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
