The document provides an overview of the male reproductive system, including the testes, epididymis, vas deferens, seminal vesicles, prostate gland, bulbourethral glands, penis, and scrotum. It describes the functions of each part, including sperm production in the testes, sperm transport through the epididymis and vas deferens, seminal fluid secretion by the accessory glands, and ejaculation of semen through the urethra. The document also discusses sperm maturation, the composition and function of semen, and the roles of hormones and temperature regulation in spermatogenesis and male fertility.

1. MALE
REPRODUCTIVE
PHYSIOLOGY
I
Dr. Nilesh Kate
(MBBS. MD)
DR NILESH N KATE
ASSOCIATE PROFESSOR
ESIC MEDICAL COLLEGE
GULBARGA.

2. An Overview of the Male reproductive
system
 Gonads :- Testis
 Accessory sex
glands :-
Seminal Vesicles,
Prostate Gland,
Bulbourethral
Glands
 Ducts :-
Epididymis,
Vas deferens,
Ejaculatory ducts
Urethra
 Supporting structures :-
Spermatic Cord
Scrotum
Penis

3. TESTES
 Primary reproductive organs or gonads.
 Correspond with ovaries
 Functions --
 Production of sperm.
 Secrete Testosterone.
 Suspended outside the body cavity by
scrotum

4. FUNCTIONAL ANATOMY OF TESTES
 Location – suspended by spermatic cord into the scrotum.
 Weight – 25 gms.
 Coverings (inner to outer)
1) Tunica vasculosa – innermost
--- made up of loose connective
tissue.
2) Tunica albuginea – Fibrous capsule of testes.
Consists of collagen fibers & elastic fibres.
Mediastinal testis – posterior part expand into
thick mass.
Numerous septa from it divide testes into Lobules.

5. STRUCTURE OF TESTES
 Fibrous capsule –
tunica albuginea –
surrounds testes
 Scrotal cavity – lined by
tunica vaginalis –
parietal and visceral
layers (between 2
layers small amount of
fluid is present)
Figs 27-4/5

6. TESTES
 Blood supply.
 Arterial – testicular
artery branch of
abdominal aorta.
 Venous – joins
Pampiniform plexus
anterior to Ductus
deferens.
 Lymphatic drainage –
lumbar & preaortic lymph
nodes.
Saturday, April 25, 2015

7. 1
GROSS STRUCTURE
Rete
Testes
Each lobule contains
•Seminiferous tubule (1)
Compartment…
80 cm long
2 parts –
Convoluted part
Straight part. (20-30) joins to
form Rete testes.
It gives 20 efferent ductules to
form head of Epididymis.
•Interstitial compartment

8. Saturday, April 25, 2015

9. Seminiferous Tubules
 Capsule– Fibroelastic
connective tissue.
 Basement
membrane ( basal
lamina)
 Epithelial layer.
(complex stratified)
 2 compartments basal
& adluminal
Saturday, April 25, 2015

10. Seminiferous
Tubule
Primary
spermatocytes
Spermatids
sertoli cell
SpermMICROSCOPIC STRUCTURE

11. Seminiferous Tubules
Saturday, April 25, 2015

12. CELLS
 Spermatogenic cells
 4-8 layers.
 Extend from basal
lamina to lumen.
 Basal compartment
early stages of
spermatogenesis.
 Adluminal – later stages
like sec Spermatocytes,
early late Spermatids &
spermatozoa.

13. CELLS
 SERTOLI CELLS
 Pyramidal shape.
 Occupies both compartments
 Forms tight junctions.
 Form blood-testes barrier:
 Prevents autoimmune
destruction of sperm..
 Prevents immune attack.
 Maintain luminal fluid
composition. ( low in
glucose & proteins
 High in androgen &
potassium.
Saturday, April 25, 2015

14. SERTOLI CELLS
 FUNCTION
 Physical Support and nutrition
 Phagocytize residual bodies
 Secrete MIS, Inhibin, Transport Proteins (Fe & Cu),
Plasminogen activator, Oestrogen (aromatase),
Seminiferous tubular fluids.
 Secrete androgen-binding protein (ABP):
 Binds to testosterone and concentrates
testosterone in the tubules.

