A&P II Reproductive System

What are the primary sex organs?

Gonads: Testes(male), and ovaries(female).

What do Gonads produce?

Sex cells (gametes)

What do Gonads secrete?

Steroid sex hormones - Androgen's (males), Estrogen's and Progesterone (females).

What do Sex Hormones play roles in?

Development and function of the reproductive organs, sexual behavior and drives, growth and development of many other organs and tissues.

Sex Determination in Humans
# Chromosomes

-Primarily determined by the presence or absence of a Y chromosome
-Chromosomes are composed of DNA and proteins
-In humans, most normal somatic cells have 46 chromosomes or 23 pairs of chromosomes
-Of the 23 pairs, 22 are referred to as autosomes
-The 23

How are sperm delivered?

Through a system of spermatic ducts: Epididymis, ductus deferens ejaculatory duct, and the urethra.

What are the 3 accessory glands of the Male Reproductive System?

1. Seminal vesicles
2. Prostate Gland
3. Bulbourethral glands.

What do the accessory glands do?

Empty secretions into the ducts during ejaculation.

What divides the testis?

lobules, each containing 1 - 4 seminiferous tubules.

What are Sperm conveyed through?

Seminiferous tubules, epididymis.

Male & Female Reproductive Duct

-Male reproductive tract is referred to as the mesonephric duct
-Female reproductive tract is referred to as the paramesonephric duct (Mullerian)

What encloses nerve fibers, blood vessels, and lymphatics that supply the testes?

Spermatic cord.

What are Interstitial (Leydig) cells?

Outside the seminiferous tubules that produce androgens(testosterone)

When does sexual differentiation begin?

12 weeks of gestation ; gonads develop at 5-6 wks as gonadal ridges

SRY gene

Sex determining Region of Y chromosome; in males TDF initiates development of testes and stimulates mesonephric ducts to develop into the male anatomy

MIH

Mullerian-Inhibiting Factor; secreted by testes causing degeneration of the paramesonephric ducts

Development of External Genitalia

Gential Tubercle- Becomes (glans penis) or (glans clitoris)
Urogenital Folds (encloses urethra in male) or (forms Labia minors)
Labioscrotal Folds- Become (scrotum) or (Labia Majora)

% Accessory Glands produce?

Seminal Vesicles = 60% semen
Prostate = 30% semen
spermatic duct secretions = 10%
Bulbo = used to lubricate Glans Penis

Homologous

same evolutionary origin but not necessarily the same function
Penis as to clitoris
Scrotum as to Labia Majora

External Male Genitalia

1. Penis
2. Scrotum

Follicle Stimulating Hormone

MEN: stimulates sperm production
WOMEN: initiates growth of ovarian follicles each month and stimulates ovulation

Andropause

the decrease of the male hormone testosterone

Luteinizing Hormone

A protein hormone that stimulates ovulation in females
and
androgen production in males.

Blood-Testis Barrier

Separates Sperm from immune system
Prevents antibodies and other large molecules in the blood from getting to germ cells

Counter current heat exchange

warm arterial blood would heat the testis and inhibit sperm production- without pampiniform plexus
Must be held at 35 degrees C

what are the Phases of Sexual Response

1. Excitement
2. Plateau
3. Orgasm
4. Resolution

How many ml of semen are ejaculated?

2- 5 ml.

Diploid

cell or organism having two sets of chromosomes or twice the haploid number

What is Infertility?

When sperm count falls below 20 million sperm/ml.

Haploid Cells

A cell containing only one set of chromosomes.

Bacterial STD's

1. Chlamydia - Urethral Discharge & testicular pain
2. Gonorrhea - pain and pus discharge
3. Syphilis - hard lesions at site of infection

Viral STD's

1. Genital Herpes -Blisters & Pain
2. Genital Warts -Warts on perineal region
3. Hepatitis B & C - Inflammatory Liver Disease

2 Stages of Ejaculation

1. Emission
2. Explusion

What is Spermatogensis?

Sequence of events that produces production of sperm in the seminiferous tubules of the testes.
Spermatids into spermatozoa

What happens during Mitosis of Spermatogenesis?

(Cloning) doubles its DNA then divides into 2 identical daughter cells
Spermatagonia can undergo mitosis to produce more or can mature into a cell that will go through meiosis

What happens during Meiosis of Spermatogenesis?

(Variation by division of sex cells) Spermatocytes form spermatids.

Spermatogonium

A spermatogonium is cell containing 2 sets of chromosomes that will divide to give rise to diploid primary spermatocytes

What does the Hypothalamus release?

Gonadotropin releasing hormone (GnRH).

What does GnRH stimulate?

The anterior pituitary to secrete FSH and LH.

Spermiogenesis

the maturation of the spermatids into spermatozoa ; discarding excess cytoplasm and growing tails

What does Inhibin do?

Inhibits the release of FSH and GnRH.

What are the ovaries?

Female Primary Sex Organs (gonads)

What do Ovaries Secrete?

