Compendium 7: Reproductive

I. Reproductive System

• A. Human Life Cycle
• B. Male Reproductive System
• C. Female Reproductive System
• D. Female Hormone Levels
• E. Control of Reproduction
• F. Sexually Transmitted Diseases

II. Development and Aging

• A. Fertilization
• B. PreEmbryonic and Embryonic Development
• C. Fetal Development
• D. Pregnancy and Birth
• E. Development after Birth
  
  

I. Reproductive System

A. Human Life Cycle

---Mitosis and Meiosis---

All cells contain 46 chromosomes

Mitosis takes place with growth and repair

Meosis take place is testes and ovaries (sperm and egg)

During Meiosis the number of chromosomes is 23

Zygote is the first cell of new human

Sperm and egg both carry 23 chromosomes

Zygote has 46 chromosomes

(http://en.wikipedia.org/wiki/Image:Sexual_cycle.svg)

B. Male Reproductive System

---Parts of the male reproductive system---

Testes: Produce sperm and sex horomones

Epididymides: Ducts where sperm mature and are stored

Van Deferentia: Conduct and store sperm

Seminal Vesicles: Contribute nutrients and fluid to sperm

Prostate Gland: Contributes fluid to sperm

Urethra: Conducts sperm

Bulbourethral Glands: Mucus containing fluid to semen

Penis: Gland of sexual intercourse

(http://healthcare.utah.edu/healthinfo/adult/men/maleanat.htm)

---Orgasm in Males---

During sexual arousal autonomic nerves release Nitric oxide which leads to the production of cGMP. cGMP fill erective tissue upwith blood. Veings take the blood away from the penis are compressed which causes an erection.

Contractions that expel the sperm are part of the male orgasm

400 million sperm in 3.5 ml of semen

---Male Gonads, the Testes---

The scrotum helps regulate the temperature of testes

Seminiferous tubles are packed with cells undergoing spermatogenesis

During the production of sperm primaray spermocytes moves away from outer wall, increase in size and go through meiosis I.

Secondary Spermocytes go through meiosis II to produce 4 spermatides each containing 23 chromosomes

It takes 74 days form sperm to develop

Sperm has 3 parts (head, middle piece, and tail)

Middle piece produces energy for the tail

Sperm only live up to 48 hours in female

---Hormonal Regulation in Males---

Hypothalamus controls Testes GnRH

FSH promotes production of sperm

LH controls production of testostrone

Testostrone is main sex horomone; gives male characteristics and helps with muscular development

C. Female Reproductive System

---Genital Tract---

Ovaries: Produce eggs and sex hormones

Oviducts: Conduct eggs; location of fertilization

Uterus: Fetus develops here

Cervix: Opening of Uterus

Vagina: Birth canal; menstral flow exit; and sex organ

---External Genitals---

Vulva: two large folds

Glans clitoris: Sexual arousal

Urinary and reproductive system are completely seperate

(http://biology.clc.uc.edu/courses/bio105/reproduc.htm)

---Orgasm in Females---

Labia minora, vaginal wall, and clitoris become engorged with blood

Vagina expands and elongates

D. Female Hormone Levels

---Ovaria Cycle: Non-pregnant---

Primary oocyte undergoes meiosis I. Haploid with 23 chromosomes

Secondary oocyte goes through meosis II only if fertilized

This process is ovulation

If egg is not fertilized the corpus luteum degenerates and cause menstral cycle

---Phases of Ovarian Cycle---

Hypothalamus produces GnRH which produces FSH and LH

---Estrogen and Progesterone---

Estrogen is responsible for secondary sex characteristics

Both are responsible for breast development

Menopause: no long have ovarian cycle

---Uterine Cycle: Non-pregnant---

Days 1-5: Flow of blood out of vagina

Days 6-13: Proliferative Phase

Day 14: Ovulation

Days 15-28: Secretory Phase

(http://en.wikipedia.org/wiki/Image:MenstrualCycle2.png)

---Fertilization and Pregnancy---

Placenta formed from maternal and fetal development

Egg implants in endometrium

E. Control of Reproduction

---Birth Control Methods---

Contraceptives (medications and devices)

IUD

Diaphram

Condoms (male and female)

Implants

Injections

Pills

Vasectomy and Tubal Ligation

---Infertility---

Low sperm count (caused by drinking and smoking)

Body weight

Blocked oviducts

Treatments include Arificial Insemination, In Vitro fertilization, Gamate Intrafallopian Transfer, Surrogate mothers

F. Sexually Transmitted Diseases

---STD's from Virus---

HIV

Genital Warts (caused by HPV, warts on penis and vaginal opening)

Genital Herpes (herpes simplex virus)

Hepatitis (infects the liver)

Hepatitis A: through oral/anal contact

Hepatitis B: Sexual contact/blood

Hepatitis C: Post transfusion

Hepatitis D and G: Sexually transmitted

Hepatitis E: Contaminated water

---STD's by Bacteria---

Chlamydia

Gonorrhea

Syphilis

II. Development and Aging

A. Fertilization

---Steps of Fertilization---

Several sperm try to fertilize egg by only one will succeed

When sperm touches the egg, the plasma membrane depolarizes so no other sperm can get in

(http://en.wikipedia.org/wiki/Image:Sperm-egg.jpg)

B. PreEmbryonic and Embryonic Development

---Processes---

Cleavage: Divides

Growth: Grows

Morphegenesis: Shaping

Differentiation: Structure and Function

---Extraembryonic Membranes---

Chorion: Fetal half of placenta

Allantois: umblical blood vessels

Yolk Sac: First site of blood cell formation

Amnoin: Cushion for the embryo

---Stages of Development---

PreEmbryonic (first week, divides as it passes to the uterus)

Embryonic (2nd week-end of 2nd month)

2nd week: Implatation occurs; chorion produces HCG; Gastrulation occurs

3rd week: Nervous system and heart develop

4th and 5th week: Body moves, little limb buds appear, head enlarges

6th-8th week: Can recognize as a human, reflex actions

C. Fetal Development

Blood of mother and fetus never mix

Umbilical Cord is lifelife of fetus

Umbilical arteries carry oxygen poor blood away from fetus

Umbilical veins take oxygen rich blood to fetus

---Events of Fetal Development---

3rd and 4th month: Head is large, bone starts to appear, male or female, fetal heartbeat is loud

5th-7th month: Movement in felt, translucent skin, weighs 3 pounds

8th-9th month: About 7.5 pounds, head down by cervix

---Development of Male and Female Genitals---

Males XY; Females XX

at 6 weeks males and females have same buds but will appear where penis or clitoris will be

at 14 weeks should be able to see if male or female

D. Pregnancy and Birth

Energy level flucuates in mother

The uterus relaxes (progestrone controls this)

Blood volume increases by 40%

Cardiac output increases by 20 to 30%

Vericose veins

---Birth---

Uterus contracts throughout birth

True labor contractions are regular every 15 minutes and last for 40 seconds

Oxytocin stimulates the contractions

Stage 1: Effacement and breaking of the water

Stage 2: Contractions every 1 to 2 minutes lasting 1 minute, baby is delivered

Stage 3: After birth, placenta is delivered

E. Development after Birth

---Hypothesis of Aging---

Genetic basis

Decline in hormonal system

Failure or decline in other systems

---Effects of age on body systems---

Skin: Thinner and less elastic, feels cold

Processing and transporting: Heart shrinks, arteries and more rigid, higher blood pressure

Integration and Coordination: Cognitive skills remain the same, reaction time slowes, decrease in bone density

Reproductive System: Menopause and andropause