(final) Lecture 16 (6/6/16) PT. 1 Flashcards
Sperm production takes place in the…
testes
Each testis contains around how many coiled tubules? What are they called?
~500 coiled tubules
seminiferous tubules
The inner lining of each tubule is lined with germinal tissue, which includes 2 kinds of cells:
germ cells
sustentacular (sertoli or nurse) cells
Germ cells:
- through meiosis, these cells produce haploid sperm cells
- all four resultant cells are viable sperm cells
Sustentacular cells:
(sertoli or nurse cells)
- nourish and protect germ cells
- secrete lubricating fluid to aid outward movement of sperm as they exit testis
- also produce AMH (anti-Mullerian hormone)
What is AMH and what does it do?
(anti-Mullerian hormone)
- produced by sustentacular/nurse cells
- regulates other hormones
The sperm exits the testis via what?
efferent ductules
The degeneration of the paramesonephric ducts while a male is developing as a fetus is because of what?
sustentacular cells (which produce AMH)
Spermatogonia divide first by what?
mitosis
divides into two; one stays in current location and one goes into center of tubule/lumen
After mitosis of the spermatogonia, one stays in current location and one goes to center of lumen. Then how does it divide?
meiosis
Interstitial endocrinocytes secrete what?
hormones
- androgens
- testosterone
The head of sperm contains nucleus and an organelle called a(n)…
acrosome
Acrosome:
- organelle in the head of sperm
- contains digestive enzymes that helps sperms 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 _____________ which in turn drain into ____________.
efferent ductules
epididymis
Epididymis came from what embryonic structure?
mesonephric duct
What else is a derivative of the mesonephric duct?
vas/ductus deferens
The tail of the epididymis dilates (expands) into _____________.
ductus deferens
The ductus deferens passes up spermatic cord and into the body through what canal?
inguinal
As each duct passes behind (dorsal to) bladder, it has appended to it a gland called the…
seminal vesicle
Just prior to attachment of the seminal vesicle, the ductus deferens enlarges into a(n)…
ampulla
Where is the sperm held right before ejaculation?
ampulla
Fluid from seminal vesicle lubricates path, provides energy-rich nutrients for sperm, and does what else?
secretes are slightly alkaline, so they neutralize slight acidic environment of vagina
Prostaglandins:
-promote uterine contractions to help facilitate sperm movement up uterus into fallopian tubes.
What do fibrinogens do?
form a temporary clot in the vagina
Once beyond the seminal vesicle, it is referred to as what?
ejaculatory duct
The ejaculatory ducts are paired structures that empty into the…
prostatic urethra
Within the prostate gland in the male, what comes together to join the urethra?
ejaculatory ducts
Prostate secretions:
prostatic fluid
- clotting enzyme
- profibrinolysin
The clotting enzyme activates what?
the fibrinogen and convert it to fibrin
What type of tissue is in the prostate?
connective tissue
glandular tissue
smooth muscle tissue
What dissolves the temporary clot?
profibrinolysin
What do the bulbourethral glands do?
lubricates pathway through urethra
secretes alkaline mucus that neutralizes acidity along urethra
Erection is what kind of innervation?
parasympathetic function
S2, S3, S4
Erection is stimulated by what kind of stimuli?
Conveyed via what nerve?
sensory
pudendal
Conscious thoughts (cerebral cortex) can either stimulate or inhibit erection center where?
in hypothalamus
Ejaculation is what kind of function?
sympathetic function
Sympathetic fibers innervate smooth muscle of what?
ductus deferens
”..Point and Shoot..”
Point = erection = parasympathetic Shoot = ejaculation = sympathetic
Ejaculation produces what kind of contractions?
peristaltic
Peristalsis propels sperm and seminal fluid out of what?
distal end of urethra
Gonadotropin Releasing Hormone (GnRH):
(hypothalamus)
stimulates secretion of Follice Stimulating Hormone (FSH) and Luteinizing Hormone (LH) from anterior pituitary
Hormone regulation in males
Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH):
(anterior pituitary)
responsible for stimulating spermatogenesis and testosterone production and secretion
Hormone regulation in males
Testosterone:
- stimulates development of male sex organs, as well as secondary sexual characteristics
- participates in feedback loop involving GnRH
- also inhibits secretion of LH
Hormone regulation in males
Inhibin:
- secreted by sustentacular cells in response to sperm production
- inhibits secretion of FSH
