ANATOMY Flashcards
At what spinal level does the Coeliac Trunk leave the aorta?
T12
At what level does the Superior Mesenteric Artery leave the Aorta?
L1
At what levels does the Inferior Mesenteric Artery leave the Aorta
L3
What vessels leave the Aorta at L1
SMA, middle adrenal (suprareneal), renal vessels
What vessels leave the Aorta at L2
Gonadals
At what spinal level does at the aorta birfucate
L4
Into which vessels does the stomach drain? (List all)
Left & Right Gastrics drain directly into the portal vein.
Short gastric vessels (fundus), and left gastro-epiploiec drain into the splenic vein –> portal vein. Right gastro-epipoloiec drains into the superior mesenteric –> hepatic portal vein.
Which vessels are involved with portal-caval anastomoses, and how are they clinically important?
Portal hypertension can cause distension of these veins, which can lead to rupture, clinical manifestations and discomfort to the patient.
- Oesophageal varices form due to anastomeses between left gastric vein & oesophageal vessels which drain into the azygous system.
- Paraumbilical anastomeses can lead to caput medusae. Small vessels in ligamentum teres anastomose with superficial epigastric & thoracoepigastric veins.
- Rectal anastomoses can lead to haemorrhoids as superior rectal veins anastomose with the middle/inferior rectal veins which drain to the internal pudendal –> internal iliac
What are the posterior relations of the kidney?
Diaphrahm, costo-diaphragmatic recess, ribs 11 & 12
What are the anterolateral relationships of the kidneys?
Right: adrenal glands, liver, descending duodenum, IVC, right colic flexure, small intestine
Left: adrenal gland, stomach, tail of pancreas, spleen, left colic flexure, small intestine
What are the inferior relationships of the kidney?
Psoas major, quadratus lumborum, transversus abdominis
What spinal levels are sympathetic innervation of the foregut from?
T6-T9
What spinal levels are sympathetic innervation of the midgut from?
T9-T11
What spinal levels are sympathetic innervation of the hindgut from?
T12-L2
What spinal levels generally innervate the pelvis/perineum organs?
Sympathetic - T10-L2/L3
Parasympathetic - S2-S4
Describe the blood supply to the kidney from the Abdominal Aorta to the Right Atrium
Renal vessels leave Aorta at L1 –> 5 segmental arteries –> interlobar arteries –> arcuate arteries –> interlobular arteries –> afferent arterioles –> glomerular capillaries –> efferent arterioles –> peritubular capillaries/vasa recta –> peritubular/vasa recta venules –> interlobular veins –> arcuate veins –> interlobar veins –> renal veins –> IVC (L1) –> RA
What spinal level of sympathetic innervation does the kidney receive?
T10-L2 (referred pain = loin to groin)
At which spinal levels are the kidney located?
T11-L3
At what spinal level is the renal hilum
L1
What are all the anatomically significant things at L1?
Pylorus of stomach/transpyloric plain (L1/L2)
SMA leaves Aorta
Renal vessels leave Aorta
Renal Hilum
Middle Adrenal vessels leave Aorta
Head of Pancreas in this region (direct irritation to L1/L2 spinal nerves in pancreatitis)
Name the layers which surround the kidney from the cortex outwards.
Cortex
Peri-renal fat
Renal Fascia
Para-renal fat
Does the kidney receive parasympathetic stimulation, and if it does, where is it from?
Yes - Vagus nerve to smooth muscle of renal pelvis and calyces. (from posterior vagal trunk)
Does the adrenal gland receive parasympathetic stimulation, and if it does, where is it from?
No it does not. Sympathetic only.
What are the branches of the internal iliac artery?
Anterior Division:
- Umbilical (obliterated leads to medial ligaments) which gives off superior vesicle
- Uterine/vaginal arteries in female
- Inferior vesicle arteries in male
- Internal pudendal artery –> inferior rectal
- Middle rectal
- Inferior gluteal (S1-2 or S2-3 more commonly)
- Obturator
Posterior Division:
- Iliolumbar Artery
- Lateral sacral
- Superior Gluteal (S1)
What forms the greater pelvic aperture?
