Anatomy and Embryology Flashcards
What does the bony pelvis consist of?
Two innominate bones
Sacrum
Coccyx
What is the role of the bony pelvis?
Support upper body
Transference of weight from vertebral column to femurs
Attachment for muscles and external genitalia
Protection of pelvic organs
What connects the ASIS and PSIS on the ilium?
Iliac crest
What is the attachment site of the iliacus muscle on the ilium?
Iliac fossa
Which is more superior the ischial spine or ischial tuberosity?
Spine
What part of the ischium do you “sit on” ?
Ischial tuberosity
Where does the inguinal ligament attach to the pubis?
Pubic tubercle
What type of joint is the pubic symphysis?
Secondary cartilaginous
What type of joint is the hip joint?
Synovial
What are the borders of the true pelvic cavity?
Pelvic inlet and outlet
Which muscle forms the musculofascial part of the pelvic cavity?
Levator ani
Which structures can be damaged in a pelvic fracture?
Iliac vessels Lumbosacral plexus Autonomic nerve supply Lymphatics Muscles Organs
Where does the sacrotubeous ligament attach?
Sacrum
ischial tuberosity
Where does the sacrospinous ligament attach?
Sacrum
Ischial spine
What would cause the ligaments to relax?
Pregnancy
What is the purpose of the ligaments of the pelvis?
To ensure sacrum is not pushed superiorly when weight transferred through vertical column
What is the difference between the male and female cavity?
AP and transverse diameters larger in female
Sub-pubic angle winder in female
Pelvic cavity shallower in female
Bones thin/light in female
Oval rather than round obturator foramen in female
What are the name of the fontanelles?
Anterior
Posterior
Sphenoid
Mastoid
What is the vertex?
Area of foetal skull outlined by the fontanelles and parietal eminences
Which diameter of a baby’s head is bigger?
Occipitofrontal
In which position should the foetus enter the pelvic cavity?
Occiput-transverse
Which pelvic diameter is bigger at the pelvic inlet?
Transverse
Which pelvic diameter is bigger at the pelvic outlet?
AP
What position should a baby ideally be in for delivery?
Direct occiput-anterior
What is the “station” of the foetal head?
Distance from foetal head to ischial spine
Into which two regions can the pelvic be divided?
False/greater
True/lesser
Describe the bony ring which defines the pelvic inlet
Formed by sacral promontory, alae of sacrum, arcuate line, pectineal line and pubic crest
Describe the pelvic outlet
Bordered by tip of coccyx posteriorly
Inferior margin of sacrotuberous posterolaterally
Ischial tuberosities laterally
Pubic arch anteriorly
Which palpable bony landmark is used as a guide to administer a pudendal nerve block?
Ischial spine
Which muscle covers the sphenoid and mastoid fontanelles?
Temporalis
What are gametes?
Haploid cells
Spermatozoa in males
Oocyte in females
Which organs produce gametes?
Male = testes Female = ovaries
Where is the perineum located?
Inferior to pelvic floor
Superior to the skin and fascia
What forms the pelvic roof?
Peritoneum
What is the Pouch of Douglas?
Space between the rectum and the uterus which is the most inferior part of the peritoneal cavity when standing
Where is the vesico-uterine pouch?
Between the bladder and uterus
What are the three layers of the uterus?
Perimetrium
Myometrium
Endometrium
Describe ovulation and fertilisation
1 ovum released from surface of the ovary into peritoneal cavity
Gathered by fimbrae into infundibulum of uterine tube
Moved along by cilia
Normally fertilised in ampulla
Which layer of the uterus is responsible for cramping?
Myometrium
Define ectopic pregnancy
A fertilised egg implants out with the uterine cavity
Where do the testes originate?
On the posterior wall of the abdominal cavity
Through which structure do the testes descend?
Inguinal canal
Where is sperm produced?
Seminiferous tubules
Which muscle helps to control the temp of testes?
