SUGER anatomy Flashcards
The inguinal canal
- a passage through the muscles of the anterior abdominal wall
- deep inguinal ring
- invagination of transversalis fascia that covers the contents of the inguinal ligament
- above the midpoint of the inguinal canal
- superficial inguinal ring
- lies just superior to the pubic tubercle
- invagination of the external oblique aponeurosis
- this also covers the contents of the canal
the inguinal ligament
runs from the asis to the pubic tubercle
what does the inguinal canal contain in males
the spermatic cord
what does the inguinal canal contain in females?
the round ligament of the uterus
spermatic cord structures
rule of 3
- 3 coverings
- external, cremasteric and internal spermatic fascia
- 3 arteries
- testicular, artery of the vas, cremasteric artery
- 3 veins
- testicular, vein of the vas, cremasteric artery
- 3 nerves
- ilio-inguinal (skin sensation anterior 1/3 of genetalia)
- genitofemoral (to cremaster muscle)
- sympathetic (vas and testicular pain)
- 3 others
- vas deferens, lymphatics and tunica vaginalis
spermatic cord fascia
- acquires a layer of fascia from each of the three abdominal wall layers
- leaves the superficial ring with three layers of covering
- most internal is from transversalis
- most externalis from ext oblique
Tunica vaginalis
- a sac covering the testis
- derived from the peritoneum
- works like peritoneum allowing friction free movement
epididymis
- very coiled duct at the back of the testis - along which sperm travels to the vas deferens
- there’s a head that’s superior and highly coiled
- then there’s a posterior body
- then there’s a tail that turns back on itself and communicates with the vas deferens
cremaster muscle
a muscle of the spermatic cord by which the testicle can be partially raised
it runs in the inguinal canal
it is derived from muscle of the internal oblique
inferior epigastric artery
- arises from external iliac
- hernias medial to this vessel are direct hernias
- hernias lateral to this vessel are indirect
dartos muscle
a sheet of smooth muscle, situated immediately underneath the skin. It acts to help regulate the temperature of the scrotum, by wrinkling the skin – this decreases surface area, reducing heat loss.
tunica albuginea
a fibrous capsule that encloses the testes. It penetrates into the parenchyma of each testicle with diaphragms, dividing it into lobules.
these lobules contain the seminiferous tubules
prepuce
foreskin
suprarenal glands
adrenal glands
at top of kidney
embedded in perinephric fat
Right: tetrahedral and lies behind the liver and IVC
Left: crescent shaped and lies behind the stomach and pancreas
divisions of arteries once they have entered the kidney
- renal artery divides into segmental branches
- segmental branches divide to form interlobar arteries
- interlobars are either side of each pyramid
- interlobar arteries divide to form arcuate arteries
- arcuate arteries (in cortex) divide to form afferent arterioles
arterial blood supply to kidneys
- renal arteries which come off aorta just inferior to the sup mesenteric
- aorta lies slightly left of midline
- for this reason right renal artery is longer than the left and passes the IVC posteriorly
blood supply to adrenal glands
- superior adrenal artery (arises from inf phrenic artery)
- middle adrenal artery (arises from the abdominal aorta)
- inferior adrenal artery (arises from the renal arteries)
venous drainage of adrenal glands
- right and left adrenal veins
- right drains straight into the IVC
- left first drains into the left renal vein
layers of the adrenal glands
Cortex - derived from embryonic mesoderm
- Zona glomerulosa - mineralocorticoids (e.g. aldosterone)
- Zona fasciculata - corticosteroids (e.g. cortisol)
- Zona reticularis - androgens (e.g. DHEA)
Medulla - derived from the ectodermal neural crest cells
- secretes catecholamines (such as adrenaline) from chromaffin cells in response to stress
what is the surface marking for the aortic bifurcation
the umbilicus
NB it bifurcates into the common iliac arteries
3 common spots for renal caliculi
- where the pelvis of the kidney becomes the ureter
- at the pelvic brim
- where the ureter passes through the bladder wall
psoas muscle
- arises from the sides of the lumbar vertebra
- passes almost vertically down under the inguinal ligament
- attaches to the lesser trochanter of the femur
- converges with the iliacus to form the iliopsoas
iliacus muscle
- fills the iliac fossa
- thigh flexor
- passes under inguinal ligament
