Anatomy of the male reproductive tract

state the 7 parts of the male reproductive tract

1. testis

2. epididymis

3. ductus deferens

4. accessory glands

5. penis

6. blood vessels

7. muscles

what are the 4 accessory glands

1. ampulla

2. seminal vesicles

3. prostate

4. bulbourethral gland

what is the name of the blood vessel plexus?

• pampiniform plexus

2 functions of the testis

1. spermatozoa production

2. testosterone function

identify the membranous layers surrounding the testes from inner to outer

1. tunica albuginea

2. visceral vatinal tunic

3. vaginal cavity

4. parietal vaginal layer

5. scrotal fascia

6. tunica dartos

7. peritoneum

what is the tunica dartos and its function

• smooth muscle

  • used for long lasting contraction of scrotum

what does the scrotal skin contain, why?

• sweat glands

  • cooling

what do sperm develop within?

• seminiferous tubules in the germinal epithelium

what are the tubules divided by?

• septae

what do the seminiferous tubules lead into?

• rete testis/tubules

  • into the mediastinum

what does the mediastinum lead to?

• epididymis

What can we identify (top to bottom)

1. epididymis

2. efferent ducts

3. seminiferous tubules in a lobule

4. lobule

5. tunical albugenia

6. septae (3 arrows)

Describe the histology visible here

• dotted line = seminiferous tubules

• lumen in the centre

• straight line = germinal epithelium with outer, middle + inner

• leydig cells - circle

what are the 3 parts of the seminiferous germinal epithelium?

1. outer

2. middle - deep adluminal compartment

3. inner - peripheral adluminal compartment

state the role/what’s found in each of these germinal epithelium layers:

1. outer

2. middle - deep adluminal compartment

3. inner - peripheral adluminal compartment

1. spermatogonium, sertoli cells = FSH

2. primary spermatocytes

3. spermatids

seminiferous tubules - what is the sequence?

1. convoluted tubule

2. straight tubule

3. rete tubules

4. efferent ducts

5. epididymis

what takes place in the convoluted tubule of the seminiferous tubules?

• spermatozoa production

describe what we should see on a testicular ultrasound

1. medium echogenicity

2. homogeneous texture

3. central hyperechoic mediastinum

what can testicular ultrasound be used to detect?

• cryptorchidism

• orchitis

• neoplasms

• atrophy/traums

what are the 3 regions of the epididymis

1. head

2. body

3. tail

what is the epididymis surrounded by?

• smooth muscle

why is the epididymis surrounded by smooth muscle?

• spermatozoa transport

how do we determine epididymal transit time

• time it takes to go from EH to ET

what is the role of the head + body epididymus?

• continuous transport of spermatozoa

what is the function of the tail end of the epididymus?

• storage of mature spermatozoa

• smooth muscle contracting during sexual stimulation

• sperm transported to ductus deferens

ductus deferens:

• what else is it known as

• what is its wall mostly made of

• why is it made of this?

1. vas deferens

2. smooth muscle

3. propel spermatozoa

blood supply to testis:

1. what is the plexus called

2. what is the artery and vein

3. 2 functions of it

1. pampiniform plexus

2. testicular artery + vein

3. heat exchange and testosterone transfer vein to artery

what is included in the spermatic cord

1. pampiniform plexus

2. ductus deferens

3. lymphatics

4. nerves

what does the testicular artery branch from, relevance?

• abdominal aorta

• need to make sure you ligate properly in surgery!

where does the testicular vein drain into:

1. L

2. R

1. renal vein

2. caudal VC

what is the function of the accessory glands?

• to produce seminal plasma

which accessory gland is the horse lacking?

• disseminate part of the prostate

what accessory glands does the horse have?

• ampulla

• vesicular

• prostate body

• bulbourethral

what accessory glands do large ruminants have?

• ampulla

• vesicular

• both prostate parts

• bulbourethral

what accessory gland are small ruminants lacking?