Dartos muscle
Describe the route of sperm from production to ejaculation
Produced in sem. tubules Pass to rete testis Then head of epididymis Then vas def Ejec duct Right and left ducts join Prostatic urethra Membranous urethra Spongy urethra External urthral meatus
What does the spermatic cord contain?
Vas def Testicular artery Pampiniform plexus of veins Sympathetics Genital branch of genitofemoral nerve and lymphatics
Which structures pass through levator ani in the male?
Rectum and urethra
What is the function of the levator ani muscle?
Supports pelvic organs and maintains continence
What is the role of the external anal sphincter?
Voluntary control of faecal continence
What are the nerves roots of the pudendal nerve?
S2,3,4
What type of nerve fibres does the pudendal nerve contain?
Somatic motor and sensory
Sympathetics
What is the most common space for a perianal abscess?
Ischioanal fossa
Why may a peri-anal abscess spread through the ischioanal fossa?
Large space
Filled with fat - poor blood supply and few immune cells
Which important structure may be accidentally damaged during hysterectomy?
Ureter
How may fluid be drained from the Pouch of Douglas?
Needle placed through posterior fornix of vagina
What is the broad ligament?
Ligament formed by double layer of peritoneum
Extends from uterus to lateral pelvic walls and floor
What is a cystocoele?
Hernial protrusion of the bladder into the vaginal wall
What is a rectocoele?
Hernial protrusion of rectum into vaginal wall
List the components of the fluid secreted by seminal vesicles
Proteins Enzymes Fructose Mucous Vit C Flavins Phosphoylcholine Prostaglandin
What is the main function of the fluid secreted by prostate gland?
Activate sperm
What are the main function of the fluid secreted by the bulbourethral glands?
Lubricates urethra and helps to neutralise acid in urethra
What are the common surgical incision site sin obstetrics?
Lower segment Caesarean section
Laparotomy
Abdominal/vaginal hysterectomy
Which three muscles make up the abdominal wall?
Ext oblique (out) Int oblique (mid) Transversus abdominis (in)
Which two types of fascia are found in the abdominal wall?
Campus fascia
Scarpus fascia
Which fascia found in the abdominal wall fades in ascend through to the thorax?
Scarpus
What is the difference between scarpus and campus fascia?
Campus is fattier
Scarpus is more membranous
Which abdominal muscle is in the midline?
Recuts abdominis
Which muscle has a “hands in pockets” alignment?
External oblique
Where does external oblique attach superiorly?
Ribs 5-11
Which muscle has a “hands on chest” alignment?
Internal oblique
At what point does external oblique become its aponeurosis?
Mid-clavicular line
What happens to the aponeurosis of internal oblique?
Splits in two to sandwich the rectus abdominis
Which is recuts abdominis split into segments?
Mechanical efficiency
How is the linea alba formed?
Intertwining of the aponeuroses
Where does the linea alba run from/to?
From xiphoid process to pubic symphysis
Which is the arcuate line?
1/3 distance between umbilicus and pubic symphysis
Where is the rectus sheath?
Immediately deep to the superficial fascia
Which fascia make the internal spermatic fascia in the cord?
Transversalis fascia
What can be found in extra-peritoneal fat?
Vessels
Which nerves become the thoracoabdominal nerves?
7th-11th intercostals
What is the nerve root of subcostal nerve?
T12
What is the nerve root of iliohypogastric?
L1
What is the nerve root of ilioinguinal?
L1
When do the intercostals become the thoracoabdominal nerves?
When they pass the costal cartilage of the false ribs
Where do the nerves which supply the anterolateral abdominal wall run?
Between the int oblique and transversus abdominis
Which arteries supply the anterior abdominal wall?
Superior and inferior epigastric
What is the superior epigastric artery a continuation of?
Internal thoracic
Where can superior and inferior epigastric arteries be found?
Posterior to rectus abdominis
What are the inferior epigastric arteries a branch of?
