Review for Lab Exam 2 (See Study Guide) Respiratory (8 questions) Be able to calculate vital capacity, minute volume Review and understand what you did in lab, the equipment you used to derive your data (yes, yes, spelling counts), and understand the results of your breathing experiments Recognize structures in your study guide on the torso models or in photographs Urinary System (16 questions) Be able to recognize all the structures, including all parts of the nephron and the adrenal glands (know these structures well!!) [torso, plaque models, individual models, photos] Review your urinalysis lab/results and be sure to understand what you did in lab (specific gravity, Clinistix, etc)

Review for Lab Exam 2 Reproductive (torso,isolated models) (4 questions) Be able to recognize the major reproductive structures for the male: testes, epididymis, ductus deferens, seminal vesicles, prostate Be able to recognize the major reproductive structures for the female: ovaries, fallopian tubes, uterus, vagina, ligaments *Endocrine (photo, torso model) (2 questions) Be able to recognize major endocrine organs Cat Dissections (photo, cadaver) (18 questions) Know the cardiovascular system well and be able to recognize the vessels, using either a cat or a photograph of a cat. Be able to recognize major structures listed on your Lab guide using either a cat or a photograph of a cat.

Anatomy and Physiology Reproductive System – Male I, II Martini’s Visual Anatomy and Physiology First Edition Martini w Ober Chapter 25 Reproductive System – Male I, II Lectures 20, 21 84 min (38 slides); 90 min if lab exam review slides are added

Overview of the Reproductive System We can sum up the reproductive system in just a few words…

Lecture Overview Function of the male reproductive system Overview of the anatomy of the male reproductive system Descent of the testes Structure of the testes Formation of sperm cells Structure of sperm cells Male internal accessory organs Male external accessory organs Erection, orgasm, and ejaculation Hormonal control of the male reproductive system

Male Reproductive System There are three main functions of the male reproductive system Produce and maintain sex cells (sperm) Transport sperm and supplemental fluids to the female reproductive tract Secrete male sex hormones Sex organs can be divided into Primary sex organs (gonads) = testes (sperm, hormones) Accessory (secondary) sex organs = internal and external reproductive organs In order for sexual reproduction to take place, we need: 1) mobile cells, 2) cells that are nutrient laden. These two things are impractical to combine into one cell, so males have sperm (DNA with propellers!!), and females have large, nutrient-laden eggs as their sex cells (gametes).

Male Reproductive System Figure from: Martini, Anatomy & Physiology, Prentice Hall, 2001 Testis → Epididymis → Vas (ductus) deferens → Ejaculatory duct → Urethra

Male Reproductive Organs posterior view Figure from: Hole’s Human A&P, 12th edition, 2010

Descent of Testes Figure from: Hole’s Human A&P, 12th edition, 2010 Descent begins 1-2 months before birth under the influence of testosterone Descent is necessary for sperm production Failure of testes to descend = cryptorchidism

Structure of the Testis Figure from: Hole’s Human A&P, 12th edition, 2010 Surrounded by the tunica albuginea – a tough, white, fibrous capsule that encloses each testicle Septa divide each testicle into about 250 lobules Each lobule contains 1-4 highly coiled seminiferous tubules that give rise to sperm Interstitial cells (of Leydig) lie in between seminiferous tubules and secrete male sex hormones Rete Testis

Review of Mitosis and Meiosis Figures from: Martini, Anatomy & Physiology, Prentice Hall, 2001 Major differences between mitosis and meiosis: 1) mitosis produces identical daughter cells, meiosis produces cells with recombined DNA; 2) daughter cells in mitosis have a diploid number of chromosomes whereas in meiosis gametes contain the haploid chromosome number; 3) two daughter cells are produced as a result of mitosis, whereas four cells are produced after meiosis. Mitosis – production of two identical diploid daughter cells Meiosis – production of four genetically varied, haploid gametes

Chromosome Crossing Over Figure from: Hole’s Human A&P, 12th edition, 2010 mixes up traits different colors represent the fact that one homologous chromosome comes from the individual’s father (paternal) and one from the mother (maternal) Tetrad the genetic information in sperm cells and egg cells varies from cell to cell

