Embryonic and Fetal Development Online Lab

Rotation

8 Weeks- All Major Body Parts are Present

Umbilical Cord Forms

Implantation

Fertilization


10 Significant Events During Embryonic / Fetal Development:

Event 1: Fertilization:
-What: Sperm penetrates the oocyte. The fusion of the oocyte with the sperm nuclei is the creation of the zygote.
- When: 1 day post ovulation.
- Why it is significant: Obviously, without this event, there would be no pregnancy / baby. I find it amazing that there is such a small period of time for fertilization to occur: ovulation usually only lasts approximately 24 hours.

Event 2: Implantation:
- What: Embryo implants itself into wall of uterus. Chorion secretes enzymes to digest away some of the tissue and blood vessels of the endometrium of the uterus.
- When: Week 2
- Why: It is important that the embryo implants in the right place, which is the uterus. The uterus sustains a healthy pregnancy. If an embryo does not implant, it results in a miscarriage. If it implants in the wrong place, like in the oviduct, it will result in an ectopic pregnancy, which is not a viable pregnancy.

Event 3: Development of Nervous System & Heart:
- What: Nervous system is first organ system to appear. Thickening appears along entire length of embryo, and invagination occurs as neural folds appear. When neural folds meet at midline, the neural tube is formed, which later develops into brain and spinal cord. Development of heart: first, there are right and left tubes, which fuse, and heart begins pumping blood.
- When: Weeks 3 & 4
- Why: These organ systems are vital to a healthy baby.

Event 4: Heartbeat can be detected.
What: The heart is fully functional, and can be seen on an ultrasound.
When: Week 4
Why: Doctors say that once a heart beat is seen, the chances of a successful pregnancy are much higher than before.

Event 5: Umbilical Cord is formed.
What: A "body stalk" connects the embryo to the chorion, and also contains the extrembryonic membrane, the allantois. Its blood vessels become the umbilical blood vessels. Head and tail then lift up, and the body stalk moves anteriorly by constriction. When this process if finished, the umbilical cord is fully formed, and it connects the developing embryo to the placenta.
When: Weeks 4-5
Why: The umbilical cord is a fetus' source of nourishment and survival.

Event 6: Brain Waves can be detected.
What: I don't really have much information for this, because I found this fact at some other website I had gone to to research the development of embryos. All I know is that the brain is functioning enough to have the waves detected.
When: Week 6
Why: I figure once the brain is fully functioning, and can be detected, it is another strong sign that the fetus is developing the way it should, and that it is strong and healthy.

Event 7: All Major Body Parts are now Present.
What: To think that a tiny little embryo (1.5 inches) has already formed all of it's major body parts!
When: Week 8
Why: Significant because it's so early in development, but all the major parts are present. (Sorry, I know it sounds repetitive, but I don't know how else to say it.)

Event 8: Ossification occurs.
What: Cartilage begins to be replaced by bone as ossification centers appear in most of the bones.
When: Month 3-4
Why: Again, a great sign of growth. When this happens, the fetus becomes "stronger", and things are developing as they should.

Event 9: Fetal Movement.
What: Although the embryo is able to move at approx. 5 weeks, fetal movement can be detected by the mother around 20 weeks for first-time mothers, and as early as 16 weeks for mothers who have had babies previously.
When: Months 4-5, depending.
Why: Fetal movement that is strong enough for a mother to feel is important because it is an indication of a healthy baby. If a mother goes a certain period of time without feeling any movement, she knows the fetus may be in distress, and can seek medical attention.

Event 10: Rotation and Birth
What: The fetus usually rotates so that its head is pointed toward the cervix. This is in preparation for birth through the birth canal. Birth- the fetus is pushed downward by contractions, the cervix stretches and the baby makes its appearance to the world.
When: Months 8-9
Why: Rotation is important because a delivery of a baby that has not rotated is much more dangerous to the fetus. The head should come out first so that the "biggest" part of the baby comes out first. When this doesn't happen, the baby can get stuck. Birth is important for obvious reasons.

Chapter 17 Compendium Review- Pictures

Process of Birth



Stages of Pregnancy

Fetus- 7 Months

Fetus- 4 Months

Fetal Blood Circulation

Embryo- 8 Weeks

Pre-Embryonic Development

Cleavage

Stages of Fertilization

Chapter 17 Compendium Review

I. Fertilization
II. Pre-Embryonic and Embryonic Development
III. Fetal Development
IV. Pregnancy and Birth
V. Development After Birth