External iliac
Which arteries supply the lateral abdominal wall?
Intercostal and subcostal arteries
What are the intercostal and subcostal arteries a continuation of?
Posterior intercostals
What pre-emptive alteration can be made to the vascular of the abdominal wall before surgery?
Ligate inferior epigastric before it is damaged/removed
So that the sup epigastric has time to accommodate for the loss of blood supply
How is a lower segment caesarean section carried out?
Cut made in suprapubic region across subcut tissues
Through deep fascia/rectus sheath
Rectus abdominis moved out the way towards nerve supply
Cut through transversalis fascia then peritoneum
Why is a midline incision not ideal?
Not very vascular so healing is poor and risk of complication is increased
If lateral port is required in laparoscopy which structure may be injured?
Inferior epigastric
Where is the deep inguinal ring?
Halfway between ASIS nad pubic tubercle
Which female reproductive organs/accessory organs are found in the pelvic cavity?
Ovaries
Uterine tubes
Uterus
Superior part of vagina
Which female reproductive organs/accessory organs are found in the perineum?
Inferior part of vagina Perineal muscles Bartholin's glands Clitoris Labia
Which type of tissue is found beneath the perineal muscles?
Erectile tissue
What is culdocentesis?
When fluid is drained from the Pouch of Douglas
What is the role of the pouch of Douglas?
Maintains uterus in midline position
What does the broad ligament contain?
Uterine tubes and round ligament
What does the round ligament attach to?
Lateral aspect of uterus
Superficial tissue of perineum
What structure does the round ligament pass through?
Deep inguinal ring
What is the round ligament a remnant of?
Gubernaculum
Which layer of the uterine body sheds during menstruation?
Endometrium
How much of the uterus is taken up by the cervix?
1/3rd
What holds the uterus in position?
Ligaments
Endopelvic fascia
Muscles of pelvic floor
How should the uterus be positioned?
Anteverted
Describe an “anteverted” uterus
Cervix tipped anteriorly relative to axis of vagina
Describe an “anteflexed” uterus
Uterus tipped anteriorly relative to axis of cervix
Describe a “retroverted” uterus
Uterus tipped posteriorly relative to the axis of the vagina
Describe a “retroflexed” uterus
Uterus tipped posteriorly relative to the axis of the cervix
What type of epithelium is found in the cervix?
Secretory columnar epithelium
Where does fertilisation normally occur?
Ampulla
What is a bilateral salpingo-oophrectomy?
Removal of uterine tubes and ovaries
What could an ectopic pregnancy on the right hand side be mistaken for?
Appendicitis
When do the fimbrae open up into?
The peritoneal cavity
What hormones do the ovaries secrete?
Oestrogen and progesterone
What stimulates the ovaries to produce hormones?
FSH and LH
What are the 4 parts of the vaginal fornix?
Lateral x2
Anterior
Posterior
At what positions can the ischial spine be palpated on digital vaginal examination?
4 and 8 o’clock
How is the position of the uterus assessed on examination?
Bimanual palpation
Which two triangles can the perineum be split into?
Urogenital and anal triangle
What type of muscle is levator ani?
Skeletal
Which nerves supply the levator ani?
Nerve to the levator ani - superior
Pudendal - inferior
What are the nerve roots of nerve to levator ani?
S3,4,5
What is the perineal body?
A bundle of collagenous and elastic tissue into which the perineal muscles attach
Where is the perineal body?
Posterior to the vagina, just deep to skin
At the junction of the anal and urogenital triangles
Which nerve supplies the perineal muscles?
Pudendal
Where are the Bartholin’s glands located?
4 and 8 o’clock positions around the orifice of the vagina
What do Bartholin’s glands do?
Produce lubrication
Where are the breasts located?
From ribs 2-6 at the lateral border of the sternum to the mid-axillary line
On deep fascia
What is the retromammary space?
Space between fascia and breat
How does the breat attach to skin?
