Anatomy Flashcards
What is the homologous structure of bulbourethral glands in females?
Bartholin’s glands
The appendices artery is a branch of what?
Ileocolic artery (branch of
Posterior caecal artery)
What vessel does the ureter cross and where?
It crosses beneath the uterine artery- 2cm superior to the ischial spine (water under the bridge), at the level of the internal Os
Nerve supply of area around EAS
Inferior anal nerve
Most common nerve to be damaged in sacrospinous fixation?
Pudendal nerve (runs beneath sacrospinous ligament)
Symptoms: neuralgia over perineum
Lowest level of dermatomal block to abolish pain from uterus
Sympathetic nerve supply to uterus is by which spinal nerves
T10
T10/11/23 and L1 (inferior hypogastric plexus)
Obturator nerve root
L2-L4
Supplies adductor region of thigh
Dermatome: transverse suprapubic incision at CS
L1
Layers to reach epidural space and level usually done at
Skin, subcutaneous fat, supraspinous ligament, interspinous ligament and ligamentum flavum
L3/4
Difference between spinal and epidural
Spinal- anaesthetic injected directly into the dural sac contacting CSF
Epidural = just epidural space
Types of FGM
type 1: part or total removal of the clitoris or clitoral hood
type 2: part or total removal of the clitoris and the labia minor
type 3: narrowing of the vaginal opening
type 4: all other harmful procedures to the female genitalia for non-medical purposes
Nerve that passes anterior to the psoas major muscle
Genitofemoral nerve
Nerve supply of cervix
Pelvic splanchnic (S2-4)- extension of inferior hypogastric plexus
Tortuous glands in endometrium following ovulation- type of endometrium?
Secretory
Sacroiliac joint type
Synovial
Nerve route (origin) of iliohypogastric and ilioinguinal nerve
L1- lumbar plexus
Borders of lesser sciatic foramen
Structures that pass through lesser sciatic foramen?
Borders:
Superior – sacrospinous ligament and ischial spine
Anterior – ischial spine, lesser sciatic notch and ischial tuberosity
Posterior – sacrotuberous ligament
Internal pudendal artery and vein
Pudendal nerve (first leaves the pelvis via the greater sciatic foramen, and then re-enters via the lesser sciatic foramen)
Obturator internus tendon
Nerve to obturator internus
What does the ductus venosus connect?
Umbilical vein and IVC (oxygenated blood)
Nerve supply to bladder
Neurological control is complex, with the bladder receiving input from both the autonomic (sympathetic and parasympathetic) and somatic arms of the nervous system:
Sympathetic – hypogastric nerve (T12 – L2): causes relaxation of the detrusor muscle, promoting urine retention.
Parasympathetic – pelvic nerve (S2-S4): causes contraction of the detrusor muscle, stimulating micturition.
Somatic – pudendal nerve (S2-4): innervates the external urethral sphincter, providing voluntary control over micturition.
In addition to the efferent nerves supplying the bladder, there are sensory (afferent) nerves that report to the brain. They are found in the bladder wall and signal the need to urinate when the bladder becomes full.
Sympathetic = storage
Parasympathetic = Peeing
Contents of the inguinal canal
Spermatic cord (biological males only)
Round ligament (biological females only)
Ilioinguinal nerve –
Note: only travels through part of the inguinal canal, exiting via the superficial inguinal ring (it does not pass through the deep inguinal ring)
This is the nerve most at risk of damage during an inguinal hernia repair.
Genital branch of the genitofemoral nerve
Ligament arising from lateral border of cervix and attached to end-pelvic fascia?
Cardinal ligament
Dorsal nerve of clitoris is a terminal branch of which nerve?
Pudendal nerve
Path of lateral cutaneous nerve of thigh (lateral femoral cutaneous nerve)
Passes through psoas major muscle, and emerges from its lateral border, crosses the iliacus muscle obliquely, toward the anterior superior iliac spine (ASIS).
It is crossed by the deep circumflex iliac artery and the deep circumflex iliac vein.
