Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint ® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii Chapter 28, part 2 The Reproductive System
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Seminiferous tubules Contain spermatogonia Stem cells involved in spermatogenesis Contain sustentacular cells Sustain and promote development of sperm Spermatogenesis
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 28.5 The Seminiferous Tubules Figure 28.5a, b
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 28.5 The Seminiferous Tubules Figure 28.5c
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 28.6 Figure 28.6 Chromosomes in Mitosis and Meiosis
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Spermatogenesis involves three processes Mitosis Meiosis Spermiogenesis Spermatogenesis
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 28.7 Spermatogenesis Figure 28.7
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Each spermatozoon has: Head Nucleus and densely packed chromosomes Middle piece Mitochondria that produce the ATP needed to move the tail Tail The only flagellum in the human body Anatomy of spermatozoon
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 28.8 Figure 28.8 Spermiogenesis and Spermatozoon Structure
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Testes produce mature spermatozoa Sperm enter epididymus Elongated tubule with head, body and tail regions Monitors and adjusts fluid in seminiferous tubules Stores and protects spermatozoa Facilitates functional maturation of spermatozoa Male reproductive tract
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 28.9 The Epididymus Figure 28.9
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Begins at epididymus Passes through inguinal canal Enlarges to form ampulla Ejaculatory duct at base of seminal vesicle and ampulla Empties into urethra Ductus deferens AKA vas deferens
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Urinary bladder to tip of penis Three regions Prostatic Membranous Penile Urethra
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Seminal vesicles Active secretory gland Contributes ~60% total volume of semen Secretions contain fructose, prostaglandins, fibrinogen Accessory glands
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Prostate gland Secretes slightly acidic prostate fluid Bulbourethral glands Secrete alkaline mucus with lubricating properties Accessory glands
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 28.10a-e Figure The Ductus Deferens and Accessory Glands
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Typical ejaculate = 2-5 ml fluid Contains between 20 – 100 million spermatozoa per ml Seminal fluid A distinct ionic and nutritive glandular secretion Contents of Semen
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Male external genitalia consist of the scrotum and the penis Skin overlying penis resembles scrotum Penis Contains three masses of erectile tissue 2 corpora cavernosa beneath fascia 1 corpus spongiosum surrounding urethra Dilation of erectile tissue produces erection External genitalia
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure Figure The Penis
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings FSH (Follicle stimulating hormone) Targets sustentacular cells to promote spermatogenesis LH (leutinizing hormone) Causes secretion of testosterone and other androgens GnRH (Gonadotropin releasing hormone) Testosterone Most important androgen Hormones and male reproductive function Animation: Male Reprroductive System Flythrough PLAY
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure Figure Hormonal Feedback and the Regulation of the Male Reproductive Function