1. Animal Science 434 Lecture 13:Epididymis, Ejaculation and Semen

2. Head Neck Middle Piece Annulus Principal Piece End Piece Acrosome Sperm Structure

3. Sperm From Different Species

4. Nucleus Sperm Head Nucleus (Equatorial Segment)

6. Plasma Membrane Acrosome Nucleus

7. Acrosome Nucleus Plasma Membrane Acrosin Hyaluronidase

8. Middle piece Laminated columns (flexibility) Capitulum Course outer fibers Mitochondrial helix (energy) Posterior head Axoneme (9 + 9 + 2)

9. Midpiece Annulus Principal Piece Fibrous Sheath or helix

11. Axoneme Middle Piece Principal Piece

12. Axoneme

13. Microtubule Sliding in Sperm Tail

14. Sperm Metabolism Glucose-6-phosphate Anerobic Metabolism (Glycolysis) Fructose-6-phosphate Phosphohexoisomerase Lactate + 2 ATP + 2 H 2 O Tricarboxcylic Acid Cycle Glucose Fructose 36 ATP/Glucose 36 ATP/Fructose Fatty Acids Aerobic Metabolism Hexokinase

15. Sperm Metabolism Glucose-6-phosphate Anerobic Metabolism (Glycolysis) Fructose-6-phosphate Phosphohexoisomerase Lactate + 2 ATP + 2 H 2 O Tricarboxcylic Acid Cycle Glucose Fructose 36 ATP/Glucose 36 ATP/Fructose Fatty Acids Aerobic Metabolism Hexokinase phosphatase

16. ATP Utilization in Sperm motility (60%) substrate cycling (40%) –wasted maintenance of ionic gradients –very small amount transcription and translation –none after condensation of nucleus and loss of residual body

17. Sperm Metabolism Temperature dependent –ATP production increases as temperature increases ATP dependent processes are temperature dependent –motility increases with increasing temperature

18. Effect of Temperature on Motility Velocity (µm/s) Temperature (C)

19. Transport of Sperm Caput Rete Testis Seminiferous Tubule Vas Efferentia Vas Deferens Corpus Cauda bulk fluid flow contractions of of myoid cells fluid flow RT secretion fluid flow cilia contractions

22. Epididymal Function 1.Maturation –change in fertility –develop motility –nuclear condensation –cytoplasmic droplet 2.Concentration –remove water

23. Epididymal Function 3. Secretion –T DHT –energy substrates (GPC, free fatty acids, carnitine) –glycoproteins, lipids, enzymes 4. Transport –smooth muscle contraction 5. Storage –cauda

24. Hormonal Control of Epididymis Caput –tubal testosterone Corpus –tubal dihydrotestosterone (DHT) –vascular testosterone Cauda –tubal DHT –vascular testosterone Absolute need for Androgen

25. Erection Sensory Sympathetic Inhibit vasoconstriction relaxation of penile retractor muscle relaxation of penile retractor muscle Parasympathetic contraction of ischiocavernosus muscle contraction of ischiocavernosus muscle decreased venous outflow decreased venous outflow dilation of vessels dilation of vessels engorgement of corpus cavernosum engorgement of corpus cavernosum Psychic

26. Emission and Ejaculation Sensory Psychic Sympathetic smooth muscle contraction of prostate, seminal vesicles, vas deferens, cauda epididymis, closure of the sphincter to the bladder smooth muscle contraction of prostate, seminal vesicles, vas deferens, cauda epididymis, closure of the sphincter to the bladder emission Parasympathetic striated muscle contraction of ischiocavernosus, bulbospongiosus, pelvic urethral striated muscle contraction of ischiocavernosus, bulbospongiosus, pelvic urethral ejaculation

27. Ejaculate Characteristics SpeciesTime lapse forComposition of Bull1 secondsingle fraction Ram1 secondsingle fraction Boar5 - 25 minutesfractionated sperm-free sperm-rich coagulum Stallion30 - 60 secondsfractionated sperm-free sperm-rich mucus Human10 - 30 secondssingle fraction but coagulated

28. Components of Semen water sperm substrates –fructose –sorbitol –inositol –glycerol phosphatidyl choline (GPC) –citric acid inorganic salts –sodium, potassium, calcium, magnesium, chloride proteins

29. Initial Semen Evaluation color volume concentration motility viability morphology

30. Ejaculate Characteristics SpeciesEjaculateSpermTotal Sperm% VolumeConc. (x10 9 ) MotileNormal (x10 9 /ml) /Ejaculate Bull8.01.5127595 Ram1.03.039595 Boar200.25507090 Stallion80.15127040-90 Man2-6.15.96530-70