Sacral promontory, arcuate line of ilium, pectin pubis of pubic bone
Which pelvis is the true pelvis? (Major/greater or minor/lessor?)
Minor/Lesser is true pelvis
Does the major or minor pelvis contain the pelvic contents?
Minor/lesser/true contains pelvic contents
Does the superior pelvic aperture (inlet) or inferior pelvic aperture (outlet) divide the pelvis into true & false pelvis?
Greater/Inlet divides it.
What makes up the inferior pelvic aperture (pelvic outlet)
Pubic symphysis –> ischiopubic rami –> sacrotuberous ligaments –> tip of coccyx
Names the joints of the pelvis
Sacrioiliac (x2), pubic symphysis
What type of joints are the sacroiliac joints?
Synovial plane joints with a posterior fibrous component.
What type of joint is the pubic symphysis?
Secondary cartilaginous with hyaline cartilage on syphyseal surface and united by fibrocartilage.
What are the 6 ligaments of the Sacroiliac joints?
- Iliolumbar
- Anterior sacroiliac
- Posterior sacroiliac
- Sacrotuberous
- Sacrospinous
- Interosseus
In which plane are the ASIS and pubic tubercles orientated?
Coronal
In which plane are the pubic symphysis and coccyx orientated?
Horizontal
What planes/angles are the pelvic inlet and outlet from the horizontal?
Inlet: 60degrees Outlet: 10degrees
What are the differences between the male and female pelvis?
Female pelvis has:
- wider superior and inferior apertures,
- wider sciatic notch,
- narrower depth of true pelvis
- thinner/lighter bones.
What are the two measurements used for the superior pelvic aperture and the inferior aperture?
Anteroposterior
Transverse
superior aperture AP is called “Conjugate”
There are three different ‘conjugate’ measurements of the superior pelvic aperture. Describe them and their lengths.
True Conjugate: Superior pubic ramus symphysis –> Sacral promontory. Only made on radiographic films. 11cm or more.
Diagonal Conjugate: Inferior pubic symphysis –> sacral promontory. Estimated using internal examination. 11.5cm or more.
Obstetric Conjugate: Thickest part of pubic symphysis –> sacral promontory. Usually 10cm or more.
Which is the shortest measurement of the pelvic aperture? Diagonal, Obstetric or True?
Obstetric (10cm) shortest.
Diagonal = 11.5cm True = 11cm
Where are the preganglionic cell bodies of the parasympathetic neurons innervating the pelvis/perineum located?
Lateral horns of S2-S4.
Describe the general path the parasympathetic neurons travel from the S2-S4 spinal cord to the pelvic viscera.
Preganglionic cell bodies in lateral horns of S2-S4. Fibres exit via ventral horn –> ventral roots –> spinal nerve –> pelvic splanchnic nerves –> pelvic plexus (R&L inferior hypogastric) –> synapse in intramural ganglia within organs. Post ganglionic fibres are very short.
What is the sympathetic innervation of the adrenal glands?
T5-T9
Describe the general path the sympathetic fibres travel from the spinal cords to their target organs in the pelvis/perineum.
Located in lateral horn of T10-L2/3. Travel out of spinal cord via ventral horn –> ventral root –> white rami communicans –> sympathetic chain (no synapse) –> grey rami communicans –> splanchnic nerves –> synapse on pre-aortic ganglia (eg coeliac, renal, IM, SM etc). Post synaptic fibres split into two bundles (L & R) and descend to L & R superior hypogastric plexus (just below bifurcation of aorta; sympathetic only) and then continue to inferior hypogastric plexus (pelvic plexus, mixed with parasympathetic) from where they travel with arteries to their target viscera.
Describe the viscera pain afferents of the pelvis.
Pain follows sympathetics above pelvic pain line, parasympathetics below
What is the pelvic pain line?
The pelvic pain line is approximately at the lowest level of the peritoneum. It is the point where pain fibres change from following sympathetic fibres (above the line) to parasympathetic fibres (below the line).
What are the branches of the lumbosacral plexus?
Sciatic nerve - L4-S3
Superior Gluteal nerve L4-S1
Inferior Gluteal nerve L5-S2
Pudendal S2-S4
(note Obturator nerve is also located in the true pelvis)
Internal Iliac veins have communications with two areas of clinical importance. What are they?
