AnimalDairy Science 434 Lec 3 Male Reproductive Tract

Animal/Dairy Science 434 Lec 3: Male Reproductive Tract Anatomy

Male Reproductive System LEARNING OBJECTIVES: To learn the nomenclature and structures of the male reproductive system. To understand the functions of these structures and how they are interrelated to prove the complete reproductive process in the male.

Testis Factory • 1 -25 X 109 sperm/day • “Plant” must be air conditioned Penis Delivery System • Erection • Protrusion • Ejaculation Epididymis Finishing School • Fluid Absorption • 8 -25 X 109 sperm – membrane changes – nuclear & flagellar stabilization – motility, fertility – cytoplasmic droplet translocation Tail of Epididymis Warehouse and Delivery Accessory Sex Glands Alterations & Packaging • Metabolic substrates • Surface coatings • Transport for sperm • Storage 10 -50 X 109 sperm • Sperm for 5 -10 ejaculates • Smooth muscle contractions upon sexual stimulation

Bull Reproductive Tract

Reproductive Organs of the Bull Testis

Bull Testis Tunica Vaginalis • parietal • visceral Tunica Albuginea

Bull Tract Testis Scrotum

Scrotal Cross Section testicular parenchyma mediastinum

Testis Testicular Parenchyma Mediastinum

Structure of the Testis Seminiferous Tubule Tunica Albuginea Rete Testis (within the mediastinum)

Mediastinum Rete Testis Seminiferous Tubule The Testis

Structure of the Testis Caput Epididymis Spermatic Cord Vas Deferens Vas Efferentia 6 -12 tubules Seminiferous Tubule Tunica Albuginea Corpus Epididymis Rete Testis (within the mediastinum) Cauda Epididymis

Spermatic Chord Pampiniform Plexus Testicular Artery

39°C Pampiniform Plexus

Counter Current Exchange

Testis Arterial Pulse

Bull Tract Testis Scrotum Tunica Dartos

Contraction of the Tunica Dartos Testis Tunica Dartos • Smooth muscle • Androgen dependent (Testosterone)

Spermatic Chord Vas Deferens Cremaster Muscle Pampiniform Plexus Parietal Tunica Vaginalis

Spermatic Chord

Bull Tract Pelvic Genitalia Spermatic Chord Pampiniform Plexus Testis Scrotum Gubernaculum Epididymus Tunica Dartos

Pelvic Genitalia of the Bull Pelvic Urethra Muscle

Bulb of the Penis

Reproductive Organs of the Bull Rectum Prostate Cowpers Gland Seminal Vesicles Ampulla Bladder Retractor Penis Muscle Vas Deferens Sigmoid Flexure Glans Penis Caput Epididymis Scrotum Testis Gubernaculum Cauda Epididymis

Cross Section of Bull Penis

Penis Cross Section DEC = dorsal erectile canals CC = corpus cavernosum U = urethra CS = corpus spongiosum

Prepuce

Glans Penis

Glans Penis

Arterial Supply

Temperature Regulation of Testis • Pampiniform plexus • Muscle contractions – Tunica Dartos (smooth muscle) • sustained contractions – Cremaster (striated muscle) • only temporary contractions • primarly controls the pampiniform plexus • Scrotal sweating • Convection around scrotum • Polypnea (panting)

Thermoregulation of Testis

Tunica Dartos Cremaster