Human A&P: module 06.04 Reproductive System and (H) Fertilization to Birth

Mrs. Jessica Romito

SUMMARY

• Review modules
• 06.04 The Reproductive System
• 06.04H From Fertilization to Birth
• Review worksheets
• 06.04 page 2 The Reproductive System Worksheet
• 06.04H page 2 The Fertilization and Development Worksheet
• Review assessments
• 06.04 quiz
• 06.04H graphic organizer

OBJECTIVES

• By the end of this iClass, you will to be able to:
• Describe the basic anatomy and physiology of the human reproductive system
• Describe the process of human development from fertilization to birth and major changes that occur in each trimester of pregnancy
• Find the information to complete the course worksheets and review the completed worksheets
• Understand the expectations for the module assessments

STANDARDS

• SC.912.L.16.13: Describe the basic anatomy and physiology of the human reproductive system. Describe the process of human development from fertilization to birth and major changes that occur in each trimester of pregnancy.

MODULE 06.04

• Make sure you’ve watched the iClass on module 6 Part 1 (start at 15:36)
• Complete the worksheets on page 2, 3, 4
• Make sure you READ the information on each module page IN ADDITION to the information from the worksheets

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REVIEW OF MEIOSIS

• Creation of a haploid cells, gametes
• Occurs in the sex organs
• Testes in males
• Creates sperm cells, spermatozoa
• Ovaries in females
• Creates egg cells, oocytes
• Two gametes combine during reproduction to create a zygote

HUMAN GAMETES

1. Female reproductive systems are responsible for the production of EGGS. ��
2. Fertilization and development take place in the FEMALE reproductive system. ��
3. The production of SPERM takes place in the male reproductive system.

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VIDEO: MALE AND FEMALE REPRODUCTIVE SYSTEMS

The Male Reproductive System

• The production of sperm occurs in the male reproductive system.
• Sperm are male gametes or sex cells.
• Sperm cells are haploid, meaning they carry half the genetic content necessary to form a zygote.
• The other half of the genetic content comes from the woman’s egg.
• Sperm are produced in the testes.
• They’re contained in the sac-like scrotum.
• An important male hormone called testosterone is also generated in the testes.
• During puberty, as the male body goes through hormonal and physical changes, the testes begin to produce increased amounts of testosterone initiating sperm production and promoting the development of secondary sex characteristics—like the growth of body hair, and the deepening of the voice.
• Each testis consists of small, coiled tubes called seminiferous tubules.
• There are between 300 and 600 tubules in each testis.
• Sperm cells are produced in the seminiferous tubules but then move to the epididymis where they mature and are stored.
• Mature sperm exit the epididymis through a tube called the vas deferens.
• The two vas deferens empty to the urethra, the same structure through which urine empties.
• As sperm enter the urethra, the seminal vesicles, Cowper’s glands, and the prostate gland secrete fluids into the urethra—that nourishes and protects sperm.
• That fluid mixture is called semen.
• Once semen exits the penis, it is capable of fertilizing a woman’s egg.

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TESTES

Label the structures

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A SEMINIFEROUS TUBULES where sperm are produced

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B EPIDIDYMIS where sperm mature and are stored

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C VAS DEFERENS where sperm leave the epididymis

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D URETHRA where sperm exit the testis to join with semen (nourishes and protects sperm)

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A

B

C

D

MALE REPRODUCTIVE SYSTEM

4. Sperm are male GAMETES, or sex cells. They are HAPLOID, meaning they carry half the genetic content necessary to form a zygote.
5. The other half of the GENETIC content comes from the female egg.
6. FERTILIZATION is the process of male and female gametes joining together to form a ZYGOTE.
7. Sperm are produced in the TESTES. They are contained in a saclike structure called the SCROTUM.
8. An important male hormone, TESTOSTERONE, is also produced in the scrotum.
9. Each testis consists of small, coiled tubes called SEMINIFEROUS TUBULES. There are between 300 and 600 tubules in each testis.
10. Sperm cells are produced in the seminiferous tubules, but then move to the EPIDIDYMIS where they mature and are stored.
11. Mature sperm exit through the VAS DEFERENS. The two vas deferens empty through the URETHRA, the same structure through which urine empties.
12. The seminal vesicles, Cowper’s glands, and prostate gland secrete fluids into the urethra that nourish and protect the SPERM. That fluid mixture is called SEMEN, which leaves the body through the penis.