I. Fertilization
A. Fertilization is the union of a sperm and egg to form a zygote, the first cell of the new individual.
- Only the nucleus from the sperm head fuses with the nucleus of the egg.
- Zygote receives cytoplasm and organelles only from mother.
- Although several sperm penetrate the corona radiata ( few layers of adhering follicular cells), and several sperm attempt to penetrate the zona pellucida (the extracellular matrix surrounding the egg), only one sperm enters the egg.
- Sperm head binds tightly to zona pellucida, and acrosome releases digestive enzymes that create a pathway for the sperm through the zona pellucida.
- When the sperm binds to the egg, their plasma membranes fuse, and this sperm enters the egg entirely.
- Fusion of nucleus' occur.
- As soon as sperm touches egg, the egg's plasma membrane depolarizes to prevent the binding of any other sperm.
- Zona pellucida becomes impenetrable from any further fertilization.
(Insert Stages of Fertilization picture / http://www.fiu.edu/ / http://www.fiu.edu/~srose/femsexfiu/pregnancy.html)
II. Pre-Embryonic and Embryonic Development
A. Processes of Development:
1a. Cleavage: Immediately after fertilization, they zygote divides so that there are first 2, then 4, 8, 16, and 32 cells, etc.
- No increase in size.
-Mitotic: Each cell receives a full complement of chromosomes and genes.
(Insert Cleavage picture / dtc.pima.edu / http://dtc.pima.edu/~biology/202alpha/lesson13/lesson13c.htm)
2a. Growth: During embryonic development, cell division is accompanied by an increase in size of daughter cells.
3a. Morphogenesis: Shaping of embryo. First evident when cells move, or migrate, in relation to other cells.
4a. Differentiation: Cells take on specific structure and function. Nervous system is first.
B. Extraembryonic Membranes
1b. Not part of embryo and fetus; located outside of embryo.
2b. Chorion: Develops into fetal half of placenta, which gives embryo / fetus nourishment and oxygen and takes away its waste.
3b. Allantois: Extends away from embryo. Accumulates small amount of urine produced by fetal kidneys and gives rise to urinary bladder. Its blood vessels become umbilical blood vessels, to take blood to and from fetus.
4b. Yolk Sac: First embryonic membrane to appear. First site of blood cell formation.
5b. Amnion: Enlarges as embryo and then fetus enlarges. Contains fluid to cushion and protect embryo.
C. Stages of Development
1c. Fertilization to Birth
- 280 days = gestation period.
2c. Pre-embryonic development: Events of first week.
- Morula: Compact ball of embryonic cells that become a blastocyst.
- Inner Cell Mass: the cells of the blastocyst arrange themselves so that there is an inner cell mass surrounded by an outer layer of cells. Inner cell mass will become embryo, and the layer of cells will become the chorion.
(Insert Pre-embryonic Development picture / Frolich PowerPoint Slide 19)
3c. Embryonic Development: Begins with second week and lasts until end of second month of development.
- Second Week: Embryo begins process of implanting itself in the wall of uterus at end of first week.
- At this point, embryo is approx. the size of a period. ( . )
- As week progresses, the inner cell mass becomes the embryonic disk, and two more extraembryonic membranes form. (Yolk sac, and amniotic cavity.) (Mader 354-357)
- Gastrulation: turns inner cell mass into embryonic disk. Example of morphogenesis, when cells move or migrate, in this case to become tissue layers called the primary germ layers.
- By completion of gastrulation, embryonic disk has become an embryo with three germ layers: ectoderm, mesoderm, and endoderm. (Mader 358)
- Fetal “germ layers” destined to become specific adult structures. (Frolich PowerPoint Slide 21)
4c. Third Week: Appearance of two organ systems:
- Nervous System
- Heart
5c. Fourth and Fifth Week:
- Body stalk (future umbilical cord) connects embryo to the chorion which has projections called chorionic villi.
- Umbilical cord is formed.
- Limb buds appear.
- Head enlarges.
- Sense organs become more prominent.
- Can make out developing eyes, ears, and nose.
6c. Sixth through Eighth Weeks:
- Form becomes easily recognizable as human.
- Nervous system allows for reflex movement.
- Embryo is approx. 1.5 in long.
- All organ systems are established. (Mader 359)
(Insert Embryo at 8 Weeks Picture / epigee.org / http://epigee.org/pregnancy/methods.html)
4c. Ectopic pregnancy—fertilized egg implants but not in uterine wall. (Frolich PowerPoint Slide 19)
- This pregnancy cannot be successful, because oviduct is unable to support it.
III. Fetal Development
A. Carbon dioxide and other wastes move from the fetal side to the maternal side, and nutrients and wastes move from the maternal side to the fetal side of the placenta by diffusion.
B. Path of Fetal Blood: Umbilical vein carries blood rich in nutrients and O2 away from placenta and to fetus.
- Blood is returned to right atrium.
- Mixed blood enters heart.
- All blood entering right atrium by-passes the lungs.
(Mader 361)
(Insert Fetal Blood Circulation Picture / http://www.brainconnection.com/ / http://www.brainconnection.com/topics?main=gal/fetal-circulation)
C. Events of Fetal Development: Months 3-9
1c. Months 3-4
- Beginning of 3rd month, fetal head is still very big relative to the rest of the body.
- Head growth slows, rest of body increases in length.
- Epidermal refinements (fingernails, eyelashes, eyebrows, etc.) appear.
- Cartilage begins to be replaced by bone.
- Fontanels: Six large membranous areas in skull.
- Possible to distinguish sex sometime in 3rd month.
