1. Chapter 19 Reproductive System
Anatomy
Male Reproductive System

2. Introduction Primary Sex Organs Gonads Testes – male
Produce sperm – male gamete (sex cell) – exocrine function
Produce testosterone – male hormone – endocrine function
Ovaries – female
Produce Ova/egg – female gamete (sex cell)
Produce estrogen – female hormone
Accessory Sex Organs
Remaining sex organs

3. Sex Hormones Testosterone/Estrogen
For the development and functioning of the reproductive organs
For growth and development of other organs and tissues of the body

4. Male Reproductive Organs Figure 19.1
Scrotum
Fleshy pouch divided into two chambers each housing a testis (male gonads)
Extends outside of the body posterior to base of penis
Superficial dartos smooth muscle which wrinkles the scrotal surface
Deeper skeletal muscle – cremaster
Contracts to pull testes closer to the body
Sperm need to be cooler than body temperature

5. Testis Appearance Olive-size Covered by capsule – tunica albuginea
Capsule extends in dividing testis into lobules
Lobules contain tightly coiled seminiferous tubules
Sperm producing factories
Empty sperm into rete testis which empty into the epididymis

6. Interstitial Cells
Surrounding the seminiferous tubules
Produce testosterone – male reproductive hormone
Duct System
Accessory male organs
Transports sperm from the testes through the penis
Epididymis, ductus (vas) deferens, ejaculatory duct, urethra

7. Male Reproductive Tract
Epididymis
Appearance
Tightly coiled threadlike tube; 20 feet long
Location
On top of the testis, descends along the posterior surface
Epididymis becomes the ductus/vas deferens as it turns up towards the body

8. Function Passageway for sperm to the ductus/vas deferens
2 week journey
Immature sperm and non-motile
Allows time for sperm to mature
Contains cells to reabsorb cellular debris from abnormal or damaged sperm
Contains cells to absorb nutrients from blood
Secretes a substance which prevents premature capicitation
Becoming motile and fully functional
Requires secretion from seminal glands and acidic conditions inside female tract

9. Ductus (Vas) Deferens Appearance Long, winding tube Location
Continuation of the epididymis
Passes thru the inguinal canal into the abdominal cavity
Arches over the urinary bladder
Enclosed with nerves and blood vessels in connective tissue forming the spermatic cord
Peristaltic contractions empties sperm into the ejaculatory duct which passes through the prostate gland

10. Function
Store sperm for several months
Transport sperm from to ejaculatory duct
Vasectomy
Small incision into the scrotum cutting through the part of the vas deferens in the scrotum
Sperm are still produced but can no long be expelled out of the body

11. Ejaculatory Duct Figure 19-5
Junction of ductus deferens with duct from seminal vesicle
Extends about 1 inch into the prostate gland
Empties sperm into the prostatic urethra

12. Urethra
Location
Extends from the base of the urinary bladder to the tip of the penis
Last part of the duct system
Regions
Prostatic urethra
Passes through the prostrate gland
Contains the internal urethral sphincter
Membranous urethra
Passes through the muscles of the pelvic floor
Contains external urethral sphincter
Penile urethra
Passes through the length of the penis

13. Urethral Function Carries both urine and semen Semen
Sperm and fluids from the accessory glands
Semen and urine never pass at the same time
During ejaculation, the internal urinary sphincter contracts preventing passage of sperm to bladder and passage of urine to urethra

14. Accessory Glands Produce seminal fluid Seminal vesicles Prostate gland
Bulbourethral glands
Functions
Contribute fluids of semen – seminal fluids
Nutrients for motility
Activate the sperm
Peristalsis of sperm and fluids
Produce buffers against acidity of urethra and vagina

15. Seminal Vesicle
Paired tubular glands which attach to the vas deferens at the base of the urinary bladder
Secretes the major portion of the seminal fluid (60%)
Thick, yellowish secretion
Fructose - sugar - energy for the sperm motility
Prostaglandins for peristalsis in male and female tract
Fibrinogen – forming a temporary clot of semen in vagina after ejaculation
Alkaline secretion to neutralize acids
Secretion causes sperm to become motile