15. Spermatogenesis
 Definition:-
Formation of spermatozoa from spermatogonia
 Characteristic features:-
` Puberty
Mitosis and Meiosis
1 spermatogonium form 512 spermatids
Duration 74 days
Non-motile in semineferous tubules

16. Spermatogenesis
Spermatogonium (46)
Mitosis
Daughter Cells (46)

17. Spermatogenesis
Spermatogonium (46)
Mitosis
Daughter Cells (46)
Growth
Primary Spermatocyte (46)
Meiosis I
Secondary Spermatocytes (23)
Spermatogonium
Meiosis II
Early Spermatids (23)

18. Spermatogenesis
Spermatogonium (46)
Mitosis
Daughter Cells (46)
Growth
Primary Spermatocyte (46)
Meiosis I
Secondary Spermatocytes (23)
Spermatogonium
Meiosis II
Early Spermatids (23)
Spermiogenesis
Late Spermatids (23)

19. Spermatogenesis
Spermatogonium (46)
Mitosis
Daughter Cells (46)
Growth
Primary Spermatocyte (46)
Meiosis I
Secondary Spermatocytes (23)
Spermatogonium
Meiosis II
Early Spermatids (23)
Spermiogenesis
Late Spermatids (23)
Spermatozoa (23)
(Lumen)

20. SPERMIOGENESIS
 Nucleus – Head
 Centriole – proximal forms
basal body & distal forms
axial filaments
 Golgi app – cap
(Proteolytic enzymes)
 Mitochondria – surrounds
tail (movements)
 Cell membrane --
coverings

21. EM of a Mature sperm cell
55-65 micrometre in length

22. STRUCTURE OF SPERMATOZOON (55-65 μm)
 Head
Acrosome
 Neck
Basal body
 Tail
Middle piece
Principal piece
End piece
 Axoneme – central skeleton.
 Fibrous sheath
 Mitochondria – ATP for
motility.

23. SPERMATOZOA
 120 millions per day
 Maturation and capacitation
Role of Epididymis – secretions makes more motile
Role of seminal vesicle and prostate gland –
stimulate sperm motility
Role of female genital tract – Uterus & tubular
musculature – sucking effect.
Capacitation – Get ability to fertilize in female genital
tract.

24. FACTORS AFFECTING
SPERMATOGENESIS
 Temperature.
 Need lower than body temp
(320
c)
 Mechanisms – location
outside, evaporative
cooling in scrotum,
countercurrent heat
exchanger in artery & vein.
 Defective --Hot bath,
Cryptorchidism &
varicocoele
 Seasonal variation
 Sperm count more in
winter than in summer.
 Infectious diseases.
 Mumps – degeneration
of semineferous
tubules
 Hormonal control

25. SEMEN
 Fluid ejaculated during orgasm.
 Volume --2-5 ml/ ejaculate
 Vas deferens contribute 10%-
 Seminal vesicle- 60%
 Prostate gland- 30%
 pH -7.5
 Fibrinogen-help for coagulum- It dissolves after 15 to 30 min
because of fibrinolysin.(from Prostate)
 Life span of the sperm in the vagina 1-2 days.
 Low temp.-several week .
 -100’C(frozen for years)

26. COMPOSITION OF HUMAN
SEMEN
 Color : White, opalescent
 Specific gravity : 1.028
 pH : 7.35 – 7. 50
 Sperm count : 35-200 million
average about 100 million/ml.
 Fructose (1.5 – 6.5mg/ ml)
 Phosphorylcholine
 Ergothioneine
 Ascorbic acid
 Flavins
 Prostaglandins
From seminal vesicles
(contributes 60% of total volume )

27. COMPOSITION OF HUMAN
SEMEN
 Spermine
 Citric acid
 Cholesterol,
 Phospholipids
 Fibrinolysin, fibrinogenase
 Zinc
 Acid phosphatase
 calcium
 Phosphate
 Bicarbonate
 Hyaluronidase
From prostate
(contributes 30% of total volume )
buffers

28. Epididymis
~ 7 m long
Head - superior,
receives
spermatozoa
Body – distal and
inferior
Tail - leads to
Ductus deferens
Rete testis and
Efferent ductules

29. EPIDIDYMIS
 Route of exit of Sperm
 Nutrition
 Provide Motility

30. Function: Sperm storage and
maturation
Epididymis

31. VAS DEFERENS
 Continuation of tail of epididymis
 Route of exit of sperm
 Ductus deferens stores sperm
 Vasectomy – ligated and sectioned

32. Function: Transport sperm to
urethra
Vas Deferens

33. SEMINAL VESSICLES.
 Do not store sperm
 Provide the bulk of the semen, a mixture
of secretions, sperm and mucous
 Fructose and prostaglandins from
seminal vesicles

34. Function: Produce 60% of alkaline semen
including fructose to provide energy for
sperm.
Ejaculatory Duct
SEMINAL VESSICLES

35. Bulbourethral glands (Cowper’s
glands)
Pea size, paired, at base of
penis
Produce about 10% of semen
Alkaline mucus - function??
Protection from acidic Ph in
vagina

