MALE REPRODUCTIVE SYSTEM Flashcards
Cutaneous fibromuscular sac containing the testes and lower parts of spermatic cords
Scrotum
Hangs below pubic symphysis, between anteromedial aspect of thighs
Scrotum
Scrotum is divided into R and L sides by?
Raphe
Describe skin of scrotum
- thin
- pigmented
- w thinly scattered crisp hairs (w sebaceous & sweat glands, pigmented cells, nerve endings)
- ko subcutaneous adipose tissue
Responds to mechanical stimulation of hairs and skin to various temperature
Nerve endings in scrotum
Muscles found in scrotum
Dartos
Cremasteric
Contracts the scrotal skin in response to cold
Dartos
Retracts the testes towards the abdomen
Cremasteric
Scrotum blood supply
- external pudendal branches of femoral artery
- scrotal branches of internal pudendal artery
- cremasteric branch from inferior epigastric artery
Scrotum nerves
- Ilio-inguinal and genital branch of genitofemoral nerve
- Posterior scrotal branches of perineal nerve
- Perineal branch of posterior femoral cutaneous nerve
ABDOMINAL LAYER
Skin Superficial fascia External oblique aponeurosis Internal oblique aponeurosis Transversalis fascia (not the muscle)
SPERMATIC CORD LAYER
External spermatic fascia
Cremasteric muscle and fascia
Internal spermatic fascia
SCROTAL LAYER
Skin Dartos muscle External spermatic fascia Cremasteric muscle fascia Internal spermatic fascia
Ellipsoidal
4-5 cm length
2.5 cm breadth
3 cm anteroposterior
Wt: 10.5-14g
Testis
Ellipsoidal
4-5 cm length
2.5 cm breadth
3 cm anteroposterior
Wt: 10.5-14g
Testis
Suspended in the scrotum by scrotal tissues (non striated dartos and spermatic cords)
L is abt 1cm than R
Testis
Testis 3 coats
(1) tunica vaginalis
(2) t. albuginea
(3) t. vasculosa
Internal testis
Dominated by lobules w 1-4 convoluted seminiferous tubules each
Testis loose CT contains?
Interstitial (Leydig) cells
Endocrine component of testis secreting testosterone
Leydig cells
Seminiferous tubules are lined by?
Complex stratified epi containing spermatogenic cells and supporting cells (sertoli)
Seminiferous tubules are lined by?
Complex stratified epi containing spermatogenic cells and supporting cells (sertoli)
What produces Mullerian inhibitory substance (MIS)?
Fetal sertoli cells
What prevents development of female internal genitalia by causing mullerian dust to regress?
Fetal sertoli cells
Testis blood supply
1Internal spermatic or testicular artery from aorta
2Cebtripetal branches (towards rete testes) or centrifugal arterioles in interstitial tissue between seminiferous tubules
3Intertubular cap
4Peritubular cap
5(toward t. albuginea) centrifugal veins or (toward rete testes) centripetal veins
6Pampiniform plexus of veins
7Internal spermatic vein
8Inferior vena cava (R) or left renal vein (L)
What plays a role in maintaining temperature of testes?
Pampiniform plexus
What is composed of dd, spermatic artery, nerves, pampini plex and autonomic nerves?