16. Prostate Gland Appearance Single gland; chestnut shape
Ejaculatory duct passes through
Location
Surrounds the prostatic urethra
Function
Secretes prostatic fluid – 30% of seminal fluid
Thin, milky, alkaline fluid
Contains an antibiotic that may help prevent urinary tract infections in males
Secretion is released into the urethra

17. Bulbourethral Glands Location Inferior to the prostate gland
Appearance
Very small pea-sized gland
Function
Secretes a clear, thick, sticky, alkaline mucous fluid
Lubricates the penis for sexual intercourse
Cleanse the urethra of traces of acidic urine

18. Penis Figure 19-6 Tubular organ, contains penile urethra Three regions
Root
Attaches penis to body wall
Body/shaft
Contains erectile tissue to deliver the sperm to the female vagina
Spongy tissue that fills with blood causing the penis to enlarge and become rigid – Erection

19. Glans
Expanded distal end surrounding opening
External urethral meatus
Covered by loose skin
Prepuce (foreskin)
Removed by circumcision

20. Chapter 19 The Reproductive System
Anatomy
Female Reproductive System

21. Female Reproductive System
Functions
Produce the female gametes (ova)
Nurture and protect the developing fetus
Produce female sex hormones
Primary reproductive organ – Gonad
Ovaries
Exocrine function – produce eggs/ova
Endocrine function – produce hormones
Estrogens, progesterone

22. Ovary Figure 19-8 Function Development of egg cells to maturation
Appearance
Paired, almond shaped organs
Pale white or yellowish color
Nodular consistency resembling lumpy oatmeal
Location
Suspended by ligaments in the pelvic cavity
Broad ligament; Ovarian ligament
Nourishment/removal of waste
Ovarian artery and vein
Function
Development of egg cells to maturation
About 3 months

23. Uterine Tubes/Fallopian Tubes Figure 19-11
Location
Extend from the ovaries to the uterus
Appearance
Muscular tube lined with cilia
Expands near ovaries to form funnel shaped structure – infundibulum containing finger-like projections called fimbriae
Does not make physical contact with the ovaries
Fimbriae contain cilia that beat toward the tube forming currents with move the ovum into the tube

24. Function
Receive the ovulated egg
Depends on movements of the cilia of fimbriae
Some eggs are lost in the peritoneal cavity and might even be fertilized there
If fertilization is to occur, the secondary oocyte must meet the sperm in 12 – 24 hours
Unfertilized oocytes will degenerate
Carry egg (zygote if fertilization occurred) to the uterus
Muscular walls for peristalsis
Rhythmic beating of cilia in uterine tubes

25. Uterus Appearance Hollow, muscular organ Shape of an inverted pear
Fundus, body, cervix
Cervix - Lower 1/3 of the uterus projecting into the vagina
Location
Between urinary bladder and rectum
Superior to the vagina usually bent forward over the urinary bladder
Held in place in the pelvic cavity by ligaments
Broad ligament

26. Function
Implantation
Attachment of embryo
Site of embryo development
Prepares each month for zygote
If no fertilization, menstruation occurs

27. Tissue Layers of Uterus
Endometrium
Inner mucus lining
Two layers
Superficial functional layer
Undergoes changes due to sex hormone levels
Deeper basilar layer
Reponsible for reforming the functional layer monthly
Embryo burrows into this lining – implantation
Sloughs off about every 28 days if fertilization does not occur

28. Myometrium
Thick muscular layer
Contracts during childbirth
Perimetrium
Outer layer
Visceral peritoneum

29. Vagina Appearance Elastic, muscular tube; 3-4 inches long
Opening is the vaginal orifice covered by the hymen
Contains resident bacterial supported by nutrients in mucus of vagina
pH is 3.5 – 4.5 restricts growth of pathogens
Location
Extends from the uterus to the outside
Posterior to the bladder/Anterior to the rectum

30. Functions
Transports uterine secretions
Transports the fetus during childbirth – birth canal
Receives the penis during intercourse

31. External Genitalia Figure 19-12
Female reproductive structures external to the vagina
Also called the Vulva
Mon pubis, labia, clitoris, vestibular glands
Mons pubis
Fatty rounded area over the pubic symphysis
Covered with pubic hair after puberty