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THE FEMALE REPRODUCTIVE SYSTEM

• Females are responsible for the production of eggs.
• Fertilization and development also take place in the female reproductive system.
• Eggs are created in a woman's ovaries.
• Ovaries also produce the female hormones estrogen and progesterone.
• The female reproductive system includes two ovaries.
• They are only about four centimeters long and two centimeters wide.
• Each ovary amazingly contains about 200,000 small egg sacs called follicles.
• Each follicle contains an immature egg.
• While women are born with thousands of egg sacs, only about 500 ever mature during the woman's life.
• When the egg sac matures, its follicle moves to the surface of the ovary, breaks open and releases the egg.
• It's a process referred to as ovulation.
• The egg then travels through the oviduct, also called the fallopian tube.
• If fertilization occurs, it happens here.
• Then the egg travels to the thick-walled muscular uterus.
• It is in the uterus that the fetus develops.
• At the bottom of the uterus is the cervix.
• That's the opening into the vagina, which leads to the outside of the body.

FEMALE REPRODUCTIVE SYSTEM

Label the parts

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A OVARIES where eggs are produced

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B FALLOPIAN TUBE (OVIDUCT) how the egg travels from the ovary to the uterus

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C UTERUS where a fetus develops

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D VAGINA opening leading to the outside of the body

A

B

C

FEMALE REPRODUCTIVE SYSTEM

1. A female’s egg can potentially be fertilized by a male’s sperm to form a ZYGOTE.
2. Eggs are created in the woman’s OVARIES, which also produce the female hormones estrogen and PROGESTERONE.
3. The female reproductive system contains two ovaries, each of which contains about 200,000 small egg sacs called FOLLICLES.
4. While women are born with thousands of egg sacs, only about 500 ever mature during the woman’s life.
5. When the egg sac matures, its follicle moves to the surface of the OVARY, breaks open, and releases the egg. This process is referred to as OVULATION.
6. The egg then travels through the oviduct, also called the FALLOPIAN TUBE. If FERTILIZATION occurs, it happens here in the fallopian tubes.
7. Then the egg travels to the thick-walled, muscular UTERUS. This is where a FETUS develops from the fertilized egg.
8. At the bottom of the uterus is the VAGINA. That’s the opening to the vagina, which leads to the outside of the body.

06.04 ASSESSMENT

• Six multiple choice question quiz

FERTILIZATION

• Fertilization is the process of male and female gametes joining together to form a zygote.
• Sperm travels up the vaginal canal and fuses with the egg in the female’s fallopian tube.
• The zygote travels down the fallopian tube and attaches itself into the lining of the uterus.
• The lining provides nourishment for the egg as it divides, eventually forming a fetus.
• This occurs for the first 13 weeks during which the placenta (a whole new organ) is being made which will nourish the fetus for the final 27 weeks of gestation
• As the cells divide, they become specialized and develop into the many organs and cells that can be found in the human body.

VIDEO: FERTILIZATION

FERTILIZATION AND DEVELOPMENT

1. Fertilization involves the fusing of a male SPERM with a female ovum, also referred to as an EGG. This results in the formation of a ZYGOTE.
2. The zygote slowly moves through the FALLOPIAN TUBE, as it gradually undergoes a series of CELL DIVISIONS referred to as cleavage.
3. In the process of cleavage, the zygote repeatedly divides and develops into a ball of cells called a MORULA.
4. After several days, the MORULA continues to undergo cell division until eventually forming a hollow ball of cells called a BLASTOCYST.
5. After about a WEEK, the blastocyst becomes imbedded in the wall of the UTERUS in a process called IMPLANTATION. This signifies the beginning of pregnancy.

FERTILIZATION AND DEVELOPMENT

6. Following implantation, the blastocyst further develops into a three-layered structure called the GASTRULA.
7. The three layers, referred to as GERM layers, eventually give rise to specific body tissues and ORGANS.
8. The outer layer, called the ECTODERM, develops into the nervous system and SKIN.
9. The middle layer, called the MESODERM, develops into the muscles, BONES, kidneys, heart, blood vessels, and REPRODUCTIVE system.
10. The ENDODERM, the inner layer, gives rise to the liver, LUNGS, certain glands, and the DIGESTIVE system.

FERTILIZATION AND DEVELOPMENT

11. Following the development of the germ layers, a more complex EMBRYO forms which has two outer membranes: the CHORION and the AMNION.
12. The chorion contributes to the PLACENTA, through which gases, nutrients, and wastes are exchanged between the mother and the embryo.
13. The UMBILICAL CORD is a tube that connects the embryo to the placenta.
14. From the NINTH week of development until birth, the developing embryo is referred to as a FETUS. By this time, the major body systems have developed.
15. By the 14^TH week, the hands, arms, legs, feet, nose, eyes, and EARS have developed. �

FERTILIZATION AND DEVELOPMENT

15. From approximately FOUR months until birth, the fetus grows rapidly.
16. The length of pregnancy, referred to as the GESTATION period, is about NINE months in humans.
17. At roughly NINE months of development, a pituitary hormone called OXYTOCIN increases, which stimulates the birth process.
18. During labor, the UTERUS contracts rhythmically for several hours. The opening to the CERVIX widens, and strong contractions push the fetus out through the vagina.
19. After the baby is born, it begins to BREATHE on its own.