Spermatic cord
Distal cont of epididymis
Fxn: transport of sperm from epi to ejac ducts
Lined by: low columnar epi w 3 musc layers that propel sperm along its 40cm length
Palpable in scrotum (sterilization w minimal incision)
Bld supply: artery from superior vesical artery
Ductus deferens or vas def
Formed by union of duct of the seminal vesicle w a deferent duct
2 cm in length
Lined by: columnar epithelium
Ejaculatory ducts
Highly convoluted organ about 7.5cm long
Running along posterior surface of testis from its upper and lower plate
Epididymis
3 regions of epididymis
Caput (head) upper pole of testes
Corpus (body)
Cauda (tail) lower pole
Site of accumulation, maturation and storage of spermatozoa
Lined by pseudostratified columnar cells
Epididymis
Sacculated contorted tubes
Above prostate, between bladder and rectum
5cm long
Duct of seminal vesicles joins dd at ampulla behind the prostate to form the ejaculatory duct that passes forward into pg
Seminal vesicles
Role in human fertility, maturation, motility and immunosuppressive action of female genital tract
Seminal vesicles
Secretion contains: fructose and citric acid also prostaglandins
SV
Aid fertilization by reacting w female cervical mucus to make it more receptive to sperm movement and causing backward, reverse peristaltic contractions in uterus and fallopian to move ejac sperm to ovaries
SV
Seminal Vesicles are lined by
Columnar epi w goblet cells in diverticula
Partly glandular, partly fibromuscular
Surrounding the beginning of urethra at the base of bladder
Posterior surface palpable by rectal exam
Reg and firm w a midline groove
Prostate
Secretes seminal fluid (contains ca, ph, clotting enz, profibrinolysin) slightly alkaline
Prostate
Has 3 concentric rings of glands surrounded by smooth muscle and fibrous capsule
Smooth muscle contracts during ejac of squeeze prostatic sec into urethra
Prostate
Blood supply of prostate
Internal pudendal
Inferior vesical
Middle rectal arteries
Penis: Radix or root attached to
Perineum
Sensitive distal end of the body that includes external opening of urethra
Glans
Penis 3 cylinder of erectile tissue
2 corpora cavernosa
Corpus spongiosum
Form the dorsum and sides of penis
Form crura that support the erect penis in the root
2 corpora cavernosa
Single cylinder found on the ventral surface
Surrounds the spongy urethra
Forms glans
Called bulb at the root
Corpus spongiosum
Penis blood supply
Deep arteries of penis (c. cavernosa)
Branches of dorsal penile arteries
Penis venous drainage
Deep dorsal vein
Penis nerves
2nd, 3rd and 4th sacral spinal segments via the pudendal nerve and pelvic plexuses
ARTERIAL SUPPLY
1 Testis
2 Scrotum
3 Prostate
4 Penis
1 Testicular art from aorta via spermatic cord
2 Pudendal art
3 Vesicular and rectal branches of internal iliac art
4 Internal pudendal art
VENOUS DRAINAGE
1 Testis
2 Scrotum
3 Prostate
4 Penis
1 Pampini wc forms testicular veins; L drains to left renal vein R drains to inferior VC
2 Scrotal veins
3 Prostatic venous plexus drains into internal iliac veins
4 Venous plexus (joins Prostatic venous plexus)
INNERVATION
1 Testis
2 Scrotum
3 Prostate
4 Penis
1 Sympa sphlancnic nerv
2 Branches genitofemoral, inguinal and pudendal nerv
3 Parasympa via sphlancnic nerv and sympa from inferior hypogastric plexus
4 Branches of pudendal nerv
LYMPH ATIC DRAINAGE
1 Testis
2 Scrotum
3 Prostate
4 Penis
1 Para-aortic LN
2 Superficial inguinal LN
3 Internal iliac and sacral LN
4 Superficial inguinal LN
Process by wc primary spermatocytes undergo cell div to form haploid gametes
Meiosis
1st: 2 haploid
2nd: 4 hap spermatids
Provide nutrients, remove waste
Phagocytose excess cytoplasm or poor dev spermatids
Blood testes Barrier - tight jxn
Produce androgen-binding CHON to raise local androgen conc
Sertoli cells
Process: haploid spermatids dev to mature spermatozoa
Spermatogenesis
Takes how many days to release sperm to seminiferous tubules
74 days
Where does sperm pass for further maturation making sperm motile and capable of fertilization?
Epididymis
Epididymis contracts during orgasm to
Transport sperm to dd
New cycle of spermatogenesis starts every
16 days
Lasts 74 days
Head is to acrosome
Lysosome
Tail is to axoneme
Centriole
Normal semen acc to WHO
1.5mL vol
Conc: 15million/mL or more
Count: 39 million/ejaculate
Motility: 40% or more
Morphology: 4% N or more
WBC less than 1 million leuk/mL
pH 7.2-7.8
Testes secrete 95% of male sex steroid called androgens
Adrenal secrete remaining 5%
Synthesis of testosterone in leydig cells
CHOL –> pregnenolone –> 17a-OH preg –> DHEA –> androstenediol
Progesterone –> 17a prog –> androsteredione –> testosterone
1 bind to androgen receptors
2 conv to dihydrotestosterone wx also binds to androgen
3 conv to estradiol wc binds to estrogen receptor
Effects of testosterone
Penile erection
Lubrication
Parasympa
Emission and ejac
Sympathetic
Sympa impulses leave cord at
T12 to L2
Thru hypogastric and pelvic sympa nerve plexus to initiate emission (the forerunner of ejaculation)
Emission begins with
Contraction of vas def and ampulla to cause expulsion of sperm to internal urethra
Order of contraction
Vas def
Muscular coat of prostate g
SV
With arousal what happens to the vagina?
Lengthens
Distends
Dilates
Arousal phase mediated by
Parasympathetic NS
Orgasm phase mediated by
Sympathetic NS
Reflex rhythmic contractions
3-20 0.8/second