- Portal-caval anastomoses between middle-superior rectal vein provides a communication with the portal circulation.
- Communications with vertebral plexus via lateral sacral veins allows for spread of pelvic cancers to the vertebrael column
What are the muscles of the pelvic floor?
- Levator Ani (Puborectalis, Pubococcygeus, Iliococcygeus)
2. Cocycgeus (ischiococcygeus)
What are the attachments of the levator ani?
Pubis, ischial spine and tendinous arge (inner surface of obturator internus) to the perineal body, coccyx and anococcygeal ligament.
What are the three parts of levator ani? One of these muscles also has three parts, what are they?
- Puborectalis
- Iliococcygeus
- Pubococcygeus (three parts include puboperinealis, puboanalis and in males there is puboprastatitcus, females this is pubovaginalis)
What is the innervation of the pelvic floor/diaphragm?
Levator ani - nerve to levator ani (S4), inferior and coccygeal plexus.
Coccygeus - S4-5 sacral segments
What are the attachments of Coccygeus?
Ischial spine –> coccyx. Internal surface of sacrospinous ligament.
What are the muscles of the pelvic wall, and what are their innervation? Which muscles leaves through the greater sciatic foramen, and which through the lesser?
- Piriformis (nerve to piriformis S1-2). Exits through greater sciatic foramen and attaches to the greater trochanter of the femur.
- Obturator internus (nerve to obturator internus (L5-S1). Exist through lesser sciatic foramen and attaches to trochanteric fossa.
Describe the endopelvic fascia.
It is located superior to the pelvic floor/diaphragm. It is continuous with the transversalis fascia. Contains multiple thickenings to support the pelvic viscera.
What supports pelvic viscera?
Endoplevic fascia & Pelvic floor/diaphragm (Levator ani & Coccygeus).
What contributes to sphincter mechanisms of continence?
Pelvic floor.
Describe the perineum
Triangle shaped region between the thighs and buttocks. Subdivided into anal triangle & urogenital triangle.
What are the boundaries of the perineum?
Pubic symphysis, ischiopubic rami, ischial tuberosities, sacrotuberous ligament, coccyx, obturator internus.
What are the boundaries & contents of the Ischioanal fossa (within anal triangle).
BOUNDARIES: Perineal skin, ischial tuberosities, obturator internus (wall), levator ani (roof), external/internal anal sphincters (medial walls).
CONTENTS: Mainly fat & pudendal canal
Where is the pudendal canal, and what does it contain?
Located in the ischioanal fossa within the anal triangle of the perineum. Contains pudenal nerve, internal pudendal vessels. It lies against the obturator internus, on the lateral wall of the fossa.
What are the borders of the anal triangle?
Ischial tuberosities (line between them), sacrotuberous ligament, coccyx.
Contents of anal triangle?
Ischioanal fossa (contains pudendal canal), anal canal from recto-anal junction (S3) to anus.
The anal canal contains anal columns, anal sinuses and anal valves. What are these?
Anal columns = contain terminal branches of superior rectal vessels.
Anal valves = where the anal columns terminate and folds of mucosa pouch out to form the ‘pectinate’ line.
Anal sinuses are located just above the anal valves and produce mucous to aid defecation.
What is the pectinate line?
It is formed by the anal valves all lining up and marks the place where innervation, lymphatics and epithelium all change.
What is the epithelium, lymphatic flow and innervation ABOVE the pectinate line?
Innervation: Autonomic
Blood supply: Superior rectal arteries from inferior mesenteric artery and veins drain to portal system
Lymphatic: Drain to internal iliac nodes.
Epithelium: Columnar epithelium
WHat is the epithelium, lymphatic flow and innervation BELOW the pectinate line?
Innervation: Somatomotor/sensory
Blood supply: Internal iliac (middle rectal arteries and internal pudendal –> inferior rectal artery). Draining back to IVC.
Lymphatics: Draining to superficial inguinal nodes, which drain to external iliacs.
Epithelium: Stratified squamous.
What innervates the internal anal sphincter?
Autonomic innervation.
What are the parts of the external anal sphincter, and what innervates them?