- During 4th month, fetal heartbeat can be heard through stethoscope.
- By the end of this month, fetus is approx. 6 inches long.
(Insert Fetus- 4 Months picture / epigee.org / http://epigee.org/fetal2.html)
2c. Months 5-7
- Mother begins to feel movement.
- Lanugo: Fine down that covers the translucent skin of fetus.
- Vernix Caseosa: Coats lanugo, to protect skin from amniotic fluid.
- Eyelids fully open.
- Approx. 12 inches long.
(Insert Fetus - 7 Months picture / http://answers.yahoo.com/question?qid=1006052905521)
3c. Months 8-9
- By end of 9th month, fetus is approx. 20.5 in.
- Accumulation of fat occurs.
- Breech birth: Baby comes "rump" first.
- C-Section: Birth through incision and extraction. (Mader 363)
D. Development of Male and Female Genitals
1d. Sex of individual is determined at the moment of fertilization: Males have X and Y chromosomes, females have two X chromosomes.
2d. Internal Genitals:
- Gonads develop during 7th week of development.
- At 14 weeks, sperm or tiny follicles in ovaries are already developing.
3d. External Genitals:
- Tissues are indifferent at first.
- By 14 weeks, the "groove" persists if female, disappears int scrotum if male.
4d. Abnormal Development of Genitals:
- Some XY individuals become females, because a piece of the Y chromosome is missing.
- Some XX individuals become males, because the same small piece is present on an X chromosome.
5d. Ambiguous Sex Determination: Individual has external appearance of a female, although the gonads of a female are absent.
- Androgen Insensitivity Syndrome: Testes produces hormones, but individual develops as a female because the plasma membrane receptors for testosterone are ineffective. External genitalia develop as female. (Mader 365)
IV. Pregnancy and Birth
A. Placental Hormones cause the changes in a mother's body during pregnancy.
1a. Energy level fluctuates.
- Nausea, vomiting.
- Loss of appetite.
- Fatigue.
- Weight gain results from all of the following: breast and uterine enlargement, weight of fetus, amount of amniotic fluid, size of placenta, her own increase in body fluids, increase in storage of proteins, fats, and minerals. Can lead to lower back pain.
2a. Uterus relaxes:
- Increase in blood volume.
- Blood flow rises significantly.
- Smooth muscle relaxation.
3a. Pulmonary Values Increase.
- Increased size of uterus.
- Occupies most of abdominal cavity.
- Pushes intestines, liver, stomach, and diaphragm from top, and widens thoracic cavity.
- Blood carbon dioxide levels fall.
4a. Other Effects:
- Compression of ureters and bladder causes frequent passage of urine.
- Stretch marks.
- Possibility of pregnancy-induced diabetes. (Mader 368)
–Bladder, rectum pushed superiorly, squeezed--change in urination, defecation patterns.
–Stomach compressed--eat more often, less at each meal.
–Immune response may change appetite to avoid possible poisons for fetus.
- Postural changes to compensate for anterior weight.
- Breasts enlarge--first milk production. (Frolich PowerPoint Slide 22)
(Insert Stages of Pregnancy picture / pregnancy.more4kids.info / http://pregnancy.more4kids.info/category/stages-of-pregnancy)
B. Birth:
- Uterus contracts throughout pregnancy.
- Braxton Hicks Contractions: False labor.
- Uterine contractions push fetus downwards, and cervix stretches.
- Parturition: Process of giving birth to an offspring.
- Loss of mucous plug, that during pregnancy, keeps out bacteria and other sperm.
1b. Stage 1: Contractions cause cervical canal to slowly disappear, and lower part of uterus is pulled up toward baby's head, = Effacement.
- Baby's head helps cervical dilation.
- Amniotic membrane ruptures.
2b. Stage 2: Contractions occur every 1-2 mins.
- Desire to push.
- Episiotomy: incision to enlarge opening of vagina, to allow for birth.
- Umbilical cord is cut and tied.
3b. Stage 3: Afterbirth: Placenta is delivered.
(Mader 369)
(Insert Process of Birth picture / Frolich PowerPoint Slide 23)
V. Development After Birth
A. Stages of life: Infancy, childhood, adolescence, and adulthood.
1a. Gerontology: Study of aging.
- Human life span maximum: 120-125 years.
2a. Hypotheses of Aging
- Genetic in Origin: Aging has genetic basis.
- Some genes decrease life span. When inactive, the mitochondria do not produce energy, and the cell uses alternative pathways. Defective mitochondria may produce more free radicals than usual. Caloric restriction can shut down the genes that decrease life span.
- Whole-Body Process: Decline in hormonal system can affect many different organs of body.
- Perhaps aging results from loss of hormonal activities and a decline in functions they control.
- Aging may be due to a specific type of tissue change that affects all organs and even the genes.
- Extrinsic Factors: Diet, exercise, cigarette smoking, heavy alcohol intake, inadequate calcium intake, etc.
B. Effect of Age on Body Systems:
1b. Skin: Skin becomes thinner and less elastic because the number of elastic fibers decreases and collagen fibers undergo cross-linking. = sagging and wrinkling.
2b. Processing and Transporting:
- Cardiovascular disorders are leading cause of death today.
- Arteries become more rigid with time.
- Heart shrinks due to reduction in cardiac muscle cell size.
- Blood flow to liver and kidneys is reduced.
- Respiratory disorders.
- Loss of teeth.
3b. Integration and Coordination:
- Reaction time slows.
- Hearing, taste, and smell receptors need more stimulation.
- Lens of eyes do not accommodate as well as before.
- Loss of skeletal muscle mass.
- Decline of bone density.
- Weight gain.
4b. Reproductive System
- Females undergo menopause.
- Males undergo andropause.
(Mader 370-372)