- arises frominterior side of hip bone and also AIIS
- converves with psoas as the iliopsoas
- inserts on the lesser trochanter of the femur
obturator foramen
surfaces of the bladder
- superior
- two lateral
- base
- apex
- bladder neck
interior surface of the bladder
rugose
prostate
- completely encircles the urethra
- with progressing age it enlarges
- this may cause complete blockage of the urethra and the inability to pass urine
- venous drainage of the prostate is closely related to the vertebra
- prostatic metastases can often end up in the vertebra
three components of control of micturation
- brain
- spinal cord
- sensory from bladder
loss of brain control of micturation
- bladder fills but brain does not realise
- spinal cord asks for permission to empty
- brain does not reply
- spinal cord controls a complete normal emptying of the bladder
- low pressure in bladder - so no renal failure risk
loss of spinal cord motor control of micturation
- patient can sense that the bladder is full but cannot empty it
- high pressure and renal failure
loss of sensation of need for micturation
- spinal cord and brain do not recieve info that bladder is full
- the patient contiunuously dribbles urine
- there’s high pressure in the bladder and this may rapidly progress to kidney failure
three parts of the uterus
fundus, body and cervix
the positions of the uterus and which one is normal
ante-flexion is the normal one
the -verted ones refer to when the bend is at the cervix whereas the flexion ones are when the bend is in the uterus itself
tissue layers of the uterus
- Peritoneum - double layer that’s continuous with abdominal peritoneum
- Myometrium - thick smooth muscle layer
- Endometrium - inner mucous membrane of uterus (two parts)
- deep stratum basalis
- not shed
- superficial stratum functionalis
- proliferates in response to oestrogen
- secretory in response to progesterone
- shed during menstruation
- deep stratum basalis
ligaments of the uterus
- Broad ligament
- double layer of peritoneum attaching uterus to the pelvis
- Round ligament
- extends from the uterine horns to the labia majora
- goes through inguinal canal
- Ovarian ligament
- joins the ovaries to the uterus
- Cardinal ligament
- located in the base of the broad ligament
- extends from cervix to the lateral pelvic walls
- contains the uterine artery and vein
- Uterosacral ligament
- extends from cervix to the sacrum
- provides support to the uterus
parts of the uterine tube
arterial supply tothe uterus, fallopian tubes and the vagina?
- Uterine and vaginal come off the internal iliac
- The ovarian artery comes off the abdominal aorta just below the renal artery
- the uterine artery and the ovarian artery anastamose and so the fallopian tube is supplied by both
relate the seminal vesicle, vas deferens and ejaculatory duct
- from the deep inguinal ring, the ductus deferens passes across the side wall of the pelvis
- then turns medially onto the back of the bladder
- here, a dilated portion called the ampulla lies medial to the seminal vesicle
- the ductus deferens terminates by joining the duct of the seminal vesicle to form the ejaculatory duct
Seminal Vesicle
- there’s one on each side
- they don’t store sperm
- they secrete thick alkaline fluid tht forms the bulk of seminal fluid
- on each side the duct of the seminal vesicle terminates in an ejaculatory duct which enters the prostate
- this duct runs through the prostate to enter the prostatic urethra
the prostate
- about the size of a walnut
- secretions of the prostate are added to the seminal fluid during ejaculation
- has two ejaculatory ducts entering it (from eminal vesicles and ductus deferens)
- urethra passes through it (collecting secretions from the ejaculatory ducts)
the erectile cylinders of the penis
- one corpus spongiosum
- through which the urethra travels
- forms bulb at the root
- two corpus cavernosa
- form crura at the root
Male Urogenital Embryology
- Presence of Y chromosome
- Encodes SRY gene for testis determining factor
- TDF causes genital ridge to develop into testis
- Leydig cells secrete testosterone
- Testis cause Mesonephric duct to develop
- Sertoli cells secrete Müllerian inhibiting factor
- Paramesonephric duct degenerates
NB paramesonephric duct is AKA Müllerian duct
Female urogenital embryology
- Absense of Y chromosome
- No SRY gene so no TDF
- Genital ridge develops into ovaries by default
- Absense of testosterone causes mesonephric duct to degenerate
- Absense of Müllerian-inhibiting factor allows the paramesonephric ducts to develop