Seminiferous Tubules and Sperm Maturation Figures from: Martini, Anatomy & Physiology, Prentice Hall, 2001 It takes about 75 days for a spermatogonium to become mature spermatazoon. Spermatogonium = stem cell

Spermatogenesis Spermatogonium (2n) Primary spermatocyte (2n) Know the order of events below! Spermatogonium (2n) Primary spermatocyte (2n) Meiosis I Secondary spermatocyte (n) Meiosis II Spermatid (n) Spermiogenesis Spermatozoan (n)

Formation of Sperm Cells Figure from: Hole’s Human A&P, 12th edition, 2010 Supporting cells are sustentacular cells They: are important in regulating and supporting spermatogenesis help maintain the blood-testis barrier

Structure of a Sperm Cell Figure from: Hole’s Human A&P, 12th edition, 2010 Only flagellum in human body Mitochondria Young men produce about 300,000 sperm per MINUTE, or about 4 million sperm cells per day. Enzymes used to penetrate the egg during fertilization

Male Internal Accessory Organs Figure from: Hole’s Human A&P, 12th edition, 2010

Epididymis Figures from: Martini, Anatomy & Physiology, Prentice Hall, 2001 Takes about 2 weeks for sperm to travel through the epididymis - Maintains fluid produced in the seminiferous tubules - Recycles damaged sperm and cellular debris - Store and protects sperm, and aids in their maturation

Ductus (Vas) Deferens muscular tube about 45 cm long; transports sperm ( can store sperm for several months) extends from epididymis to ejaculatory duct Figure from: Martini, Anatomy & Physiology, Prentice Hall, 2001

Seminal Vesicles attached to ductus deferens near base of bladder secretes alkaline fluid (60% of the volume of semen) secretes fructose, prostaglandins, and proseminogelin begins capacitation of sperm contents empty into ejaculatory duct Newly made sperm contain a thick layer of cholesterol over their acrosomal cap. This prevents premature release of enzymes and damage to male reproductive system. (This cholesterol is later leached away by fluids in the female reproductive tract. This allows more Ca2+ to enter the sperm and causes more powerful lashing of the flagellum.) This process is capacitation. Figure from: Martini, Anatomy & Physiology, Prentice Hall, 2001

Prostate Gland surrounds beginning of urethra ducts of gland open into urethra secretes a thin, milky, slightly acidic fluid (20-30% of semen volume) secretion enhances fluid mobility contains seminalplasmin composed of tubular glands in connective tissue also contains smooth muscle Figure from: Martini, Anatomy & Physiology, Prentice Hall, 2001

Clinical Application - Prostate Enlargement benign prostatic hypertrophy occurs in most men over 50 BPH causes frequent urination risk factors include a fatty diet, having had a vasectomy(?), or exposure to certain environmental factors treatments include surgical removal drugs insertion of balloon into urethra freezing of tumor insertion of stent between lobes of prostate to relieve pressure on urethra

Bulbourethral (Cowper’s) Gland inferior to the prostate gland secretes thick, alkaline mucus - helps lubricate the tip of the penis (glans) and neutralize any urinary acids in urethra fluid released in response to sexual stimulation Figure from: Martini, Anatomy & Physiology, Prentice Hall, 2001

Semen sperm cells secretions of seminal vesicles, prostate gland, and bulbourethral glands (seminal fluid) slightly alkaline (offsets acidity of ♀ reproductive tract) prostaglandins (stimulates contraction in ♀ reproductive tract) nutrients enzymes (protease, seminalplasmin, fibrinolysin) 20-100 million sperm cells per milliliter usually about 2-5 ml of fluid per ejaculate Sperm count below about 20-25 mil/ml is associated with infertility.