Chapter 16 Compendium Review- Pictures

Female Genital Herpes

Tubal Ligation

Vasectomy

Intrauterine Device

Effects of Pregnancy

Female Hormone Levels: Non-Pregnant Uterine Cycle

Female Reproductive System

Testis and Sperm

Male Reproductive System

Fertilization

Human Life Cycle

Female Egg

Male Sperm

Chapter 16 Compendum Review

I. Human Life Cycle
II. Male Reproductive System
III. Female Reproductive System
IV. Female Hormone Levels
V. Control of Reproduction
VI. Sexually Transmitted Diseases

I. Human Life Cycle
A. Reproductive system is fully functional when puberty is complete.
- Girls become sexually mature between ages 11 and 13.
- Boys between ages 14 and 16.
B. Reproductive Organs and their Functions:
- Testes in males produce sperm; Ovaries in females produce eggs.
- Sperm is in ducts until it exits penis; eggs are transported via unterine tubes into uterus.
- Penis delivers sperm to vagina.
- Fertilized egg develops in uterus.
- Testes and ovaries produce sex hormones that maintain the testes and ovaries and bring about maculinization and feminization of various features. In females, sex hormone is necessary to sustain pregnancy. (Mader 320)
(Insert Sperm picture / d21c.com / http://d21c.com/sandysez/nursing?D=D)
(Insert Egg picture / http://www.zmuc.dk/ / http://www.zmuc.dk/InverWeb/Dyr/Limnognathia/reproduction_UK.htm)
C. Events of Human Life Cycle:
- Meiosis
- Fertilization
- Fetal Development
- Birth
- Childhood/Adolescence
- Adulthood (Meiosis)
- Aging
- Death (Frolich PowerPoint Slide 4)
(Insert Human Life Cycle Picture / Frolich PowerPoint Slide 4)
D. Mitosis and Meiosis
- Each cell in the body has 46 chromosomes, carrying our DNA.
1d. Duplication Division: Mitosis. When a cell divides, each new cell also has 46 chromosomes.
- Mitosis occurs during growth and repair of tissues.
2d. Reduction Division: Meiosis: Takes place only in testes of males during production of sperm and in the ovaries of females during production of eggs.
- This process reduces the number of chromosomes from 46 (AKA diploid, or 2n number) down to 23 chromosomes (AKA haploid, or n number)
- Occurs in two successive division: Meiosis I and Meiosis II.
-Flagellated sperm is much smaller than the egg. It carries the chromosomes to the egg.
- Egg provides the new individual with cytoplasm in addition to chromosomes.
3d. Zygote: The first cell of a new human being.
- The zygote gets 23 chromosomes from the sperm, and 23 from the egg, so it has 46 altogether. (Mader 320)
(Insert Fertilization picture / http://www.talbotcentral.ucr.edu/ /
http://www.talbotcentral.ucr.edu/AAA_03C_research.html)
II. Male Reproductive System
A. The following organs are found in the male reproductive system:
- Testes: Male gonads: Primary Sex organ. Paired testes, suspended from sacs of scrotum.
- Epididymis: Sperm produced by testes mature here. Tightly coiled duct lying just outside each testis.
- Vas Deferens: Mature sperm leave epididymis and enter here, where they are stored for some time. Each Vas Deferens goes into abdominal cavity, where it curves around bladder and empties into ejaculatory duct. (Mader 321)
- There are millions of sperm in a few drops of testicular fluid. (Frolich PowerPoint Slide 6)
- Urethra: Place where ejaculatory ducts enter. (Mader 321) Located near base of penis. (Frolich PowerPoint Slide 6)
- Prostate Gland: Donut-shaped. Surrounds upper portion of urethra just below bladder.
- Bulbourethral Glands: Pea-sized. Lie posterior to the prostate on either side of urethra. Secretion makes semen "gelatinous".
1a. Semen: The fluid containing sperm in which sperm leaves the penis during ejaculation. (Mader 321)
- Ejaculation: sperm travel from testes, joined by semen, and are expelled through erect penis.
- Semen is made by prostrate, seminal and bulbourethral glands at base of penis. (Frolich PowerPoint Slide 6)
(Insert Male Reproductive System picture / Frolich PowerPoint Slide 6)
- Seminal Vesicles: Lie at base of bladder. Each has a duct that joins with a vas deferens.
- Semen contains prostaglandins, which are chemicals that cause the uterus to contract, thus helping propel sperm toward egg. (Mader 321)
B. Orgasm in Males
1b. Penis: Male organ of sexual intercourse.
- Long shaft and enlarged tip called "glans penis".
- Circumcision: Surgical removal of foreskin from glans penis.
- During sexual arousal, autonomic nerves release nitric oxide, which stimulates the production of cGMP, which causes smooth muscle walls to relax and erectile tissue to fill with blood. Veins that take blood away from penis are compressed, = erection.
- Erectile Dysfuntion: Erectile tissue doesn't expand enough to compress the veins.
- Ejaculation: Sperm enter urethra from each vas deferens, glands contribute secretions to seminal fluid, and contractions cuase it to be expelled from penis in spurts. (= male orgasm)
- Refractory period: Length of time during which stimulation does not bring about an erection, usually following ejaculation.
C. Male Gonads, the Testes
1c. Testes: Produce sperm and make male sex hormones. Lie outside abdominal cavity, in scrotum. Necessary to reside in scrotal sacs because body temp is too high internally to produce viable sperm.
- Scrotum helps regulate temp of testes by holding them farther away from body.
2c. Seminiferous Tubules and Interstitial Cells
- Testes composed of lobules: compartments which contain one to three coiled seminiferous tubules, which are packed with cells undergoing spermatogenesis, the production of sperm.
- Sertoli Cells: Support, nourish, and regulate the process of spermatogenesis.
(Mader 322-323)
- In walls of tubules, stem cells that give rise to sperm are constantly undergoing meiosis.
- Sperm are then collected in epididymis.
