What you should know from Standard Grade / Int 2 etc ………•The structure of the male and female reproduction systems – do a QUICK SKETCH

•What are gametes?•What is fertilisation?•What is produced by fertilisation?

Work together to answer theseTable vs. Table Table vs. Table

Labels?

•Gametes are sex cells, sperm and eggs (ova)•Fertilisation is the fusion of male and female gametes •Zygote produced by fertilisation, which develops into embryo and then foetus.

The male reproductive system

The female reproductive system

Male or female?

Roles of the reproductive system

Sex cells – sperm

Sperm are produced in sex organs called testes.

In males, the sex cells are called sperm.

headtail middle piece

cell membrane nucleus containing DNA

Sex cells – egg

Eggs are produced in sex organs called ovaries.

In females, the sex cells are called eggs.

nucleus containing DNA

membrane jelly coat

cytoplasm

Ovulation and fertilization

The fusing of the two nuclei is called fertilization.

If a sperm meets the egg, the sperm’s nucleus can join with the egg’s nucleus.

During sexual intercourse, millions of sperm are ejaculated into the vagina.

In a female, one of the ovaries produces an egg approximately every 28 days. This is called ovulation.

Fertilization and implantation

The placentaHow does an embryo receive food and oxygen and how does it get rid of waste?

An embryo forms a structure called the placenta, which attaches to the uterus wall.

The umbilical cord joins the fetus to the placenta.

In the placenta, food and oxygen diffuse from the mother’s blood into the blood of the fetus.

Carbon dioxide and waste products diffuse from the blood of the fetus into the mother’s blood.

umbilicalcord

How does the placenta work?

Unit 2 Physiology and Health; Reproduction

Learning Outcomes

•Identify the cells and organs that produced the gametes

•Examine the structure of testes and ovaries and their functions in the production gametes

Complete the word glossary and the

diagrams

Structure Function Seminiferous tubules

Interstitial cells

Prostate gland

Seminal vesicles

Ova

Graafian follicle

Corpus luteum

Ovary

Oviduct

Uterus

Cervix

Vagina

Sperm

Sperm duct

Penis

Accessory gland

Male and Female Reproductive Organs

Male Reproductive Male Reproductive SystemSystem Testes are the site of:

• sperm production• manufacture of the male sex hormone testosterone

Sperm ProductionSperm ProductionSperm are formed by meiosis in the tiny seminiferous tubules of the testes, which unite forming coiled tubes that connect to the sperm duct.

Sperm duct

Sperm Sperm forming forming

by by meiosismeiosis

Recap on meiosis .... Put these in the right

order Stage ______________

MEIOSIS STAGES Each chromosome duplicates to become double stranded. Each strand is called a chromatid.

Stage ______________ Stage ______________

The second part of meiosis begins with the chromosomes condensing again, and the nuclear envelopes disappearing.

A new nuclear envelope forms around each set of chromosomes, and the cell finishes dividing. Each cell only has 46 chromosomes

Stage ______________ Stage ______________

Each chromosome becomes shorter, thicker and more visible. The chromatids are joined at the centromere. The nuclear envelop disappears

Spindle fibres spread out from each end of the cell and attach to the centromere of each chromosome Homologous chromosomes pair up in the centre of the cell, independently assortment.

Stage ______________ Stage ______________

A new nuclear envelope forms around each set off chromosomes. Each cell contains 23 chromosomes, and each is genetic unique.

Spindle fibres spread out at right angles to before, and attach to the chromosomes. The fibres contract, separating the two chromatids in each chromosomes, Each cell divides in two.

Stage ______________ Stage ______________

Small parts of homologous chromosomes cross over at chaismata. This exchange of genetic material increases variation.

The spindle fibres contract, separating the homologous pair into opposite sides of the cell, which begins to divide. Each chromosome is still formed of two chromatids.

Stage 1 Stage 5Each chromosome duplicates to become double stranded.

The spindle fibres contract, separating the homologous pair into opposite sides of the cell, which begins to divide. Each chromosome is still formed of two chromatids. Each strand is called a chromatid.

Stage 2 Stage 6Each chromosome becomes shorter, thicker and more visible. The chromatids are joined at the centromere.

A new nuclear envelope forms around each set of chromosomes, and the cell finishes dividing.

The nuclear envelop disappears Each cell only has 46 chromosomesStage 3 Stage 7

Spindle fibres spread out from each end of the cell and attach to the centromere of each chromosome Homologous chromosomes pair up in the centre of the cell, independently assortment.

The second part of meiosis begins with the chromosomes condensing again, and the nuclear envelopes disappearing.

Stage 4 Stage 8Small parts of homologous chromosomes cross over at chaismata.

Spindle fibres spread out at right angles to before, and attach to the chromosomes. The fibres contract, separating the two chromatids in each chromosomes, Each cell divides in two.

This exchange of genetic material increases variation.

Stage 9

MEIOSIS STAGES A new nuclear envelope forms around each set off chromosomes. Each cell contains 23 chromosomes, and each is genetic unique.

Pathway of sperm Pathway of sperm The function of the testes is to make and produce sperm. Sperm are transported to the urethra via the sperm duct (vas deferens) . The urethra takes the sperm out of the male body.

Pathway of sperm Pathway of sperm during sexual during sexual intercourseintercourse

Image source: www.fertility.com

Sperm are motile. This requires a fluid medium & a source of energy.

The process of fertilisation depends on sperm being motile to bring gametes together

TestosteroneTestosterone….the male sex hormone

• Produced by interstitial cells, in the tissue between the seminiferous tubules of the testes• Released directly into the bloodstream

Image source: http://faculty.une.edu

The sperm are mixed with fluids produced by the accessory gland.

The 2 main accessory glands are the prostate gland and seminal vesicles which nourish and stimulate the sperm.

Sperm plus these fluids is called semen.

Accessory GlandsAccessory Glands

Seminal VesiclesSeminal VesiclesMales have a pair of seminal vesicles, which secrete a thick liquid rich in:• fructose – a sugar that provides sperm with

energy for motility• prostaglandins – hormone-like compounds that stimulate contractions of the female reproductive tract. Help sperm to move more quickly towards the egg.

Prostate GlandProstate GlandSecretes a thin lubricating liquid containing enzymes. The enzymes keep the fluid at the optimum viscosity (thickness) for sperm motility.Semen is a milky liquid composed of:•sperm, •fluid from seminal vesicles•fluid from prostate gland

Demonstrate your Demonstrate your understandingunderstanding

1. Sperm are described as motile. What does this term mean?

2. Describe two conditions required for sperm to show motility.

3. Describe the role played by the seminal vesicles and the prostate gland.

4. Where is testosterone made?5. What is the difference between

sperm and semen?

Demonstrate your Demonstrate your understandingunderstanding

1. Moving2. Energy (by fructose) and fluid medium (semen)3. Seminal vesicles produces fructose and prostaglandins (hormone causing contractions) Prostate gland produces an enzyme for keeping viscosity at optimum for sperm mobility4. Interstitial cells5. Sperm part of semen alongside fluid from prostate gland and seminal vesicles.

Review ....

• Sperm duct• Interstitial cells