32. Labia
Labia majora
Hair covered skin folds
Labia minora
Located between the labia majora
Hairless
Clitoris
Small projection at anterior end of vulva
Corresponding to penis of the male
Hooded by the prepuce
Contains erectile tissue which becomes swollen with blood during sexual excitement

33. Vestibular glands
Produce mucus
Lubricates distal end of vagina during intercourse

34. Mammary Glands Figure 19-13
Glands of the breast secreting milk in a process called lactation
Breast is divided into lobes each containing ducts which converge to a single lactiferous duct
Near the nipple, the lactiferous ducts expands into the lactiferous sinus
Open onto surface of the nipple
Nipple surrounded by reddish-brown tissue called areola containing sebaceous glands
Breast is connected to chest muscle wall by suspensory ligaments

35. Chapter 19 Reproductive System
Physiology of the Reproductive System

36. Human Life Cycle Figure 16.4
Somatic body cells contain 46 chromosomes – diploid number or 2n
Sex cells – gametes – haploid number or n
Sperm cell – 23 chromosomes
Egg cell – 23 chromosomes
Fertilization
Union of sperm and egg produces a zygote with 46 chromosomes
Half the characteristics from male sex cell
Half the characteristics from female sex cell

37. Meiosis
Special type of division which occurs in gonads – ovaries, testes
Production of gametes with n number of chromosomes
Reduces the diploid number of chromosomes to the haploid number
Oogenesis
Production of the female sex cells – ova
Spermatogenesis
Production of the male sex cells - spermatozoa

38. Meiosis Consists of two successive divisions of the nucleus
Meiosis I and Meiosis II
Each division is divided into stages
Prophase, metaphase, anaphase, telophase
Results in 4 daughter cells (gametes) instead of 2
A way to reduce the number of chromosomes in half

39. Spermatogenesis Figure 19-3
Sperm production
3 processes
Mitosis
Stem cells – spermatogonia
Beings during puberty and continues throughout life
Millions of sperm produced daily
Occurs in the seminiferous tubules
One daughter cell remains in seminiferous tubule; the other is pushed into the lumen
Primary Spermatocyte

40. Meiosis I Meiosis I Chromosomes replicate
Homologous pairs – maternal and paternal come together in a process called synapsis
4 chromosomes called a tetrad
Crossing over of genetic information may occur
At the end of meiosis I daughter cells receive both copies of either the maternal chromosome or the paternal chromosome from each tetrad
Forms the secondary spermatocytes

41. Meiosis II
Each secondary spermatocyte contains 23 chromosomes but each consists of 2 chromatids
Duplicate chromatids will separate in meiosis II
Forms the spermatids
Each with 23 single chromosomes
n number of chromosomes

42. Spermiogenesis Figure 16.5b
Process of the last stage of sperm development
Excess cytoplasm is sloughed off
Sperm is compacted into three regions – head, midpiece and tail
Tail – flagella develops

43. Mature Sperm Figure 19-4 Head Nucleus containing DNA – 23 chromosomes
Covered with an acrosome
Similar to a large lysosome
In close contact with the oocyte the acrosomal membrane breaks down and releases enzymes that help the sperm penetrate through the follicle cells surrounding the oocyte

44. Midpiece
Contains centrioles which contain filaments that form the flagella
Filaments are covered by mitochondria providing he energy for movements of the flagella
Tail
Flagella
Only example of a flagellum in humans
Enable sperm to move long distances in a short time

45. Hormones Testosterone Production
FSH stimulates the seminiferous tubules to produce sperm
LH luteinizing hormone/ISCH interstitial cell stimulating hormone
Testosterone Production
Function of the interstitial cells in seminiferous tubules
Testosterone
Stimulates reproductive organs to develop
Functions in the sex drive
Causes the secondary male sex characteristics to appear

46. Male Secondary Sex Characteristics
Deepening of voice due to enlargement of larynx
Increased hair growth all over the body
Axillary regions
Pubic regions
Face
Enlargement of skeletal muscles
Thickening of bones

