5 Gametogenesis The production of gametes (sex cells) Males = spermatogenesis in the testesFemales = oogenesis in the ovaries
6 (A) Ovaries The female gonads Located within the lower portion of the body cavityIn the ovaries, each egg cell (ovum) is present in a tiny sac called a follicle
7 (A) Ovaries3. About once a month, a follicle matures and bursts. The egg is then released and travels into the oviduct (Fallopian tubules)****This is known as ovulation
8 4. Fertilization takes place within the Fallopian tubules (oviduct) forming a zygote 5. The zygote then travels down and into the uterus where it implants into the uterine lining and develops6. When embryonic development of the baby is completed, the cervix dilates (opens) and the baby travels through the birth canal known as the vagina
9 7. The ovaries also produce sex hormones known as estrogen and progesterone a) estrogen- used for the development of secondary sex characteristics like mammary glands (breasts)b) progesterone- maintains pregnancy
10 Figure 39–14 The Female Reproductive System Section 39-3
16 Figure 39–2 The Endocrine Glands Section 39-1HypothalamusThe hypothalamus makes hormones that control the pituitary gland. In addition, it makes hormones that are stored in the pituitary gland.Pineal glandThe pineal gland releases melatonin, which is involved in rhythmic activities, such as daily sleep-wake cycles.ThyroidThe thyroid produces thyroxine, which regulates metabolism.Pituitary glandThe pituitary gland produces hormones that regulate many of the other endocrine glands.PancreasThe pancreas produces insulin and glucagon, which regulate the level of glucose in the blood.Parathyroid glandsThese four glands release parathyroid hormone, which regulate the level of calcium in the blood.OvaryThe ovaries produce estrogen and progesterone. Estrogen is required for the development of secondary sex characteristics and for the development of eggs. Progesterone prepares the uterus for a fertilized egg.ThymusDuring childhood, the thymus releases thymosin, which stimulates Tcell development.TestisThe testes produce testosterone, which is responsible for sperm production and the development of male secondary sex characteristicsAdrenal glandsThe adrenal glands release epinephrine and nonepinephrine, which help the body deal with stress.
19 (II) Menstrual Cycle Mature egg develops and is released Begins at puberty and ends at menopauseHormones involved:FSH estrogenLH progesteroneStages involved in order:follicle stage ovulation corpus luteum menstruation
20 1. Follicle Stage days* FSH is secreted by the pituitary gland which stimulates maturation of egg in the follicle** As the follicle develops, it releases estrogen which stimulates the uterine lining to thicken with blood2. OvulationSecretion of LH (lutenizing hormone) from the pituitary causes a mature egg to be released from the follicle and into the fallopian tubules (oviduct)3. Corpus Luteum10-12 days* The burst follicle fills with cells forming the corpus luteum, which produces progesterone fuher thickening of the uterine lining4. Menstruation3-5 daysIf the egg is not fertilized, progesterone secretion decreases and the lining of the uterus breaks downThe lining of the uterus is sloughed off and discharged from the body through the vagina as a result (period).
25 1. Follicle Stage10-14 daysFSH is secreted by the pituitary gland which stimulates maturation of egg in the follicleAs the follicle develops, it releases estrogen which stimulates the uterine lining to thicken with blood
26 OvulationSecretion of LH (lutenizing hormone) from the pituitary causes a mature egg to be released from the follicle and into the fallopian tubules (oviduct)
27 3. Corpus Luteum Stage 10-12 days The burst follicle fills with cells forming the corpus luteum, which produces progesteroneProgesterone stimulates further thickening of the uterine lining
29 4. Menstruation3-5 daysIf the egg is not fertilized, progesterone secretion decreases and the lining of the uterus breaks downThe lining of the uterus is sloughed off and discharged from the body through the vagina as a result (period).