- Sperm that are not ejaculated are reabsorbed back into testicular tissue. (Frolich PowerPoint Slide 7)
(Insert Testis and Sperm picture / Frolich PowerPoint Slide 7)
3c. Sperm have three parts: a head, a middle piece, and a tail.
- Mitochondria: found in middle piece. Provide energy for movement of tail.
- Tail: Flagellum.
- Head: Contains nucleus covered by cap called acrosome, which stores enzymes needed to penetrate egg.
- Live for approx. 48 hours in female genital tract.
- Only 1 of millions of sperm penetrate egg (normally).
D. Interstitial Cells: Cells that secrete the androgens, or male sex hormones.
E. Hormonal Regulation in Males
1e. Hypothalamus: Ultimate control of testes' sexual function.
- Secretes hormone gonadotropin-releasing hormone (GnRH), which stimulates anterior pituitary to secrete gonadotropic hormones.
- Two types of gonadotropic hormones: Follicle-stimulating hormone (FSH) (in males, promotes production of sperm in seminiferous tubules), and Luteinizing hormone (LH) (in males, controls production of testosterone by interstitial cells).
- All hormones are involved in negative feedback relationship that provides a continuous production of sperm and testosterone.
2e. Testosterone: Main sex hormone in males. Essential for development and functin of sex organs. Brins about and maintians male secondary sex characteristics present during puberty. (Hair on face, etc.)
III. Female Reproductive System
A. Female gonads are paired ovaries, found on either side of the upper pelvic cavity.
- Produce eggs and the female sex hormones, estrogen and progesterone.
B. Genital Tract:
1b. Oviducts: (AKA fallopian tubes): EXtend from uterus to ovaries, but are not attached to ovaries.
- Fimbriae: Finger-like projections extending from oviducts that sweep over ovaries and carry them into an oviduct with the help of beating cilia that line oviducts. Moves toward uterus.
- Egg lives approx. 6-24 hours, unless fertilization occurs.
- Fertilization takes place in oviduct.
- Implantation: Embryo moves from oviduct to uterus and embeds in uterine lining.
2b. Uterus: Thick-walled, muscular organ. Lies above and tipped over urinary bladder. Oviducts join uterus at upper end, cervix enters vagina at lower end.
- Development of embryo / fetus occurs here.
- Endometrium: Lining of uterus. Helps form placenta, shich supplies nutrients for embryo / fetus.
3b. Vagina: Tube. Serves as birth canal, facilitates sexual intercourse, and acts as exit for menstrual flow.
(Insert Female Reproductive System picture / http://www.faqs.org/ / http://www.faqs.org/health/Body-by-Design-V2/The-Reproductive-System.html)
- Pap test: tests for cancer of cervix by removing cells from cervix for microscopic examination.
- Hysterectomy: Removal of uterus, including cervix. (Mader 325)
C. External Genitals: The Vulva
- Labia majora
- Labia minora: Cleft between labie minora contains openings of urethra and vagina.
- Glans clitoris: organ of sexual arousal. Contains shaft of erectile tissue.
D. Orgasm in Females
1d. Labia minora becomes engorged with blood. Blood vessels in vaginal wall release drops of fluid for lubrication. Clitoris is stimulated, and orgasm occurs when walls of uterus contract. (Mader 326)
IV. Female Hormone Levels
A. Ovarian Cycle: Nonpregnant
1a. Ovary contains multiple follicles, and each follicle contains an immature egg, called an oocyte.
- Female produces 1 egg per month.
- Ovarian Cycle: Follicle matures.
- Oocyte develops into a corpus luteium, a glnadlike structure.
- Oogenesis: Primary oocyte undergoes meiosis I. (Mader 326)
- Meiosis occurs in ovaries.
- Phase I occurs in fetal ovary.
- One egg per month (ovulation part of menstrual cycle) matures and bursts from wall of ovary to be taken up into Fallopian tube.
- Phase II of meiosis occurs the moment the egg is fertilized (if that happens). (Frolich PowerPoint Slide 10)
- Primary follicle: produces estrogen.
- Secondary follicle: produces estrogen and some progesterone.
2a. Phases of Ovarian Cycle:
- Hypothalamus: Controls the sexual function of ovaries.
- Secretes gonadotropin-releasing hormone (GnRH), which stimulates the production of FSH and LH, which control ovarian cycle.
- Positive Feedback Effect: Estrogen spike causes secretion of large amount of GnRH from hypothalamus, which leads to a surge of LH, which leads to ovulation.
- Luteal Phase: LH promotes development of corpus luteum, which secretes progesterone.
B. Estrogen and Progesterone:
- Affect uterus, etc.
- Estrogen: Responsible for secondary sex characteristics (breast development, etc.)
- Menopause: Ovarian cycle ceases, between ages 45-55.
C. Uterine Cycle: Non-pregnant:
1c. Uterine Cycle:
- Low level of estrogen and progesterone in body causes endometrium to disintegragte and its blood vessels to rupture. = menstruation (days 1-5)
- Increased production of etrogen causes endometrium to thicken. (days 6-13)
- Ovulation occurs. (day 14)
- Increased production of progesterone in ovary causes endometrium of uterus to double or triple in thickness. Thick mucoid secretion, prepared to receive embryo. (days 15-28). If no embryo is received, corpus luteum regresses, and low level of sex hormones result in endometrium breaking down for menstruation. (Mader 328-329)
(Insert Female Hormone Levels picture/ Frolich PowerPoint Slide 11)
D. Fertilization and Pregnancy:
1d. Placenta: Sustains devedloping embryo and fetus, comes from both maternal and fetal tissues.
- Produces human chorionic gonadotropin (HCG), which maintains corpus luteum in ovary.
- Rising amounts of HCG stimulates corpus luteum to produce progesterone, which shuts down hypothalamus so no new follicles begin in ovary.
- Progesterone maintains uterine lining for embryo.
