pelvis and the pelvic organs Flashcards
describe the structure of the pelvis
three bones -t he right and left hip bone which join anteriorly at the pubic symphysis, and the sacrum at the posterior
the hip bones are divided into three sections, from top to bottom: ileum, ischium and pubis
note - the sacrum has the coccyx on the bottom
explain what is meant by the true and false pelvis
the true pelvis = everything between the pelvic inlet and outlet (in the donut hole)
false pelvis = above the pelvic inlet to the top of the ileum of the hip bones
what are the contents of the true pelvis?
Contains pelvic colon, (sometimes loops of ileum), rectum, ureters, bladder, urethra, and reproductive organs
where are the testes and what are the general/major structures related to them?
Lie in the scrotum, connected to the spermatic cord
Produces sperm and testosterone, ellipsoid shape
Placed obliquely
epididymis (site of sperm storage and maturation) runs along the posterior margin
Anterior border- smooth and convex
Posterior Border - Body of Epididymis
Medial surface - smooth and convex
Lateral surface
explain the internal structure of the testes
seminiferous tubules - contain leydig, steroli and spermatogenic cells therefore produce sperm
rete testis take sperm from seminiferous tubules, to the epididymis (at the head via efferent ductules)
ductus (vas) deferens - continuous with tail of the epididymis, later joins the seminal vesicle/gland to form the ejaculatory duct, which joins the prostatic urethra
the testes are encased in a tough capsule. what are the layers of this capsule?
● Tunica Vasculosa
● Tunica albugenia- a dense, blue-white layer of collagen fibres covering tunica vasculosa and it is surrounded by the visceral tunica vaginalis…
● Tunica vaginalis- arise from the peritoneum known as processus vaginalis. During migration of the testes into the scrotum, the processus vaginalis obliterates to form the tunica vaginalis (has parietal and visceral layers)
what are the layers of the scrotum, including what these layers arise from?
Skin
Dartos fascia - arises from the superficial fascia
External spermatic fascia - arises from the external oblique
Cremaster muscle and its fascia - arises from the internal oblique and its aponeurosis
Internal spermatic fascia - arises from the transversalis fascia
what arteries supply the testes?
testicular artery
artery to the ductus deferens
cremasteric artery
how are the testes drained (veins)?
Pampiniform plexus forms testicular veins that drain testes (and is responsible for cooling them)
Left testicular vein drains into left renal vein
Right drains directly into IVC
what is a varicocele?
Swelling of the testes, occurring when pampiniform plexus becomes expanded and tortious. ‘Bag of worm appearance’
outline the route of the testes formation and descent
what can go wrong with the descent?
Develop in posterior abdominal wall, then descends down inguinal canal, into scrotum
Can stop descending - known as undescended testes/cryptorchidism. Can cause infertility due to incorrect temperature
what are the three sections of the penis?
what are the three tissues of the penis?
root, body and glans (the head)
tissues = x2 of the corpus cavernosum (which fill with blood during erection) and x1 corpus spongiosum which has the urethra running through it
what is the blood supply for the penis? (supply and drainage)
Internal pudendal artery (branch of int. Iliac artery) gives rise to the deep (or cavernosal) and dorsal arteries of the penis (smaller than the veins, run either side of the deep dorsal vein)
Deep and superficial dorsal veins and the prostatic venous plexus are responsible for drainage
explain the nerve supply of the penis and the respective function of these nerves
Sensory and sympathetic nerves = dorsal nerves (run either side of the dorsal arteries) which is a branch of the pudendal nerve
Autonomic Parasympathetic is excitatory = erection. This is from the cavernous nerves, which arise from the periprostatic nerve plexus
where is external genitalia found?
the perineum
what is the rectovesical pouch? (cadavers with penis)
what ‘pouches’ are in a cadaver with a uterus?
a fold of peritoneum between the bladder and the rectum
vesicouterine (bladder and uterus) and rectouterine
what are the internal structures of the pelvis with a penis?
vas deferens (proximal), ejaculatory ducts, part of urethra and accessory glands (prostate, seminal vesicles and bulbourethral glands)
what are the divisions of the urethra?
beginning at the base of the bladder preprostatic, prostatic, membranous and spongy (spongy being the longest part passing through the penis)
what are the ejaculatory ducts?
● Formed by the union of the vas deferens and the seminal vesicle
● Each duct passes through the prostate gland and empties into the prostatic urethra
what is the prostate gland?
fibromuscular gland that lies immediately inferior to the urinary bladder and anterior to the rectum
● It surrounds a part of the urethra and the ejaculatory ducts
● It also contributes towards 30% of the semen
what is the seminal vesicle/glands?
pair of glands posterior to (behind) the bladder
joins ductus deferens to form the ejaculatory duct
secretion from these glands contribute 60% to semen
what are the bulbourethral glands?
● Lies lateral to the membranous part of the urethra with its duct opening into the spongy part of the urethra
● Contributes to the lubrication of the urethra and pre-ejaculatory emission from the penis
what are the gross structure of the female internal reproductive system?
Ovaries
fallopian/uterine tube - fimbriae, infundibulum, ampulla (where fertilisation occurs)
uterus
cervix (has a uterine and vaginal part)
vagina
where does implantation occur?
posterior wall of the uterus
what is the mons pubis, labia majora and minora, and vestibule?
● Mons pubis- adipose tissue overlying the pubic symphysis, has pubic hair
● Labia majora- a pair of thick folds of hairy skin and adipose tissue inferior to the mons and between the thighs. The area between both is known as the pudendal cleft
● Labia Minora- a pair of thin folds of non-hairy skin and adipose tissue lying medial to/within the labia majora
● Vestibule- the cavity which lies between the labia minora, contains the external urethral and vaginal orifices and opening of the two greater vestibular glands (Bartholin’s glands)
● Clitoris- an erectile structure with a root, body and glans, similar to that of a penis.
○ It contains a pair of erectile tissues known as corpora cavernosa.
● Greater vestibular (Bartholin’s glands) - a pair of pea sized glands are located on each side of the vaginal orifice, homologous to the bulbourethral glands.
○ They secrete mucus for lubrication during sexual arousal
explain the structure of the clitoris
an erectile structure with a root, where the labia majora meet, body or prepuce, and glans (most sensitive), similar to that of a penis
○ It contains a pair of erectile tissues known as corpora cavernosa
what is the function of the vulva?
Sexual arousal and intercourse
Micturition
Prevent entry of foreign material into the urinary and genital tract.
what are the greater vestibular/Bartholin’s glands?
a pair of pea sized glands are located on each side of the vaginal orifice, homologous to the bulbourethral glands
○ They secrete mucus for lubrication during sexual arousal
nerve supply of the vulva?
the pudendal nerve
vasculature (arteries and veins) of the vulva?
Arteries - branches from the femoral artery and internal pudendal artery
Veins = corresponding internal and external pudendal veins
