Lecture Outline #26: Pelvis & male repro Flashcards
false pelvis
above pelvic brim
bowel, full bladder, pregnant uterus
pelvic cavity
continuation of the abdominal cavity
pelvic girdle contents: ilium, ischium, pubis, sacrum, coccyx
pelvic ligaments are very complex
pubic symphysis: fibrocartilage
sacroiliac jt: synovial jt (diarthrotic)
- hyaline cartilage (diarthrotic)
- fibrocartilage (syndesmotic)
true pelvis
below pelvic brim
muscular floor - pelvic diaphragm
contents - colon/rectum, bladder, vagina/uterus
external iliac a.s
do not supply any of the pelvic contents
internal iliac a.s
visceral branches go to bladder, uterus, vagina, rectum
internal pudendal a.s go to hemotumescent (erectile) organs
gonagal a.s
testicular and ovarian a.s branches
dragged into pelvis by respective gonads
pelvic diaphragm
supports pelvic organs
bounded by pubic arch, coccyx, ischial tuberosities
voluntary skeletal m. - pudendal n.
includes/stabilizes GI/UG external sphincters (external urethral, external anal, and vaginal sphincters)
prolapse of pelvic contents
pelvic floor is easily injured (childbirth/injury) and can be weakened
- prolapsed rectum: rectum comes out anus
- prolapsed uterus: uterus comes out anus
kegel excersizes
excersizes that tone pelvic floor m.s, relieve urinary difficulties, ease birthing process, speed recovery, & prevent prolapse by contracting pelvic floor
pudendal n.
- somatic motor - contraction of pelvic floor, skeletal m.
- somatic sensory - cervix & vagina, skin of perineum, external genitalia
- pelvic parasympathetic - peristalsis of descending colon to rectum, dilation of BVs in erectile tissues
sacral sympathetic n.s
branches of sympathetic chain ganglia
reduce peristalsis
contract internal urethral sphincter
initiate ejaculation
reflexive contraction of pelvic floor
perineum
space external (below) pelvic diaphragm
location of external genitalia
repro system functions
meiosis - formation of haploid (half genetic material) cells, spermatogeneisis and oogenesis
fertilization - re-combo of haploid cells = diploid conceptus. Must be internal and requires fluid-fluid transfer
female descent of gonads
gonads develop near kidneys
ovaries descend into pelvis around 6-10 weeks and drag gonadal BVs with it. Ends in pelvis around 28 weeks
male descent of gonads
gonads develop near kidneys
testis descend into pelvis around 6-10 weeks and drag gonadal BVs with it. Migration ends around 28 weeks
testicles continue through inguinal canal into scrotum with help of processes vaginalis (pocket of peritoneum)
spermatic cord descends with it (testicular NAVLs & vas deferens)
tunica vaginalis: peritoneum on surface of testes
gubernaculum: tethers gonads to perineum
inguinal canal
passage that pases obliquely through lower abdominal wall
weak spot for males
contents: spermatic cord (male), round lig (female)
inguinal hernia
indirect - intestine extrudes out thru canal into scrotum
direct - intestine pushes directly through abdominal wall
cryptorchism
one testis doesn’t descend into scrotum
testis structure
- small (4 x 2.5 cm)
- tunica albuginea - CT surrounds/supports
- tunica vaginalis - serous membrane
- seminiferous tubules - produce sperm & testosterone
- rete testis - btw seminiferous tubules & epididymis, where tubules culminate, reduces to form epididymis
epididymis
produces spermatozoa & facilitates maturation
recycles damaged/unused spermatozoa
vas deferens
carries maturing sperm to ejaculatory duct from epididymis through spermatic cord
vasectomy
transection of the vas deferens
prevents sperm from becoming part of ejaculate
testicular cancer
neoplasm of the testicles, easy to ID and treatable (can remove testicle)
seminal vesicle
liquifies semen, 60% of the seminal volume
where vas deferens meet inside prostate at ejaculatory duct
secretes fructose to keep sperm alive and give them energy
prostate gland
liquifies semen, 30% of the seminal volume, is a chemical factory
prostatic urethra runs through it
changes the pH of the ejaculate to counteract the acidity of the vagina
membranous urethra
runs through pelvic diaphragm
penile urethra
runs through penis to external urethral orifice
prostate hyperplasia/hypertrophy
prostate grows as male ages, can distort/stretch trigone of bladder which is full of baroreceptors and makes the bladder feel full.
micturition becomes difficult
40-60 yo = 60% chance 70+yo = 95% chance
prostatic cancer
if caught early, male can still live for decades
TURP procedure
trans-urethral resection of prostate
tool is inserted into external urethral orifice, through the penile urethra, membranous urethra, and into prostatic urethra where the tool chews some of the prostate gland so male can urinate
bulbourethral gland
in membranous urethra, 5% of seminal volume
produces alkaline fluid to lubricate penile urethra
seminal fluid
20-100 mill sperm per mL so 20-500 mill sperm per ejaculate
high fructose concentration
pH: 7.2-7.8
scrotum
pendant pouch of skin, sweat glands, hair, contains spermatic cord
cooler for testis (32-35C)
scrotum - pampiniform plexus
testicular veins that wrap around testicular a.s that bring in 37C blood and cools it before it gets to the testes.
testicular a. is convoluted so there is more length for testicular v. to wrap around and cool blood
scrotum - cremaster m.
encloses spermatic cord & scrotum
pulls testes in if cold, relaxes when hot = cremaster reflex
corpora cavernosa
paired hemotumescent bodies at dorsum of penis
each corpus is attached to penis via crus/crura
ischiocavernosus m.
surrounds each crus/crura, skeletal muscle
erection
veins don’t allow blood to leave as fast
corpus spongiosum
single hemotumescent body at venter of penis, terminates at glans
bulb is located just above testes, proximal ridge on shaft of penis
penile urethra perforates both bulb & glans
bulbospongiosum m.
surrounds bulb & corpus, skeletal muscle
contractions helps expel urine/semen from urethra
deep fascia of the penis
binds corpora (crus/crura) and their m.s together
corpora starts at ischial tuberosities
prepuce of the penis
forskin, extends over glans
sperm pathway
- seminiferous tubules produce sperm/testosterone
- seminiferous tubules coalesce to form efferent ducts
- efferent ducts coalesce to from epididymis
- epididymis narrows to become vas deferens
- vas deferens travels through spermatic cord, enters abdomen through inguinal canal, descends above then behind bladder, expands to form ampulla near ejaculatory duct.
- Ejaculatory duct = vas deferens + duct of seminal vesicle
- prostatic urethra
- membranous urethra
- penile urethra
- Exit via external urethral orifice
