralises acidity
where do most prostate cancers occur
peripheral zone
route of sperm once it leaves the testes
spermatic cord passes trough the anterior abdominal wall within the inguinal canal to reach the pelvic cavity
travels superiorly, then poster-inferiorly to the bladder
vas deferent connects to the seminal duct to form ejaculatory duct
rights and left ejaculatory ducts join together within prostate and drain into urethra
urethra opens at the external urethral meatus
where is the root of the penis attached
ischium of the pelvis
what are the 3 cylinders of penile erectile tissue
2x corpus cavernosum (contain deep arteries of penis) corpus spongiosum (spongy urethra)
what is contained within the superficial perineal pouch (male)
bulb (corpus spongiosum, crura, corpus cavernosum) associated muscles (bulbospongiosus and ischiocavernosus)
blood supply to penis
deep arteries of the penis
branches from internal pudendal artery from internal iliac
blood supply to scrotum
internal pudendal and branches of external iliac
lymph drainage of scrotum and most of penis
superficial inguinal nodes
lymph drainage of testes
lumbar nodes
which types of nerves innervate structures in the pelvis
sympathetic, parasympathetic and visceral afferent
body cavity
which types of nerves innervate structures in the perineum
somatic motor and sensory
body wall
nerves that cause cramping
sympathetic/parasympathetic
under hormonal control
nerves that cause uterine contraction
sympathetic/parasympathetic
under hormonal control
nerves that cause pelvic floor muscle contraction
somatic motor
nerves that receive sense pain from adnexae
visceral afferents
nerves that sense pain from uterus
visceral afferents
nerves that sense pain from the vagina
visceral afferents (pelvic part) somatic sensory (perineum)
nerves that sense pain from the perineum
somatic sensory
how does pain from the superior aspect of pelvic organs (touching the peritoneum) reach the CNS
visceral afferents run alongside sympathetic fibres
enter spinal cord between T11-L2
pain is perceived as suprapubic
how does pain from the inferior aspect of pelvic organs (not touching peritoneum) reach the CNS
visceral afferents run alongside parasympathetic fibres
enter spinal cord levels S2, 3, 4
pain perceived in S2, 3, 5 dermatome (perineum)
how pain from structures crossing from pelvis to perineum above levator ani reaches the CNS
visceral afferents run alongside parasympathetics
enter CNS at spinal cord levels S2, 3, 4
how pain from structures crossing from pelvic to perineum below levator ani reaches the CNS
somatic sensory fibres in the pudendal nerve
enter spinal cord level S2, 3, 5
causes localised pain in the perineum
what are the 2 important spinal levels for gynaecologist pain
T11-L2
S2-S4
what level is anaesthetic injected into in spinal and epidural anaesthesia
L3-L4 region
which layers does spinal anaesthetic pass through
supraspinous ligament interspinous ligament ligamentum flavum epidural space dura mater arachnoid mater SAS
which layers does epidural anaesthetic pass through
supraspinous ligament
interspinous ligament
ligamentum flavum
epidural space
arterioles are supplied by which type of nerves fibres
sympathetic fibres
what does blockade of sympathetic tone to all arterioles in the lower limb result in
vasodilatation
skin of lower limbs looks flushed, warm lower limbs, reduced sweating
route of pudendal nerve
exits pelvis via greater sciatic foramen
passes posterior to sacrospinous ligament
re-enters pelivs/perineum via lesser sciatic foramen
travel in pudendal canal
which bony landmark is used to administer pudendal nerve block
ischial spine
which ligament is closely associated with the pudendal nerve
sacrospinous ligament
what can damage to the pudendal nerve or external anal sphincter during childbirth result in
weakened pelvic floor
faecal incontinence
the urogenital system arises from which embryological origin
intermediate mesoderm
mesonephric duct aka
wollfian
paramesonephric duct aka
mullerian
weeks 4-6 sexual characteristics
wollfian and mullerian duct formation
indifferent gonad
what hormone do Sertoli cells secrete in the presence of SRY protein
anti-mullerian hormone
what is the function of anti-mullerian hormone
degeneration of the paramesonephric duct
how do Sertoli cells influence the formation of leading cells
stimulate gonadal ridge cells to form testosterone secreting leading cells
