Pelvis Flashcards
Floor of the Inguinal Canal
The Inguinal Ligament- This is the rolled up aponeurosis of External Oblique Muscles. On it’s lateral side there is the transversalis fascia
This is thickened by Lacunar Ligament
The Roof of the Inguinal Canal
Internal Oblique - Lateral two-thirds of Inguinal Ligament; they arch medially and downwards. Into flat aponeurosis, passing in front of rectus abdominis. and then moves laterally into pectineal line up to as far as the lacunar ligament.
Transversus Abdominis- in the Lateral Half of the Inguinal Ligament. In fibres of internal oblique.
These two muscles join and form the conjoint tendon@ pectineal line.
They are supplied by the ilioinguinal and iliohypogastric nerve(L1). Incision causes direct inguinal ligament above this, But if injury of ilioinguinal nerve occurs IN the inguinal canal only sensory changes of the ant. part of scrotum or labia majora occurs as the motor branch has already been given off
Posterior wall of Inguinal Canal
Transversalis fascia
Medially the conjoint tendon also provides support
- it is also strengthened by fibres called interfoveolar ligament (around medial end of deep ring) which is thickened tissue of the trasnversalis fascia & lie in front of inf. epigastric arteries
Describe location of deep inguinal ring
lies above the midpoint of inguinal ligament & is an opening of transversalis fascia when it is pulled like a sleeve becomes internal spermatic fascia.
Structures around deep inguinal ring & course of inf. Epigastric Artery
Medial to it is the inferior epigastric(branch of external iliac artery)
Lateral to Interfoveolar ligament lies the Vas deferens/ Broad ligament which hooks around it and then enters the canal
The course of the inferior epigastric vessels go from deep to trasversalis fascia perforates this and goes upwards medially and into rectus sheath behind this. It also gives off a cremasteric branch next to the deep inguinal ring. It also provides branches to periosteum of pubic ramus called pubic branch & anastomoses with pubic branch of obturator artery.*
- if obturator artery not present will open up to form accessory/abnormal obturator artery
What are the borders of Hesselbachs triangle & it’s significance
Medial: Rectus abdominis
Lateral: inferior epigastric artery
Below: Inguinal Ligament
Hernia Lateral to Lateral Border: Indirect Hernia into Inguinal Canal
Hernia Medial to Lateral Border: Direct hernia into conjoint tendon
Contents of spermatic cord
3 coverings and 6 groups
3 coverings
i. Internal Spermatic Fascia(deepest)
(Transversalic fascia)
ii.Cremasteric Fascia With cremaster muscle
(Transversus muscles follows this and attaches to pubic tubercle
iii. Superficial Spermatic Fascia
Contents:
1. Testicular veins
2.Testicular artery
3.Artery for vas deferens( from superior or inferior vasical)
4.Pampiniform plexus
5. Vas deferens- Posterior and lower part of cord
6.processus vaginalis- obliterated if patent is the pouch for indirect inguinal hernia
7. autonomic nerves- genital branch of genitofemoral nerve
8. Lymphatics-> to paraortic
9*.Spermatic cord/ Broad Ligament
10**.Ilioinguinal Nerve
- does not enter via deep ring between internal and external oblique muscles- then leaves and supplies the upper part of the thigh and ant. third of the scrotum
The layers of the testis; nerve supply of the testis
2 layers
i. Tunica Albuginea(deep layer)
ii. Tunica Vaginalis
nerve supply:
Sympathetic fibres of T10 via greater or lesser splachnic nerves nil parasympathetic
Structure of the testes and Histological description of Testes
- mediastinum testis where the septa lies to reach the tunica albuginea
- septa divides the testes into 400 lobules which contain a few seminiferous tubules which open into rete testis(a network of intercommunicating channels)
Histology
Convoluted seminiferous tubules (within the lobules) → straight seminiferous tubules (near mediastinum testis) → rete testis (within mediastinum testis) → efferent ductules → epididymis → ductus deferens → ejaculatory duct → prostatic urethra
Cells at Straight Seminiferous Tubules have spermatogonia occuring where primary spermatocytes occur–> secondary spermatocytes ->spermatids which metamorphasizes into spermatozoa
Sertoli cells-> release ABP maintains high testosterone environment
Leydig cells-> secretes testoterone
Testis make small amounts of semen
Embryological origin of the testes
gonadal ridge medial to the mesonephric ridge of the intermediate cell mass
What are the muscles of the true pelvis
obturator internus and piriformis
levator ani and coccygeus
What is the origin and insertion and innervation of pifirormis
Origin: From the lateral mass of the sacrum
Nerve to pirifromis from the sacral plexus
-covered in fascia
What is the origin and insertion of levator ani
the levator ani is made of three muscles, pubococcygeus, puborectalis, and ileococygeus and its origin is from body of the pubis to the ischial spine and contains a medial spinous plate
i.pubococcygeus comes from arises from the tendinous arch and the posterior surface of the body of the pubis
ii.Puborectalis -originates from the posterior surface of the pubis and forms a U-shape. innervated by the pudendal nerve and nerve to levator ani
iii.Ileococcygeus- originates from the ischial spine and the posterior tendinous arch of the obturator internus and inserts into coccyx perineal body and anococygeal ligament.