Deep, Superficial and subcutaneous parts. Puborectalis fuses with the ‘deep’ and forms a ‘sling’ that kinks the rectum when contracted and helps with continence (Puborectalis relaxes during defecation).
It is innervated by the inferior rectal nerve (from pudendal nerve S2-S4).
To what does the superficial layer of the external anal sphincter attach?
Perineal body & anococcygeal ligament.
What are the borders of the urogenital triangle?
Pubic symphysis, ischiopubic rami, Ischial tuberosities (line between them)
What are the contents of the urogenital triangle?
Perineal membrane, erectile tissues, muscles, opening for urethra and vagina, perineal body.
The perineal membrane divides the urogenital pouch into two spaces. What are they?
Deep pouch - located ‘above’ the perineal membrane (levator ani forms it’s roof, perineal membrane forms its floor).
Superficial pouch - located below the perineal membrane.
What does the deep pouch contain in MALES?
- Intermediate part of urethra (Membranous, where levator ani contributes to external urethral sphincter)
- Deep transverse perineal muscle (Skeletal muscle)
- Bulbourethral glands (Cowpers)
What do the Bulbourethral glands/Cowpers glands produce?
Small amount of fluid that neutralises any acidic urine present in the urethra prior to ejaculation, and lubricates urethra for passage of sperm.
What does the deep pouch contain in FEMALES?
- Proximal urethra
- Urethral sphincter
- Compressor urethrae (straps around it)
- Urethrovaginal sphincter
- Sheet of smooth muscle (Instead of deep transverse perineal muscle)
Superficial perineal pouch is located below the perineal membrane. In broad terms, what are its main contents?
- Erectile Tissues (Crus & Bulb)
- Muscles asscociated with erectile tissues (innervated by branches of pudendal nerve)
- Superficial transverse muscle
(females also contain the Greater Vestibular [Bartholins] Glands)
Describe the erectile tissues located in the superficial perineal pouch.
CRUS:
Two corpora cavernosa have a free end and an attached end each.
The attached ends (called crura) ‘line’ the pubic arches, while the free ends travel together in the penis or clitoris.
Crura are covered by the ischiocavernosus muscle.
BULB
The bulb is attached to the superficial surface of the perineal membrane. IN the male, the bulb of the penis continues into the body of the penis as the corpus spongiosum. In the female the bulb of the vestibule is a paired structure either side of the opening of the vagina, and continues into the glans clitoris.
Bulb are encased in the bulbospongiosus muscle.
Which muscle encases the crura (Crus)?
Ischiocavernosus
Which muscle encases the bulb?
Bulbospongiosus
What does the ischiocavernosus muscle encase? What does it do?
It encases the crura/erectile tissue. It functions to aid an erection in both males & females.
What does the bulbospongiosus muscle encase? What does it do?
It encases the bulb (of the vestibule in females) (of penis in males). It functions to support the pelvic floor and assist in an erection.
In males it assists with emptying urine & semen from the urethra.
In females it acts as a vaginal sphincter.
What does the superficial perineal muscle do?
Supports pelvic viscera and in males contract during erection to support the penis.
With what is the superficial perineal fascia continuous with?
It is continuous with the membranous layer of the superficial fascia of the abdomen (Scarpa’s fascia), then either the superficial penile fascia and dartos fascia of scrotum (Males) or superficial fascia of the mons pubis and labia majora (female). It then continues on to attach to the posterior border of the perineal membrane and lateral borders of the urogenital triangle.
With what is the deep perineal fascia continuous, and what is it closely associated with?
Closely associated with the superficial muscles of the perineum, and is continuous with the deep penile fascia.
Which muscles are attached to the perineal body?
- Bulbospongiousus
- Superficial transverse perineal
- Deep transverse perineal muscle
- External anal spincter
- Part of levator ani
Which erectile tissue does the glans of the penis contain?
Corpus spongiosum
Through which erectile tissue does the urethra travel in the male?
Corpus spongiosum
What is the prepuce of the penis?
The foreskin of the penis. It is composed of a double layer of skin and superficial fascia from the junction of the body to the glans of the penis.
What is the blood supply of the penis?
Arterial supply from the internal pudendal artery (From internal iliac), and small amount from external pudendal (supplies fascia of penis and anterior scrotum)
What are the branches of the internal pudendal artery?
