06/16/2023 Notes Flashcards
What is the primary gonad in males?
Testes
What is the male organ of copulation?
Penis
What is the ideal temperature for storing and producing sperm?
In the scrotum where the temperature is roughly 3 degrees celsius cooler
What divides the scrotum into two longitudinal compartments?
The fibrous scrotal septum
What does the scrotal septum do?
Limit trauma/infection to one testis instead of allowing it to affect both
What is the scrotum homologous to in females?
Labia majora
What is the distinct, ridgelike seam at the midline of the scrotum called?
Raphe
What does the wall of the scrotum consist of?
External layer of skin, thin layer of superficia fascia, and a layer of smooth muscle internal to the fascia
What is the layer of smooth muscle in the scrotum called?
Dartos muscle
What does the dartos muscle do?
Relax/contract to move the scrotum further from/closer to the body to regulate the temperature
What does the cremaster muscle do?
Work with the dartos to aid in moving the scrotum and testes closer/further to the body
What is the spermatic cord?
Blood vessels and nerves that travel to the testes within the abdomen to the scrotum
Where does the spermatic cord originate?
Inguinal canal
What are the 3 layers of the spermatic cord?
Internal spermatic fascia, cremaster muscle/fascia, and external spermatic fascia
What does the internal spermatic fascia allow the passage of?
Ductus deferens
What is an extension of the internal oblique that allows voluntary contraction?
Cremaster muscle/fascia
What artery is found within the spermatic cord and is a direct branch of the abdominal aorta?
Testicular artery
What is the plexus of veins that surround the testicular artery called?
Pampiniform plexus
What does the paminiform plexus do?
Pre-cools arterial blood prior to entering testes
What are the testes?
Small, oval organs housed in the scrotum responsible for producing sperm and androgens
Which testis hangs lower in a normal person?
Left testis
What is the male sex hormone?
Androgens
What covers each testis anteriorly and laterally?
Serous membrane called “tunica vaginalis”
Approximately how many lobules are present in each testes?
250
Each lobule contains up to 4 convoluted, thin, elongated _____.
Seminiferous tubules
What 2 cells can be found in seminiferous tubules?
Sustentacular cells (sertoli cells/nurse cells) and Germ cells
What do sustentacular cells do?
Assist with sperm development, provide a protective environment for developing sperm cells, and nourishes developing sperm
Where are sertoli cells found?
Within seminiferous tubules
What does the blood-testis barrier do?
Protect developing sperm from materials in blood stream and leukocytes
Germ cells continuously produce _____ cells in the adult male
sperm
What cell produces androgens?
Interstitial cells
What is the most common androgen?
Testosterone
What do androgens do to the body?
Develop axillary and pubic hair, deeper voice, sperm production, sex drive
Where does the testicular artery supply blood to?
Testes
Where does the right gonadal vein drain into?
Inferior vena cava
Where does the left gonadal vein drain into?
Left renal vein
What is the inflammation of a testis called, and how does that occur?
Orchitis may occur from mumps
Where does sperm that initially develops in the seminiferous tubule/ducts reside to fully mature?
Epididymis
Each testis has a set of ducts that do what?
Store and transport sperm as they mature and pass out of the male body
What is the “rete testis”?
Meshwork of interconnected channels that receive sperm from the seminiferous tubules
What are efferent ductules?
connect the rete testis to the epididymis
What does ciliated epithelia do in the efferent ductules?
Propel sperm to epididymis
What does nonciliated epithelium do in the efferent ductules?
Absorb excess fluid produced by seminiferous tubules
What is the epididymis?
A comma-shaped structure composed of an internal duct and external covering of connective tissue that stores sperm until they are fully mature and capable of being motile
How long is the “duct of the epididymis”?
4-5 m (14 ft)
What happens to sperm if they are not expelled in a timely manner?
Old sperm degenerates and are reabsorbed in the epididymis
Where does sperm enter when it leads the epididymis?
Ductus deferens
Where does the ductus deferens travel?
From the epididymis through the spermatic cord, inguinal canal, within the pelvic cavity, before it nears the prostate gland
What are the 3 layers of the ductus deferens?
Mucosa, muscularis, and adventitia
Why is the muscularis important in the ductus deferens?
Contains several layers of smooth muscle that contract to move sperm cells since they do not exhibit motility until they are ejaculated
what does the ductus deferens form as it approaches the superoposterior edge of the prostate gland?
Ampulla, enlarged portion of the ductus deferens
The ampulla unites with the proximal region of the seminal vesicle to form what?
Terminal portion of the reproductive duct system known as the Ejaculatory Duct
What does the ejaculatory duct do?
Conducts sperm from the ductus deferens and a component of seminal fluid toward the urethra
What does the urethra do?
Transport semen from both ejaculatory ducts outside the body
What are the 3 parts of the urethra?
Prostatic urethra, membranous urethra, and spongy urethra
Since the vagina is a highly acidic environment, what is secreted to help protect sperm?
an alkaline secretion known as seminal fluid that neutralizes the acidity of the vagina
How long does it take sperm to travel to the oocyte?
A few hours to a few days
What 3 glands produce seminal fluid?
Seminal vesicles, prostate glands, and bulbourethral (cowper’s) glands
What is the seminal vesicle?
Paired, elongated, hollow gland that is 2-3 inches long found posterior to the bladder adjacent to the ampulla that produces a whitish/yellow fluid containing fructose and prostagladins
What does prostagladins do?
Promote widening and slight dilation of the external os of the cervix which facilitates sperm entry into uterus
What does fructose do?
Provide energy for sperm
What is the size and shape of the prostate gland similar to?
Walnut
The prostate glands produce a thin, milky-colored, weakly acidic secretion that contains what?
Citric acid, seminalplasmin, and prostatic-specific antigens (PSA)
Why is citric acid important?
Used as a nutrient for sperm health
What does seminalplasmin do?
Carry an antibiotic that fights UTI
What does prostatic-specific antigens do?
Liquify semem following ejaculation
What does the bulbourethral gland secrete?
Clear, vicious mucin that forms mucus to protect the urethra and act as a lubricant during copulation
What fluids make semen?
Seminal fluid that combines with sperm
What is the average volume of semen when ejaculated, and how many spermatozoa are found?
3-5 mL; 200-500 million spermatozoa
How long does it take for sperm to form in the seminiferous tubules, pass through the duct system, and appear in the ejaculate?
2 weeks
Although a sexually active male may have reduced sperm count, what happens to the semen volume?
Semen volume remains close to normal
What are the 2 external genetalia in males?
Penis and scrotum
What is the elongated, movable portion of the penis called?
Body of penis/ shaft of penis
What is the tip of the penis called?
Glans
What is found within the glans?
External urethral orifice
What is the prepuce?
The skin attached to the raised edge of the glans that forms a circular fold at the distal end of the penis
What are the 3 cylindrical erectile bodies in the penis?
2 corpus cavernosa and 1 corpus spongiosum
What is the complex network found in erectile bodies that are surrounded by a central artery?
Venous spaces
What happens to the erectile bodies during sexual excitement?
Blood enters from the central artery to fill the venous space and make the erectile bodies rigid to form an erection
How to erectile bodies remain erect during sexual excitation?
Parasympathetic innervation causes erection, and as the venous spaces fill with blood, they have no way to exit until the excitement ceases
What is ejaculation?
Process by which semen is expelled from the penis with help of rhythmic contraction of the urethra
What division of the ANS is responsible for ejaculation?
Sympathetic
How does parasympathetic and sympathetic innervation work together in the male reproductive system?
Parasympathetic achieves erection while sympathetic causes ejaculation (point and shoot)
