1. Male Reproductive System

2. Human reproduction involves intricate anatomy and complex behavior
Reproductive Anatomy of the Human Male.
External:
- penis
- scrotum
Internal:
- gonads
- accessory sex glands and ducts.

3. Male Reproductive System

4. The engorgement of the penis with blood causes an erection.
The penis is composed of three layers of spongy erectile tissue.
During sexual arousal the erectile tissue fills with blood from arteries.
The resultant increased pressure seals off the veins that drain the penis.
The engorgement of the penis with blood causes an erection.

5. External structure of the penis:
glans penis
prepuce (foreskin)
There is no verifiable health benefit to circumcision.

6. Male Reproductive System

7. Male Reproductive System

9. Ejaculation/Review What is the anatomy of the penis?
The penis is made up of:
Two chambers called the corpora cavernosa, which run the length of the organ and contain a maze of blood vessels shaped like cavernous spaces (like a sponge)
The urethra, or channel for urine and sperm, which runs along the underside of the corpora cavernosa
Erectile tissue, which surrounds the urethra, two main arteries and several veins and nerves
The shaft, the longest part of the penis
The head (glans), which is at the end of the shaft
The meatus, or opening at the tip of the head where urine and semen are discharged

10. How an erection occurs How does an erection occur?
When the blood vessels of the corpora cavernosa relax and open up, blood rushes in through the cavernosus arteries to fill them. The blood then gets trapped under high pressure, creating an erection.
An erection begins with sensory and mental stimulation. During sexual arousal, nerve messages begin to stimulate the penis. Impulses from the brain and local nerves cause the muscles of the corpora cavernosa to relax, allowing blood to flow in and fill the open spaces. The blood creates pressure in the corpora cavernosa, making the penis expand and creating an erection.
The tunica albuginea (the membrane surrounding the corpora cavernosa), helps to trap the blood in the corpora cavernosa, sustaining the erection. Erection is reversed when muscles in the penis contract, stopping the inflow of blood and opening outflow channels.

11. Testes are located in the scrotum, outside the body cavity.
This keeps testicular temperature cooler than the body cavity.
The testes develop in the body cavity and descend into the scrotum just before birth.

12. Testes

13. Testes are the male gonads.
seminiferous tubules- form sperm
Leydig cells (interstitial cells)- produce androgens (ex. Testosterone, ABP).

14. Sperm Pathway
Membranous urethra
Prostatic urethra

15. seminal vesicle prostate gland bulbourethral gland Semen
Seminal fluid is thick, yellowish, and alkaline.
It contains mucus, fructose, a coagulating enzyme, ascorbic acid, and prostaglandins.
Accessory glands:
seminal vesicle
prostate gland
bulbourethral gland

16. Contains fructose, asorbic acid, coagulating enzyme, prostaglandin
Seminal vesicle:
A pair of glands that secrete a liquid component of semen into the vas deferens.
Secretion is alkaline
Contains fructose, asorbic acid, coagulating enzyme, prostaglandin
Seminal Vesicle

17. Prostate gland:
Location- surrounds and opens into the urethra where it leaves the bladder.
Secretion- slightly alkaline fluid that activates the sperm and prevents them from sticking together
Prostate problems are common in males over 40.
Prostate cancer is one of the most common cancers in men.
Prostate

18. Bulbourethral gland (Cowper’s gland):
Location- paired glands that lie beneath the prostate
Secretion- a thick, clear alkaline mucous that drains into the membranous urethra.
Function- It acts to wash residual urine out of the urethra when ejaculating semen-- raises pH; neutralizes acidity of urine.
Bulbourethral gland

19. Ejaculation
Ejaculation propels sperm from the epididymis to the vas deferens.
The vas deferens run from the scrotum and behind the urinary bladder.
Here each vas deferens joins with a duct from the seminal vesicle to form an ejaculatory duct.
The ejaculatory ducts open into the urethra.
The urethra drains both the excretory and reproductive systems.

20. Ejaculate
A male usually ejaculates about 2 – 5 mL of semen; each milliliter containing about 50 – 130 million sperm.
Bulbourethral fluid also carries some sperm released before ejaculation.
This is one of the reasons why the withdrawal method of birth control has a high failure rate.