- Inferior rectal
- Perneal & scrotal arteries
- Dorsal artery of penis
- Deep artery of penis (erectile tissues)
What is the innervation of the male genitalia?
Pudendal nerve (S2-4).
Dorsal nerve of penis is a branch of Pudendal nerve and innervates body & glans.
Perineal nerves (from pudendal nerve) innervate perineal pouches.
Scrotal nerves innervate scrotum.
What is the lymphatic drainage of male genitalia?
Skin –> superficial inguinal nodes
Testis –> lumbar & preaortic nodes
Urethra & cavernous bodies –> internal iliac and deep inguinal nodes
What is located in the pudendal cleft in the female genitalia?
Vestibule & Labia minora
The labia majora unite anteriorly & posteriorly. What are these unions called?
Anterior & Posterior commissures.
The labia minora unite anteriorly and posteriorly. What are these unions called?
Anteriorly - prepuce & frenulum of clitoris
Posteriorly - frenulum of labia
Where is the vestibule of the vagina located?
In the pudendal cleft between the labia minora.
What does the vestibule of the vagina contain?
- External urethral orifice
- Orifice of vagina
- Openings of greater vestibular glands (Bartholins Glands) [Secrete mucus during arousal]
What is the blood supply of the female genitalia?
External & Internal pudendal arteries (Mainly internal).
Branches of the internal pudendal artery are perineal, posterior labial arteries and dorsal artery of the clitoris.
External pudendal supplies anterior labia majora.
All drain via internal pudendal vein.
What is the innervation of the female genitalia?
Mainly Pudendal nerve (Small amount of ilioinguinal, genitofemoral, post cutaneous nerve of the thigh)
Blood Supply of Perineum Summary:
INTERNAL PUDENDAL: Inferior rectal, perineal, posterior scrotal/labial and doral/deep AA of penis/clitoris (erectile tissues)
EXTERNAL PUDENDAL: Superficial fascia of penis, anterior scrotum/labia majora.
Innervation of Perineum Summary:
Mainly Pudendal S2-S4.
- Branches:
- Inferior rectal nn
- Perineal nn (muscular, posterior scrotal/labial)
- Dorsal nn of penis/clitoris.
ALSO:
Perineal branches of posterior femoral cutaneous.
Branches of ilioinguinal.
Branches of genitofemoral.
SUMMARY OF LYMPH TO PERINEUM:
Mainly superficial inguinal, some to internal iliac nodes.
What are the male contents of the pelvis?
Bladder
Prostate
Genital Ducts: Ductus deferens, seminal glands
Rectum
What are the female contents of the pelvis?
Bladder Uterus Vagina Rectum Uterine Tubes Ovaries
The peritoneum covers the upper parts of the rectum (anterolaterally), the superior surface of the bladder and most of the uterus, uterine tube and ovary. What are the ‘pouches’ or reflections called in females and males?
MALES:
Rectovesical pouch
FEMALES:
Rectouterine (Pouch of Douglas)
Vesicouterine
What is the para-rectal fossa?
A space around the rectum to allow it to expand when it is full of faeces prior to defecation
Where does the rectum start & end?
Starts at rectoanal junction (S3) and ends at the rectoanal junction (level of pelvic diaphragm)
How does the rectum differ from the rest of the large bowel?
It has no:
- haustra
- teniae coli
- Mesentary.
Instead it has:
- Complete longitudinal muscle layer (which thickens into the internal analsphincter)
- The muscoa is characterised by ‘transverse rectal folds’ which act like valves.
What is the perianal (anorectal) flexure?
It is the junction between the anal canal and the rectum. It is created by the puborectalis muscle which is contracted and ‘kinks’ it.
What are the anterior relations of the rectum?
MALE: Bladder, Rectovesical pouch, Small intestine, Signmoid colon, Genital ducts, Prostate.
FEMALE: Rectouterine Pouch (of Douglas), posterior wall of vagina, Small intestine, Sigmoid colon, Rectovaginal septum, Uterus
What is the posterior relation of the rectum?
Sacrum
What is the blood supply of the rectume?
