Lec 3: Male Reproductive Tract Anatomy 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.

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

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 Spermatic Cord Vas Deferens Caput Epididymis Vas Efferentia 6-12 tubules Seminiferous Tubule Corpus Epididymis Tunica Albuginea 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)

Parietal Tunica Vaginalis Spermatic Chord Vas Deferens Cremaster Muscle Pampiniform Plexus Parietal Tunica Vaginalis

Spermatic Chord

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

Pelvic Genitalia of the Bull Pelvic Urethra Muscle

Bulb of the Penis

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

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