Female sex hormones, estrogen and progesterone.

What are Ovaries held in place by?

Ovarian ligament, suspensory ligament, and mesovarium.

3 layers the Uterine wall consists of?

1. Perimetrium (external)
2. Myometrium (mid layer)
3.Endometrium (internal)

What is the Suspensory Ligament?

Attached to pelvis wall

What is the Mesovarium?

Ancored to broad ligament

What is the Broad Ligament?

Supports the uterine tubes, uterus, and vagina; also contains the suspensory ligament and mesovarium.

Female External Genitalia
(Vulva or Pudendum)

1. Clitoris
2. Labia Minora
3. Labia Majora

Female Internal Genitalia

1. Ovaries
2. Uterine Tubes
3. Uterus
4. Vagina

What are the stages of development of a Follicle?

Primordial Follicle, Primary Follicle

What is the Primordial Follicle?

follicle cell + oocyte.

What does the Cervical Canal Communicate with?

Vagina via the external OS, Uterine body via the internal OS.

What do the Cervical Glands secrete?

Mucus that blocks sperm entry except during midcycle.

What is Breast Cancer?

Cancer that usually arises from the epithelial cells of small ducts.

What are the risk factors of Breast Cancer?

Early onset of mestruation and late menopause, no pregnancies or first pregnancy late in life, family history of breast cancer.

How is Breast Cancer Treated?

Radiation, chemotherapy, and surgery followed by irradiation and chemotherapy.

What is Menopause?

Occurs when menses have creased for an entire year, no equivalent in males.

Female Reproductive System: Functions

-Produce hormones
-Produce gametes: ova
-Protect, support and nourish a developing embryo
-Nourish newborn infant

Oogenesis

the meiosis process that forms ova
-Begins before birth
-Stalls at birth and then some cells re-enter process each month at puberty
-Process is not completed unless fertilization occurs
-Formed at ovarian follicles

Primary Oocyte

-Enters meiosis I
-Divides to produce two haploid cells:
One secondary oocyte
One polar body [smaller cell, usually is insiginificant and reabsorbed, sometimes undergoes meosis]
-Females are born with a set number of primary oocytes
-Prim. oocyte enters m

Secondary Oocyte

-Enters meiosis II
-Divides to produce two haploid cells:
One ovum
One polar body [only occurs if meosis occurs]

The Ovarian Cycle

-Is divided into a follicular phase
-And a luteal phase [what happens to the follicle after ovulation]
-Process that involves the maturation of ovarian follicle and development o the female gamete
-The ovarian cycle on average is about a 28 day cycle
-Ovu

Zygote

a fertilized egg is called a/an __ when the chromosomes of both parents have mingled to form a diploid set.

Embryo

when the three primary germ layers have formed

what are the steps of oogenesis?

1. formation of primary, secondary, and tertiary follicles
2. ovulation
3. formation and degeneration of the corpus luteum

What triggers the secretion of GnRH?

decline in progesterone and estrogen

what does secretion of GnRH trigger?

a rise in FSH and LH production, and beginning of another cycle

when does menstrual activity begin?

menarche (the first uterine cycle)
Ends with menopause

what is milk production called?

Lactation

what stimulates milk production?

Prolactin

Female Puberty

Thelarche - Breast development
Pubarche - Pubic and axillary Hair
Menarche - First menstrual period

Reproductive Cycle

Sequence of events from fertilization to giving birth
-started by FSH which stimulates the maturation of follicle in the ovary
-Ovulation is triggered by mid-cycle surge in LH
-Follicular cells secrete estrogen and progesterone

Sexual Cycle

Events that recur every month when pregnancy does not intervene
-Average 28 days
-Begins with 2 week follucular phase
-Menstruation first 3-5 days of cycle
-Ovulation ~day 14

Ovarian Cycle

1. Follicular Phase
2. Ovulation
3. Luteal Phase (post ovulatory)

Follicular phase

-From Begining of menstruation until ovulation
Preovulatory Phase- End of menstruation until ovulation

Ovulation

Rupture of mature follicle and release of its egg
-takes 2-3 minutes

Tenting effect

Uterus stands nearly verticle (plateau phase)

Gestation

Pregnancy
-Average of 266 Days from conception to birth

Hormones of Pregnancy

-Estrogens
-Progesterone
-HCG (Human Chorionic Gonadotropin)
-HCS (Human chorionic somatomammotropin)
* All primarily secreted by the placenta

Nutrition

-Placenta stores nutrients
-Demands Protein, Iron, Calcium, phosphates
-Vitamin K
-Vitamin D
-Folic Acid

3 Stages of Labor

1. Dilation
2. Expulsion
3. Placental Stage

Involution

Shrinkage of the uterus
breast feeding promotes this

Puerperium

The first 6 weeks after birth

Mammary Gland Development

High estrogen level in pregnancy causes the ducts to grow and branch extensively

Colostrum

Similar to break milk but contains less fat
1-3 days days after birth