1. Reproduction and Development in Humans
Chapter 25
Reproduction and Development in Humans

2. (I) Female Reproductive
System

4. Terms Gonads Gametes Gametogenesis (The process) Females Males Ovaries
Oogenesis
Males
Testes
Sperm
Spermatogenesis

5. Gametogenesis The production of gametes (sex cells)
Males = spermatogenesis in the testes
Females = oogenesis in the ovaries

6. (A) Ovaries The female gonads
Located within the lower portion of the body cavity
In the ovaries, each egg cell (ovum) is present in a tiny sac called a follicle

7. (A) Ovaries
3. 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 develops
6. 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

11. The Arethra:
Oops, wrong one

14. Ovary

15. Female Reproductive Structures, (side VW)
Vertebrae
Bladder
Rectum
Sperms path

16. Figure 39–2 The Endocrine Glands
Section 39-1
Hypothalamus
The hypothalamus makes hormones that control the pituitary gland. In addition, it makes hormones that are stored in the pituitary gland.
Pineal gland
The pineal gland releases melatonin, which is involved in rhythmic activities, such as daily sleep-wake cycles.
Thyroid
The thyroid produces thyroxine, which regulates metabolism.
Pituitary gland
The pituitary gland produces hormones that regulate many of the other endocrine glands.
Pancreas
The pancreas produces insulin and glucagon, which regulate the level of glucose in the blood.
Parathyroid glands
These four glands release parathyroid hormone, which regulate the level of calcium in the blood.
Ovary
The 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.
Thymus
During childhood, the thymus releases thymosin, which stimulates Tcell development.
Testis
The testes produce testosterone, which is responsible for sperm production and the development of male secondary sex characteristics
Adrenal glands
The adrenal glands release epinephrine and nonepinephrine, which help the body deal with stress.

17. The Effects of Estrogen
Section 39-3

18. Figure 39–22 The Placenta
Section 39-4

19. (II) Menstrual Cycle Mature egg develops and is released
Begins at puberty and ends at menopause
Hormones involved:
FSH estrogen
LH progesterone
Stages 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 blood
2. Ovulation
Secretion 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 Luteum
10-12 days
* The burst follicle fills with cells forming the corpus luteum, which produces progesterone fuher thickening of the uterine lining
4. Menstruation
3-5 days
If the egg is not fertilized, progesterone secretion decreases and the lining of the uterus breaks down
The lining of the uterus is sloughed off and discharged from the body through the vagina as a result (period).

21. The Menstrual Cycle
Section 39-3

22. The Menstrual Cycle
Section 39-3

23. Do Now 4/26
Describe the menstrual cycle. (remember there are 4 stage!!!!)
What is a Feedback Mechanism?

24. (II) Menstrual Cycle

25. 1. Follicle Stage
10-14 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 blood

26. Ovulation
Secretion 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 progesterone
Progesterone stimulates further thickening of the uterine lining

29. 4. Menstruation
3-5 days
If the egg is not fertilized, progesterone secretion decreases and the lining of the uterus breaks down
The lining of the uterus is sloughed off and discharged from the body through the vagina as a result (period).

32. Check your hw answers using the transparency.
Do Now 4/29:
Check your hw answers using the transparency.

33. (VI) Male Reproductive
System

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 epididymis
Sperm then leaves the epididymis through the vas deferens and into the urethra (which is a tube inside the penis)

36. The process
The penis is a structural adaptation for internal fertilization
Glands 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 semen
Testes 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 pitch
Scrotum- sac in which the testes are located
a) outside the body
b) keeps the temperature 1-2 degrees Celsius cooler than normal body temperature
c) this provides an optimum temperature for sperm production

41. HEAD with NUCLEUS & ACROSPORE
Shaft (middle region)
TAIL (MOTILITY)

44. Vasectomy
Male 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 deteriorate
After 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 cells
Offspring are not identical to the parent
Variations exist, which increases the species ability to adapt to the changing environment

47. (A) Reproductive System
Gonads- specialized organs that produce gametes
a) ovaries - female gonad
- produce ova (egg)
b) testes - male gonad
- produce sperm cell

48. Contain both male and female reproductive structures
(B) Hermaphrodite
Contain both male and female reproductive structures

49. Process by which gametes are produced in the gonads
(C) Gametogenesis
Process by which gametes are produced in the gonads
Two types:
- Spermatogenesis
- Oogenesis

50. Oogenesis
The primary oocyte goes through first meiotic division and the cytoplasm of the cell is divided unequally
The larger daughter cell is called the secondary oocyte and the smaller daughter cell is called the polar body
During second meiotic division, 1 mature ovum is produced and 3 polar bodies

51. Spermatogenesis
Primary spermatocyte goes through first meiotic division and form two daughter cells of equal size
Each 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 yolk
Egg cells are larger than sperm
Sperm are motile, egg cells are not

54. (B) Fertilization
The fusion of the nuclei of one sperm with one ova (egg) to produce a zygote
Sperm (n) + Ovum (n) =2n
Sperm (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.

