Male Reproductive System

Question 1

Contents of the anal triangle?

Answer 1

anal orifice

Question 2

Contents of the urogenital orifice?

Answer 2

root of the penis and scrotum
&
intermediate and spongy parts of the urethra

Question 3

What makes up the pelvic floor/diaphragm?

Answer 3

Levator ani muscles and coccygeus & the fascial coverings of these muscles

Question 4

What 3 muscles make up the levator ani?

Answer 4

(PPI)
Pubococcygeus
Puborectalis
Iliococcygeus

Question 5

Scrotum:

Answer 5

external outpouching of skin, fascia and muscle containing the testes, epididymides and distal ends of the sprematic cords

Question 6

Scrotum location?

Answer 6

hang posteroinferior to the penis, on the lower abdominal wall

Question 7

Scrotum layers:

SECCIT

Answer 7

• Skin & superficial fascia (containing the dartos mm)
• External spermatic fascia (continuation of EO)
• Cremaster muscle and fascia

Internal spermatic fascia

Tunica vaginalis

Question 8

Scrotum function?

Answer 8

controls temperature of the testes for optimum spermatogenesis

This is done via contraction and relaxation of the dartos and cremaster muscles

Question 9

Scrotum vascular supply?

Answer 9

Arteries:
Scrotal arteries (from external & internal pudendal arteries)
& Branches of testicular and cremasteric aa’s

Veins:
scrotal veins (following scrotal aa's to external pudendal vv

Question 10

Scrotum nerve supply?

Answer 10

Anterior (branches of ilioinguinal and genitofemoral) and posterior (branches of superficial perineal and PFCN) scrotal nerves

Question 11

Spermatic cord contents:

Answer 11

• Blood vessels: testicular artery, cremasteric aa/vv, artery to vas deferens, pampiniform plexus of testicular veins
• Nerves: genital branch of genitofemoral
• Other: vas deferens (duct transporting sperm from epididymis to ampulla), processus vaginalis (projection of peritoneum that forms the pathway of descent of testes (is fused shut in adults), lymph vessels

Question 12

What structure does the spermatic cord pass through to enter the scrotum?

Answer 12

inguinal canal:

deep inguinal ring (sup) to superficial inguinal ring (inf)

Question 13

Difference between tunic vaginalis and albugnea?

Answer 13

tunica vaginalis is a serous membrane that covers the tunica albugnea which is a rough fibrous capsule covering the testis (and forming lobules via septa)

Question 14

what embryonical structure does the tunica vaginalis develop from?

Answer 14

develops as an outpouching of peritoneum. Derived from mesoderm

Question 15

seminiferous tubules?

Answer 15

• Long, convoluted tubules (~70cm), roughly 1-4 per lobule

* Site of spermatogenesis

Question 16

4 cell types of the seminiferous tubules?

Answer 16

Myoid cells
Ineterstitial endocrine cells
Spermatogenic cells
Sustentacular cells

Question 17

What does the the hypothalamus release?

Answer 17

GnRH

Question 18

What is the effect of LH in the male?

Answer 18

(L: think Leydig cells)

stimulates the Leydig cells to produce androgens (largely testosterone)

Question 19

What is the effect of FSH?

Answer 19

(S: think Supporting cells/Sustentacular cells)

stimulates sustentacular cells to produce androgen-binding protein (ABP)

Question 20

What is the effect of ABP?

Answer 20

maintains a high concentration of testosterone for spermatogenic cells

Question 21

5 effects of testosterone?

Answer 21

(MASSL)

• Maturation and maintenance of the male reproductive tract
• Anabolic effects on bone and muscle
• Secondary sex characteristics
• Spermatogenesis
• Libido

Question 22

Negative feedback?

Answer 22

Increased blood levels of testosterone and DHT feeds back to the hypothalamus to reduce GnRH, which reduces LH and FSH production by the anterior pituitary

Question 23

what can testosterone be converted to?

Answer 23

DHT

Estrodiol

Question 24

what comprises the root of the penis?

Answer 24

left and right crura

bulb

Question 25

what tissues comprise the shaft of the penis?

Answer 25

2 x corpus cavernosa

1 x corpus spongiosum

Question 26

arterial supply to penis?

Answer 26

branches of the internal pudendal artery

Question 27

venous drainage of the penis?

Answer 27

blood from the cavernous space is drained by a plexus that flows into the deep vein of the penis

then flows to the prostate venous plexus

Blood from the superficial coverings drains into the superficial dorsal vein which then drains into the external pudendal vein

Question 28

types of nerve supply to the penis

Answer 28

autonomic: Symp/Para/VA

somatic

Question 29

somatic nerve supply to penis:

Answer 29

Pudendal nerve (S2-4) and its terminal branch the dorsal nerve of the penis

AND

branches of the ilioinguinal nerve (L1) supply the skin and root

Question 30

Autonomic supply to the penis?

Answer 30

Hypogastric and pelvic plexus consisting of:
Symp: T12-L2

Para: S2-4

Visceral afferents

Question 31

What tissues assist vein compression for erection

Answer 31

bulbospongiosus and ischiocavernosus

Question 32

what nerve class mediates erection

Answer 32

parasympathetic

Question 33

what nerve class initiates ejaculation

Answer 33

sympathetic

Question 34

Accessory ducts?

Answer 34

(EVER)
ejaculatory duct
vas deferens
epididymus
Urethra

Question 35

Accessory glands?

Answer 35

prostate
bulbo-urethral gland
seminal glands

Question 36

what does the epididymis connect/run between?

Answer 36

Rete testis

vas deferens

Question 37

layers of the vas deferens?

Answer 37

Could be wrong:
pseudostratified columnar epithelia, with 3 muscular layers:
Inner: longitudinal
Intermediate: circular
Outer: longitudinal

Question 38

how and where does the vas deferens end

Answer 38

it ends by joining the duct of the seminal vesicles and forms the ejaculatory duct and passes through the prostate

Question 39

4 parts of the urethra

Answer 39

pre-prostatic
prostatic
membranous
spongy