Superior rectal AA (from SMA)
Middle rectal AA (From Internal Iliac)
Inferior rectal AA (From internal pudendal off internal iliac)
Venous drainage allows portal-caval anastomoses
Innervation of the rectum?
Symp T12-L2 (via lumbar splanchnis to pelvic plexus)
Parasymp (S2-S4)
Pain via parasymp.
What is the lymphatic draining?
Follows veins. Superior –> inferior mesenteric.
Middle –> internal iliac nodes
Anal canal –> superficial inguinal & internal iliacs
What epithelium lines the urinary bladder, and what is its muscle called?
Lined by transitional epithelium/urothelium.
Muscle = Detrusor muscle.
What is the trigone?
Triangular area on the base of the bladder (posterior). Angles of triangle formed by where the ureters enter the bladder and the urethra leaves it. This area is less ‘stretchy’.
To what is the apex of the bladder attached?
Median umbilical ligament.
Name the surfaces/anatomical areas of the bladder.
Apex, neck, domed superior surface, two inferolateral surfaces, base (with trigone).
What are the superior relations of the bladder?
Peritoneum, with peritoneal organs (small intestine & sigmoid colon). Vesicouterine pouch and uterus in females.
What are the inferior relations of the bladder?
Urethra (prostate in males), pelvic/urogenital diaphragms
What are the posterior relations of the bladder?
Rectovesical pouch & genital ducts (males), cervix of uterus, vagina, pouch of douglas & rectovaginal septum (females). Rectum in both!
What are the anterior relations of the bladder?
Pubic bones, rectus abdominis
What are the lateral relations of the bladder?
Pelvic wall, Pelvic bones
Which sphincter allows control of continence/micturition?
External urethral sphincter.
The prostate is divided into lobes. Name them, and describe them briefly.
Anterior lobe - fibromuscular. Directly anterior to urethra.
Lateral lobes - the glandular portions.
Middle lobe - directly posterior to urethra. Prone to benign hypertrophy.
Posterior lobe - prone to cancer. Digitally examined.
What is the utricle?
The remnant of embryonic uterovaginal canal.
What is the seminal colliculus?
An enlarged area of the urethral crest (elevation on posterior urethral well) which has the central depression (utricle) in it. The seminal colliculus has a prostatic sinus on either side of it (groove) into which prostate ducts drain into.
Where does the ejaculatory duct enter the urethra?
On the seminal colliculus, pair ejaculatory openings below the utricle.
To where does prostatic cancer often spread, and how?
To lumbar vertebrae via venous system (anastomoses of bony pelvis with vesical plexus).
Is the ductus deferens intraperitoneal, retroperitoneal or extraperitoneal? How does it enter the pelvis?
It is extra-peritoneal. It enters the pelvis through the deep inguinal ring.
The union of what two structures forms the ejactulatory ducts?
Ductus deferens (ampulla) & Seminal vesicles in prostate gland.
The uterus is normally anteverted and anteflexed. What do these terms mean?
Anteflexion: the body of the uterus is bent slightly foward relative to the cervix.
Anteversion: The cervix is bent forward relative to the vagina.
What makes up the broad ligament of the uterus?
It is TWO layers of peritoneum (double) from lateral margin of uterus to pelvic wall. Includes mesometrium, Mesovarium, mesosalpinx. It contains uterine tube, ovarian ligament proper, ureter and lymph/nerves.
What are the three layers of the uterus?
Perimetrium, myometrium, endometrium
What is the mesentary of the uterus?
It is PART of the broad ligament (mesometrium) but EXCLUDES the mesosalpinx and mesoovarian and ovarian ligament)
What path do the pain afferents from the uterus follow?
Cervix: Parasympathetic (S2-4)
Body/Fundus: Sympathetic (T12-L2)
What are the ligaments of the female reproductive tract?
- Suspensory ligament of the ovary
- Ovarian ligament proper
- Broad ligament (double peritoneum layer) composed of mesometerium, mesosalpinx, mesoverium.
- Round ligament of the uterus.
Which ligament conveys vessels to the ovary?
Suspensory ligament of the ovary.
Through what does the round ligament of the ovary travel, and where does it go? What does it originate from?