56. Parthenogenesis

57. Fertilization
Union of a haploid sperm nucleus with a haploid egg nucleus
This results in a diploid zygote with the full number of chromosomes n n 2n

58. Fertilization
Union of a haploid sperm nucleus with a haploid egg nucleus
This results in a diploid zygote with the full number of chromosomes

59. Fertilization and the Stages of Mitosis

60. Two types of Fertilization
External Fertilization
Internal Fertilization
**Parthenogenesis**

61. External Fertilization
Eggs are fertilized outside the body of the female
Large number of eggs are required
This type of fertilization is found in an aquatic environment
Ex: fish and frogs

62. Spawning???

63. External Fertilization

64. External Fertilization

65. External Fertilization

66. External Fertilization

67. Do Now
What are some differences between External and Internal Fertilization? Provide examples!!!

68. External Fertilization

69. External Fertilization

70. External Fertilization

71. External Fertilization

72. Internal Fertilization
Takes place inside the body of the female
Less eggs are required
Ex: mammals, birds and reptiles

73. Internal Fertilization

74. The embryo arrives in the uterus 5-10 days after fertilization
The embryo implants into the uterine wall and establishes pregnancy
Placenta- nourishes the embryo
Umbilical cord- attaches the embryo to the placenta
Amnion- embryo develops inside the amniotic sac which contains amniotic fluid that serves as a shock absorber
Gestation Period- length of pregnancy (approximately nine months)

75. Fertilization

76. Good Review Webpage

77. Fertilization and Implantation
Section 39-4
Uterine wall
Blastocyst
Morula
4 cells
2 cells
Zygote
Ovary
Fallopian tube
Day 3
Day 2
Day 1
Day 4
Fertilization
Day 0
Day 7
Implantation of blastocyst
Egg released by ovary

78. Development
The 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 Now
Ectoderm
Mesoderm
Endoderm
Looking at the diagram above. Hypothesize the systems that will develop from these three layers.
Reproductive
Muscles,
Skeleton
Digestive
Nervous
ETC

80. Ectoderm Mesoderm Endoderm
It is the three germ layers that give rise to all the tissues and organs of an animal
Ectoderm
Mesoderm
Endoderm
Nervous system
Digestive System
lining of mouth, nostrils, and anus
epidermis of skin, sweat glands, hair, and nails
bones and muscles
blood and blood vessels
reproductive and excretory system
dermis layer of skin
lining of digestive tract
lining of trachea, bronchi, and lungs
liver, pancreas
thyroid, parathyroid
urinary bladder

81. The Three germ layers

82. Do Now Identify what is the purpose of the following: The placenta:
The umbilical cord:.  
The amniotic fluid:

83. Do Now answers
The 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.

84. Human Development

85. Fetal Development
Development 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 weeks
4 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 diet
use of alcohol (Fetal alcohol syndrome)
Tobacco
Drugs
other toxins
infections   

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.
Amniocentesis
Hormone 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. Amniocentesis
Fetal cells are removed and surveyed for genetic disorders

90. Reproductive Technologies

92.                                                                                                  
                                               
                                               
(IV) Multiple Births
1. 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 Births
1. 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.

95. The end

96. Conjoined Twins

97. Conjoined “Siamese” Twins Chang and Eng

98. Eng Bunker---Chang Bunker Born: May 11, 1811 Died: January 11, 1874

99. The developing embryo begins to split into identical twins but then stops part way leaving the partially separated egg to mature into a conjoined fetus.

100. They are more often female than male (ratio of 3:1)

101. They occur as often as once in every 40,000 births but only once in every 200,000 live births.

102. 40% are still born
70% are female - even though monozygotic twins are
more frequently male than female.
75% are still born or die within 24 hours.

103. Cephalophagus

104. This refers to one body with two heads.
Dicephalus
This refers to one body with two heads.

105. Anterior union of the lower half of the body
Ischophagus
Anterior union of the lower half of the body

107. Conjoined twins
Parasitic 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 Births
Fraternal 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 Births
Fertility drugs often cause production of more than one ovum during ovulation. Septuplets = 7 ova + 7 sperm (7 zygotes)

110. (V) Multiple Births