21. Ejaculation How does ejaculation occur?
Sexual stimulation and friction provide the impulses that are delivered to the spinal cord and into the brain. Ejaculation is a reflex action controlled by the central nervous system. It is triggered when the sexual act reaches a critical level of excitement. It has two phases.
In the first phase, the vas deferens (the tubes that store and transport sperm from the testes) contract to squeeze the sperm toward the base of the penis and the prostate gland and seminal vesicles release secretions to make semen. At this stage, the ejaculation is unstoppable.
In the second phase, muscles at the base of penis contract every 0.8 seconds and force the semen out of the penis in up to 5 spurts.

22. Spermatogenesis

24. Mature Spermatozoa
acrosome
head
nucleus
tail
mitochondria

25. Seminiferous Tubules

26. Seminiferous Tubules spermatozoa Sertoli cell spermatids
2º spermatocyte
1º spermatocyte
spermatogonium

27. Sperm Maturation & Development

28. Hormones Involved in Spermatogenesis
Gonadotropin Releasing Hormone (GnRH)
Follicle Stimulating Hormone (FSH)
Interstitial Cell Stimulating Hormone (ICSH=LH)
Testosterone
Inhibin
ABP

29. Hormonal Control of Spermatogenesis
Hypothalamus
GnRH
Anterior Pituitary
ICSH
FSH

30. Hormonal Control of Spermatogenesis
ICSH
Interstitial Cells
Testosterone

31. Hormonal Control of Spermatogenesis
FSH
Testosterone
Sertoli Cells
Spermatogenesis
Inhibin

32. Hormonal Control of Spermatogenesis
Feedback Inhibition
Inhibin
Acts on anterior pituitary
Inhibits FSH production
Testosterone
Acts on hypothalamus
Inhibits GnRH production

33. Some Other Effects of Testosterone
muscle and bone growth
facial and pubic hair growth
thickening of vocal cords
growth of pharyngeal cartilage
hair follicle effects
stimulates sebaceous glands
Increased BMR

34. Vasectomy

38. Circumcision foreskin glans penis urethral opening sutures shaft
corona

39. Circumcision

40. Male Circumcision (Mayo Clinic)
Circumcision is a religious or cultural ritual for many Jewish and Islamic families, as well as certain aboriginal tribes in Africa and Australia. Circumcision can also be a matter of family tradition, personal hygiene or preventive health care. Sometimes there's a medical need for circumcision, such as when the foreskin is too tight to be pulled back (retracted) over the glans. In other cases, particularly in certain parts of Africa, circumcision is recommended for older boys or men to reduce the risk of certain sexually transmitted infections.
The American Academy of Pediatrics (AAP) says the benefits of circumcision outweigh the risks. However, the AAP doesn't recommend routine circumcision for all male newborns. The AAP leaves the circumcision decision up to parents — and supports use of anesthetics for infants who have the procedure.
Circumcision might have various health benefits, including:
Easier hygiene. Circumcision makes it simpler to wash the penis. Washing beneath the foreskin of an uncircumcised penis is generally easy, however.
Decreased risk of urinary tract infections. The overall risk of urinary tract infections in males is low, but these infections are more common in uncircumcised males. Severe infections early in life can lead to kidney problems later on.
Decreased risk of sexually transmitted infections. Circumcised men might have a lower risk of certain sexually transmitted infections, including HIV. Still, safe sexual practices remain essential.
Prevention of penile problems. Occasionally, the foreskin on an uncircumcised penis can be difficult or impossible to retract (phimosis). This can lead to inflammation of the foreskin or head of the penis.

41. Circumcision
Easier hygiene. Circumcision makes it simpler to wash the penis. Washing beneath the foreskin of an uncircumcised penis is generally easy, however.
Decreased risk of urinary tract infections. The overall risk of urinary tract infections in males is low, but these infections are more common in uncircumcised males. Severe infections early in life can lead to kidney problems later on.
Decreased risk of sexually transmitted infections. Circumcised men might have a lower risk of certain sexually transmitted infections, including HIV. Still, safe sexual practices remain essential.
Prevention of penile problems. Occasionally, the foreskin on an uncircumcised penis can be difficult or impossible to retract (phimosis). This can lead to inflammation of the foreskin or head of the penis.