It travels through the broad ligament, and goes to the deep inguinal ring. It travels through the inguinal canal, and goes to the labia majora. It originates from the gubernaculum.
Which ligament attaches the ovary to the uterus?
Ovarian ligament proper.
What are the four parts of the uterine tube?
Intramural, Isthmus, Ampulla, Infundibiulum with fimbriae.
What is the blood supply of the ovary? How does it get back to the IVC?
Both ovarian arteries are directly off the abdominal aorta (L2). The right ovarian vein returns directly into the IVC, but the left ovarian vein enters into the left renal vein which then enters the IVC.
Lymphatic drainage of the uterus:
Body of uterus, cervix and vagina –> internal & external iliac nodes
Part of fundus (near round ligament) travels through inguinal canal –> superficial inguinal along with lower vagina.
Superolateral uterus, uterine tube and ovary along suspensory ligament of the ovary –> lumbar nodes.
What are the layers of the anterolateral abdominal wall?
- Skin
- Superficial fascia (Fatty=camper’s, Membranous =scarpa’s).
- External abdominal oblique
- Internal abdominal oblique
- b Fascia of internal oblique
- Transversus abdominis
- Transversalis (endoabdominal) fascia
- Extraperitoneal fat
- Parietal peritoneum
What are the muscles of the anterolateral abdominal wall, and what is their innervation?
External Abdominal Oblique
Interal Abdominal Oblique
Transversus abdominis
Rectus Abdominis
Innervation: T6-L1 ventral rami of spinal nerves
Which muscles contribute to the rectus sheath?
Aponeurosis of:
External Abdominal Oblique
Interal Abdominal Oblique
Transversus abdominis
What does the rectus sheath contain?
Incomplete compartment around rectus abdominis. Contains superior and inferior epigastric arteries, veins, lymph vessels, and distal portions of thoracoabdominal nerves, and abdominal portions of anterior rami of T7-T12
Where is the linea alba?
Between the two rectus muscles (midline)
Where are the semilunaris?
Between the rectus and oblique muscles (vertical lines lateral to linea alba)
Describe the layers of the superior 3/4 rectus sheath (above umbilicus)
Anterior sheath = external oblique aponeurosis, and half of the internal oblique aponeurosis.
Posterior sheath = half of internal oblique aponeurosis and transversus abdominis aponeurosis.
IE: Internal oblique splits around the rectus abdominis muscle.
Describe the layers of the inferior 1/4 of the rectus sheath (below umbilicus)
All three muscle aponeurosis (EO, IO and TA) pass in FRONT of rectus abdominis (only transversus fascia posterior to rectus abdominis)
What is the point where the rectus sheath stops called?
Arcuate line
What is the arcuate line?
The point where the rectus sheath stops inferiorly.
What is the significance of the median umbilical ligament/fold in the internal surface of the anterolateral abdominal wall?
It is the remnant of the urachus - joined the bladder to the umbilical cord during embryonic development.
Which ligaments/folds are lateral to the median umbilical ligament?
Medial umbilical ligaments (obliterated umbilical arteries) and lateral umbilical ligaments (contain inferior epigastric vessels)
List all the ligaments that are present against the internal surface of the anterior abdominal wall (eg median umbilical ligament)
- Median umbilical ligament (urachus remnant)
- Medial umbilical ligaments (obliterated umbilical aa)
- Lateral umbilical ligaments (inferior epigastric vessels)
- Ligamentum teres hepatis (round ligament of the liver - remnant of umbilical vein)
- Falciform ligament - fold of peritoneum
What is/was contained in the ligamentum teres hepatis?
It contained the umbilical vein, however after birth it obliterates and several small vessels remain (site of portal-caval periumbilical anastomoses [caput medusae])
Where is the neurovascular plane on the anterolateral abdominal wall?
Between internal oblique and transversus abdominis or posterior to rectus abdominis
What nerves supply the anterolateral abdominal wall above the level of the umbilicus?
T7-T9 supply skin above umbilicus
What nerves supply the umbilical region?
T10 supplies skin around umbilicus
What nerves supply below umbilical region of anterolateral wall?
Subcostal (T12) and the iliohypogastric & ilioinguinal nerves (L1)
What are the arteries of the anterolateral abdominal wall?