- Eventually, the placenta itself takes over production of progesterone and some estrogen, so corpus luteum is no longer needed and it regresses. (Mader 330)
(Insert Effect of Pregnancy picture / Frolich PowerPoint Slide 12)
V. Control of Reproduction:
A. Birth Control
- Abstinence
- The pill
- Intrauterine device
(Insert Intrauterine Device picture / http://www.fiu.edu/ / http://www.fiu.edu/~srose/abortioncontracep.html)
- Hormone skin patch
- Depo-Provera
- Diaphragm and spermicidal jelly
- Condoms (male and female)
- Implants (Mader 331)
B. Vasectomy and Tubal Ligation:
1b. Sterilization.
- Vasectomy: Cuts and seals the vas deferens on each side so the sperm are unable to reach the seminal fluid, and are reabsorbed.
(Insert Vasectomy picture / Frolich PowerPoint Slide 8)
- Tubal Ligation: Cuts and seals the oviducts, so the passage of egg is blocked.
(Insert Tubal Ligation picture / http://www.mala.bc.ca/ / http://www.mala.bc.ca/incline/tubals.html)
C. Morning-After Pills
- "Emergency Contraception": Medication upsets normal uterine cycle, so an embryo can't implant itself. Causes loss of unimplanted or implanted embryos.
D. Infertility: Failure of a couple to achieve pregnancy after one year of regular, unprotected intercourse.
- Consitutes approx. 15% of american couples.
1d. Some causes:
- Low sperm count. (Associated with smoking and drinking.)
- Body weight in females causes failure to ovulate.
- Blocked oviducts due to pelvic inflammatory disease and endometriosis.
E. Assisted Reproductive Technologies:
- Artificial Insemination by Donor
- In Vitro Ferilization
- Gamete Intrafallopian Transfer (Egg and Sperm placed in oviducts immediately after they are brought together, whereas in In Vitro, eggs are brought to maturity in glassware, sperm are added, and after about 2-4 days, implanted in woman.)
- Surrogacy
- Intracytoplasmic Spermm Injection: single sperm injected in egg. (Mader 334)
VI. Sexually Transmitted Diseases
A. Caused by viruses, bacteria, protists, fungi, and animals.
1a. STD's caused by Viruses:
- Drugs used fro treatment of these STDs only slows replication of virus: does not cure.
2a. HIV Infections: AIDS is last stage of an HIV infection.
- Approx. 38.6 million affected worldwide.
- Approx. 25 million have died.
- Helper T lymphocyte: primary host for HIV. These are the same cells that stimulate immune response, and the immune system becomes severely impaired.
- Highly contagious in first stage. Minimal symptoms.
- Helper T lymphocyte count eventually falls, and the person becomes susceptible to all kinds of illnesses.
- Persons usually die from an opportunistic disease, such as pneumonia.
3a. Genital Warts:
- Caused by human papillomaviruses.
- Warts are seen on penis and foreskin of men and near vaginal opeining in women.
- New vaccine is now available.
4a. Genital Herpes:
- Caused by herpes simplex virus.
- Type 1- Cold sores and fever blisters.
- Type 2- Genital Herpes.
- Tingling / itching sensation. Blisters on genitals, which rupture and leave blisters. Increased risk of acquiring HIV.
- Symptoms are recurrent.
(Insert Genital Herpes picture / http://www.femail.com.au/)
5a. Hepatitis:
- Infects liver, and can lead to liver failure, liver cancer, and death.
- Six Viruses, labeled: A, B, C, D, E, and G.
- A & E are usually from contiminated water! (Mader 336-337)
- Hep B: most commonly sexually transmitted hepatitis.
- Transmitted through sexual contact and by contaminated blood.
- Vaccine available for both Hep A and B. (Frolich PowerPoint Slide 15)
B. STDs Caused by Bacteria:
- Curable with antibiotics.
1b. Chlamydia: Caused by tiny bacterium.
- Usually mild or asymptomatic.
- Increases risk of HIV.
- If untreated, infection can spread from cervix to uterine tubes, resulting in pelvic inflammatory disease. Very painful. Causes infertility.
2b. Gonorrhea:
- Latent infection leasds to pelvic inflammatory disease, which can cause sterility in males.
- Gonorrhea proctitis: infection of anus.
- Gonorrhea can spread to internal parts of body, causing heart damage or arthritis.
- Now showing resistance to antibiotics.
3b. Syphilis:
- Treated w/ penicillin.
- Three stages: Primary- hard chancre (ulcerated sore with hard edges) indicates site of infection. Second Stage- Rash occurs even on palms and soles of feet. Hair loss, gray patches on mucous membranes may occur. Tertiary Stage- Lasts until patient dies. Affects cardiovascular system by causing aneurysms, particularly in aorta. Can also affect nervous system, causing psychological disturbances. Also, gummas, large ulcers, may develop on skin or within internal organs.
- Congenital Syphilis: bacteria passees into placenta and child is born blind or with many malformations. (Mader 338)
4b. Other Common Infections of Reproductive Tract:
* Bacterial vaginosis (BV):
–Accounts for ~ 50% of vaginitis in American women.
–Caused by a disruption of the normal flora in the vagina leading to an overgrowth of certain bacteria.
* Trichomoniasis
–Caused by a protozoan.
–Can cause a frothy discharge, with a foul smell and itching.
–Common cause of vaginitis.
* Candidiasis
–An overgrowth of normal yeast (fungus called Candida) in the vagina.
–Characterized by tissue that is red, inflammed and itchy; sometimes a white, curdy discharge as well.
–Birth control hormones and use of antibiotics make women more prone to this overgrowth.
(Frolich PowerPoint Slide 16)
C. Prevention of STDs
• Abstinence.
• Develop long-term monogamous relationships.
• Be aware if your partner is an intravenous drug user because prevalence of STDs are higher in that group.
• Practice safer sex.
– Always use a latex condom during intercourse.
–Limit or do not use alcohol and drugs that can impair your judgment or change your behavior. (Frolich PowerPoint Slide 17)