It enters the thigh by passing beneath (the lateral part of) the inguinal ligament in the muscular lacuna, or through (the lateral part of) the inguinal ligament itself.
It then passes over the sartorius muscle, travelling from medial to lateral.
Coeliac trunk/ SMA/ IMA- at what level does each branch from aorta?
CT- T12/L1
SMA- L1
IMA- L3
Main blood supply to transverse colon?
Middle colic artery
Sutures enclosing largest fontanelle?
Frontal (metopic), coronal, sagittal
Pelvic measurements: transverse/ oblique/anteroposterior at inlet/mid-cavity and outlet
Transverse:
Inlet: 12.7cm
Mid: 11.5cm
Outlet: 10cm (distance between ischial tuberosities)
Oblique:
Inlet: 11.5cm (Iliopectineal eminence to opposite SI joint)
Mid: 11.5cm (lower SI joint to midpoint of obturator membrane)
Outlet: 11.5cm
Anteroposterior:
Inlet: 10cm (sacral prominently - Symphysis pubis)
Mid: 11.5cm (S3 to midpoint of pubic symphysis)
Outlet: 12.7cm (pubis to sacrococcygeal joint)
Fetus born with absence of mastoid process (or poorly developed). Which structure is at increased risk of damage during delivery?
Facial nerve (CN VII)
Scarpa’s/ Dartos/ Colles fascia
Scarpa’s = deep membranous layer of the superficial fascia of the abdomen (deep to Camper’s)
Dartos fascia = scarpas that extends superficially to the spermatic cord and scrotum
Colles fascia = continuation of darts fascia as it blends with deeper layers of peritoneum
Muscle of pelvic floor not inserted into the perineal body?
Coccygeus
Pelvic floor muscles
Levator ani (puborectalis, pubococcygeus and iliococcygeus), coccygeus
Contents of the deep perineal pouch
Muscles:
- Deep transverse perineal muscle
- External urethral sphincter
- Compressor urethrae muscle (females)
- Urethrovaginal sphincter (females)
- Internal pudendal vessel
- Dorsal nerve of clitoris
Other:
Membranous portion of urethra (males)
Proximal portion of urethra (females)
Bulbourethral gland (males)
What is the deep perineal pouch and what are its inferior and superior borders?
The space between superior and inferior layers of the urogenital diaphragm
Inferior border = perineal membrane
Superior border = superior fascia of urogenital diaphragm
Obturator nerve: obstetric cause of entrapment and sensory/ motor loss.
Compression between head of foetus and bony structures of pelvis
Sensory: upper medial thigh
Motor: weakness leg adduction
Common peroneal nerve: obstetric cause of entrapment and sensory/ motor loss.
Compression lateral head of fibula and leg bars (lithotomy position)
Sensory: foot and anterolateral leg
Motor: ‘foot drop’, loss of anterior compartment extensors
Lateral femoral cutaneous nerve: obstetric cause of entrapment and sensory/ motor loss.
Obstetric cause: pregnancy
Sensory: lateral thigh
Motor: nil
Femoral nerve: obstetric cause of entrapment and sensory/ motor loss.
Pressure from a foetus in a difficult birth
Sensory: anterior thigh and knee
Motor: Quadriceps (SLR) weakness, loss of knee jerk
Internal/ external anal sphincter innervation
Internal (above dentate line):
- Sympathetic contraction
- PS relaxation
- Pelvic splanchnic nerves (S4) via inferior hypogastric plexus
- Sensitive to stretch
External (below dentate line):
- Innervation via inferior rectal branch of pudendal nerve and perineal branch of S4
Where is the hypothalamus located in the brain?
Diencephalon
Where is the pituitary located?
