reproduction

Reproduction

Discuss at your table:

Are you like your parents? What part of you is like your mother? What part is like your father?

How come we are not identical copies?

Objectives:

1. Identify the major structures of the male and female reproductive system. 2. Describe the function of each structure of the male and female reproductive system.

Reproductive System The Reproductive System, unlike other

systems we have studied, IS NOT ESSENTIAL to the survival of an INDIVIDUAL.

What the Reproductive System is important to is the Survival of the SPECIES.  Reproduction is absolutely essential to the continuation of the SPECIES…SOME OF US MUST REPRODUCE!

Genetic Information

EVERY cell in the human body contains a nucleus which has the pattern for your body on 23 pairs of chromosomes.

Except: Blood cells and sex cells

Chromosomes are the pattern for your body carrying inherited information like eye color.

Pair Up your cards and put them in order:

A, A 2, 2 3, 3 5, 5 6, 6 7, 7 Etc.

Card Traits

black red A hair color dark light 2 height tall short 3 eye color dark light 5 hair texture curly straight K sex boy girlChromosomes contain genes which have

specific information (traits) on them

The Human Reproductive System

The testes and ovaries produce and store special cells called sperm and egg cells. 

The egg cell contains information from the mother

The sperm cell contains information from the father

Each contains only one of each pair of chromosomes. How many is that?

Fertilization

The egg cell and sperm cell join together in a process called FERTILIZATION.  From a single Fertilized Egg cell, or ZYGOTE, come all the cells in a human body.

Male reproductive system

Male reproductive system is specialized to produce sperm

A.  The TESTES, which are Reproductive Organs of a MALE, begin to produce the hormone testosterone, making the male reproductive organs develop.

C. Neither Testes or Ovaries are capable of producing working sperm or eggs until PUBERTY.

Male Reproductive System

THE MALE REPRODUCTIVE SYSTEM 1. At puberty, males begin to produce sperm in

the testes.

2. The TESTES develop within the Abdominal Cavity, just before birth the Testes descend through a canal into an EXTERNAL SAC called the SCROTUM.

Male Reproductive System

4. The Testes are outside the body, in the scrotum, where the temperature is about 3 degrees Cooler than the body internal temperature

5. Sperm development in the Testes Requires the Lower Temperature.

Male Reproductive System

8. Cells that respond to Testosterone are found all over the body.

9. Testosterone produces a number of SECONDARY SEX CHARACTERISTICS that appear in Males at Puberty – Voice Deepens, Beard Grows, and Body Hair.

Male Reproductive System

Sperm Development

1. Sperm come from Special Cells within the Testes that have divided with half of the genetic information of a regular cell.

2. A Mature Sperm consists of THREE Regions:     A.  HEAD - which contains the Nucleus (The 23

Chromosomes) and enzymes that help the sperm penetrate the protective layers that surround and Egg Cell.

    B.  MID PIECE - packed with energy releasing Mitochondria (Energy Source).  The Mitochondria supply the energy that is required for sperm to reach an Egg.

    C.  TAIL – Consists of a Single, Powerful FLAGELLUM that propels the Sperm.

Male Reproductive System 4. Sperm goes through the Vas Deferens

5. Each Vas Deferens merges with the Urethra. 

In a Male, both Urine and Sperm exit the body through the Urethra.

6. In the Urethra, Sperm Mix with Fluids that are secreted by three glands to make SEMINAL FLUID -which Protects and Nourishes the Sperm.

Male Reproductive System SEMEN: THE COMBINATION OF SPERM

AND SEMINAL FLUID BETWEEN 100 AND 200 MILLION SPERM

ARE PRESENT IN 1 milliliter OF SEMEN OR ABOUT 5 MILLION SPERM PER DROP!

The Penis is the Male Reproductive Organ that makes it possible for Sperm to be delivered to the body of the Female.

Male Reproductive System 300 - 400 million Sperm are released in

the Reproductive Tract of a Female during a single Ejaculation; the chances of a Single Sperm Fertilizing an Egg if one is available, are GOOD

Most sperm are Killed by the Acidic Environment of the Female Reproductive Track. Only a few Sperm reach the site of Fertilization.