Male External Reproductive Organs Figure from: Martini, Anatomy & Physiology, Prentice Hall, 2001

Scrotum pouch of skin and subcutaneous tissue Figure from: Martini, Anatomy & Physiology, Prentice Hall, 2001 pouch of skin and subcutaneous tissue dartos muscle – smooth muscle in dermis; contracts to cause wrinkling of the scrotum (traps heat) medial septum divides scrotum into two chambers each chamber lined with a serous membrane each chamber houses a testis and epididymis Cremaster muscle can retract testes

Penis Connection of penis to body wall (root)

Penis Figure from: Hole’s Human A&P, 12th edition, 2010

Penis Figure from: Hole’s Human A&P, 12th edition, 2010 Preputial glands in the prepuce (foreskin) produce a waxy material called smegma. This can be a source of bacterial growth if hygiene is poor. Circumcision is the surgical removal of the prepuce.

Erection, Orgasm, and Ejaculation parasympathetic nerve impulses blood accumulates in erectile tissues Orgasm culmination of sexual stimulation accompanied by emission and ejaculation Emission and Ejaculation emission is the movement of semen into urethra ejaculation is the movement of semen out of the urethra largely dependent on sympathetic nerve impulses

Mechanism of Penile Erection Bulbospongiosus m. Ischiocavernosus m.

How Does Viagra ™ (Sildenafil) Work? Erotic stimuli Nitric Oxide (NO) Parasympathetic stimulation (Required to start cascade) GTP Guanyl cyclase Interior of smooth muscle cell Smooth muscle relaxation, dilation of blood vessels cGMP Phosphodiesterase 5 (PDE5) VIAGRA (Also Cialis, Levitra) GMP

Mechanism of Emission and Ejaculation Figure from: Hole’s Human A&P, 12th edition, 2010

Hormonal Control of Male Reproductive Functions Figure from: Hole’s Human A&P, 12th edition, 2010 hypothalamus controls maturation of sperm cells and development of male secondary sex characteristics negative feedback controls concentration of testosterone

Actions of Testosterone increased growth of body hair sometimes decreased growth of scalp hair enlargement of larynx and thickening of vocal cords thickening of skin increased muscular growth thickening and strengthening of the bones Know these actions

Review Spermatogenesis Spermatozoa Spermatogonia, 1o spermatocyte, 2o spermatocyte, spermatid, spermatozoan Is a result of meiotic division Under the control of FSH Is guided and regulated by sustentacular cells Produces 4 haploid gametes (spermatozoa) Spermatozoa Head, midpiece, and tail Acrosomal cap – enzymes use for fertilization Non-motile when produced – must undergo capacitation

Review Male Accessory Organs Epididymis Maintains fluid produced in the seminiferous tubules Recycles damaged sperm and cellular debris Store and protects sperm, and aids in their maturation Vas (ductus) deferens – muscular tube for sperm transport and storage Seminal vesicle Alkaline fluid with fructose, prostaglandin, and fibrinogen About 60% of semen volume in ejaculate

Review Male Accessory Organs (cont’d) Prostate gland Thin, milky fluid 20-30% of semen volume in ejaculate Seminalplasmin Bulbourethral glands Cowper’s glands Thick, mucus-like substance Lubricates glans of penis Neutralizes acids in urethra

Review Semen External Reproductive Organs Sperm + seminal fluid 20-100 million sperm per ml in ejaculate (2-5 ml) Contains enzymes External Reproductive Organs Scrotum Contains and separates testes Cremaster and dartos muscles regulate temperature of testes Penis Root, body (shaft), and glans; prepuce (foreskin) Erectile tissues (c. cavernosum, c. spongiosum) Urethra (common pathway for urine and sperm) Prepuce

Review Erection, orgasm, emission, and ejaculation Erection Filling of erectile tissues with blood; venous drainage is blocked Controlled by parasympathetic NS (nitric oxide) Orgasm - highly pleasurable culmination of the sexual experience, accompanied by emission and ejaculation Emission - movement of semen into urethra Ejaculation - movement of semen out of urethra Orgasm, emission, and ejaculation are controlled by the sympathetic NS

Review Hormonal control of male reproductive system FSH LH (ICSH) Meiosis in primary spermatocytes Secretion of inhibin by sustentacular cells LH (ICSH) Secretion of androgens (testosterone) by interstitial cells Levels of FSH and LH inhibit release of GnRH and FSH/LH Effects of androgens