Pea-sized and protrudes from end of hypothalamus. Sits in a bony cavity called the sella turcica (part of the sphenoid bone) in the middle cranial fossa
Borders of greater sciatic foramen
Contents of greater sciatic foramen
Borders:
Superior – anterior sacroiliac ligament
Posteromedial – sacrotuberous ligament
Anterolateral – greater sciatic notch of the ilium
Inferior – sacrospinous ligament and ischial spine
Nerves: sciatic, superior gluteal, inferior gluteal, pudendal, posterior femoral cutaneous, nerves to quadratus femoris and obturator internus
Vessels: Superior gluteal artery & vein, inferior gluteal artery & ven, internal pudendal artery & vein
internal pudendal artery exits pelvis via greater sciatic foramen and re-enters via the lesser sciatic foramen
Piriformis muscle
The inguinal canal is reinforced posteriorly by which structure?
Conjoint tendon
What is the major component of the anterior wall of the inguinal canal?
Aponeurosis of external oblique
What forms the floor of the inguinal canal?
Inguinal and lacunar ligaments
Nerve roots in the lumbar plexus?
Where is the plexus located?
Nerve branches/ roots and what they supply
T12-L4
Plexus is located within the substance of psoas major
Iliohypogastric (T12-L1)
- Transversus abdominus
- Internal oblique
- Sensory: upper buttock, skin mons pubis
Ilioinguinal (L1)
- Transversus abdominus
- Internal oblique
- Sensory: anterior scrotal nerves in males, anterior labial nerves in females
Genitofemoral (L1, L2)
- Cremaster in males
- Sensory: femoral branch L1 (upper proximal thigh), genital branch L2 (small area scrotum)
Lateral femoral cutaneous (L2, L3)
- Sensory: lateral thigh
Obturator (Anterior divisions of L2-4)
- Obturator externus
- Adductor longus
- Adductor brevis
- Gracillis
- Pectineus
- Adductor Magnus
- Sensory: cutaneous branch (medial thigh)
Femoral (posterior divisions of L2-4)
- Iliopsoas
- Pectineus
- Sartorius
- Quadriceps femoris
- Sensory: anterior cutaneous branches (anterior thigh), saphenous (medial lower leg)
Boundaries of femoral triangle
Contents of femoral triangle
Superior: Inguinal ligament
Medial: Medial border of the adductor longus
Lateral: Medial border of the sartorius
Floor: Pectineus, Adductor longus and Iliopsoas muscles
Roof: Fascia Lata (cribriform fascia at the saphenous opening)
Contents:
- Femoral nerve and terminal branches
- Femoral sheath
- Femoral artery and branches
- Femoral vein and its proximal tributaries inc SFJ
- Deep inguinal lymph nodes and lymphatic vessels
Lymphatic drainage of scrotum/ testicles
Scrotum: superficial inguinal nodes
Testicle: lumbar and para-aortic nodes
Lymph drainage of breast/
/ Fallopian tubes/ cervix/ uterus/ vagina
Breast: 75% axillary, 25% parasternal
Ovary: para-aortic nodes (primarily lateral aortic nodes)
Fallopian tubes: para-aortic nodes
Cervix: external iliac (majority) & para-aortic lymph nodes
Uterus: internal iliac LN, fundus –> para-aortic LN, lumbar and superficial inguinal LN
Vagina (upper 1/3): internal and external iliac nodes
Vagina (middle 1/3): internal iliac nodes
Vagina (lower 1/3): superficial inguinal nodes
Approximate length of male urethra in centimetres
Parts of the male urethra
Cell type lining male urethra
22.5 (15-29cm long)
Divided into 3 or 4 parts: pre-prostatic urethra, prostatic urethra, membranous urethra and spongy urethra
Proximal end of urethra (prostatic) is transitional cell epithelium in continuation with the bladder.
Epithelium changes to stratified columnar, then stratified squamous (non-keratinising) near the urethral orifice.
