GU Phys 1 Flashcards
What structure is a continuation of the renal pelvis?
ureter
ureter
- size
- location
- 6mm D
- 25 cm L
- descends retroperitoneal to bladder base
layers of the ureter
- inner mucosa
- muscularis (circular and longitudinal smooth muscle)
- adventitia
what type of epithelium is the inner mucosa of the ureter?
transitional
what action moves urine in the ureters?
peristaltic waves
what is the relationship between contraction of ureter and volume of urine?
- contraction matches rate and volume of urine formation
- there is local autoregulation of contraction
- distention increases contraction
urinary bladder
- midline
- muscular sac
- retroperitoneal
trigone
-trianglular anatomical region at the base of the bladder
what are the layers of the bladder? (3)
- mucosa (still transitional epi)
- muscular
- adventitia
what muscle makes up the muscular layer of the bladder?
detrusor
bladder location
- female
- male
- female: anterior to uterus and vagina
- male: anterior to rectum, superior to prostate
condition of the bladder when empty
pyramidal rugal folds
condition of the bladder when filling
expands, pear shape, moves anteriorly
condition of the bladder when full
- 10cm L
- 500 mL
- urine if formed continuously but held until release is convenient
female urethra
- length
- location
- 3-4 cm
- meatus inferior to clitoris, anterior to vaginal introitus
length of male urethra
20 cm
internal urethral sphincter
- where
- type of control
- proximal end of urethra
- involuntary
external urethral sphincter
- where
- type of control
- surrounds urethra passing through pelvic floor
- voluntary
when is the reflex arc activated for micturition?
-at 200 ml
afferent neural control of micturition (aka urine-ing)
- to sacral spinal region
- to cerebrum to sense need to void
efferent neural control of micturition
- via PNS pelvic splanchnic nerves
- to detrusor smooth muscle = contract
- to internal urethral sphincter = relax
when neural control of the bladder is activated and it’s convenient, what happens?
-bladder is emptied through voluntary relaxation of external urethra sphincter
What happens if neural control of bladder is activated but unheeded?
- reflex bladder contractions subside
- urine continues to accumulate
- at additional 200-300 mL, micturition reflex occurs
urochrome
- aka urobilinogen
- from Hb breakdown
scrotum
- exterior pouch, pigmented skin, sparse hair
- midline septum makes 2 compartments
what is a major function of the scrotum?
maintain testes at optimum temp
dartos muscle
- sm muscle in superficial layer
- wrinkles the scrotal skin
cremaster muscle
-muscle bands which elevate the testes
testes
- paired
- oval shaped
- 4 cm L x 2.5 cm W
tunica vaginalis of testes
- outer layer
- derived from peritoneum
- parietal and visceral layers
tunica albuginea of testes
- fibrous connective tissue capsule
- septal extensions create lobules
- each lobule contains 1-4 seminiferous tubules
what is the site of spermatogenesis?
seminiferous tubules
seminiferous tubules
-highly convoluted
-conduct sperm from testes
-
what cells are contained in in the seminferous tubules?
interstitial cells of Leydig :
-exterior to tubules
what do the interstitial cells of Leydig secrete?
testosterone
What 2 cell types are contained with in the walls of the testes…. kiwi… ?
- germ cells
- sertoli cells
germ cells contain ?
spermatogonia
sertoli cells
- lg, glycogen containing cells
- from basal lamina to lumen
- tight junctions b/w cells
- forms blood-testis barrier
- immune avoidance
blood supply to the testes
- testicular arteries
- testicular veins
testicular arteries arise from what?
abdominal aorta
testicular veins
- form a tortuous network
- called the pampiniform complex
- surrounds testicular a.
- acts as a countercurrent heat exchanger
spermatic cord
- fibrous connective tissue sheath
- connects testes to pelvic cavity
- pathway for vessels, nerves and vas deferns
what is the epidiymis?
a highly coiled tube, 6m (20f)
head of the epididymis
- caps superior aspect of testis
- receives sperm
- from efferent ductules
body and tail of epididymis
posterolateral to testis
functions of the epididymis
- sperm maturation and storage
- 20 day process
- smooth muscle contraction propels sperm forward
location of the vas deferens
- palpated anterior to the pubic bone
- arches deep to ureter
- descends along posterior aspect of bladder
vas deferens purpose
-conducts sperm during ejaculation from epididymis toward pelvic cavity through inguinal canal
the terminus of the vas deferens
- expands to form ampulla
- joins duct of seminal vesicle to form ejaculatory duct
peristaltic activity of the vas deferens
thick layers of smooth muscles create peristaltic waves for sperm movement
the urethra conducts what 2 things?
- urine
- semen
3 regions of the urethra
- prostatic
- membranous
- penile
prostatic urethra
- exiting bladder
- surrounded by prostate
membranous urethra
passes through urogenital diaphragm
penile urethra
- passes through penis
- terminates at external urethral meatus
internal urethral sphincter
- where
- muscle type
- fxn
- at junction of inferior bladder and proximal urethra
- smooth muscle, involuntary
- contraction prevents urine release during ejaculation
external urethra sphincter
- where
- muscle type
- fxn
- at membranous prostate
- skeletal muscle, voluntary
- controls release of urine
where are the seminal vesicles?
- posterior wall of bladder
- bilateral, 5-7 cm
what amount of semen comes from the seminal vesicles?
60%
what do the seminal vesicles empty to?
vas deferens at ejaculation
what is the composition of semen at the seminal vesicles?
- yellowish, viscous, alkaline fluid
- fructose and glucose
- buffers
- ascorbic acid
- PG
- semenogelin
what is semenogelin
- protein that coagulates semen
- protects sperm and prevents capacitation
where is the prostate gland
- posterior to bladder
- palpated through anterior rectal wall
- encircles upper part of urethra
semen volume in the prostate
25-30%
action at prostate during ejaculation
-empties to prostatic urethra when smooth muscle contracts
prostatic secretions
- acid phosphatase
- citric acid
- fibrinolysin
- fertility promoting peptide (FPP)
- prostate specific antigen (PSA)
- zinc
function of PSA
hydrolyze semenogelin to liquify semen
zinc
stabilizes chromatin
bulbourethral glands (aka Cowper’s glands)
- bilateral, pea size
- inferior to prostate
- produce thick clear mucus and glucose
- pre ejaculate that empties to penile urethra
function of the pre ejaculate secreted by the bulbourethral glands
lubrication and neutralize urine
ejaculatory fluid + sperm = ?
semen
make up of semen
- 2.5-3.5 mL
- 100 million sperm / mL
- ph: 7.3-7.6
- analyzed for sperm count, motility, morpholgy
what is the result if there is 20-40 million sperm/mL ?
50% infertile
what is the sperm count cut off that classifies as sterile?
<20 million sperm/mL