47. Oogenesis Figure 19-9 Process of production of female gametes – ova
Total number of eggs a female can release is determined by the time she is born
Release of eggs begins during puberty and ends in her 50’s or earlier
Menopause – gradual decline and end to a woman’s ability to reproduce

48. Oogonia – female stem cells
Somatic cells containing the 2n number of chromosomes
These cells are located in the periphery of the ovary
These cells go through mitosis in the female FETUS
Daughter cells are called primary oocytes – in prophase I of meiosis
Primary ooctye is pushed into the ovary connective tissue and is surrounded by follicle cells

49. At birth all the cells are primary oocytes
Oogonia no longer exist
This the females’ life supply of eggs approximately 2 million
Waiting to undergo meiosis and produce functional eggs
Remain at this point until puberty

50. Meiosis
Production of 4 daughter cells but the cytoplasm is not evenly distributed
One functional ovum with cytoplasm
3 nonfunctional polar bodies which disintegrate
Ovary releases a secondary oocyte not a mature ovum
Meiosis II does not occur producing a mature ovum unless fertilization occurs

51. Puberty Ovarian cycle Cyclic changes that monthly in the ovary
Results in one of these oocytes ovulating each month
Female has approximately 40 years of reproductive life: age 11 – 51
Typically one ovulation per month
Fewer than 500 ooctyes are actually released

52. Ovarian Cycle Figure 19-10 Step 1 Formation of primary follicles
Formation of follicle cells around the primary oocyte
Step 2 Formation of secondary follicles
At puberty pituitary gland secretes FSH, follicle stimulating hormone
FSH stimulates a small number of primary oocytes to grow and mature each month

53. Step 3 Formation of mature Graafian follicle
Up until this time the primary oocyte has been suspended in meiosis I prophase
At this time LH luteinizing hormone causes the primary oocyte to complete meiosis I
Produces one daughter cell (secondary oocyte) and one polar body
Secondary oocyte begins Meiosis II

54. Step 4 Ovulation
Egg is released
Meiosis II is completed only occurs if fertilization occurs
Otherwise the secondary oocyte deteriorates and is removed from the body in the menstrual flow

55. If fertilization occurs
Secondary oocyte divides into a second polar body and an ovum
Second polar body deteriorates and dies quickly
The fertilized ovum moves into the uterus and attempts to embed itself
The ovum has the n number of chromosomes

56. Step 5 Formation and degeneration of corpus luteum
After ovulation, the empty follicle collapses and the follicular cells multiply to produce an endocrine gland called the corpus luteum which secretes estrogen
This secretion will continue for about 10 days and then stop if fertilization does not occur
If fertilization does occur it will continue to secrete estrogen until the placenta develops to take over the secretion

57. Uterine/Menstrual Cycle
Cyclic changes that the endometrium of the uterus undergoes
Response to changing levels of ovarian hormone in the blood
Female cycle is about 28 days
Ovulation generally occurs midway about day 14

58. Menses
Day 1 – 5
Functional layer of endometrium is detaching from the uterine wall
Bleeding occurs from 3 – 5 days
Detached tissues and blood pass through the vagina as menstrual flow - menstruation
Day 5 ovarian follicles are beginning to produce estrogen

59. Proliferative Stage Day 6 – 14
Basal layer of uterus regenerates the functional layer
Endometrial blood supply is increased
Glands are formed
Endometrium thickens and becomes well vascularized
Ovulation occurs

60. Secretory Stage
Day 15 – 28
Corpus luteum producing progesterone and estrogen
Increased blood supply in endometrium
Glands secrete nutrients into the uterine cavity
Will sustain a developing embryo until it has implanted

61. If fertilization does not occur the corpus luteum will stop secreting hormones
Blood vessels in functional layer will go into spasms and kink
Endometrial cells deprived of oxygen and nutrients will begin to die leading to the menstrual phase

62. Secondary Sex Characteristics
Caused by estrogen secretion
Enlargement of accessory female reproductive organs – uterine tubes, uterus, vagina, external genitals
Development of breasts
Appearance of axillary and pubic hair
Increased fat deposits in skin especially in abdomen and hips
Widening and lightening of pelvis
Onset of menses