Chapter 16 Flashcards
Where does sperm production take place
in the testes
what’s in testes?
SEMINIFEROUS TUBULES – that produce hundreds
inner lining of tubes
GERM CELLS – through meiosis, these cells produce haploid sperm cells. All four resultant cells are viable sperm cells.
SUSTENTACULAR (Sertoli or Nurse) CELLS – nourish and protect germ cells. They also secrete lubricating fluid to aid outward movement of sperm as they exit testis via efferent ductules and eventually epididymis. Also produces AMH (anti-Mullerian hormone), which regulates other hormones (e.g. testosterone, estradiol)
how does sperm production work 1(46)—meiotic division
2 (23)—-second meiotic division—4(23)—– 4 sperm
Between seminiferous tubules are clusters of endocrine cells called
INTERSTITIAL (aka ‘LEYDIG’) CELLS.
INTERSTITIAL (aka ‘LEYDIG’) CELLS. in testes secrete?
male sex hormones – ANDROGENS, the most important of which is TESTOSTERONE.
about how big are sperm?
their construction?
smallest in the body (~1/20 mm).
Simple construction: head and tail.
describe the tail of sperm
- its a flagellum-whipping motion provides motility
- base of tail contains a coiled mitochondrion to provide power for movement
head of sperm contains?
ucleus and an organelle called an ACROSOME. Acrosome contains digestive enzymes that helps sperm to penetrate egg (if present)
Seminiferous tubules lead into straight tubules, then??
into larger set of tubules called RETE TESTIS.
Rete testis ultimately drains into larger tubules called efferent ductules, which in turn drain into
EPIDIDYMIS
Epididymis includes
HEAD, BODY, and TAIL.
epididymis goes to?
DUCTUS DEFERENS.
DUCTUS DEFERENS passes up spermatic cord, and into
body through inguinal canal.
describe the location of the right and left ductus deferns?
pass cranially over ureters, then loops dorsal to them behind the urinary bladder.
As each duct passes behind (dorsal to) bladder, it has appended to it a gland called the
SEMINAL VESICLE.
ust prior to attachment of the seminal vesicle, the ductus enlarges into an
ampulla
-The ampulla is a position of sperm storage prior to ejaculation.
ductus
mesonephric duct
ampulla is
for sperm storage
how the spermatic cord loops
ventral to (“in front of”) the attachment of the ureter of the bladder.
seminal vessicle/seminal fluid
Plastered up against the dorsal side of urinary bladder.
Exocrine glands – provide secretions that make up most of seminal fluid.
Fluid lubricates path of exiting sperm.
Fluid is energy-rich (sugar rich) , providing food for sperm.
Fructose(sperm need sugar-provides them nutritition)
Secretions slightly alkaline – helps to neutralize slightly acidic environment of vagina.
PROSTAGLANDINS from seminal vessicle? exocrine
romote uterine contractions to help facilitate sperm movement up uterus into fallopian tubes.
Fibrinogen-forms a temporary clot in vagina.
whats important about the seminal vessicle-what does it lead too?
Once beyond the seminal vesicle, ductus is referred to as the ejaculatory duct. These are paired structures which empty into the prostatic urethra.
PROSTATE GLAND
what’s at it?
what is it made of?
what does it secrete?
Ejaculatory ducts come together to join the urethra within the mass of the prostate gland.
Prostate is a single, midline gland just inferior to urinary bladder.
Prostate is a mass of connective tissue, glandular tissue, and smooth muscle.
Prostate secretions:
Prostatic fluid
Clotting enzyme
profibrinolysin