Male Reproductive System PDF

The Reproductive System Part II: Male Anatomy & Physiology II BIOL2220 1 Version 09.2  The Reproductive System Male - Anatomy Overview 1. Scrotum Skin. Da...

The Reproductive System Part II: Male Anatomy & Physiology II BIOL2220 1 Version 09.2  The Reproductive System Male - Anatomy Overview 1. Scrotum Skin. Dartos Muscle (Smooth). Septum. Cremaster Muscle (Skeletal). Temperature: -3oC Below Body Temperature. Controlled By Cremaster. Spermatic Cord: Testicular Artery. Venous Plexus. Nerves. Vas Deferens. 2. Testes Tunica Vaginalis. Tunica Albuginea (Capsule). Septa: Lobules Seminiferous Tubules Epididymis. 3. Seminiferous Tubules Site Of Spermatogenesis Consists Of Different Types Of Key 2 Cells.  The Reproductive System Male - Anatomy Overview: Ducts and Glands of Males 8. Seminal Vesicle 4. Ducts 60% Of Semen. Epididymis. Prostaglandins Vas Deferens.. Ejaculatory Duct. 9. Prostate Gland Urethra. Surrounds Prostatic Urethra. 30% Of Semen. 5. Epididymis Supports Sperm. Located In Scrotum. Pseudo-Stratified Epithelium w/ Microvilli. 10. Penis Smooth Muscle. Spongy Urethra. Sperm Mature & Store. Erectile Bodies: Corpus Spongiosum. 6. Vas Deferens: Forms Ejaculatory Duct Corpora Cavernosa (2). Transport From Scrotum To Pelvis. Capsule. Pseudo-Stratified Epithelium. Vascular Spaces. Lamina Propria. Forms Ejaculatory Duct w/ Seminal Vesicle Duct. Empties Into Prostatic Urethra. Thick Muscularis. Propels Sperm During Ejaculation. 3 Layers Of Muscularis: Inner Longitudenal. Middle Circular. Outer Longitudenal. 7. Urethra Shared w/ Urinary System 3 Stages: Prostatic. Membranous. 3 Spongy (Penile).  The Reproductive System Basic Flow Chart Male – Anatomy & Physiology Hypothalamus Spermatogonium Undergo Growth & Differentiation. 1 (-) (-) The Hypothalamus Releases Gonadotropin Releasing 2 2 Hormone Through The Hypothalamic-Hypophyseal Portal Venous System. GnRH (-) 3 In Response, The Anterior Pituitary Releases Luteinizing (-) Hormone & Follicle Stimulating Hormone. Anterior Pituitary 4 LH Stimulates Interstitial (Leydig) Cells To Produce 6 Testosterone. Testosterone Is Required To Support Spermatogenesis & 2nd Order Sexual Development In Males. 3 3 Inhibin LH FSH 5 FSH Stimulates Sertoli Cells To Directly Nurture & Transport Developing Sperm Inside The Seminiferous Tubule. 1 Interstitial Fluid Seminiferous Tubules Spermatogonium 4 5 Interstitial Sertoli 1O Spermatocyte Cells Cells (Leydig) Meiosis I Spermatogenesis 1 2 Spermatocyte O 4 Testosterone 7 Meiosis II Spermatid Sperm 4  The Reproductive System Basic Flow Chart Male – Anatomy & Physiology 1 Sertoli Cells Support A Negative Feedback Loop In The Epididymis, Sperm (Non-Motile) Are Stored & 6 To The Hypothalamus & Anterior Pituitary That 10 Undergo Maturation (Now Capable Of Fertilization). 8 Involves The Release Of Inhibin. Seminiferous The Vas Deferens Is The Primary “Conduit” From The Tubule Spermatogenesis Ensues With 2 Successive Scrotum/ Epididymis To The Pelvis & Is The Primary 7 (And Continuous) Meiotic Divisions Resulting In 11 Effector Of The Ejaculatory Act Through Use Of Its 3 Spermatids (Haploids 1n). Layer Muscularis. 