Ch 18 NOTES Reproduction

Section 18.2 Male Reproductive System

I. Structure and Function: • produce sex hormone, testosterone• produce and store the male reproductive

cells, sperm• deliver sperm to the female reproductive

system to join with an egg in the process of fertilization.

• Testes - two small glands that produce the male sex cells, sperm – 100 million per day starting at puberty.

• Testosterone – male sex hormone also produced in the testes that start sperm production.

• Scrotum - holds testicles, keeps at specific temperature.

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Male Reproductive System

Seminal vesicle

Prostate glandBulbourethral gland

Front View

Urinary bladder

Vas deferens

Urethra

Penis

Epididymis

Testis

• Undescended testis: when one or both of the testes may not descend into the scrotum before birth.

• Penis – an external sexual organ through which sperm leave the body. The tip is covered with loose skin, called the foreskin.

• Circumcision – surgical removal of the foreskin of the penis (visual)

Other Structures and the Pathway of Sperm

1. Sperm produced in the testes will mature and be stored in the epididymis.

2. During sexual arousal sperm will travel from the epididymis through the vas deferens to the

3. Seminal Vesicles where fluid is added to give the sperm energy for mobility.

4. Next the prostate gland adds fluid to protect the sperm as the two vas deferens join to form the urethra at the base of the bladder. The urethra is the common passageway for both semen and urine.

5. The bulbourethral gland adds fluid that protects the sperm from acidic conditions in the urethra.

The mixture of sperm cells and these fluids (seminal vesicle, prostate and bulbourethral) is called semen.

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Seminal vesicle

Prostate gland

Bulbourethral gland

Side View

Scrotum

Urinary bladder

Vas deferens

Urethra

Penis

Epididymis

Testis

D. Release of Sperm

- Semen are released from the penis during the process of ejaculation. 1. Semen – thick fluid containing

sperm and other secretions from reproductive system.

2. Ejaculation – series of muscular contractions and semen is expelled from the penis.

3. Fertilization – union of a sperm and an egg.

4. Nocturnal Emission or wet dream – usually occurs when a male begins to produce sperm, occurs normally when the male ejaculates during sleep.

II. Keeping Healthy

Cleanliness• Dry well after showering to prevent fungal

infections that can cause jock itch

Sexual Abstinence• Avoid a number of serious infections of the

reproductive system and other body systems by refraining from sexual activity

Protection from Trauma• Wearing a cup during

athletic activities• Take care when lifting

heavy objects. An inguinal hernia can result when part of the intestine pushes into the scrotum.

Self-Exams• Monitor your body for signs of

possible medical problems• Pain when urinating, unusual

discharge, or sores on the genitals• Examine the testes for testicular

cancer. 1/3 of testicular cancer cases occur in young men in their teens and twenties. (visual)

Medical Checkups• Enlarged Prostate • Prostate Cancer – 2nd most common

cause of cancer death among older men• Diagnose Infertility – a condition of

being unable to reproduce generally caused by•Exposure to chemicals•Having mumps after puberty•Having undescended testis

Section 18.3 – The Female Reproductive System

Structure and Function

• Produce and store female reproductive cells: eggs (ova)• Produce sex hormones and provide a nourishing environment in which a fertilized egg can develop

Ovaries • 2 almond size glands where eggs are produced• Two important

functions 1-produce the female sex hormones estrogen and progesterone and 2-release mature egg cells about once a month during ovulation

Fallopian Tubes

• Two passageways that carry eggs away from the ovary and to the uterus or womb• This is also where fertilization usually takes place if sperm are present

Uterus• Hollow, muscular,

pear-shaped organ with a narrow base called the cervix• The site where a

fertilized egg can develop and grow

Vagina• Also called the

birth canal, the vagina is a hollow, muscular and elastic passageway leading from the uterus to the outside of the body• Sperm first

enter the females body through the vagina

The Menstrual Cycle• Females are born

with the only eggs they will ever have• Starting around

puberty, females will usually produce one mature ovum each month during the process called the menstrual cycle

Factors Affecting the Menstrual Cycle

•Average cycle lasts 28 days (it can also be normal for some individuals to go longer or shorter than this)•Diet, Stress, Exercise, Weight gain or loss can affect the cycle•Puberty is also a time when the cycle can be irregular•Menopause occurs between 45-55 when the ovaries will no longer release eggs, gradually the menstrual cycle stops and a woman can no longer become pregnant

Stages of the Menstrual Cycle

The Menstrual Cycle

Days 1–4 The uterine lining is shed during menstruation.

Days 5–13 An egg matures in one of the ovaries, and the uterine lining starts to thicken.

Egg

Egg

Maturing Egg

Days 14–15 The ovary releases the mature egg during ovulation.

Days 16–22 The egg travels through the fallopian tube to the uterus, and the uterine lining continues to thicken.

Days 23–28 The unfertilized egg enters the uterus.

Stages of the Menstrual Cycle•During the first half of the cycle, an egg matures in one of the ovaries and the lining of the uterus, the endometrium, thickens•Ovulation: Sometime near the middle of the cycle (ie. day 14) a mature egg is released and travels into the fallopian tube• This is when a female is most fertile, or

able to become pregnant

• It can take 7 days for the egg to travel from the fallopian tube to the uterus•Menstruation (Menstrual Period): several days later, IF fertilization didn’t take place around ovulation, the uterine lining (endometrium) breaks down and passes out of the female’s body. This stage will last 3-5 days on average

Menstrual Discomfort• Abdominal cramps possibly caused by contractions of the uterus• Premenstrual Syndrome (PMS) – nervous tension, mood swings, headaches, bloating, irritability experienced before the menstrual period• Doctors recommend

reducing salt, sugar and caffeine intake and get regular exercise or other stress relieving techniques

Toxic Shock Syndrome•Rare but serious medical condition associate with tampon use and a bacterial infection that can possibly lead to death•Seek medical attention immediately if you experience these symptoms: sudden high fever, rash, vomtting, diarrhea, dizziness• Lower your risks by using the lowest absorbency needed and change tampons often

Keeping Healthy

•Cleanliness•Daily washing of the external vaginal area and regularly change sanitary pads or tampons during menstruation•Female hygiene sprays, douches, and deodorants are not necessary and may be harmful if they cover up signs of an infection or cause irritation

Keeping Healthy•Sexual Abstinence• The only way to eliminate the risk of sexually transmitted infections is to abstain from sexual activity

•Prompt Treatment for Infections• Some infections may not be related to sexual activity• Vaginitis caused by yeast, bacteria, or other microorganisms can cause thick discharge, odors, itching, and burning sensations during urination. Seek a doctor if you ever notice these symptoms

Self-Exams•Monitor the body for possible signs of medical problems• Self-Breast Exam performed by all women (including teens) once/month, a week after their menstrual period, to detect Breast Cancer

Medical Checkups• A yearly checkup of the reproductive system is recommended for all females who have reached puberty• A doctor will examine the breasts

and genitals and may perform a pelvic exam and Pap smear. A Pap smear is a sample of cervical cells examined under a microscope to detect cervical cancer

•Mamograms – x-rays of the breast that can help detect breast cancer. These are usually performed at about age 40

Doctors can also detect and treat other reproductive problems

• Ovarian Cysts – growths on the ovaries• Endometriosis –

when the endometrium grows outside the uterus in the pelvic area

• Infertility – the inability to become pregnant. This is most often due to a blocked fallopian tube and problems with ovulation