34 Figure 39–12 The Male Reproductive System Section 39-3
35 (A) Testes Are the male gonads Produce sperm Sperm is produced in the seminiferous tubules and stored in the epididymisSperm then leaves the epididymis through the vas deferens and into the urethra (which is a tube inside the penis)
36 The processThe penis is a structural adaptation for internal fertilizationGlands secrete a liquid into the urethra which combines with the sperm cells. This liquid serves as a transport medium for the sperm cells and is called semenTestes also produce the male sex hormone called testosterone
37 Testosterone regulates the maturation of sperm and the development of secondary sex characteristics such as beard development and voice pitchScrotum- sac in which the testes are locateda) outside the bodyb) keeps the temperature 1-2 degrees Celsius cooler than normal body temperaturec) this provides an optimum temperature for sperm production
44 VasectomyMale sterilization or vasectomy is a simple procedure in which a piece of each vas deferens is cut out just above the epididymis and the cut ends are tied. This procedure is normally done under local anesthetic in the doctor's office.Because the sperm stored in the epididymis can no longer flow through the vas deferens, the man's ejaculate does not contain sperm.
45 (III) Fertilization and Implantation Fertilization occurs in the fallopian tubules (oviduct)If the egg is not fertilized within 24 hours after ovulation, it will deteriorateAfter fertilization, the zygote undergoes cleavage and becomes an embryo
46 (I) Sexual Reproduction Two parents give rise to new offspring by the fusion of nuclear materials from two different cellsOffspring are not identical to the parentVariations exist, which increases the species ability to adapt to the changing environment
47 (A) Reproductive System Gonads- specialized organs that produce gametesa) ovaries - female gonad- produce ova (egg)b) testes - male gonad- produce sperm cell
48 Contain both male and female reproductive structures (B) HermaphroditeContain both male and female reproductive structures
49 Process by which gametes are produced in the gonads (C) GametogenesisProcess by which gametes are produced in the gonadsTwo types:- Spermatogenesis- Oogenesis
50 OogenesisThe primary oocyte goes through first meiotic division and the cytoplasm of the cell is divided unequallyThe larger daughter cell is called the secondary oocyte and the smaller daughter cell is called the polar bodyDuring second meiotic division, 1 mature ovum is produced and 3 polar bodies
51 SpermatogenesisPrimary spermatocyte goes through first meiotic division and form two daughter cells of equal sizeEach daughter cell (secondary spermatocyte) goes through the second meiotic division forming four motile sperm cells of equal size
53 Comparison of Ova and Sperm Egg cells contain stored food in the form of yolkEgg cells are larger than spermSperm are motile, egg cells are not
54 (B) FertilizationThe fusion of the nuclei of one sperm with one ova (egg) to produce a zygoteSperm (n) + Ovum (n) =2nSperm (23) + Ovum (23) = 46
55 Parthenogenesis An embryo develops from an unfertilized egg typically involves the development of eggs into viable offspring from females without fertilization by sperm..Parthenogenesis is no longer only for lower invertebrates, such as aphids, mites and nematode worms--it's also been found in fish, bees, birds and lizards.the second polar body -- the daughter cell produced along with the egg in the second stage of meiosis -- acts like a sperm and re-enters the egg. Essentially the egg fertilizes itself! As this polar body contains identical genetic material to the egg, having been produced by normal division of an already haploid cell, the resulting diploid cell has only half the genetic diversity of the female's original cells. Thus fewer bands appear in the DNA fingerprint of the offspring.
74 The embryo arrives in the uterus 5-10 days after fertilization The embryo implants into the uterine wall and establishes pregnancyPlacenta- nourishes the embryoUmbilical cord- attaches the embryo to the placentaAmnion- embryo develops inside the amniotic sac which contains amniotic fluid that serves as a shock absorberGestation Period- length of pregnancy (approximately nine months)
77 Fertilization and Implantation Section 39-4Uterine wallBlastocystMorula4 cells2 cellsZygoteOvaryFallopian tubeDay 3Day 2Day 1Day 4FertilizationDay 0Day 7Implantation of blastocystEgg released by ovary
78 DevelopmentThe zygote, which is a fertilized egg consisting of one cell, will begin to divide rapidly by mitosis forming the early developing human embryo. Fertilization and the initial stages of this mitotic cell division occur in the oviduct. The early embryo is migrates down the fallopian tube and completes most of its development in the wall of the uterus.