Blood supply to rectum & anal canal
Upper 2/3: IMA (superior rectal artery)
Lower 1/3: internal iliac (middle rectal artery)
Anal canal: internal pudendal (inferior rectal artery)
All 3 arteries anastomose
Respective 3 veins also anastomose (portal-systemic connection)
Piriformis: nerve supply/ origin/ insertion/ action/ blood supply
Piriformis syndrome
Nerve supply: L5 to S2 via nerve to piriformis
Origin: sacrum
Insertion: greater trochanter
Action: External rotation of hip
Blood supply: superior and inferior gluteal arteries and lateral sacral arteries
Piriformis syndrome: tingling in buttock and shooting pain down leg (piriformis is pressing on sciatic nerve)
Pudendal nerve: Origins, terminal branches, muscles innervated
Origins: Sacral nerves S2-4
Terminal branches: inferior rectal nerves, perineal nerve, dorsal nerve of clitoris
Muscles: bulbospongiosus, ischiocavernosus muscles, levator ani muscles (iliococcygeus, pubococcygeus, puborectalis), external anal sphincter, female external urethral sphincter
Two testicular cell types, what they secrete and what receptors they have
Sertoli: secrete inhibin (negative feedback on FSH & LH), FSH receptors –> spermatogenesis
Leydig cells: secrete testosterone, have LH receptors
Testicular blood supply and what they branch from?
Scrotum blood supply
Testicular: 3 arteries
- Testicular arteries (branch direct from aorta)
- Cremasteric artery (branch from inferior hypogastric)
- Artery to vas deferens (branch of internal iliac)
Scrotum
- Anterior scrotal artery (branch of external pudendal artery)
- Posterior scrotal artery (branch internal pudendal artery)
Rectus sheath: what is it formed from. How is it different above and below the arcuate line?
Formed by aponeuroses of transversus abdominus, external and internal oblique muscles.
Above arcuate line: anterior to rectus muscles is aponeurosis of external and internal oblique. Aponeurosis of transverses abdominus and internal oblique is posterior to rectus muscle.
(internal oblique divides into 2 lamellae)
Below arcuate line: all 3 aponeuroses are anterior to rectus.
Arcuate line is one third the distance between the umbilicus and pubis
What type of joint is the pubic symphysis
Secondary cartilaginous
Medial umbilical ligament/ median umbilical ligament- what are they remnants of?
MEDIAL umbilical ligament = fetal umbilical arteries
MEDIAN = urachus
How many lobules in each testis?
Between 250 and 400
Lobule = structural unit of the testis. Each lobule contains 1-3 seminiferous tubules
Bladder wall structure
4 layers: mucosa, submucosa, detrusor, adventitia.
Mucosa has further 2 layers: transitional epithelium, lamina propria
Detrusor has further 3 layers: inner and outer layers of longitudinal muscle with a middle circular smooth muscle layer
What vein does SMV/ IMV drain into?
SMV- hepatic portal vein
IMV- splenic vein
Blood testis barrier is formed by what type of cell
Sertoli
Neurovascular supply to ovary
Venous drainage of ovary
Ovarian arteries (directly from aorta)
The ovaries receive sympathetic and parasympathetic innervation from the ovarian (aortic) and uterine (pelvic) plexuses, respectively (T10-12)
Left ovarian vein into left renal
Right ovarian into IVC
Venous drainage of uterus/ vagina
Uterus: uterine vein into internal iliac
Vagina: vaginal venous plexus into hypogastric veins (internal iliac)
The average kidney contains how many nephrons
Between 800,000 and 1.5 million
Glycoprotein layer of the oocyte that binds spermatozoa and is essential for the acrosome reaction
Zona pellucida
Contents of the superficial perineal pouch
Ischiocavernosus muscle
Bulbospongiosus muscle
Superficial transverse perineal muscle
Crura of penis/ clitoris
Bulb of penis/ vestibular bulbs
Greater vestibular glands (females- Bartholins)
Branches of internal pudendal vessels and perineal nerves
Contents of the broad ligament
Fallopian tubes
Ovarian artery
Uterine artery
Ovarian ligament
Round ligament of uterus
Where do the ducts of the bulb-urethral (Cowper’s) glands enter the male urethra?