Build A Limb Lab

Once again, because of the blog, the pictures are in "reverse" order. First picture is at bottom... then works it's way up. :)

Neurons- and Schwann Cell (Sorry, this was placed out of order by the blog... should come right above the first picture of the Neuron in Progress...)

Release of Calcium from Sarcoplasmic Reticulum, and it's Binding to Myosin.

Sarcomeres- Contracted

Muscle Cell w/ Labeled Parts: Sarcolemma, T-tubules, Sarcomere, Myosin Cross-Bridges, etc.

Muscle Cell- in progress

Action Potential Ends / Repolarization

Action Potential Begins

Movement of Charged Sodium and Potassium Ions Across Membrane:
Resting Potential

Propagation of Action Potential Along Axon

Neuron- In Progress

Emma's "Knee"- She was so proud. :)

Extended Knee: Quadricep Contracted

Bent Knee: Hamstring Contracted

Finished Knee: Tendons "peeled back" to see all labeled parts.

Finished Knee: Outside Labeled

Process: Building the Knee

My Materials: We always have a stockpile of play-do in our house. :)
1. Introduction: My assignment for this lab was to create a moving limb with neuron triggering muscle to pull on bone and make a joint move. I chose to make a model of the knee. The parts of the knee that I included in my model are as follows: Both the quadricep and hamstring muscles, that contribute to contracting the knee, fat, bursa, patella, artiulcar cartilage, patellar tendon, tibia, fibula, meniscus, synovial fluid, synovial membrane, and femur.
- The quadriceps and hamstring muscles move the knee joint.
- The femur (thigh bone), tibia (shin bone), and patella (knee cap) make up the knee joint.
- Meniscus: Covers the end of the bones and acts as "cushion". Helps absorb shock and allows the knee joint to move smoothly.
- Bursa: Fluid-filled sac that facilitates movement and reduces friction.
- Patella: the knee-cap. Triangular-shaped, covers and protects knee joint. Articulates with femur.
- Patellar Tendon: Attaches quad muscle to tibia.
- Articular Cartilage: Covers the ends of bones. It has a smooth, slippery surface, which allows the bones of the knee joint to slide over each other without rubbing.
- Synovial Fluid: Lubricates joints.
- Synovial Membrane: Secretes synovial fluid.
2. List of Limb Parts and Their Model Representations: I chose to use different colors of play-do for each part of the knee. They are labeled on the diagram itself, but I will list them here, as well.
- Quadricep and Hamstring Muscles: Red
- Bursa: Green
- Fat: Yellow
- Patella: Greenish "Mixed"
- Tibia: Light Yellow
- Femur and Fibula: White
- Tendons: Purple
- Synovial Fluid: Brown
- Meniscus: Pink
- Articular Cartilage: Orange
* I also built a sensory, inter, and motor nueron to show the propagation of action potential along an axon, a separate model demonstrating action potential, a skeletal muscle cell, the release of calcium from a sarcoplasmic reticulum and calcium binding to myosin.
3. The Models: Please see above pictures with corresponding captions.
4. Conclusion: Our bones are moved by muscle contractions. The way that a muscle contracts is as follows: A sensory neuron takes nerve impulses (action potential) from a sensory receptor to the Central Nervous System. An interneuron in the CNS receives the input from sensory neurons and from other interneurons, sums up the impulses, and communicates them to motor neurons. The motor neuron (whose axons are in the nerves) takes nerve impulses away from the CNS to an effector, in this case, the muscle fiber. When nerve impulses arrive at an axon terminal, the synaptic vesicles release ACh into the synaptic cleft. When ACh is released, it diffuses across the cleft and binds to receptors in the sarcolemma. Next, the sarcolemma generates impulses that spread over the sarcolemma and down T-tubules to the sarcoplasmic reticulum. The release of Ca2+ from the sarcoplasmic reticulum leads to sarcomere contraction. A single muscle fiber (cell) has many myofibrils that are each divided into sarcomeres, which contract. When the myofibrils of a muscle fiber contract, the sarcomeres shorten. The actin filaments slide past the myosin filaments toward the center, and the muscle pulls on the bone to move it.

