Male Reproductive System - Part 2

Question 1

what ducts make up the intratesticular genital ducts?

Answer 1

• tubuli recti
• rete testis
• efferent ductules

Question 2

tubuli recti

Answer 2

• short, straight tubules
• initially lined only by Sertoli cells
• changes to simple cuboidal epithelium w/ microvilli and single cilium

Question 3

rete testis

Answer 3

• plexus of anastamosing channels lined by simple cuboidal epithelium
• many cells w/ single luminal cilium

Question 4

efferent ductules

Answer 4

• 10-20 tubules leading from rete testis to ductus epididymis
• thin circular layer of smooth muscle under epithelium basal lamina
• lined w/ “pseudostratified columnar” of alternating clusters of nonciliated cuboidal cells and ciliated columnar cells

Question 5

function of nonciliated cells in efferent ductules

Answer 5

absorb fluid secreted by seminiferous tubules

Question 6

what are the excretory genital ducts?

Answer 6

• epididymis
• vas deferens
• urethra

Question 7

epididymis description

Answer 7

• smooth muscle circular layers - peristaltic contractions move sperm toward ductus deferens
• lined by pseudostratified columnar epithelium w/ 2 cell types: basal cells and principal cells

Question 8

basal cells of epididymis

Answer 8

• round
• appear undifferentiated
• precursors of principal cells

Question 9

principal cells of epididymis

Answer 9

• columnar
• nonmotile stereocilia on luminal surface
• cytoplasm contains large Golgi complex, lysosomes, many apically located pinocytic and coated vesicles
• fluid resorption?

Question 10

what do principal cells of epididymis secrete (3 things) and function?

Answer 10

carnitine, sialic acid, glycerophosphocholine

-probably inhibits capacitation (where sperm becomes capable of fertilizing an oocyte)

Question 11

ductus (vas) deferens

Answer 11

• thick muscular wall: inner and outer layers of longitudinal smooth muscle separated by a middle circular layer
• narrow, irregular lumen
• pseudostratified columnar epithelium (similar to ductus epididymis)
• ends in prostatic urethra

Question 12

seminal vesicles

Answer 12

• pseudostratified columnar epithelium
• extensively folded mucosa
• yellow lipochrome pigment granules
• secretory granules
• lamina propria: fibroelastic CT w/ inner circular and outer longitudinal smooth muscle
• adventitia: fibroelastic CT

Question 13

what causes changes in height of seminal vesicle epithelium?

Answer 13

testosterone levels

Question 14

secretory product of seminal vesicles

Answer 14

viscous fluid containing substances that activate sperm - makes up 70% of human ejaculate

Question 15

energy source for sperm motility?

Answer 15

fructose (from seminal vesicle secretions)

Question 16

ejaculatory duct

Answer 16

• straight continuation of ductus deferens
• receives duct of seminal vesicle
• NO muscular wall

Question 17

where does ejaculatory duct end?

Answer 17

-enters prostate gland and terminates in a slit on colliculus seminalis in prostatis urethra

Question 18

prostate gland - location

Answer 18

surrounds urethra as it exits the urinary bladder

Question 19

prostate gland composition

Answer 19

30-50 discrete, branched tubuloalveolar glands arranged in 3 concentric layers around urethra: mucosal, submucosal, and main

Question 20

function of tubuloalveolar glands of prostate

Answer 20

empty contents, via excretory ducts, into prostatic urethra

Question 21

3 layers of glands in prostate and differences in function?

Answer 21

• mucosal: secrete directly into urethra

- submucosal and main: secrete into ducts that empty into prostatic sinus

Question 22

what surrounds prostate?

Answer 22

fibroelastic capsule w/ smooth muscle

Question 23

how is the prostate divided into lobes?

Answer 23

septa from capsule penetrate gland and divide it

Question 24

epithelium of prostate

Answer 24

• simple or pseudostratified columnar (may have patches of cuboidal or squamous)
• cells have numerous lysosomes and secretory granules

Question 25

what do basal cells of prostate epithelium produce and why is this clinically relevant?

Answer 25

high MW keratin - differences in high MW keratin expression are diagnostic for normal vs. hyperplastic vs. neoplastic prostate

Question 26

corpora amylacia

Answer 26

- glycoprotein concretions in lumen of alveoli - may become calcified - increase w/ age

Question 27

prostatic secretion

Answer 27

thin fluid containing: - proteolytic enzymes (fibrinolysin) - citric acid - acid phosphatase - lipids

Question 28

what is prostatic secretion regulated by?

Answer 28

dihydrotestosterone

Question 29

where are bulbourethral/cowper's glands located and where do they empty into?

Answer 29

adjacent to membranous urethra + empty into urethra lumen

Question 30

bulbourethral glands: lining, what surrounds them, what do they secrete?

Answer 30

- lined by simple cuboidal or columnar epithelium - fibroelastic capsule w/ smooth and skeletal muscle - mucous secreting

Question 31

corpora cavernosa of penis

Answer 31

- paired masses of erectile tissue - contain irregular vascular spaces lined by continuous layer of endothelium - spaces separated by CT trabeculae and smooth muscle

Question 32

how do the vascular spaces in the corpora cavernosa change w/ location?

Answer 32

spaces decrease in size towards periphery

Question 33

what happens during erection?

Answer 33

parasympathetic impulses constrict arteriovenous shunts -> dilate helicine arteries -> vascular spaces become engorged with blood

Question 34

corpus spongiosum of penis

Answer 34

- single mass of erectile tissue - contains uniform size vascular spaces throughout - trabeculae w/ more elastic fibers and less smooth muscle than corpora cavernosa

Question 35

tunica albuginea of penis

Answer 35

- thick fibrous connective sheath | - surrounds corpora cavernosa and spongiosum

Question 36

what permits extension of penis during erection?

Answer 36

dense collagen bundles in tunica albuginea

Question 37

glans penis

Answer 37

- dilated distal end of corpus spongiosum - contains dense CT and longitudinal muscle fibers - covered by prepuce

Question 38

lining of prepuce

Answer 38

stratified squamous nonkeratinized epithelium

Question 39

glands of littre

Answer 39

mucus secreting glands throughout the length of penile urethra

Question 40

cryptorchidism

Answer 40

- developmental defect | - testes fail to descend into scrotum

Question 41

why does cryptorchidism result in sterility?

Answer 41

temperature of undescended testes (i.e, normal body temp) inhibits spermatogenesis

Question 42

how does cryptorchidism affect testosterone production?

Answer 42

it doesn't

Question 43

cryptorchidism and cancer?

Answer 43

associated w/ higher incidence of testicular malignancy than in normally descended testes

Question 44

can cryptorchidism be corrected?

Answer 44

yes, surgically - usually b/w 5-7 y/o | -but affected individuals produce abnormal sperm

Question 45

Klinefelter's syndrome

Answer 45

- excess # of X chromosomes (most often XXY) - tall, thin stature - some mental retardation - small testes - elevated gonadotropin levels - infertility

Question 46

what are developmental defects in Klinefelter's syndrome regulated by?

Answer 46

SRY gene - sex-determining region Y - male phenotype but XX genotype, or - female w/ XY or XXY genotype

Question 47

Kartagener's syndrome

Answer 47

hereditary disorder marked by immotile cilia syndrome that results in infertility in men (defect in dynein)

Question 48

hypospadia

Answer 48

urethra does not develop properly - may open near base of penis