Suspensory ligaments
How is a mass described in the breast?
What quadrant
Fixed to underlying tissue
What position should a breast exam be conducted in?
Standing with hands on hips to contract pec major
Where does lymph from breast tissue drain to?
From outer to ipsilateral axillary then supraclavicular from inner can go to ipsi or contralateral
Lower inner can drain to abdo lymph
Which artery does the internal thoracic come off of?
Subclavian
Name the male accessory reproductive organs
Vas deferens
Seminal glands
Prostate glands
Penis
How long is the male urethra?
20cm
What is the spongy urethra within?
Corpus spongiosum
What is the rectovesical pouch?
Space between the rectum and the bladder in males
What is the trigone of the bladder?
Triangle on the internal bladder
Made of 2 ureteric orifices and internal urethral orifice
Which muscle mostly makes up the bladder wall?
Detrusor
What is the role of the detrusor muscle?
Contract around the ureteric orifices to prevent backflow of urine (or ejaculate) when contracting to expel urine
Where do the testes originate?
Posterior wall of abdominal cavity
Through which structure do the testes descend?
Inguinal canal
What nerve types are found in the spermatic cord?
Autonomic (vas def)
Somatic (cremaster)
What is the conjoint tendon?
Medial end of combined aponeuroses of internal oblique and transversus abdominis
What is the role of the conjoint tendon?
Anchor muscles inferiorly to pubic bone
Which sac do the testis sit in?
Tunica vaginalis
What is a hydrocoele?
Excess fluid within the tunica vaginalis
What term is given to twisting of the somatic cord?
Torsion
Where is the epididymis located?
Prox end - posterior aspect of superior testis
Where can the vas deferens be palpated?
In spermatic cord in the scrotum superior to the testis
How is blood drained from the testis?
Left
Testicular vein to renal vein
Right
Testicular vein to IVC
Which part of the urethra does the prostate surround?
Prostatic urethra
Where do most prostate cancers occur?
Peripheral zone
What is paraphimosis?
Retraction of the prepuce constricting the neck of the glans causing it to swell
What is the root of the penis attached to?
The ischium of the pelvis
What are the 3 cylinders of erectile tissue called?
Right and left corpus cavernosum and the corpus spongiosum
What runs in the corpus cavernosum?
Deep arteries of penis
What runs in the corpus spongiosum?
Spongy urethra
What does the perineal pouch in the male contain?
Root of penis Spongy urethra Transverse perineal muscle Internal pudendal vessels Pudendal nerve
Which muscles are found in the penis?
Ischiocavernosus
Bulbospongiosus
Describe the blood supply to the penis
Deep arteries of penis from internal pudendal from internal iliac
Describe the blood supply to the scrotum
Internal pudendal and branches from external iliac
Describe the lymph drainage from scrotum and penis
Superficial inguinal lymph nodes
Note does not include glans
Where does lymph from the testes drain?
Lumbar nodes around abdominal aorta
What nerve types are structure in the pelvis innervated by?
Symps, parasymps and visceral afferents
What nerves types are structures in the perineum innervated by?
Somatic motor and sensory
With nerve types are responsible for uterine cramping?
Symps/parasymps
With nerve types are responsible for uterine contraction?
Symps/parasymps
With nerve types are responsible for pelvic floor muscle contraction?
Somatic motor
With nerve types are responsible for pain from the adnexae?
Visceral afferents
With nerve types are responsible for pain from the uterus?
Visceral afferents
With nerve types are responsible for pain from the vagina?
Visceral afferents - pelvic part
Somatic sensory - perineum
With nerve types are responsible for pain from the perineum?
Somatic sensory
Describe the pain sensation from pelvic organs touching the perineum
Visceral afferents pick it up
Run alongside sympathetic fibres
Enter spinal cord T11-L2
Perceived as suprapubic
Describe the pain sensation from pelvic organs not touching peritoneum
Visceral afferents pick it up
Run alongside parasympathetic fibres
Enter spinal cord at S2,3,4
Pain perceived in that dermatome - in perineum
How is pain sensed from the uterus, uterine tubes and ovaries?
visceral afferents back to T11-L2
How is pain sensed from the cervix and superior vagina?