Exercise Essay

Exercise improves muscular strength, endurance, and flexibility. It also improves cardiorespiratory endurance. It helps prevent the buildup of plague in blood vessels, thereby fighting heart disease. Exercise has even been shown to help prevent certain types of cancer! A person can increase their bone strength, as well, with certain types of exercising, such as weight training. Obviously, exercise also helps a person to lose weight and maintain a healthy weight once it has been established. Emotionally, exercise can help relieve depression and create a stronger self-image. Vigorous exercise releases endorphins, known to alleviate pain and create a feeling of tranquility. These are all great reasons people should make exercise a part of their daily routine. So, then, why don't they?
In the Essay on Obesity and the Environment, there are many good points made regarding the how and why our current environment facilitates the lack of exercise our modern-day lives have become accustomed to. We have so many conveniences these days that allow us a "better quality of life." In most towns today, there are several choices of fast food that is cheap and readily available to the consumer. What kind of fast food? High calorie, high fat, bad-for-you food. Hamburgers, fried chicken, tacos loaded up with sour cream, cheese, etc., all available in "super-size." Funny how you don't see a fast food restaurant dedicated to salads, or tofu wraps. Why? Would Americans choose these healthier alternatives if they were available? I'm not sure, generally speaking, but I am sure that my husband and children would prefer McDonald's any day. :) I know it's a terrible thing to admit, but if we are being honest, those bad-for-you foods are tastier and more appealing to most people than a tofu wrap. I think it would be ideal if we could find a happy medium, somehow. For example, a fast food restaurant that specialized in healthy, yummy pitas would probably have a fairly decent response. I know I would choose that kind of food over McDonald's, for sure. But really, there are none. Perhaps business owners fear that consumers would not make the healthy choice, and they would therefore not make the money they desire. This is understandable, and the basis of this essay. People want what tastes good, not necessarily what is better for them health-wise. And this is why we face the problems we face today in regards to obesity.
Technology inhibits exercise. I'm sure people were much healthier before they could drive everywhere, when walking was commonplace. No one walks anymore. Some of this is due to location: it is not really feasible to walk from Chino Valley to Prescott for work. Most of it is convenience-based, going back to the idea of the "better quality of life". Meaning, why walk when you can drive? I've seen people on my street drive to the mailboxes that are very much in walking distance. This, to me, says a great deal about what people value these days, and that is convenience. Technology has made it so that many of us have virtually no physical labor required of us in our daily lives. Thus, exercise becomes a choice.
It is true that exercise makes you feel better and gives you more energy. So why don't we all do it on a daily basis? Some would say lack of energy. :) This is a repetitive, somewhat amusing cycle: if we exercised, we'd have more energy, yet we can't seem to force ourselves to exercise. Personally, this goes back to many of the same issues I wrote about in the Nutrition essay. I hate to sound so cliche, but I fall back on my lack of time excuse. (Yes, I know, it is an excuse.) But when you work, take care of your children, and try to maintain your home on a daily basis, it is difficult to find time for everything. What gets cut out of my priorities most often? Exercise. Perhaps because, if I finally do have any time to myself, it is spent doing things for others. I have often thought how great it would be to go take a Yoga class at the YMCA, but I then immediately remind myself of the fact that gas is ridiculously expensive, and I can't afford to drive into Prescott just to take a class. So, why not get a Yoga video and do it at home? I've bought it: just don't find the time to do it everyday. Could I wake up earlier in the morning, before the kids, and do it then? Maybe... if I could keep my eyes open after being woken up 4 times in the middle of the night by two children. But realistically, I know I could find that time, if it was something I truly cared about and made a top priority. Unfortunately, it isn't. This is also cyclical, for me. I have serious body-issues, and am fully aware that the only way to change this and make myself happier is to kick myself in the butt and exercise, regularly. Yet I still don't do it. ???
Scotland has found ways to promote a healthier lifestyle. One example is their aim to put across health messages by promoting active travel behaviour through cycling and walking initiatives. I think this is great, and kind of goes hand in hand with the suggestion of another article for workplaces to incorporate at least 15-30 minutes a day into their employees work schedule to allow for an exercise period. This reminds me of when I was teaching in Prescott, and they began a program that included getting meters for those interested to keep track of how many steps they took per day. A group of teachers would spend their lunch hour (half-hour) walking around the track. It seemed really fun, but to be honest, most of them were gym teachers. Teachers of core classes rarely found the time to eat lunch, because they were tutoring kids, grading papers, attending meetings, returning phonecalls, etc. That's the problem with it being a lunch hour. However, if there had been actually scheduled time aside from lunch, I bet more people would have participated. Then again, I bet many wouldn't, and the administration would therefore have allotted time for us that wasn't being used for its intention. And the excuses continue! ;)
I think that, in many ways, we are taking steps in the right direction. For example, even when I was in high school, they did away with all of the vending machines and were making better, healthier food choices for what they offered their students. It seems that many schools are following this path, along with educating the students as to the benefits of exercise, etc. Starting young is really key, I think. If you begin at a young age, it is very natural for kids to make good choices as they become adults, instead of trying to undo "bad" behavior and learn to make better choices. Physical activity (not strenuous exercise) should be stressed, as well, for those who are completely opposed to "hard" exercising everyday. Although our daily lifestyles are always busy and fast-paced, many people would benefit from (and more than likely enjoy) a 30-minute walk as many days per week as they can manage. This, I do, and as I said, that's 30 minutes of peace and quiet that I truly appreciate.
I don't think it's realistic to think that people would be willing to give up their cars to improve our lifestyle to become more healthy. I know I wouldn't... so what are the answers? As I said before in the Nutrition essay, it all comes down to personal choice and priorities. It would be nice if our community helped in our choices, but they can only do so much. Perhaps if our society wasn't so motivated by money, our lives wouldn't be so fast-paced and busy all the time, and we would have more time to allot for what should be most important: the health of our bodies.