36. Function: Secretes mucous &
alkaline buffers to neutralize
acidic conditions of urethra.
Cowper’s Gland

37. PROSTATE GLAND.
 Largest accessory glands
 Alkalinity and clotting enzymes from
prostate.

38. Function: Produces up to 1/3 of the
semen & includes nutrients & enzymes to
activate sperm.
Prostate

39. Pathway
of Sperm
 Seminiferous tubules
 Rete testis
 Epididymis
 Vas (Ductus) deferens
 Ampulla of vas deferens
 Ejaculatory duct
 Prostatic urethra
 Membranous urethra
 Penile (spongy) urethra
Fig 27.8

40. URETHRA: EJACULATION
 During emission phase of ejaculation
sperm are emptied into urethra by
sympathetically induced contractions
 Motor neuron induced contractions of
skeletal muscles at base of penis expell
the semen during expulsion phase of
ejaculation

41. Functions: Transport urine & semen
Urethra
Bladder

42. SPERMATIC CORD
 Suspends the testes
 Contains –
Ductus deferens
Vessels and nerves
 Coverings –
Internal spermatic fascia
Cremastric fascia
External spermatic fascia

43. Spermatic Cord
Can be palpated as it
passes over the pubic brim.
Constituents :
1. Pampiniform plexus of
spermatic vein
2. Spermatic artery
3. Ductus (vas) deferens
4. Lymphatics
5. Nerves-ilioinguinal and genitofemoral
Fig 27.3

44. SCROTUM
Function: supports and protects
testes
Structure: Skin & underlying
superficial fascia
 Dartos muscle in dermis
 Cremaster muscle - continuous
with abdominal wall muscles (?)
Involuntary contraction
(cremasteric reflex) in response
to ________
Scrotal sac forms 2
separate chambers
Cremaster muscle

45. Function: Maintain temperature of
testes approx. 30
C below normal body
temp.
Scrotu
m

46. Penis
Root - fixed to ischial ramus
Body with erectile tissue.
Glans – enlargement of corpus
spongiosum
Prepuce - foreskin – partially
covers glans and surrounds
external urethral meatus (may
be removed in circumcision.)
Preputial glands - produce
smegma (supports bacterial
growth, such as E. coli)
Fig 27.9

47. Functions: Urination and
Copulation
Penis

48. MALE SEXUAL ACT
 Stages of the male sexual act
1.Erection
2.Emission
3.Ejaculation
NERVE SUPPLY
i) Parasympathetic nerve (nervi erigentis) (S2, S3 and S4 ): Supply to
the erectile tissue of the penis. Takes part in erection of penis.
-impotance.
 ii) Sympathetic nerves (hypogastric nerve) (T12,L1, L2):Supply to
epididymis, vasdeferens,seminal vesicles, ejaculatory ducts. Takes
part in emission.
iii)Somatic (pudendal nerve) (S2,S3 and S4): Supply to bulbus
cavernosus.It takes part in ejaculation.

49. Sexual sensations
 Sexual end organs.
 Sexual signals pass trough pudendal nerve.
Penis.
 Pudental nerve
 Sacral plexes
 Undefined of the brain

50. STAGES
 PENILE ERECTION
 Role of parasympathetic nerves
 Erection ---- by sacral portion of spinal cord- pelvic
nerves- penis
 Nitric oxide – vasoactive peptide ach relax the
artery of the penis & relax the trabecular network of
smooth muscles fibres in the erected tissue of
corpora cavarnosa and corpora spongiosa
 Arterial blood – venous blood occluded by
compressing central vein of penis.
 Ballooning effect erectile tissue –penis become hard
& elongated

51. LUBRICATION
 Parasympathetic stimulation- promotes erection &
urethral gland & bulbourethral gland to secrete
mucus
 Mucus help for lubrication at coitus.
 Most of the lubrication of coitus is produced by
female sex organ.
Painful sensation- inhibit sexual sensation

52. EMISSION & EJACULATION
 Sympathetic nerve
T12 L1 L2
hypogastric and pelvic sympathetic
nerve plexus
to intiate emission and ejaculation
 Contraction of vasdeferns
 Expulsion of semen in to urethra
 Contract prostate & seminal vesicle
 Expel prostatic and seminal fluid in to
urethra
 All the fluid mix in the internal
urethra with mucus –emission. it is
called fore runner of the ejaculation

53. Filling of the urethra
Pundenal nerve
Sacral
Feeling a sudden fullness & excite rhythmical contraction
Contraction of ischiocavernous & bulbocavernous muscle
Compress the base of the penile erection
Rhythmical , wavelike impulse in pressure
Ejaculation of semen from the urethra to the exterior
ejaculation

54. Emission and ejaculation is
called male orgasm .

55. THANK
YOU