Primary Sex Organs
-gonads in males
-ovaries in females
-produce sex cells
-secrete sex hormones
Accessory Reproductive Organs
-ducts, glands, and external genitalia
What is the male reproductive role?
-make male gametes (sperm) and deliver them to the female reproductive tract so fertilization can occur
What is the female reproductive role?
-produce female gametes
-ova or eggs
What are the sex hormones in males?
What are the sex hormones in females?
-estrogens and progesterone
What is process of arousal controlled by?
-lie w/in the scrotum
Pathway of sperm to the outside of the body
What accessory sex glands empty their secretions into ducts during ejaculation?
-sac of skin and superficial fascia that hangs outside the abdominopelvic cavity
-septum divides testes so they have their own compartment
Why is it good that the scrotum is outside the body?
-viable sperm cannot be produced at body temp., the location causes the location 3 degrees lower
What happens to the scrotum when it is cold?
-testes are pulled closer to body wall for warmth
-becomes shorter and wrinkly
-decrease surface area and increase thickness
What happens to the scrotum when it is warm?
-skin is flaccid and loose to increase surface area for cooling (sweating)
-testes hang lower
-smooth muscle that wrinkles the scrotal skin
-bands of skeletal muscle that elevate the testes
What are the 2 tunics that surround the testes?
1. tunica vaginalis
2. tunica albuginea
-similar to peritoneum
-fibrous capsule of the testes
-divide testes into 250 lobules which contained seminiferous tubules
-surrounded by myoid cells
-thick stratified epithelium
-contains spermatogenic cells
-form straight tubules
-sperm forming cells
-supporting cells that help sperm formation
-contract rhythmically, helping squeeze sperm and testicular fluids thru tubules out of the testes
-conveys sperm into the rete testis
-tubular network on the posterior side of the testes
What happens after sperm leaves the rete testis?
-leave thru the efferent ductules and enter epididymis
-sperm passes thru the head, body, and move into the tail of epididymis where they are stored until ejaculation
Interstitial Endocrine Cells
-produce androgen (testosterone)
-secrete androgens in the surrounding interstitial fluid
-supply the testes
-drain the testes
-arise from the pampiniform venous plexus
Pampiniform Venous Plexus
-surrounds the portion of each testicular artery within the scrotum like a vine
-cooler venous blood in here absorbs heat from the arterial blood cooling it before it enters the testes
-help keep testes at their cool homeostatic temperature
-a connective tissue sheath encloses nerve fibers, blood vessels, and lymphatic
-pass thru inguinal canal
-most common cancer in young men in ages 15 to 35
-increase risks are mumps, orchitis, and exposure to toxins before birth
-painless solid mass
-inflammation of the testes
-nondescent of the testes
-testes actually form in the body and then descend and find their way to the scrotum
-around the anus
-suspends scrotum and contains the root of the penis and the anius
-diamond shaped region between pubic symphysis, coccyx, and ischial tuberosities
-designed to deliver sperm into the female reproductive tract
-penis and scrotum make up the external genitalia
-an attached root and a free body or shaft that ends in an enlarged tip
-cuff formed when the skin slides distally
-reduces risks of HIV and other reproductive system infections
-foreskin is surgically removed
-spongy network of connective tissue and smooth muscle (vascular spaces)
-during sexual excitement, these fill with blood causing the penis to become rigid and enlarged (erection)
-form the glands and bulb of the penis
-make up most of the penis
-bounds by fibrous tunica albuginea
-ends form crura of the penis
-produces sterilization when you don't want children anymore
-snip scrotum, snip the vas deferens before it goes through the canal which causes sperm to never travel and mature
-can still have erection
Epididymis Head, Body, and Tail
-head contains efferent ductules and cap superior part of testes
-body and tail are on the posterolateral area of the testis
Duct of the Epididymis
-pseudostratified epithelial cells
-allows them to absorb testicular fluid and to pass nutrients to the sperm
How are sperm ejaculated?
-smooth muscle of the duct of epididymis contracts, expelling sperm into the ductus deferens
Can sperm be stored in the epididymis for several months?
-yes, but if they are held longer, epithelial cells will phagocytize them
-sperm are continuously generated
-runs upwards as part of the spermatic cord from the epididymis thru the inguinal canal into the pelvic cavity
-runs up from the bladder to form the ampulla to join the seminal vesicle and form the ejaculatory duct
-enters prostate and empties into the urethra
What happens in the ductus deferens during ejaculation?
-smooth walls create peristaltic waves that squeeze sperm forward along the tract and into the urethra
-conveys both urine and semen
Seminal Glands (Seminal Vesicles)
-pouched, coiled, and foiled back on itself
-fibrous capsule encloses a thick layer of smooth muscle that contracts during ejaculation to empty the gland
Seminal Gland Mucosa
-contains crypts that have a yellowish alkaline fluid containing fructose sutra, citric acid, a coagulating enzyme (vesiculase) and other prostaglandins that enhance sperm motility or fertilizing ability
-join ductus deferens
-sperm and seminal fluid mix together
-contains a stroma of smooth muscle and dense connective tissue
-during ejaculation, smooth muscle contracts, squeezing prostatic secretion into the prostatic urethra
-activates sperm and
What does the prostate gland produce?
-a milky, slightly acidic fluid that contains citrate, several enzymes and acid and prostate specific antigen
-breaks down clotted ejaculation
-benign prostatic hyperplasia
-strain to urinate
-enhances risks of bladder infection and kidney damage
-elevated levels of PSA can indicate this
-produce a thick, clear mucus, and lubricates the glans penis when a man becomes sexually excited
-mucus neutralizes traces of acidic urine and lubricates urethra prior to ejaculation
-milky, white, somewhat sticky mixture of sperm, testicular fluid, and accessory gland secretions
-transport medium and nutrients
-contain chemicals that protect and activate sperm and facilitate movement
What does semen contain?
