B115 Male Reproductive Anatomy & Physiology

Lesson Outline  Male Reproductive Terms  Male Reproduction Process  Glands  Semen Evaluation  Abnormalities  Fertilization

Infovets Educational Resources – – Slide 3 Male Reproductive Terms  Testicle: The male sex gland that produces sperm.  Spermatozoa: The male’s sex cell that is responsible for fertilization.  Seminiferous Tubules: Small structures in the testicles that are responsible for spermatogenesis (sperm production).  Semen: Sperm and additional fluids produced by several accessory glands.

Infovets Educational Resources – – Slide 4 Male Reproductive Terms  Epididymis: Cord attached to the testicle that is responsible for sperm maturing and final development.  Vas Deferens: Tube that connects the epididymis with the urethra. Sperm cells move through here to the urethra.  Urethra: Tube that carries urine from the bladder  Seminal Vesicles: Organs which contain fluids necessary for sperm survival.  Prostate Gland: Gland that contributes seminal fluid necessary for healthy sperm.

Infovets Educational Resources – – Slide 5 Male Reproductive Terms

Infovets Educational Resources – – Slide 6 Male Reproductive Terms

Infovets Educational Resources – – Slide 7 Male Reproductive Terms

Infovets Educational Resources – – Slide 8 Male Reproduction Process  Gonadotrophin production by the hypothalamus causes the pituitary to produce FSH and LH.  These stimulate the cells of the testicle to produce testosterone, and spermatozoa or sperm.  In the tiny seminiferous tubules of the testicle, immature sperm are produced.  These sperm move to the epididymis where they fully mature and are stored prior to ejaculation.

Infovets Educational Resources – – Slide 9 Male Reproduction Process  During ejaculation, the sperm travel through the vas deferens, and into the urethra.  In the vas deferens and urethra, additional fluid from the secondary sex glands (seminal vesicles, prostate, bulbourethral glands) is added which helps keep the sperm alive.  Sperm are very sensitive to extremes in heat or cold.

Infovets Educational Resources – – Slide 10 Male Reproduction Process  The scrotum is sack like structure designed to regulate the optimal temperature for sperm production by drawing the testicles closer to the body or away from the body.  Animals that are sick, have a fever, or are fat (causing insulation for the sperm) often have lower numbers of healthy sperm. Severe cold, and stress, can also cause decreased numbers of normal sperm.  It takes 60 days for sperm to completely mature so many reproductive problems in bulls may not show up for several months.

Infovets Educational Resources – – Slide 11 Male Reproductive Tract Glands  Seminal Vesicles:  Produce a fluid that protects and transports the sperm.  Prostrate Gland:  Located near the urethra and the bladder.  Produces fluid that is mixed with seminal fluid.  Cowper’s Gland:  Produces fluid that cleans and neutralizes the urethra.

Infovets Educational Resources – – Slide 12 Semen Evaluation  Semen is evaluated on three things:  Concentration  Morphology  Motility

Infovets Educational Resources – – Slide 13 Concentration  Number of sperm cells per milliliter  Most important fertility Indicator  Average ejaculate ranges from 4 to 6 milliliters and contains 6 to 8 billion sperm cells.

Infovets Educational Resources – – Slide 14 Mobility  Microscope at 400X  70% or more mobile cells at 40 degrees centigrade (104 F)

Infovets Educational Resources – – Slide 15 Mobility

Infovets Educational Resources – – Slide 16 Morphology  Proportion of abnormal sperm  Should not exceed 20%  Most bulls produce some abnormalities

Infovets Educational Resources – – Slide 17 Sperm Morphology

Infovets Educational Resources – – Slide 18 Double Head

Infovets Educational Resources – – Slide 19 Abnormal Head

Infovets Educational Resources – – Slide 20 Abnormal Head

Infovets Educational Resources – – Slide 21 Elongated Head

Infovets Educational Resources – – Slide 22 Swollen Neck & Tail

Infovets Educational Resources – – Slide 23 Detached Head

Infovets Educational Resources – – Slide 24 Broken Tail

Infovets Educational Resources – – Slide 25 Coiled Tail

Infovets Educational Resources – – Slide 26 Sperm Abnormalities

Infovets Educational Resources – – Slide 27 Sperm Abnormalities

Infovets Educational Resources – – Slide 28 Sperm Abnormalities

Infovets Educational Resources – – Slide 29 Sperm Abnormalities

Infovets Educational Resources – – Slide 30 Fertilization  Fertilization is the union of the sperm and the egg.  Conditions for fertilization:  Male and female compatibility  Female in Heat  Egg is mature

Infovets Educational Resources – – Slide 31 Sperm on an Egg

Infovets Educational Resources – – Slide 32 Embryos  The result of fertilization, early stage of development of the fetus.