Ch. 23 - The Reproductive System

Question 1

Define the role of the reproductive organs

Answer 1

To produce, sustain and transport, sex cells and hormones.

Question 2

List the male sex organs

Answer 2

Primary organs:
- Testes

Internal accessory organs:

• Epididymides
• Ductus Deferentia
• Seminal Vesicles
• Prostate Gland
• Bulbourethral Glands

External organs:

• Scrotum
• Testes
• Penis

Question 3

Define the function of the testes

Answer 3

Production of Sperm cells and male sex hormones.

Question 4

Describe a Sperm cell

Answer 4

The sperm cell consists of:

• Head - containing the Nucleus, with an Acrosome at the apex of the head
• Midpiece - containing Mitochondria
• Tail

Question 5

Describe the purpose of the male orgasm

Answer 5

The culmination of sexual stimulation.

Accompanied by:
- Emission - the movement of sperm cells from the testes, and secretions of the prostate gland and seminal vesicles, into the urethra, mixing to from semen.

• Ejaculation - increased pressure in the erectile tissues, helps to force semen through the urethra to the outside of the body.

Question 6

Describe the control of male reproductive function and hormones

Answer 6

Reproductive function is controlled by hypothalamic and pituitary hormones:

• FSH - Follicle-Stimulating Hormone
• LH - Luteinising Hormone

Male sex hormones are called androgens with Testosterone being the most important.

Question 7

List the female sex organs

Answer 7

Primary organs:
- Ovaries

Internal accessory organs:

• Uterine Tubes
• Uterus
• Vagina

External organs:

• Labia Majora
• Labia Minora
• Clitoris
• Vestibule

Question 8

Define the function of the Ovaries

Answer 8

Produce female sex cells and hormones.

Question 9

Describe Ovulation

Answer 9

Ovulation is the release of a secondary oocyte from an ovary.

Release of an oocyte involves structures including the primordial follicles, and the processes of oogenesis and follicle maturation.

Question 10

Describe the control of female reproductive function and hormones

Answer 10

• Hypothalamus
• Anterior Pituitary Gland
• Ovaries

Together they secrete hormones that control sex cell maturation.

They also control development and maintenance of female secondary sex characteristic and changes that occur during the monthly reproductive cycle.

The most important female sex hormones are oestrogen’s and progesterone.

The female reproductive cycle is approx. 28 days in length.

A female’s reproductive life is shorter than a male’s, beginning with menarche during puberty, and ending with menopause.

Question 11

Discuss birth control and methods of contraception

Answer 11

Birth control is the voluntary regulation of the production of offspring and when they are conceived.
It usually involves some method of contraception, some of which will protect against STI’s:

• Coitus Interruptus - withdrawal of the penis from the vagina before ejaculation
• The Rhythm Method - abstaining from intercourse 2 days before and 1 day after ovulation
• Mechanical Barriers:
  
  • Male/Female Condoms
  • Diaphragms
  • Cervical Caps
• Chemical Barriers - spermicidal creams, foams, gels
• Combined Hormone Contraceptives - oestrogen and progestin administered variety of ways such as patch, or orally
• Injectable Contraception - medroxyprogesterone IM, stops maturation and oocyte release for 3 months
• Hormonal Implant - slow release capsule containing a potent form progesterone, inserted under the skin
• IUD’s(Intra-Uterine Devices) - object placed into the uterine cavity that interferes with implantation of a blastocyst
• Surgery:
  
  • Males - Vasectomy
  • Females - Tubal Ligation

Question 12

Discuss Sexually Transmitted Infection’s(STI’s)

Answer 12

STI’s often do not show symptoms until they have become very serious.

Most reproductive diseases are caused by STI’s.

Examples of diseases that may be transmitted sexually:

• Chlamydia
• Trichomoniasis
• HIV
• Gonorrhoea
• Syphilis

Pelvic Inflammatory Disease may be a complication of Gonorrhoea or Chlamydia and can lead to female sterility or ectopic pregnancy.

Genital Herpes is a common STI.
Genital Warts are caused by HPV(group of over 60 different viruses), which is linked to the development of cervical cancer.

Question 13

Briefly discuss the end of reproductive life

Answer 13

In women this is signalled by menopause.

In men it does not occur as significantly, with some men being able to father children into their later years.