- Superior epigastric (internal thoracic)
- Inferior epigastric (external iliac)
Both run just behind rectus abdominis
Others which contribute:
- Musculophrenic branches
- Deep circumflex iliac (from ext. iliac)
- Lumbar.post intercostal
- Superficial circumflex iliac
- Superficial epigastric (from femoral)
Veins of the anterolateral abdominal wall.
Deep veins (same arteries)
- Superior epigastric
- Inferior epigastric
Superficial veins:
Subcutaneous venous plexus that can drain into:
1. Internal thoracic vein (superomedially)
2. Lateral thoracic (superolaterally)
3. Superficial & inferior epigastric inferiorly (periumbilical VV anasomtomoses)
What is the inguinal canal?
A passage through the anterior wall from deep inguinal ring to superficial inguinal ring, connecting the extraperitoneal space of abdomen with scrotum or labia majora.
How does the inguinal canal development (IE descent of gonads)
- Gubernaculum (genitoinguinal ligament) runs from gonadal ridge to inguinal region through abdominal wall and to labioscrotal swelling.
- Outpouching (evagination) of parietal peritoneum (processus vaginalis) follows the gubernaculum to the scrotum.
- Testes (with nerves & vessels) descend into scrotum via processes vaginalis (drag layers of wall with it).
- Stalk of processus vaginalis is obliterated leaving a small remanent of parietal peritoneum around testis (tunica vaginalis).
- Ovaries descent to pelvis and gubernaculum becomes the round ligament of the uterus.
What does the gubernaculum become in females?
Round ligament of the uterus.
What does the gubernaculum become in males?
Scrotal ligament - tethers testis to base of scrotum to stop them moving around. Also called “gubernaculum testis”
What goes through the inguinal canal?
MALES: Spermatic cord & coverings
FEMALES: Round ligament of ovary
BOTH: Genitofemoral nerve (genital branch), ilioinguinal nerve (inguinal branch), lymphatics, autonomic nerves, vessels
What are the layers of the spermatic cord, and from what layers do they originate?
External spermatic fascia [external abdominal oblique]
Cremasteric muscle & fascia [Internal abdominal oblique]
Internal spermatic fascia [transversalis fasica]
*Note: Processus vaginalis [from peritoneum] obliterates but forms the tunica vaginalis in the testis/scrotum.
What makes up the anterior wall of the inguinal canal?
External abdominal oblique, and internal oblique laterally.
What makes the posterior wall of the inguinal canal?
Transversalis fasica, peritoneum and conjoint tendom medially.
What makes up the floor of the inguinal canal?
inguinal ligament and lacunar ligament medially
What makes up the roof of the inguinal canal?
Internal oblique and transversus abdominis
What are the layers of the spermatic cord, and what are they contents?
LAYERS: External spermatic fascia (ext. oblique), cremasteric muscle & fascia (int. oblique), internal spermatic fascia (transversalis fascia).
CONTENTS: Ductus deferens Artery to ductus deferens Panpiniform plexus Testicular artery Genitofemoral nerve (genital branch) Ilioinguinal nerve (inguinal branch) Autonomic nerves Lymphatics Other vessels
What are the layers of the testis
Superficial/dartos fascia External spermatic fascia Cremasteric muscle/fascia Internal spermatic fascia Tunica vaginalis Tunica albuginea
What is the inguinal triangle?
It is viewed on the interior surface of the anterior abdominal wall. The boundaries are the rectus abdominis, the inferior epigastric vessel and the inguinal ligament.
Describe how the inguinal triangle, femoral ring and deep inguinal ring are relatively located to each other.
The femoral ring is located BELOW the inguinal triangle (the inguinal ligament forms its roof and the floor or the inguinal triangle).
The deep inguinal ring is located laterally to the inferior epigastric, so OUTSIDE the inguinal triangle.
What is an indirect inguinal hernia? And what is a direct inguinal hernia?
Indirect - enters inguinal canal through deep inguinal ring and exits via superficial inguinal ring (ie travels indirectly through abdominal wall). Patent processus vaginalis is a predisposing factor.
Direct - pushes through the anterior abdominal wall medially to inferior epigastric (so in the inguinal triandle) and passes directly through the wall.