What is the origin of the coccygeus and it’s insertion?
arises from the ischial spine, and inserts itself
What is the course of the rectum
The rectum is a continuation of the sigmoid colon at around S3, the sigmoid mesocolon ends and the rectum has no mesentery but is covered in fat more bulky posteriorly. The teania coli at this point broadens out into anterior and posterior segments which meet laterally to complete an outer layer of longitudinal muscle. Hence there are no sacculations of the rectum. The rectum turns downwards and backwards as the anal canal at the coccyx and slung forward by puborectalis. Near the top of the anal external sphincter. The superior rectal artery and superior rectal vein. On the upper part there is mesentary anteriorly and its side and middle third there is some anteriorly and the bottom third only has a forward reflection forming the recto/vesicouterine pouch.
What is the content of the rectovesical pouch?
In front of the rectovesical pouch uppermost base of the ureter and the top of the seminal vesicle, below this is the prostate, ends of vas deferens and ureter
What is the blood supply of the rectum
The rectum is supplied by:
i.Superior rectal artery(A division of the inferior mesenteric artery)- gets it’s name when entering the pelvic brim and crosses the LEFT common iliac artery MEDIAL to the ureters @S3 veterbra it divides into left and right
ii.Inferior rectal artery(pudendal artery from internal iliac artery)- will anastomose with i. at the submucosal layer of the rectum
iii.middle rectal artery
It’s venous supply corresponds to its arteries but is free to anastomose and does so submucosally(internal rectal plexus) and the muscular wall(external rectal plexus) and drains from the i.superior rectal vein via inferior mesenteric veins in between the artery and ureter.
ii.inferior rectal vein drains via the internal pudendal veins
What is the lymphatic drainage of the lymph nodes
Lymphoid follicles in the mucous membranes drain to epiploic nodes on the surface of the rectum and perorectal nodes of the mesorectum.
Superior rectum -
inferior rectum- internal iliac nodes
What is the nervous supply of the rectum
Sympathetic plexus comes from the inferior mesenteric plexus
Parasympathetic supply is via pelvic splachnic nerves from S2-S4 via the inferior hypogastric plexus(motor and stretching sensation muscles)
Describe the bladder
The bladder is a pyramidal shaped structure in the pelvic brim with it’s apex facing the pubic symphysis and has a urachus attached to it forming the median urachus. The posterior wall lie in front of the rectum/vagina. The inferolateral wall lie in front of obturator internus, and the lowest part of the bladder, the neck which is pierced by the urethra at the internal urethral orifice/base of prostate for the males.
What is the trigone of the bladder?
The trigone is a section of the bladder found on the base, which is triangular in shape. It has two uretheral orifices at the top laterally and a ureteral orifice centrally and below. It is fixed with connective tissues in the women anteriorly of the vagina and the prostate in men. It is smooth walled and the mucus membrane is firmly attached to the underlying muscle. The orifice is connected by a firm muscular ridge termed the inteureteric bar The urethral pierce the muscle obliquely thus preventing reflux of urine. It also contains a superficial muscle underneath extending into the urethra. It i
What is the blood supply of the vas deferens and seminal vesicles
The blood supply of the vas deferens is via the artery of the vas deferens a branch of the superior OR inferior vesical artery. Seminal vesicles via branches of the middle rectal and inferior vesical arteries
What are the basic information of the prostate?
- Is is a fibromuscular organ lying below the bladder but above the pelvic diaphragm, and is penetrated by a urethra. It provides about 30% of seminal fluid. Its structure is described as having a base, an apex, posterior and inferolateral surfaces. Its base is the upper surface fused with the neck of the bladder. The apex is the LOWEST part. Where the pierced prostatic urethra then perforates through and becomes the membranous urethra, surrounded by sphincter urethrae. The inferolateral area is clasped by the pubourethalis of the levator ani and the anterior region is behind the retropubic space and is connected to the body of the pubis via puboprostatic ligaments. The posterior surface is in front of the rectum but separated by retrovesical fascia The ejactulatory ducts pass through prostate and travels obliquely into the prostatic urethra. There is a strong layer of connective tissue called the capsule, in the periphery of the glands, and outside there is a false capsule. Between these layers are the vesicoprostetic plexus of the veins.
What is the prosthatic urethra?
- It is a continuation of the urethra as it passes through the apex of the prostate. It runs downwards and backwards from the internal meatus, there a midline ridge termed the urethral crest from the posterior wall forming two shallow depressions termed the prostatic sinus. At the midline of the sinus a seminal colliculius/verumontanum forms a rounded eminence. Where a prostatic utricle which is a small recess represeiting the fused ends of the Mullerian ducts & the ejaculatory part lies there as well.