Membranous urethra (contains the external urethral sphincter and is the narrowest of the 3 parts of the male urethra)
Layers of testis (outermost to innermost)
Skin
Dartos muscle
Fascia later
Tunica vaginalis (parietal)
Tunica vaginalis (visceral)
Tunica albuginea
Tunica vascularis
Plane of pelvic inlet is at what angle to the horizontal
60 degrees
Levator Ani: innervation/ arterial supply and 3 muscle components
Innervation: Pudendal, perineal and inferior rectal nerves, S3 and S4 spinal nerves
Arterial supply: inferior gluteal artery
Muscle components: puborectalis, pubococcygeus and iliococcygeal muscles
Where is labour pain typically referred to in the early stages of labour
T11 and T12 dermatomes
Pain then spreads to T10 and L1 dermatomes
POPQ classifications of prolapse
Grade 0- no prolapse
Grade 1- >1cm above hymen
Grade 2- Within 1cm (proximal or distal to the plane of the hymen
Grade 3- >1cm below the plane of the hymen but protrudes <2cm or less than the total length of the vagina
Grade 4- complete eversion of the vagina
Baden-Walker or Beecham classification for degree of uterine descent in prolapse
1st degree: cervix is visible when the perineum is depressed- prolapse is contained within the vagina
2nd degree- cervix prolapsed through the Introitus with the fundus remaining in the pelvis
3rd degree- complete prolapse (entire uterus outside the Introitus)
Bladder
Arterial supply
Venous drainage
Lymphatic drainage
Arterial:
BRANCHES OF INTERNAL ILIAC:
- Superior vesical artery
- Vaginal artery (female)
- Inferior vesicle artery (male)
- Minor branches of gluteal and obturator arteries
Venous drainage:
- Vesicle venous plexus
Lymphatic drainage:
- Internal/ external and common iliac nodes
Vaginal artery is a branch of which artery?
Internal iliac
Ureter:
- Arterial supply
- Innervation
- Histology
- Arterial supply: renal artery, uterine/ vaginal arteries, gonadal artery, middle rectal artery, superior vesicle (and inferior vesicle in men) arteries
- Innervation: T11-L2
- Histology: 3 layers: adventitia, smooth muscle, transitional epithelium
Which nerves provide the primary cutaneous sensory innervation to the labia majora?
Anterior – ilioinguinal nerve, genital branch of the genitofemoral nerve
Posterior – pudendal nerve (perineal branch), posterior cutaneous nerve of the thigh.
What is the obturator foramen bound by?
Ischium and pubis
What goes through the obturator foramen?
Obturator nerve & vessels
How many vertebrae normally make up the coccyx?
4
What are the 4 main muscles of the pelvic wall?
Posterior wall: piriformis
Lateral wall: obturator interns
Pelvic Floor: levator ani & coccygeus
Levator ani = iliococygeus, pubococcygeus and puborectalis
What nerve roots does the sacral plexus take its fibres from?
Major branches of sacral plexus and what they supply
L4, L5, S1-4
Superior Gluteal Nerve (L4, L5, S1)
- Gluteus minimus
- Gluteus medius
- Tensor fascia lata
Inferior Gluteal Nerve (L5, S1, S2)
- Gluteus maximus
Sciatic nerve (L4, L5, S1, S2, S3)
Motor
- Tibial portion: posterior compartment of thigh, posterior compartment of leg and sole of foot
- Common fibular portion: short head of biceps femoris, anterior and lateral compartments of leg and extensor digitorum brevis
Sensory:
- Tibial portion: skin of posterolateral leg, lateral foot and sole of foot
- Common fibular portion, skin of lateral leg and dorsal of foot
Posterior femoral cutaneous nerve (S1, S2, S3)
- No motor functions
- Innervates skin on posterior surface of thigh and leg and skin of perineum
Pudendal nerve (S2, S3, S4)
Motor:
- Skeletal muscles in perineum, external urethral sphincter, external anal sphincter, levator ani
Sensory:
- Penis and clitoris
- Most of skin of perineum
Smaller branches:
- Nerve to piriformis
- Nerve to obturator internus
- Nerve to quadratus femoris
Autonomic nerve supply to pelvis
Parasympathetic:
- Pelvic splanchnic nerves (S2-4) supply pelvic viscera via inferior hypogastric and pelvic plexuses
Sympathetic
- Pelvic sympathetic trink supply pelvis via hypogastric plexuses
What four arteries enter the true pelvis?