• prostate body

what accessory glands do small ruminants have?

• ampulla

• vesicular

• disseminate prostate

• bulbourethral

what accessory gland is the pick lacking?

• ampulla

what accessory glands does the pig have

• vesicular

• both prostate parts

• bulbourethral

what accessory glands is the dog lacking?

• vesicular

• disseminate prostate

• bulbourethral

what accessory glands does the dog have?

• ampulla

• body of prostate

what accessory glands is the cat lacking

• ampulla

• vesicular

• prostate disseminate part

what accessory glands does the cat have

• prostate body

• bulbourethral

what accessory glands does the rabbit have

• ampulla

• vesicular

• both prostate parts

• bulbourethral

What can we identify?

• DD = ductus deferens

• UB = urinary bladder

• A = ampulla

• VG = vesicular gland

• PG = prostate gland, body

• UM - urethralis muscle

• BuG - bulbourethral gland

What can we identify in this bull sample

• DD = ductus deferens

• UB - urinary bladder

• A - ampulla

• VG - vesicular gland

• PG - prostate gland

• UM - urithralis muscle

• IcM - ischiocavernosus muscle

• BsM - bulbospongiosus muscle

What can we identify in this boar sample?

• DD = ductus deferens

• UB = urinary bladder

• VG = vesicular gland

• PG = prostate gland

• UM = urithralis muscle

• BuG = bulbourethral gland

• BsM = bulbospongiosus muscle

What can we identify in this dog sample

• DD = d.deferens

• UB = urinary bladder

• PG = prostate gland

• UM = urithralis muscle

describe the dog prostate gland

• bilobed

• dorsal and ventral midline sulcus

• entirely surrounds the urethra

what diseases are associated with dog prostate?

• enlargement

• compression of rectum

• problems urinating

• benign prostatic hyperplasia

• bacterial prostatitis

• prostatic cysts

Describe and compare these two dog prostate ultrasounds

A - longitudinal view, obling, mildly echogenic, hypoechoic urethra

B - transverse view, ovoidal in shape, hypoechoic urethra

Describe the urethralis muscle; type, function, what it surrounds

1. striated muscle

2. transports semen

3. pelvic urethra

Describe the bulbospongiosus muscle; type, function, what it surrounds

1. striated

2. transports semen and contains bulbourethral gland

3. penile urethra

What two types of penis are there

• fibroelastic

• musclocavernosus

what are the 2 parts of the penis

• body shaft - penile shaft

• glans penis

what are the 2 erectile tissues

• corpus cavernosum

• corpus spongiosum

where is the coprus cavernosum found and what is it surrounded by

• basis of crura

• tunica albuginea

what does the corpus spongiosum surround?

• urethra

what is the crura penis attached to

• ischiatic arch

ischiocavernosus muscle; type, function, what it surrounds

1. striated

2. erection

3. cura penis, penile urethra

what species has a fibroelastic penis

• ruminants

• pigs

what is a special feature of fibroelastic penis?

• sigmoid flexure

how does the fibroelastic penis change during erection

• little change - sigmoid flexure stretches as retractor penis muscle relaxes

  • no change in girth/length due to blood flow

In which species do we find a musculocavernosus penis?

• stallion

• dog

how does the musclocavernosus penis compare to the fibroelastic

• less connective tissue

• more musculature

how does an erection change a musculocavernossu penis?

• increase in length

• increase in girth

• due to increased blood flow within the muscles

2 functions of os penis

• structural support

• alignment during mating

which speciess have an os penis

• dog

• ferret

• badger

• bats

• racoon

glans penis:

1. what part of the penis is this

2. supported by what

3. opens what?

4. shape?

1. distal tip

2. corpus only

3. urethra

4. changes b/w species

what is the shape of the gland penis in:

1. boar

2. dog

3. cat

4. rams

1. corckscrew

2. bulbis glandis - parslonga glandis

3. keratinised barbs/spikes

4. urethral process extends beyond glans