Visceral afferents back to S2-4
How is pain sensed from the inferior vagina, perineal muscles, glands and skin of perineum?
Pudendal nerve to S2-4
At which vertebral level does the subarachnoid space end?
S2
At which level is a spinal/epidural anaesthetic performed?
L3/4
Which structures are passed through for a spinal anaesthetic?
Supraspinous ligament Interspinous ligament Ligamentum flavum Epidural space Dura mater Arachnoid mater
Which structures are passed through for an epidural anaesthetic?
Supraspinous ligament
Interspinous ligament
Ligamentum flavum
Into epidural space
Describe sympathetic outflow
Originates in autonomic centres in the brain
Exits spinal cord at T1-L2
Travels to sympathetic chains
Passes into all spinal nerves
Which type of nerve supply do arterioles get?
Sympathetic
What needs to be monitored when giving a spinal anaesthetic?
Blood pressure
What are the signs a spinal anaesthetic is working?
Reduced sweating
Warm lower limbs
Flushed skin in lower limbs
Which nerve is responsible for motor control of external anal and urethral sphincters?
Pudendal
In which cases would you need an pudendal nerve block?
Episiotomy incision
Forceps use
Perineal stitching
Describe the course of the pudendal nerve
Exits pelvis via greater sciatic foramen
Passes posterior to sacrospinous
Re-enters pelvis/perineum via lesser sciatic foramen
Travels in pudendal canal
What travels in the pudendal canal?
Pudendal artery and vein
Nerve to obturator internus
Pudendal nerve
What is the pudendal canal?
Passageway within the obturator fascia
In which location is an episiotomy usually performed?
Ischioanal fossa
Which two muscle groups make up the pelvic floor?
Levator ani
Coccygeus
What is the urogenital hiatus?
The anterior gap between the medial borders of the pubococcygeus
What passes through the urogenital hiatus?
Urethra
Vagina
Name the three parts of the levator ani
Puborectalis
Pubococcygeus
Iliococcygeus
Name the pelvic ligaments
Transverse cervical
Utero-sacral
Lateral ligament of bladder
Lateral rectal
What does the deep perineal pouch contain?
Part of the urethra Bulbourethral glands (male) NVB for penis/clitoris Ischioanal fat pads Compressor urethrae Deep transverse perineal muscle
What is the perineal membrane?
Thin, tough, deep fascia which lies superficial to the deep perineal pouch
What does the superficial perineal pouch contain in the male?
Root of penis Proximal spongy urethra Superficial transverse perineal muscle Internal pudendal vessels Pudendal nerve
What does the superficial perineal pouch contain in the female?
Clitoris
Bulbs of vestibule
Bulbospongiosus and ischiocavernous
When does the pelvic floor actively contract?
Coughing
Sneezing
Vomiting
Basically any increase in intra-abdo pressure
What is involved in maintaining urinary continence?
External urethral sphincter
Compressor urethrae
Levator ani
Bladder neck support
What is involved in maintaining faecal continence?
Puborectalis bending rectum anteriorly
What can cause injury to pelvic floor?
Pregnancy/childbirth Chronic constipation Obesity Heavy lifting Chronic cough/sneeze Menopause
How may vaginal prolapse be treated?
Sacrospinous fixation
Incontinence surgery
Describe sacrospinous fixation for prolapse
Sutures placed in sacrospinous medial to ischial spine
Describe incontinence surgery for prolapse
Mesh put in to create a sling around the urethra
Where does the gonadal artery branch from?
L2 abdominal aorta
Where does the superior rectal artery branch from?
Continuation of the inferior mesenteric
What is the median umbilical ligament a remnant of?
