34/35. Male Reproductive System

Question 1

Gender

Answer 1

How an individual identifies
May not align with sex

Question 2

Chromosomal sex

Answer 2

XX or XY chromosomes or some other combination

Question 3

Phenotypic sex

Answer 3

Appearance of genitalia

Question 4

Characteristics of biological sex and gender

Answer 4

We are conditioned to view sex and gender as binary constructs
Sex does not equal gender
Both sex and gender occur on a spectrum

Question 5

What does intersex mean

Answer 5

Various combinations in which a person is born with a reproductive or sexual anatomy that doesn’t fit the typical definitions of female or male
About 1/100 births

Question 6

Types of Male reproductive structures

Answer 6

Include primary and secondary sex organs

Question 7

Primary male sex organs

Answer 7

Testes - produce sperm

Question 8

Secondary male sex organs

Answer 8

Epididymis
Vas deferens
Seminal vesicles
Prostate gland
Bulbourethral gland

Question 9

Characteristics of scrotum

Answer 9

Pouch that holds testes
Responds to external temperature
Consists of dartos muscle (smooth muscle) that creates wrinkles on skin to regulate surface area and heat loss

Question 10

Tunica of the testes

Answer 10

Tunica vaginalis and tunica albuginea

Question 11

Structure/function of tunica vaginalis

Answer 11

Serous sac covering testis (from peritoneum)

Question 12

Structure/function of tunica albuginea

Answer 12

Fibrous capsule of testis
Invaginates to create lobules composed of coiled seminiferous tubules
Location of sperm production

Question 13

Pathway of sperm in the testes

Answer 13

Produced in the seminiferous tubules
Carried into the epididymis
Then enters vas deferens

Question 14

Characteristics of the epididymis

Answer 14

Contains highly coiled duct
Sperm becomes fully mature, become motile
Takes bout 20 days
Sperm is ejaculated from epididymis
Sperm CN be stored for several months and then are phagocytized if not released

Question 15

Characteristics of the spermatic cord

Answer 15

Tube of fascia containing structures from the abdomen to scrotum
Structures leave abdomen, travel through the inguinal canal to enter the spermatic cord
Includes cremaster muscle

Question 16

Characteristics of cremaster muscle in spermatic cord

Answer 16

Skeletal muscle continuation from internal oblique
Elevate and lower testes to regulate temperature of testes

Question 17

Blood supply and sperm transportation of spermatic cord

Answer 17

Testicular (gonadal) artery is blood supply to testes
Pampiniform plexus is testicular veins that branch out and surround testicular artery to cool blood supply to testes
Vas deferens is a muscular tube that transports sperm during ejaculation to the prostate

Question 18

Characteristics of the testicular vein and artery

Answer 18

Testicular (gonadal) artery ordinates in abdominal aorta
Testicular (gonadal) vein merges with the left renal vein on the left side and the IVC on the right side
Both artery and vein travel through inguinal canal to enter spermatic cord
Testicular vein branches to form pampiniform plexus

Question 19

Descent of the testes

Answer 19

Body is too hot to produce viable sperm, testes descend into scrotum where it’s 5 degrees cooler
Gubernaculum guides testes descent through inguinal canal into scrotum

Question 20

What is an inguinal hernia

Answer 20

Increasing intraabdominal pressure pushes intestines through weak areas of the abdominal wall and into the inguinal canal & scrotum
Can cut off blood supply to intestine causing death of tissue
More common in males due to descent of testes in inguinal canal
Abdominal wall often repaired with mesh patch

Question 21

What is a vasectomy

Answer 21

Method of birth control
Surgical procedure cut and seal the vas deferens
Sperm are produced but can no longer exist the body, broken down in epididymis
Reversal is possible but not always successful

Question 22

Characteristics of the vas deferens

Answer 22

Vas deferens enters pelvic cavity through inguinal canal
Vas deferens joined by seminal vessicle to create ejaculatory duct within prostate gland

Question 23

Characteristics of the seminal vesicles

Answer 23

Located behind bladder
Release into semen:
Fructose- energy supply for sperm cells
Prostaglandins- promote dilation of cervical canal and contraction of uterus
Bicarbonate- buffers acidic environment

Question 24

Characteristics of prosthetic gland

Answer 24

Prostate gland located inferior to bladder
Ejaculatory duct joins the urethra within the prostate gland
Prostate gland releases into semen:
Seminalplasmin-antibiotic to combat urinary tract infections
Prostate specific antigen (PSA)- liquefies semen after ejaculation

Question 25

What is prostate cancer?

