Male and Female Reproductive Systems

Did you know?

• The reproductive system is the only system not designed for the survival of the individual, but the survival of the species

• The female egg cell is the largest human cell• 500 million sperm are produced per day in a mature

male• The ovaries of a newborn girl have about 600,000

eggs• A female is capable of giving birth to about 35

children in her lifetime

Male Reproductive systemMale External Organs

• Scrotum & penis• Male scrotum is outside the body to keep

sperm just outside body. Sperm viable just below body temp.

• When temperature is too low, scrotum retracts towards the body

• When too hot, scrotum distends further away from the body

• Both are covered by skin

Penis• Urethra-

– Carries urine or semen

• 2 Corpora Cavernosa– The erectile tissue with

many small cavities fill with blood to form erection

• Glans- head of penis• Corona- posterior border

of glans

Male Reproductive System

Testes

Internally divided into many lobulesEach lobule contains a seminiferous tubuleSpermatogenesis takes place hereInterstitial cells near septa that separate lobules

Secrete testosterone

Testosterone

• The “masculinizing hormone”• Responsible for change in voice• Stimulates protein anabolism males

usually more muscular /stronger• Changes size and shape of bones• Produces body and facial hair• Maintains development of male accessory

organs

Spermatogenesis-10 Weeks to Development2N diploid N haploid

Sperm

flagellum

With enzymes that help break through Zona pellucida that surrounds egg.

Haploid package of genesAcrosome contains enzymes to penetrate the eggMiddle section packed with mitochondriaFlagella to swim

Sperm Facts• Average of 180 million released at a time, can be

up to 400 million

• Sperm count less than 60 million is considered clinically infertile

• Die in fresh water

• Die as they dry out

• Sperm can live in a female for up to 7 days

Accessory Ducts & Glands• Seminal Vesicle- produces about 60% of

seminal fluid. –Proteins, enzymes, mucous, vitamin C,

fructose• Prostate Gland- produces a slightly basic fluid

(7.3 pH) to help neutralize acidity of vagina to preserve sperm. 10-30% of seminal fluid

• Bulbourethral Gland (Cowper’s Gland)- produces clear pre-ejaculate to lubricate urethra and neutralize urine residue

• Ejaculatory Duct- Semen passes through during ejaculation

Male Fertility Testing

•Sperm counts

•Fructose levels

•Motility

•Structure

Disorders of Male Reproductive

• Testicular Cancer- – Most common cancer in

males under 40– Male teens should learn

testicular examinations to feel for tumor growth

• Hernia-– Portion of intestines

breaks through abdominal wall into scrotum

• Prostate Cancer– Prostate grows with

age, and can become cancerous

– Rare under 40– Pain passing urine or

slow passage– Highly treatable if

detected early• STDs

Circumcision

Vasectomy

Post Vasectomy Sperm Counts to ensure successful

Female Reproductive SystemFemale External Genitalia- Vulva

http://www.medicinenet.com/female_reproductive_system/article.htm

Ovaries• Made of several

thousand ovarian follicles– Each contains an

ovum• Produce one

mature ovum per month

• Produce sex cells & hormones– Estrogen &

Progesterone

Female Reproductive System

Ovum Development

• Each ovum is in a follicle• Each follicle goes through

a cycle of development each month releasing estrogen

• When egg is released from mature follicle, ovulation occurs

• Corpus Luteum- follicle without egg that produces progesterone, necessary to maintain pregnancy

Fallopian Tubes

• Not connected to ovary

• Eggs are discharged into abdomen and find their way to fallopian tubes

• Lined with cilia to help move egg towards uterus

Uterus• About the size of a

pear• Lies behind bladder• Late stages of

pregnancy moves up and can push on diaphragm

• Almost all muscle• Grows considerably to

hold baby & fluid• Cervix is lower narrow

section

Functions of Uterus• Three functions– Menstruation• Low levels of

hormones after 14 days after ovulation trigger shedding of endometrium• Repairs itself after

in preparation for pregnancy

– Pregnancy– Labor

Vagina

• Made of smooth muscle

• Lined with a mucous membrane

• Organ that sperm enters

• Organ baby exits

Breasts• Lies over pectoral muscles• Mostly fatty tissue• 15-20 radially arranged lobes

containing several lobules• Lobules contain milk-

secreting cells• Cells arranged in grape-like

clusters called alveoli• Alveoli drain into lactiferous

ducts that head towards nipple

• Areolar colored region around nipple– Turns from pink to brown

in early pregnancy

Menstrual Cycle

• Typically 28 days• Three phases– Menstruation– Postmenstrual– Premenstrual

• One ovum matures per month for 30-40 years

• Consists of changes in– Breasts– Uterus– Ovaries– Vagina– Anterior Pituitary

secretion of hormones

Ovulation

• 1st day of period is 1st day of cycle

• Ovulation occurs 14 days before next period

• Cycle may vary in length of days

• Ovum only lives short time after it is ejected

Hormones Involved• Follicle Stimulating Hormone (FSH)- stimulates

ovarian follicle to start growing and secreting estrogen

• Estrogen- Responsible for breast growth, thickening of endometrium

• Leteinizing Hormone (LH)- triggered by elevated blood estrogen. Causes maturation of ovum & follicle, ovulation, and formation of corpus luteum

• Progesterone- secreted by corpus luteum and helps maintain pregnancy. If pregnant, placenta maintains level, if not, levels drop and menstruation occurs

Cycling of Hormones

Menstrual Cycle

How does “The Pill” work?• A 21 day combination of

estrogen & progesterone

• Suppresses FSH & prevents ovulation

• Last 7 pills are placebo to maintain practice of pill taking

• Antibiotics, anti-seizure, migrane medicine reduce effectiveness of pill

• Does NOT protect against STDs

Female Disorders/Conditions

• Ovarian Cysts– May cause pelvic or

abdominal pain or bleeding if rupture

– Most commonly benign but should be investigated

– Result of follicles growing too large

– Many go away on their own

• HPV & STDs

• Endometriosis– Endometrial lining grows

outside of the uterus– Very painful periods– Abnormal bleeding– Could cause infertility

• Fibroids– Benign tumors– Pain, heaviness in

abdomen• Menopause– Mechanisms of

menstruation cease to function due to age

Ectopic Pregnancy

Tubal Ligation