79 Do NowEctodermMesodermEndodermLooking at the diagram above. Hypothesize the systems that will develop from these three layers.ReproductiveMuscles,SkeletonDigestiveNervousETC
80 Ectoderm Mesoderm Endoderm It is the three germ layers that give rise to all the tissues and organs of an animalEctodermMesodermEndodermNervous systemDigestive Systemlining of mouth, nostrils, and anusepidermis of skin, sweat glands, hair, and nailsbones and musclesblood and blood vesselsreproductive and excretory systemdermis layer of skinlining of digestive tractlining of trachea, bronchi, and lungsliver, pancreasthyroid, parathyroidurinary bladder
82 Do Now Identify what is the purpose of the following: The placenta: The umbilical cord:. The amniotic fluid:
83 Do Now answersThe placenta is a combination of maternal and fetal tissue which allows for the exchange of materials with the fetus and mother. Needed materials such as food and oxygen diffuse through the placenta to the fetus, while wastes from the fetus diffuse to the mother. The umbilical cord is a fetal structure containing blood vessels which allows materials to be carried between the fetus and placenta in both directions. The amniotic fluid surrounds the fetus and helps to provide a shock absorber to protect the fetus against mechanical injury in the event the mother is shaken or injured in some manner.
85 Fetal DevelopmentDevelopment is a highly regulated process After this small cluster of cells called the gastrula forms in humans, tissues begin to form. In humans, the embryonic development of essential organs occurs in early stages of pregnancy. During the first three months of human development, organs begin to form. The human embryo is usually referred to as a fetus when human like features become visible in its structure. All organs and body features are developed by the end of the sixth month. During the last three months of pregnancy, organs and features develop well enough to function after birth.
86 What are some things that could affect fetal development? 6 weeks4 months
87 What are some things that could affect fetal development? The embryo (or fetus) may encounter risks from faults in its genes and from its mother's exposure to environmental factors such as:inadequate dietuse of alcohol (Fetal alcohol syndrome)TobaccoDrugsother toxinsinfections
88 Reproductive Technologies Reproductive technology has medical, agricultural, and ecological applications. In many instances, these technologies have progressed at a faster rate than the ethical considerations resulting from these technologies. Some of these techniques include birth control methods used to block the process of fertilization. Many technologies now exist to enhance the process of fertilization and development in humans and other organisms.AmniocentesisHormone therapy can cause increased egg production. Surgery can open blocked fallopian tubes in females and the vas deferens in males.In vitro fertilization (test-tube babies) is a widely used technique to aid infertile couples, allowing them to have children where this otherwise would not be possible.
89 AmniocentesisFetal cells are removed and surveyed for genetic disorders
92 (IV) Multiple Births1. Identical twins- Develops from one zygote separating into two during cleavage. One sperm and one egg is involved and therefore the babies will look identical and must be of same sex
93 (IV) Multiple Births1. Identical twins- Develops from one zygote separating into two during cleavage. One sperm and one egg is involved and therefore the babies will look identical and must be of same sex
94 Identical twins do not have identical fingerprints Identical twins do not have identical fingerprints. They are a product of their environment.
107 Conjoined twinsParasitic twins: Asymmetrical conjoined twins, one twin being small, less formed, and dependent upon the other. Fetus in fetu: Situation in which an imperfect fetus is contained completely within the body of its sibling.
108 (V) Multiple BirthsFraternal twins- Develop from two separate eggs, each fertilized by separate sperm cells. Therefore, the babies may not look identical and could be of different sex. Simply ciblings!
109 (V) Multiple BirthsFertility drugs often cause production of more than one ovum during ovulation. Septuplets = 7 ova + 7 sperm (7 zygotes)