Male reproductive system

Testes

sperm & testosterone production >> seminiferous tubules synthesize gametes

Epididymis

sperm maturation site >> gains motility and fertilizing capacity

Vas Deferens

sperm transport >> duct carries sperm to pelvic urethra

Scrotum

thermal control >> tunica dartos maintains core temperature >> houses testes & epididymis

Vesicular glands

provides fructose and nutrient vehicle

Prostate Gland

Secretes high-mineral activating fluid

Bulbourethal Gland

flushes urine residues prior to ejaculation

What temperature do testes need for thermoregulation?

must be 3-5 5°C cooler than body temperature

Accessory Sex Glands

seminal vesicles, prostate, bulbourethral glands >> add fluid volume, nutrients & buffers to the semen

Copulatory organ in males

the penis

Fibroelastic (bull, boar, ram)

rigid structure that extends via the straightening of the sigmond flexure

Vascular (stallion)

engorges with blood to achieve erection

Where is the vans deferens?

housed in the spermatic cored

Semen

mixture of seminal & prostate fluid and sperm >> produced by seminal vesicles, prostate gland, Cowper's gland

Role of the penis

essential for depostiton of sperm, houses uretha (spongy tissue), dependent on species (sigmoid flexure)

Where are the testes located in avian males?

Internally within the body cavity along the backbone (near the kidneys).

What is the viability of avian sperm at high core body temperatures?

Avian sperm remains viable at high core body temperatures (106°F).

How large is the epididymis in avian males?

Very small; does not store sperm.

What is the function of the vas deferens in avian males?

Acts as the primary site for sperm storage and maturation.

What accessory sex glands are present in roosters?

Absent; roosters do not have seminal vesicles, prostate, or bulbourethral glands.

Copulatory organ in avain

No true penis; mating occurs via "cloacal kiss" to transfer semen (minus ducks who have a highly developed phallus)

Where are the testes located in mammals?

External

Where are the testes located in avians?

Internal

What is the semen volume of a boar?

High volume (200+ mL)

What is the semen volume of a rooster?

Low volume (< 1 mL)

What is the semen concentration in roosters?

Highly concentrated

Do roosters have accessory gland fluids in their semen?

No

What is the mechanism of erection in livestock?

Sigmoid flexure release

What is the mechanism of erection in poultry?

Absent/cloacal transfer

What triggers the secretion of LH and FSH from the pituitary gland?

Pulsatile release of GnRH from the hypothalamus.

What stimulates Leydig cells to convert cholesterol into testosterone?

LH (Luteinizing Hormone).

What are the effects of testosterone in males?

Promotes male secondary characteristics, muscle protein accretion, libido, and intratesticular support for spermatogenesis.

What stimulates Sertoli cells to support germ cell development?

FSH (Follicle-Stimulating Hormone) and local testosterone.

What do Sertoli cells secrete to concentrate testosterone locally?

Androgen-Binding Protein (ABP).

What hormone do Sertoli cells secrete to exert negative feedback on pituitary FSH release?

Inhibin.

What is the function of the acrosome in sperm?

It is a cap-like vesicle containing digestive and proteolytic enzymes.

What does the nucleus of a sperm contain?

A tightly packed, hypercondensed haploid genome.

What is the neck of the sperm?

A short segment linking the head to the midpiece.

What is found in the midpiece of a sperm?

Densely packed mitochondria that form a mitochondrial sheath around the core.

How is the tail of a sperm subdivided?

Into the principal piece and the shorter end piece.