Answer 25

Most common malignancy in men >50 yrs
Early states are generally asymptomatic
Can metastasize to other parts of body if untreated
Digital rectal exam performed by physicians to feel for bumps or hard spots on prostate

Question 26

Characteristics of the urethra and its specific regions

Answer 26

Carries urine and seminal fluid (semen) to exit the penis
Has specific regions:
Prostatic urethra- through prostate, joined by ejaculatory ducts
Penile (spongy) urethra- through penis

Question 27

Characteristics of the bulbourethral gland

Answer 27

Produces mucus-like substance that conditions penile urethra before ejaculation
Neutralizes acidic urine and lubricates urethra

Question 28

Characteristics of the penis and tissue

Answer 28

Copulatory organ in chromosomal males
Comprised of highly vascularized erectile tissue with a substantial blood supply that becomes engorged with blood during sexual arousal
2 sets of erectile tissue:
Bulb of penis extends as corpus spongiosum
Crura extend and dime together as corpora cavernosa

Question 29

Structures of penis

Answer 29

Root of penis- attached part not visible
Body of penis- free external portion
Glans- enlarged distal end
Foreskin (prepuce)- cuff of skin surrounding glands
External urethral orifice- end of urethra

Question 30

Formation of the penile structures

Answer 30

Bulb and crura form root of penis below pubic symphysis
Corpus spongiosum and corpora cavernosa form body of penis
Corpus spongiosum expands distally to form the glans
Penile urethra travels through corpus spongiosum

Question 31

Muscles of the penis

Answer 31

Bulbospongiosus muscle- sheet of muscle covering bulb of penis
Ischiocavernosus muscle- sheet of muscle covering each crus of penis
Muscles assist with erection and expulsion of fluid from urethra

Question 32

What is penile circumcision?

Answer 32

Surgical procedure to remove foreskin of penis
Common in some countries but less world wide
Benefits: reduced risk of UTI as infant
Drawbacks: possible loss of sensation and lack of consent for procedure

Question 33

Blood supply to penis

Answer 33

Internal iliac artery gives off a branch, internal pudendal artery, that leaves pelvis and travels to external genitalia to supply blood to erectile tissues
Internal pudendal artery gives rise to dorsal and deep arteries of the penis

Question 34

Innervation of the penis

Answer 34

Pudendal nerve originates from sacral spinal cord segments
Leaves pelvis and runs underneath pelvic floor towards penis
Gives off many branches, one branch is the dorsal nerve of the penis which Carrie’s general sensation from the penis
Sympathetics and parasympathetics to the erectile tissues arise from the inferior hypogastric plexus

Question 35

What occurs during erection in the Sexual response function

Answer 35

Erection of penis:
parasympathetics dilate arteries increasing blood flow to tissues
muscles relax allowing tissue to expand
constriction of veins by tissue slows blood drainage

Question 36

What occurs during ejaculation in the sexual response function

Answer 36

Sympathetics cause strong contraction of smooth muscles throughout reproductive ducts and glands
Constrict internal urethral sphincter to prevent semen from entering bladder
Rapid contraction of bulbospongiosus muscle pushes semen through urethra and out

Question 37

Characteristics of spermatogenesis

Answer 37

Formation of sperm
Spermatogonia differentiate into sperm, takes ~75 days
Occurs in seminiferous tubules of testes
Produce 400 million sperm daily
Starts at puberty til death
Broke into 3 stages: formation of spermocytes, meiosis, and spermatogenesis

Question 38

Step 1 of spermatogenesis

Answer 38

Formation of spermocytes
Spermatogonia (stem cells) located in outer region of seminiferous tubules
Spermatogonia undergo continuous mitosis that results in 2 daughter cells:
Type A- remain in outer region to maintain germ cell line
Type B- move toward lumen as primary spermocyte

Question 39

Step 2 of spermatogenesis

Answer 39

Meiosis
Process of 2 subsequent divisions where diploid cell ends with 4 haploid cells
Meiosis 1- primary spermatocyte divides into 2 secondary spermatocyes
Meiosis 2- secondary spermatocytes divide into haploid spermatids

Question 40

Step 3 of spermatogenesis

Answer 40

Spermatids go through a process to differentiate into sperm
Sperm have 3 parts:
Head with nucleus
Midpiece with mitochondria to produce energy for tail
Tail- flagellum that propels
Sperm detached from epithelium of seminiferous tubule and enters lumen