formation of which structures induced by the presence of testosterone (embryology)
epididymis, vas deferens, seminal vesicles
what is the function of dihydrotestosterone
induces male specific external genitalia development and prostate
what causes persistent mullerian duct syndrome
mutations of anti-mullerian hormone or its receptors
how does persistent mullein duct syndrome present
uterus, vagina and uterine tubes
testes in ovarian location
male external genitalia
what spinal level do testes originate
T10
which structures pulls the testes caudally
gubernaculum
what is the commonest uterine abnormality
septated uterus
what are the three components that make up the pelvic floor
pelvic diaphragm
muscles of perineal pouches
perineal membrane
whats the deepest layer of the pelvic floor
pelvic diaphragm
which muscle groups make up the pelvic floor
levator ani
coccygeus
three parts of levator ani
puborectalis
pubococcygeus
iliococcygeus
attachments of levator ani
pubic bones, ischial spines and tendinous arch of levator ani
perineal body, coccyx and walls of organ in midline
which structures form the roof and floor of the deep perineal pouch
roof = levator ani floor = pelvic membrane
what lies within the deep perineal pouch
part of urethra (and vagine) bulbourethral glands (male) neuromuscular bundle for penis/clitoris (dorsal vein of clitoris/penis) extensions of sischioanal fat pads external urethral sphincter compressor urethrae deep transverse perineal muscle (male)
what is contained in the male superficial perineal pouch
bulb and corpus spongiosum crura and corpus cavernosum bulbospongiosus ischiocavernosus spongy urethra superficial transverse perineal muscle internal pudendal vessels and pudendal nerve
what is contained in the superficial perineal pouch (female)
clitoris and crura (corpus cavernosum)
bulbs of vestibule
bulbospongisus
ischiocavernosus
common O&G surgical incisions
vertical midline incision
pfannenstiel incision
what are the layers of the anterolateral abdominal wall
skin superficial fascia rectus sheath external oblique internal oblique rectus abdominis transversus abdominis
attachments of the external obliques
attach between the lower ribs and iliac crest, pubic tubercle and linea alba
attachments of the internal obliques
attach between lower ribs, thoracolumbar fascia, iliac crest and linea alba
attachments of traversus abdominis
attach between lower ribs, thoracolumbar fascia, iliac crest and linea alba
what is the nerve supply to the anterolateral abdominal wall
7th-11th intercostal nerves (thoracoabdominal nerves)
subcostal (T12)
iliohypogastric (L1)
ilioinguinal (L1)
in which plane does the nerve supply to the anterolateral abdominal wall travel
between internal oblique and traverses abdominis
blood supply to the anterior abdominal wall
superior epigastric arteries
inferior epigastric arteries
from which artery does the superior epigastric artery emerge
internal thoracic
from which artery does the inferior epigastric artery emerge
external iliac artery
blood supply to the lateral abdominal wall
intercostal and subcostal arteries
from which arteries do the intercostal and subcostal arteries arise
posterior intercostal arteries
which muscle do the superior and inferior epigastric arteries lie posterior to
rectus abdominis
how can traumatic injury to muscle be minimised when making an incision
incise in same direction as muscle fibre
layers incised through in an LSCS incision
skin and fascia anterior rectus sheath rectus abdominis (separate muscles laterally) fascia and peritoneum retract bladder uterine wall amniotic sac
layers to stitch closed after LSCS
uterine wall with visceral peritoneum
rectus sheath
fascial layer if increased BMI
skin
layers when opening a laparotomy (vertical midline incision)
skin and fascia
linea alba
peritoneum
layers to stitch closed in a laparotomy
peritoneum and linea alba
fascia if increased BMI
skin
why might healing of a midline incision be poor
limited blood supply
complications of middle incision
dehiscence
incisional hernia
how to avoid inferior epigastric artery when localising a lateral port
outer third of the line from umbilicus and ASIS
how to distinguish between uterine artery and ureter
the ureter passes inferior to the artery
‘water under the bridge’
which incision is often used in an abdominal hysterectomy
pfannenstiel
same as LSCS