9 Rete Testes The Vas Deferens Merges With The Seminal Vesicle To Spermiation Occurs With Sertoli Cells 12 (Mediastinum) 8 Removing Excess Cytoplasm As Form The Ejaculatory Duct. The Seminal Vesicle Constitutes 60% Of Seminal Volume & Contains Spermatids Become Spermatozoans. Fructuose, Citric Acid, Nutrients, Prostaglandins & 9 Spermiogenesis Continues With The Fibrinogen. During Ejaculation, These Contents Are Efferent Emptied Into Ejaculatory Duct. Release Of Sperm Into Lumen Of The Ductules Seminiferous Tubules. The Ejaculatory Duct (The Confluence Of The Vas 13 Deferens & Seminal Vesicle) Merges With The Urinary 10 9 Sperm Are Conducted Through The Tract e.g. Prostatic Urethra At The Prostate Gland. The Epididymis Rete Testes (Mediastinum), Through The Prostate Gland (30% Of Semen By Volume) Secretes A Efferent Ductules Into The Epididymis. Milky Fluid Containing Citrate Ions, Phosphate Ions, Clotting Enzymes & Profibinolysin. 11 Vas Deferens 13 14 The Bulbourethral Gland Secretes Mucous Prostate BulboUrethral 14 Into The Membranous Urethra. It is Gland Gland analogous with the Bartholin Gland of the female. 12 Seminal Vesicles Ejaculatory Duct Semen Is 15 15 Ultimately Urethra Urethra Ejaculated (Membranous) (Penile - Spongy) From The Urinary Bladder Urethra Penile/Spongy Urethra Into (Urine) (Prostatic) 5 The Vagina.  The Reproductive System Male Sexual Response Male – Anatomy & Physiology Psychic Elements And/Or Glans Penis Stimulation Reflex Reflex Mechanisms Mechanisms Parasympathetic Sympathetic Parasympathetic Sympathetic Impulses Impulses Glandular Arterial Dilation (NO) With Bulbourethral Contraction & Increased Blood Flow To Emission Filling Of Corpora Cavernosa & Corpus Internal Urethra Spongiosum Spinal Cord Erection Lubrication Relay Rhythmic Contractions Ejaculation 6  The Reproductive System Testosterone Male – Anatomy & Physiology General The Testes Secrete Male Sex Hormones (Androgens). Testosterone Is The Most Potent And Abundant Of These. Interstitial Cells Of Leydig Produce Testosterone. Interstitial Cells Comprise 20% Of Mass Of Adult Testes. Interstitial Cells Are Not Numerous In Children. Adrenal Cortex Also Secretes Androgens. All Androgens Are Steroid Hormones. Synthesized From Cholesterol. Fetal Development Development Of Male Sexual Organs In Fetus. Descent Of Testes In Newborn. Primary And Secondary Sexual Characteristics After Puberty, Causes Penis/Scrotum To Enlarge 8 Fold. Growth Of Body Hair: Pubis, Face, Chest, Back. Voice: Effect On Laryngeal Mucosa & Larynx. Skin: Increases Thickness And Ruggedness. Increase Protein Formation & Muscular Development. Bone Growth And Calcium Retention. Increase Basal Metabolism. RBC: More Than That In Women. 7  The Reproductive System Sperm Male – Anatomy & Physiology Seminiferous Tubules Contain Germinal Epithelium Called Spermatagonia Located In Outer 2-3 Layers Of Tubular Structure. Spermatogonia Grow To Form Spermatocytes. Spermatocytes Undergo Two Consecutive Meiotic Divisions. No Formation Of New Chromosomes From The Second Division. One Spermatocyte Divides Into 4 Spermatids, Each Containing 23 Unpaired Chromosomes. Spermatids Mature For Two Months To Become Spermatozoa (Mature Sperm). Meiotic Division Animation 8  The Reproductive System Sperm Male – Anatomy & Physiology Head Contains Nuclear Material That Will Fertilize Ovum. Acrosome Located On Top Of Sperm. Formed From Golgi And Contains Hyaluronidase & Proteolytic Enzymes That Are Important For Entry Of Sperm Into Ovum. Mitochondria Random Facts Surround Spiral Body. 1.Is Ejaculated During Male Sexual Act. 2.Majority Of Fluid (60%) Comes From Seminal Vesicle. Tail 3.pH Of Semen = 7.5. 4.Prostatic Fluid: Milky Appearance. 5.Seminal Vesicle & Mucus Gland Secretion: Mucoid Consistency. Extends Out From Sperm’s Body And 6.Semen Is Weakly Coagulated Prior To Ejaculation And Dissolves In 15-30 Similar To Cilia. Min After Ejaculation. 7.Average Volume Of Ejaculated Semen = 3.5 ml. 8.Average Sperm Count = 120 (35-200) Million/ml. Flagellar Movement For Sperm Motility. 9.Infertile: Sperm Count < 20 Million/ml. 10.Sperm Can Live For Weeks In Male Genital Tract. 11.Once Ejaculated, Sperm Can Live 24-48 Hours At Body Temp. 9 12.At -1000 c Sperm Can Be Maintained For Years.  The Reproductive System Composition Of Male Secretions & Male – Anatomy & Physiology Chemical Effects Seminiferous Sperm - Acrosome Hyaluronidase Facilitate Penetration Of Corona Tubule & Radiata & Zona Pellucida Of Epididymis Ovum. Protealytic Enzymes Seminal Vesicle Fructose Make Cervical Mucous More Responsive To Sperm. Proteases Contractions In Uterus & Fallopian Tubes. Seminalplasmin Nourish Sperm Through The Point Of Fertilization. Prostaglandins Fibrinolysin Prostate Gland Citrate Ions Neutralize Acidity & Chemically Enhance Female Reproductive Environment For Sperm. Phosphate Ions Calcium Clotting Enzyme Profibrinolysin Bulbourethral Mucous Neutralize Acidity In Female & Lubrication. Gland 10  The Reproductive System Capacitation & Male – Anatomy & Physiology Fertilization Capacitation Multiple Changes Occur During The Contact With The Fluids Of Female Tract That Activate The Sperm For The Final Process Of Fertilization – Capacitation Of The Sperm (1 -10 Hrs). Uterine Fluids Wash Away Inhibitory Factors. Sperm Swim as Their Membranes Becomes More Permeable To Ca++. Acrosomal Reaction & Penetration Of Ovum Sperm First Pass Through Multiple Layers Of Granulosa Cells Using Enzymes In Acrosomal Head (Hyaluronidase). Acrosomal Head Binds To A Receptor In Zona Pellucida Of Ovum. Remaining Enzymes Release, Which Opens Pathway For Sperm To Penetrate Through Oocyte Membranes. Genetic Material Enters Oocyte, Then Fertilization Occurs. 11  The Reproductive System Male - Anatomy Histology The Seminal Vesicle And Vas Deferens Combine This Cross Section Of The Penis Shows The Note The Head, Mid-piece, And Tail. To Form An Ejaculatory Duct (Black) That Passes Erectile Tissues Of Both The Corpus Notice The Light Staining Acrosome At Through The Prostate. Notice Also The Roughly Spongiosum (Lower Right) And One Of The The Tip Of The Head. Equal Amounts Of Stroma (Red) And Smooth Corpora Cavernosa (Upper Left). Muscle (Blue) That Make Up This Gland. This Image Does Not Show The Glandular Portion Of The Prostate. Seminiferous Tubules & Leydig (Interstitial) Cells. Epididymis. Vas Deferens. 12