FETAL DEVELOPMENT: 1^ST TRIMESTER (month 1)

• Blastocyst implants itself into the uterine lining, where it receives important nutrients.
• Some of the cells begin to develop into specialized types of tissues in the body, while others develop into tissues that support and protect the embryo as it grows.
• During gastrulation, the cells divide into three cell layers called the
1. Ectoderm
• Develops into the skin and nervous system
2. Mesoderm
• Forms many of the body’s internal structures such as muscles, bones, blood cells, and reproductive organs
3. Endoderm.
• Forms the lining of the organs in the digestive system, respiratory system, and excretory system

FETAL DEVELOPMENT: 1^ST TRIMESTER (month 2)

1. Neurulation is the first step in the development of the nervous system.
• Part of the ectoderm thickens and folds to form a neural tube that eventually develops into the brain and spinal cord.
2. Specialized membranes form to protect and nourish the growing embryo.
1. A sac filled with amniotic fluid surrounds the embryo to cushion and protect it.
2. Other membranes form the placenta to connect the embryo to the mother.
• It is through this one organ that the fetus receives its oxygen and nutrients and disposes of its wastes.

FETAL DEVELOPMENT: 1^ST TRIMESTER (month 3)

• After eight weeks of development, the embryo is called a fetus.
• After three months of development, most of the major organs of the fetus are fully formed.
• However, most of the tissues and organs are not ready to function on their own.
• The fetus is about eight centimeters long and can move and show signs of reflexes.

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FETAL DEVELOPMENT: 2^ND TRIMESTER (months 4 through 6)

• Tissues become more specialized and begin to function.
• The heart is now large enough for heartbeats to be heard with a stethoscope.
• Bone starts to replace cartilage to form the early skeleton, and the mother begins to feel the fetus moving.
• Around week 13, the fetus's intestines return to its abdomen from the umbilical cord, where they've been growing for the past couple of weeks.
• The fetus also begins to form urine and discharge it into the amniotic fluid.
• The liver and pancreas are functioning at this time,
• The brain is continuing to develop rapidly, and
• The nervous system begins to control some of the body functions.
• In females, ovarian follicles begin forming, while the prostate gland develops in males.
• The fetus also has its own individual fingerprint patterns on the skin of its tiny fingers at this point, and eyebrows and eyelashes grow in.

FETAL DEVELOPMENT: 3^RD TRIMESTER (months 7 and 8)

• The fetus doubles in mass during this time,
• The lungs and other organs continue to develop and prepare for life outside of the uterus.
• The lungs are still developing until shortly before birth, but rhythmic breathing movements begin before the lungs are fully developed.
• During the last two months, the eyelids open again after being shut since the end of the first trimester,
• The body begins storing its own nutrients and minerals, such as calcium and phosphorus.
• It usually takes nine months for a fetus to fully develop; babies born earlier than eight months are considered premature and may have incomplete lung development.

FETAL DEVELOPMENT: 3^RD TRIMESTER (month 9)

• A combination of factors triggers the process of childbirth, including
• hormones released by the brain’s pituitary gland.
• These hormones trigger the movement of involuntary muscles in the uterus and abdomen that begin rhythmic contractions known as labor.
• As the labor continues, the opening of the cervix expands until it is large enough for the baby’s head to pass through.
• At some point in this process, the amniotic sac around the fetus breaks and contractions of the uterus push the baby, usually head first, out through the vagina.
• As you know, human growth and development does not stop when the baby is born…it is just getting started! This includes important organs, like the brain, that continue to develop long after birth.

ASSIGNMENT 06.04H

Fertilization and Development Graphic Organizer

Create a graphic organizer (flow chart, Venn diagram, etc.) to describe the major events in each of the trimesters of fetal development. You can use any graphic organizer format that you wish, but you must include each trimester and supporting details about each.

• First Trimester
• Second Trimester
• Third Trimester
• Details to discuss include:
• Blastocyst
• Gastrulation
• Ectoderm
• Endoderm
• Mesoderm
• Neurulation
• Nervous system development in each trimester
• Bone and specific organ development in each trimester

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ASSIGNMENT 06.04H

Contact Information

Mrs. Jessica Romito

Phone Number: (301) 485-9114

Time Zone: Eastern

Email: jromito@laurelsprings.com

Mrs. Romito's iClassroom

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LSS Live Academic Help Room

Monday–Friday 8 am to 11 pm Eastern Time�5 am to 8 pm Pacific Time

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