Umbilical artery
Which sex has the inferior vesical artery?
Male
Where does the anterior scrotal branch from?
External iliac
What does the uterine artery anastomose with?
Ovarian artery
Vaginal artery
Where do the venous plexuses of the pelvis mainly drain to?
Internal iliac
Where does blood in the superior rectal vein drain to?
Hepatic portal system
Where does blood from lateral sacral veins drain to?
Internal vertebral venous plexus
Which ureter is more likely to be damaged and why?
Left
More medial and crosses common iliac which makes it more vulnerable
What are the ant and post borders of the perineum?
Pubic symphysis
Tip of coccyx
What are the contents of the anal triangle?
Anal aperture
External anal sphincter
Ischioanal fossa
Pudendal nerve
What is the perineal membrane?
Deep, strong fascia found in the urogenital triangle with pouches on the surfaces
Provides attachment for muscles
What is the deep perineal pouch?
Potential space between the deep fascia of the pelvic floor and the perineal membrane
What is the superficial perineal pouch?
Space between the perineal membrane and the perineal fascia
What does the superficial perineal pouch contain?
Erectile tissues
Bartholin’s glands
What are the two components of the perineal fascia?
Deep fascia
Superficial fascia
What are the two components superficial perineal fascia?
Superficial layer
Deep layer
What is the superficial layer of the superficial perineal fascia a continuation of?
Camper’s fascia from the abdomen
What is the deep layer of the superficial fascia continuous with?
Scarpa’s fascia
Which structures travel through Alcock’s canal?
Pudendal nerve
Internal pudendal artery
Internal pudendal vein
Which cartilage separates the three bones of the hip?
Triradiate cartilage
What is the acetabulum?
Part of the hip bone which articulates with the femur
What do the inferior and superior rami of the pubis create?
Obturator foramen
Pubic rami fractures usually require surgery
true/false
False
Usually stable
What are the two holes in the pelvic floor?
Urogenital hiatus
Rectal hiatus
What are the three main components of the pelvic floor?
Levator ani
Coccygeus
Fascial coverings
Which three paired muscles make up the levator ani?
Pubucoccygeus
Puborectalis
Iliococcygeus
Which nerves innervate coccygeus muscle?
Anterior rami of S4 and S5
Where does the renal pelvis collect urine from?
Major calyces
What is the point where the renal pelvis narrows to make the ureter called?
Ureteropelvic junction
Along the anterior surface of which muscle do the ureters travel?
Psoas major
At what level do the ureters cross the pelvic brim to enter the pelvic cavity?
SI joints
In which two operations are the ureters most at risk?
Oophorectomy
Hysterectomy
What is the blood supply to the abdominal ureter?
Renal artery and testicular/ovarian artery
What is the blood supply to the pelvic ureter?
Superior and inf vesical arteries
Where do sensory fibres from the ureter enter the spinal cord?
T11-L2
Approx how much urine does the bladder hold?
300-400ml
What connects the bladder to the umbilicus?
Median umbilical ligament
What is the main arterial supply to the bladder?
Superior vesical artery (of internal iliac)
Where does the superolateral part of the bladder drain lymph to?
External iliac lymph nodes
Where do the neck and the fundus of the bladder drain lymph to?
Int iliac
Sacral
Common iliac
What nerve gives sympathetic innervation to the bladder?
Hypogastric nerve (T12-L2)
What nerve gives parasympathetic innervation to the bladder?
Pelvic nerve (S2-S4)
What is the somatic nerve supply to the bladder?
Pudendal nerve (S2,3,4)
What lines the urethra?
Stratified columnar epithelium
What is the arterial supply to the prostatic urethra?
Inf vesical artery
What is the arterial supply to the membranous and bulbar urethra?
Bulbourethral artery (branch of internal pudendal)
What is the arterial supply to the spongy urethra?
Internal pudendal
What is the blood supply to the female urethra?
Internal pudendal