42. Circumcision
Decreased risk of sexually transmitted infections. Circumcised men might have a lower risk of certain sexually transmitted infections, including HIV. Still, safe sexual practices remain essential.
Prevention of penile problems. Occasionally, the foreskin on an uncircumcised penis can be difficult or impossible to retract (phimosis). This can lead to inflammation of the foreskin or head of the penis.
Decreased risk of penile cancer. Although cancer of the penis is rare, it's less common in circumcised men. In addition, cervical cancer is less common in the female sexual partners of circumcised men.
Circumcision might not be an option if certain blood-clotting disorders are present. In addition, circumcision might not be appropriate for premature babies who still require medical care in the hospital nursery.
Circumcision doesn't affect fertility, nor is circumcision generally thought to enhance or detract from sexual pleasure for men or their partners.

47. Female Reproductive System

48. Effects of Estrogen breast development external genitalia growth
bone growth
fat deposition
Increase protein anabolism
Decrease blood cholesterol
Facilitate calcium uptake
Promotes hydration of skin
Feminizes brain

49. Female Reproductive System
uterine tube
ovary
fimbriae
uterus
cervix
bladder
vagina
urethra
clitoris
l. minora
l. majora

51. Internal reproductive: Vagina Cervix
Fallopian tube (uterian tube/oviducts)
Fimbrae
Ovary
Uterus
Endometrium
Myometrium
Perimetrium
uterus
uterine tube
ovary
endometrium
fimbriae
myometrium
perimetrium
cervix
vagina

72. Fimbrae & Fallopian Tube

73. Oogenesis in the Ovary

74. Oogenesis
Ovary- contains 400,000 oocytes; release about 500 in a lifetime
Ovary- under influence of FSH. The follicles mature every 28 days
Primary follicle produces estrogens
And primary oocyte completes its 1st division produces 2ndary oocyte and polar body

75. Oogenesis
Aprox 1/2 way through the 28 day cycle the follicle reaches the mature Vesticular or Graffian follicle stage.

76. Oogenesis
Estrogen levels rise and release LH and FSH and triggers ovulation.

77. Oogenesis
The 2ndary oocyte travels down the uterine tube to the uterus.
If fertilized by sperm, it will produce a zygote
Ovum in uterine tube

78. Ectopic Pregnancy

79. Ovarian Cyst

80. Endometriosis
In some women, endometrial tissue grows outside the uterus. Growths may form on the ovaries, fallopian tubes, bladder, intestines, and other parts of the body. When it's time for your period, these clumps break down, but the tissue has no way to leave the body. While this is rarely dangerous, it can cause pain and produce scar tissue that may make it tough to get pregnant. There are treatments for endometriosis, but there is no cure.

81. Oogenesis

82. Hormones Involved in the Female Reproductive Cycle
Gonadotropin Releasing Hormone (GnRH)
Follicle Stimulating Hormone (FSH)
Luteinizing Hormone (LH)
Estrogen
Progesterone
Inhibin
Relaxin

83. Female Hormonal Cycle
Hypothalamus
GnRH
Anterior Pituitary LH
FSH

84. Female Hormonal Cycle
FSH LH
Follicle Cells
Estrogen

86. The Uterine Cycle

89. Hormone Fluctuation

90. Menopause: cessation of ovarian and menstrual cycles.
Usually occurs between ages 46 and 54.
Due to ovaries decreased responsiveness to gonadotropins.
Menopause affects:
changes in sexual desire
triggers mood swings
causes debilitating hot flashes
may lead to bone and heart problems
short-term memory loss
insomnia

91. Milk drains into a series of ducts opening at the nipple.
Mammary glands.
Are present in both males and females.
Are not a component of the reproductive system.
Contain epithelial tissue that secrete milk.
Milk drains into a series of ducts opening at the nipple.

92. Mammary Gland

93. Life’s Greatest Miracle

94. INQUIRY Where are sperm cells formed within the testes?
What portion of the sperm contains 23 chromosomes?
What 3 accessory glands produce seminal fluid?
What is the term for the primary human sex organs?
What structure is formed following ovulation?
6. What hormones are produced from the corpus luteum?
7. List several effective means for preventing conception.