Internal iliac artery
Superior rectal artery (branch of IMA)
Ovarian artery
Median sacral artery
Origin of the femoral artery
External iliac artery becomes femoral artery as it passes beneath the inguinal ligament (midway between the PS and ASIS)
Abdominal aorta branches and spinal level
Inferior phrenic arteries (T12)
Coeliac artery (T12)
SMA (L1)
Middle suprarenal arteries (L1) - adrenal glands
Renal arteries (L1/2)
Gonadal arteries (L2)
IMA (L3)
Median sacral artery (L4)
Lumbar arteries (L1-4)- supply abdominal wall and spinal cord
Aorta bifurcates into common iliac arteries at L4-5 (right is 1cm longer than left and directly passes L5)
Branches of internal iliac artery
ANTERIOR DIVISION
- Umbilical artery: artery to vas deferens (male), superior vesical artery
- Inferior vesical artery
- Obturator artery
- Internal pudendal artery (terminal branch)
- Inferior gluteal artery (terminal branch)
- Uterine artery
- Vaginal artery
- Middle rectal artery
POSTERIOR DIVISION
- Iliolumbar artery
- Lateral sacral artery
- Superior gluteal artery
Inferior epigastric artery
- Course
- Branches
Course:
- Arises from external iliac artery, immediately superior to the inguinal ligament
- It travels superiorly in an oblique path, passing the medial border of the deep inguinal ring.
- It then pierces the transversals fascia to travel within the rectus sheath, posterior to the rectus abdominis muscle.
- At the level of the umbilicus, it terminates by dividing into numerous branches which anastomose with the superior epigastric artery
Branches
- Muscular branches supply the parietal peritoneum, muscles of the anterior abdominal wall, subcutaneous tissue and skin
- Cremasteric artery supplies cremasteric muscle and spermatic cord
- Public branch, supplies the pubic bones and pubic symphysis
Blood supply to ureter
Renal artery
Aorta
Gonadal arteries
Common iliac artery
Internal iliac artery
Superior and inferior vesical arteries
Nerve supply to vagina
Upper vagina: inferior hypogastric plexus (only sensitive to stretch)
Lower vagina: sensory fibres from pudendal nerve
Structure of internal/ external anal sphincter
Internal = smooth muscle of rectum (ring)
External = deep (integrates with elevator ani), superficial (has bony attachment) and subcutaneous
How many lobules in each breast?
What is each lobe separated by?
15-20
Separated by fibrous septa
Breast blood supply & lymph drainage
Blood supply:
- Perforating branches of internal thoracic artery
- Intercostal artery
- Axillary artery
Lymph:
- Lateral quadrants –> anterior axillary and pectoral nodes
- Medial quadrants –> internal thoracic nodes
- Posterior –> intercostal nodes
- Right and left breasts communicate
What is the dentate/ pectinate line?
The area where the anal glands open.
It represents the transition zone between the columnar epithelium of the proximal and the stratified squamous epithelium of the distal canal.
Boundary between ectodermal and endodermal origin of anal canal.
What is the pudendal cleft?
Area between the two labia majora
In the upright position, the expected angle between the brim of the pelvis and the horizontal plane is approximately
55 degrees
Epithelium lining the anal canal
Upper half: Simple columnar epithelium
Lower half: stratified squamous non-keratinising epithelium
Epithelium lining endocervix
Columnar
Nerve supply to skin over femoral triangle
Ilioinguinal nerve
Nerve supply to anterior one third of labia major?
Ilioinguinal nerve (L1) & genitofemoral nerve (L2)
The remainder is supplied by the pudendal nerve via the posterior labial branch of the perineal nerve (S3)
