Male Reproductive System
Septum
#3!
Bulbourethral glands
-->secrete a fluid prior to ejaculation that neutralizes acidity of the urethra and clears out urine
Seminal vesicles
-->secrete fluids that make up most of the volume of semen ~fructose for sperm nutrition ~prostaglandins (cause uterine contractions to move sperm toward egg) ~enzymes (to neutralize acidity of vagina)
Prostrate gland function
-->surrounds urethra and has multiple ducts ~secretes fluids that make up about 1/3 of semen *enzyme that make semen sticky *enzyme that liquifies semen so sperm can be released from it
What is the function of the epididymis?
-sperm are transported here where they are matured/stored *gain the ability to swim and fertilize the egg (acrosome reaction) -->these processes are stimulated by proteins secreted by the epididymis epithelium
What is the function of the vas deferens?
-stores/transports sperm during ejaculation *propels sperm by peristaltic action
What are two structures that assist with temp. regulation in the testes and what are their functions?
1. pampiniform plexus-->helps dissipate heat 2. cremaster muscle-->draws testes closer to the body in cold temps.
What is the route of sperm?
1. testes (sperm development only) 2. epididymis (maturation/storage) 3. vas deferens 4. ejaculatory ducts 5. urethra a)prostatic b)membranous c)spongy/penile
What is the main function of Sertoli cells? (a.k.a., What is the relationship of Sertoli cells, spermatogenesis, and the immune system?)
Create the blood-testes barrier, an immune suppressive region, with their very tight junction
What supporting cells are extremely important for proper sperm development?
Sertoli and Leydig cells
What are additional functions of Sertoli cells?
a) supply nutrients for developing sperm (spermatogenic cells) b) phagocytize cytoplasm of spermatids c) actively move spermatogenic cells toward the tubule lumen
What is the function of androgen-binding protein (ABP)?
accumulates testosterone in the seminiferous tubules *so, Testosterone+ABP-->stimulate spermatogenesis
What happens to sperm that are not ejaculated?
after several months of storage, they are phagocytized by the epithelial cells of the duct of the epididymis
How does erectile tissue permit the penis to become erect?
an erection results from the engorgement of erectile bodies with blood; this presses on small veins which slows venous drainage and maintains engorgement -->strengthened by collagen fibers in the dense connective tissue ~also restricts expansion of erectile tissue/drainage of blood
What can happen if the inguinal canal does not seal off after descent of the testis?
an inguinal hernia can occur (caused by increased intra-abdominal pressure)
What happens to the testes @7 months?
blood vessels/vas deferens are pulled through
What hormone targets the Leydig cells?
controlled by lutenizing hormone (LH) from the anterior pituitary -->stimulates leydig cells to secrete testosterone
What is erectile tissue?
erectile tissue is made up of 3 erectile bodies ~each is covered by a sheath of dense connective tissue filled with network of partitions that consist of smooth muscle/connective tissue filled with vascular spaces
Tunica albuginea
fibrous capsule surrounding the testes
Which tissue is removed during circumcision?
foreskin
Spermatic cord
formed by the abdominal wall layers as the testes descend
What are the testes guided by as they descend?
gubernaculum
Why is the internal urethral sphincter so important?
it prevents back flow of semen into bladder during ejaculation
Where are the Leydig cells located?
located in the loose connective-tissue between the seminiferous tubules
What is the function of Leydig cells?
make/secrete androgens (sex hormones), mainly testosterone *maintains male secondary sex characteristics/organs *also, involved in the initiation of spermatogenesis
Corpus spongiosum
midventral erectile body (surrounds spongy urethra)
Corpus cavernosum
paired, dorsal erectile bodies
Erection is governed by...(part of the ANS)
parasympathetic (pelvic splanchnics) [dilates arteries/relaxes muscle]
What is the function of accessory glands in the male reproductive system?
secrete fluids to assist sperm transport
What two structures join to form the ejaculatory ducts?
seminal gland+vas deferens
What are the 3 accessory glands?
seminal vesicles, prostrate gland, bulbourethral glands
Ejaculation is governed by...(part of the ANS)
somatomotor
Semen
sperm plus the secretions of the accessory glands/ducts
What step of spermatogenesis produces mature sperm?
spermiogenesis
What is the body of the penis suspended by?
suspensory ligament
Emission is governed by...(part of the ANS)
sympathetic (splanchnics)
Why is it necessary for the testes to lie outside of the abdominal cavity?
temp reg. is necessary because sperm production requires a temp of 95 degrees (below reg. body temp)
Where do the testes develop? Do they stay there?
testes develop on the posterior body wall but then they descend to the scrotum
What happens to the testes @3 months?
testes/part of the peritoneum travel throughout the anterior abdominal wall
What hormone targets Sertoli cells and what is its effect?
the follicle stimulating hormone (FSH) from the anterior pituitary stimulates the Sertoli cells -->causes them to secret androgen-binding protein (ABP)
Where do sperm develop?
the seminiferous tubules
Tunica vaginalis
the testes are encased in this serous sac
What is the relationship among the tunica albuginea, septa, and seminiferous tubules of the testes?
the tunica albugenia is a fibrous capsule which sends connective tissue, the fibrous septa which divide the lobules of the seminiferous tubules
Why must developing sperm be protected by the blood-testes barrier?
they are haploid cells (contain only half the number of chromosomes in a normal cell), so they are recognized as non-self
Where are Sertoli cells located?
they surround the spermatogenic cells -->extend from the basal lamina to the lumen of the seminiferous tubules
What happens to the testes @birth?
tunica vaginalis separates from peritoneum
Inguinal canal
tunnel created through the abdominal wall by the descent of the testes
What are the stages of spermatogenesis?
{see course packet } 1. formation of spermatocytes -spermatogonia divide *type A daughter cells stay to continue mitosis *type B daughter cells become primary spermatocytes 2. meiosis -genetic recombination (2n-->n) *primary spermatocytes-->secondary spermatocytes--> speratids 3. spermiogenesis -spermatids-->sperm ~basically, rearranging contents of the cell
Penis
{use your imagination}
If the prostate gland were enlarged, what symptoms would a patient have? What is the clinical term for this?
~benign prostatic hyperplasia compressed prostatic urethra causes difficulty urinating, urine retention, constant leaking, UTIs, and formation of kidney stones