Female Reproductive System The main function of the female

reproductive system is to produce Eggs

EACH TIME AN EGG IS RELEASED, THE BODY MUST BE PREPARED TO NOURISH A DEVELOPING EMBRYO.

Female Reproductive System Puberty in females starts with changes in

hormones.

Estrogen causes the reproductive system to complete its development, and also produce SECONDARY SEX CHARACTERISTICS - Enlargement of Breast and Reproductive Organs, Widening of the Hips, and growth of Body Hair.

Female Reproductive System Each Ovary contains about 400,000

PRIMARY FOLLICLES, which are clusters of cells surrounding a single ovum (egg).

2. During her lifetime fewer than 500 Ova (Eggs) will actually be released, averaging one egg about every 28 days.

When a Follicle has completely matured, the Ovum (Egg) is released.  THIS PROCESS IS CALLED OVULATION

Female Reproductive System If TWO Eggs mature, Fraternal, or Non

Identical Twins may result. Ovulation begins at Puberty and

USUALLY continues until a female is in her late forties, when MENOPAUSE occurs.

During Ovulation the Follicle ruptures, and the Ovum is swept from the Ovary into one of the TWO FALLOPIAN TUBES.  The Fallopian Tubes provide a way for an egg to travel from the Ovary to the Uterus.

Female Reproductive System

Female Reproductive System IT IS DURING ITS JOURNEY THROUGH

THE FALLOPIAN TUBE THAT AN EGG CAN BE FERTILIZED.  An Egg must be fertilized within 48 hours of its release - after that, the egg begins to break down.  Unfertilized eggs dissolve in the Uterus.

After a FEW DAYS, the Ovum passes from the Fallopian Tube into the UTERUS

Female Reproductive System

Leading from the Uterus (CERVIX) to the outside of the body is a muscular tube called the VAGINA or Birth Canal.

Menstrual Cycle THE MENSTRUAL CYCLE IS THE SERIES

OF CHANGES THAT OCCUR IN THE UTERUS EACH MONTH.

The Menstrual Cycle has FOUR Stages: THE FOLLICULAR PHASE, OVULATION, THE LUTEAL PHASE AND MENSTRUATION

These Stages are Regulated by the Hormones of the Endocrine System

http://kidshealth.org/teen/sexual_health/girls/female_repro.html

Menstrual Cycle During the 1st stage, the Egg Matures,

and the Lining of the Uterus GROWS THICKER, many tiny Blood Vessels grow into the thickened lining, in preparation for receiving a Fertilized Egg.

The development of an Egg in this stage of the Cycle takes about 14 DAYS

Menstrual Cycle The 2nd Stage, OVULATION, the

shortest phase in the Cycle (3-4 DAYS), is the release of an egg from a ruptured follicle. Following Ovulation, an egg is swept into a fallopian tube, where it travels toward the uterus awaiting fertilization.  The Egg has enough stored nutrients to survive about 48 hours.

Menstrual Cycle The 3rd Stage lasts about 14 Days.

The Cells of the Ruptured Follicle grow larger and fill the cavity and begin to secrete large amounts of PROGESTERONE and ESTROGEN.  The Increase levels cause the Pituitary Gland to stop Secreting LH and FSH.

Menstrual Cycle Hormones cause the lining of the Uterus to

become even thicker The Lining is prepared to receive the Embryo

four or five days after the Egg is released from the Ovary.

An Embryo that settles into the lining of the uterus, hormones continue to be released, which cause the Uterus to maintain its thickened lining.

Most of the time, no embryo arrives, less hormone is produced.

Menstrual Cycle The Decrease in Levels of hormones

causes the lining of the uterus to come loose from the inside of the uterus

The mixture of Blood and the Cells that made up the lining of the uterus is called MENSTRUAL FLUID.

Menstrual Cycle The passage of this Fluid through the

Vagina and out of the body is called MENSTRUATION OR THE MENSTRUAL PERIOD THE LAST STAGE. IT USUALLY LASTS FROM THREE TO SEVEN DAYS.  At the end of the Period, a NEW Cycle Begins

The AVERAGE Menstrual Cycle is 28 DAYS LONG.

Menstrual Period

Almost ALL Women START their Menstrual Period 14 DAYS AFTER Ovulation occurs.

The length of the First stage of the cycle, the period when the Follicle is growing, DIFFERS from women to women.