-ATP which provides energy
-suppressant of the immune response
-antibiotic chemicals destroy bacteria
Prostaglandins in Semen
-decrease viscosity of mucus guarding the cervix of the uterus
-stimulate reverse peristalsis in the uterus
-facilitate sperm movement thru the female reproductive tract
-enhance sperm motility
-causes sperm to stick to the walls of the vagina and prevents the immobile sperm from draining out of the vagina
What does alkalinity do the semen?
-helps neutralize the acid environment of the males urethra and the females vagina
-protecting sperm and enhancing motility
-antibiotic chemical that destroys certain bacteria and other factors that reduce immune response in female tract
How much sperm is released in 2-5ml?
-20 to 150 million sperm per ml
-enlargement and stiffening of the penis from engorgement of the erectile bodies with blood
What does sexual excitement trigger?
-a parasympathetic reflex that promotes the release of nitric oxide
-NO relaxes smooth muscle, dilating arterioles and the erectile bodies fill with blood
-corpus cavernosa compresses drainage veins, maintaing engorgement
-spongiosum keep urethra open during ejaculation
What can stimulate an erection?
-touch, mechanical stimulation, erotic sights, sounds, and smells
-emotional or higher mental activity
How does alcohol inhibit an erection?
-prevents blood flow to penis so the drainage veins don't collapse
-inability to attain an erection
-propulsion of semen from the male duct system
-spinal reflex is initiated and massive discharge of nerve impulses occurs over the sympathetic nerves
What happens to bladder sphincter muscle during ejaculation?
-constricts, preventing expulsion of urine or reflux of semen into the bladder
What happens to the reproductive ducts and accessory glands during ejaculation?
-contract, emptying their contents into the urethra
What happens to the bulbospongiosus muscles of the penis during ejaculation?
-rapid series of contractions
-propel semen from urethra
-contractions are accompanied by intense pleasure
-muscle contraction, rapid heartbeat, and elevated BP
-entire ejaculatory event
-a period of muscular and psychological relaxation
-a latent or refractory period (minutes to hours) during which a man is unable to achieve another orgasm
-latent period increases with age
-the inability to attain an erection
-parasympathetic nerves serving the penis do not release enough NO
-reduce systemic blood pressure
-sequence of events in the seminiferous tubules of the testes that produce sperm (spermatozoa)
How many chromosomes are contributed by each father?
-divide the seminiferous tubules into the basal compartment and the adluminal compartment
-earliest primary spermatocytes
-meiotically active cells and the tubule lumen
Blood Testis Barrier
-tight junctions between sustentocytes
-prevents the membrane antigen of sperm from escaping thru the lamina into the bloodstream where they would activate the immune system
Thymus and Sperm
-sperm doesn't activate until 14, so the thymus education doesn't exist for them
How do the spermatogonia recognize themselves as 'self'?
-outside the barrier and can be influenced by bloodborne chemical messengers that promote spermatogenesis
Is the blood pressure different in the male reproductive system?
-it is 2 times higher than the rest of the circulation
Hypothalamic Pituitary Gonadal Axis (HPG)
-regulate the production of gametes and sex hormones
-under CNS control
1st of HPG
-hypothalamus release gonadotropin-releasing hormone (GnRH)
-this controls the release of the two anterior pituitary gonadotropins (FSH) & (LH)
2nd of HPG
-GnRH binds to pituitary cells making them secrete FSH & LH into blood
3rd of HPG
-FSH stimulates spermatogenesis by causing the sustentocytes to release androgen binding protein (ABP)
-FSH enhances testosterones stimulatory effects
-keeps testosterone in the vicinity of the spermatogenic cells high, stimulating spermatogenesis
4th of HPG
-LH binds to endocrine cells surrounding the seminiferous tubules
-stimulates them to secrete testosterone
-rising testosterone trigger spermatogenesis
5th of HPG
-testosterone stimulates maturation of sex organs, development and maintenance of secondary and libido
6th of HPG
-rising levels of testosterone inhibit hypothalamus release of GnRH and inhibit gonadotropin release
7th of HPG
-inhibin is a barometer for of the normalcy of the spermatogenesis
-when sperm count is high, more inhibin is released, inhibiting FSH and GnRH
-when sperm count falls, inhibit secretion declines
-indirectly stimulates the testes by its effect on FSH and LH release
-the more GnRH released, the testes secrete more testosterone, but hypothalamic inhibition keeps rising until hormone interaction is achieved
-(mature sperm in the semen)
FSH & LH
-directly stimulate testes
Testosterone and Inhibin
-exert negative feedback controls on the hypothalamus and anterior pituitary
What happens in the absence of GnRH and gonadotropins?
-testes atrophy and sperm and testosterone cease
-synthesized from cholesterol and exerts its effects by activating specific genes which enhances synthesis of certain proteins in the target cells
-can be converted to estradiol
-converted in the prostate
-converted before it can bind in the nucleus
-female sex hormone that brings about its stimulatory effects
Male Secondary Sex Characteristics
-pubic, axillary and facial hair
-skin thickens and becomes oiler
-somatic effects of testosterone (basics of male libido)
-testicles can be pulled up back into the wall
How can laptops affect sperm?
-put them on top of the scrotum and gets very hot
-guys should use a temperature controller to stop the heat from penetrating the sperm because it can mutate sperm