The Male Reproductive System

Testes

Male gonad that has both an exo and endocrine function of producing sperm cells and testosterone respectively

Scrotum

What protects the testes and keeps testes coller for optimal sperm production at 35 C or 95 F

7th month

What month do the testes drop into the scrotum

Cremaster and Dartos Mm

What muscles regulate testicular movement?

Countercurrent Heat Exchange Mechanism

The testicular artery carries arterial blood that cools as it descends and the ascending testicular vein carries venous blood away heats as it ascends back to the pelvic cavity

Tunica Vaginalis

External testes covering

Tunica Albuginea

Internal testes covering

Seminiferous tubules

Sperm production site with around 250 pyramidal shaped lobules each containing 1-4 highly convoluted tubules located in the testes

Spermatic Cord

What suspends the testes within the scrotum and contains blood vessels, lymphatic, sensor and motor autonomic nerves, ductus deferens, and smooth muscle

Gubernaculum

A tough, fibrous tissue that anchors the testes to the scrotum

Tubuli Recti

Short, straight tubules that come off of the seminiferous tubules

Rete Testis

Network of tubular spaces on posterior testes that come off of the tubuli recti

Efferent Ductules

Connect rete testis to the head of the epididymis

Epididymis

Very long, high coiled tube about 1.5 inches in length after coiling that is the location of sperm maturation and storage and lined with columnar epithelia possessing stereocilia on apical surface

4-6 meters

How long is the epididymis?

70-90 days

How long does sperm production take?

Ductus Deferens

Located within spermatic cord and carries sperm out of testes into pelvic cavity and empties into the ampulla

Ampulla

Thickened portion posterior to the urinary bladder that the ductus deferens empties into

Ejaculatory Duct

Runs through the prostate gland and location of where semen is made, sperm combines here with secretions from seminal and prostate glands

Urethra

Conduit for both urine and semen

Prostatic Urethra

Urethral segment that runs through the prostate gland and lined with transitional to pseudostratified columnar epithelium

Membranous Urethra

Very short urethral segment that runs from from prostate gland to body wall and lined with pseudostratified columnar to stratified columnar epithelium

Penile Urethra

Urethral segment that runs through the penis and lined with stratified columnar to stratified squamous epithelium

Seminal Gland

Paired gland that secretes a viscous alkaline fluid containing sodium bicarbonate to neutralize acidic environment of the vagina and a 2-3 day supply of fructose to nourish sperm cells

70%

How much of the seminary secretion contributes to the volume of ejaculate

Prostate Gland

Secretes a milk fluid used to activate sperm (triggers sperm motility) and contributes to 25% of the volume of ejaculate

Enlarges over time starting as early as 30 and typically doesn’t cause urinary or ejaculation problems until 60

Bulbourethral (Cowper’s) Gland

A paired gland that secretes alkaline mucus to neutralize acidic environment of penile urethra and contributes 4% to the volume of ejaculate

Precum

This secretion from the bulbourethral gland is sometimes referred to as what

Penile Root

Anchors penis in pelvis and consists of the crura from the corpora cavernosa and the bulb from the corpus spongiosum

Penile Shaft

Contains cylindrically shaped erectile tissue running entire penial length that contain vascular spaces called lacunae that become engorged with blood during erection

Corpora Cavernosa

Erectile tissue on the dorsal side of the penis

Corpus Spongiosum

Erectile tissue on the ventral side of the penis

Glans Penis

Head of the penis

Prepuce

Foreskin that protects glans penis, often removed at birth (circumcision)

Follicle Stimulating Hormone (FSH)

From the adenohypophysis and stimulates sperm cells (spermatozoa) within the seminiferous tubules of the testes to develop

Interstitial Cell Stimulating Hormone (ICSH)

From the adenohypophysis that stimulates the IECs of the testes to produce testosterone

Intraparenchymal Epididymal Cysts (IECs)

Benign cystic formations of the epididymis of unknown patho-geneis

Androstenedione and Dehydroepiandrosterone (DHEA)

Androgens from the adrenal cortex, specifically zona reticularis that stimulate the production and release of testosterone from the testes

Gonadocorticoids

Testosterone

From the Intraparenchymal Epididymal Cysts (IECs) and are the strongest of all androgens that are responsible for the secondary sex characteristics in males

Secondary Sex Characteristics

Lengthening of the penis, enlargement of scrotum, growth of body hair, thicker and coarser skin, acne, deepening of voice, increase in muscle strength, broadening of chest and shoulders, rapid growth, and fat deposits around abdomen and waist (apple shaped)

Excitement Sexual Response

Mental, visual, olfatory, auditory, and tactile stimuli cause erectile tissues to engorge with blood and penis becomes erect, bulbourethral glands secrete precum

Plateau Sexual Response

Elevation of respiratory rate, heart rate, blood pressure, and muscle tension

Orgasm Sexual Response

Release of semen, feeling of great release of muscle and body tension

Emission

Release of sperm into urethra

Expulsion

Release of semen from urethral orifice

Resolution Sexual Response

Arteries constrict and reduce blood flow into penis, blood empties from erectile tissues and penis becomes flaccid

Respiratory rate, heart rate, and blood pressure returns to normal