human reproduction

Hasimah Azit

Sexual and Asexual Reproduction

Sexual reproduction occurs when a new individual is formed through the union of two sex cells (gametes). produce zygote Haploid gametes formed by meiosis in sex organs

(gonads). Asexual reproduction occurs when genetically

identical cells are produced from a single parent cell by mitosis. fission or budding

Adi Ahmad Danish

Gametogenesis

Gamete production By meiosis The chromosomal number in gamete is half of

chromosomal number in parent cell Gamete will carry different genetic constitution

-Testis is located in scrotum, outside the body to maintain the low temperature [suitable for gamete production]-Inside the testes, seminiferous tubule is densely coiled, connected to epididymis that connected to vas deferans that connected to semenal vesicle.

Male Reproductive SystemMale accessory sex organs

epididymis vas deferens seminal vesicles prostate gland urethra

Spermatogenesis

Testis and Spermatogenesis

spermatogenesisSpermatogonium

Primary Spermatocyte

Secondary Spermatocyte

Spermatid

Spermatozoa

Mitosis

Meiosis I

Meiosis II

Differentiation

Differentiation

sperm

Male Reproductive SystemSpermatozoa

Head encloses nucleus and capped by an acrosome - contains enzymes that aid in egg penetration.body and tail provide propulsion

Epididymis -

• Nonmotile sperm arrive in Epididymus - Tubules on outer surface of testis where sperm mature (18 hrs.) and are stored.

Epididymus

1. Prostate gland - large gland behind urinary bladder and produces seminal fluid.

2. Seminal vesicles - paired glands at bases of vas deferentia and produce seminal fluid.

Seminal fluid serves as a lubricant, pH buffer, and nutrient (high in sugars) seminal

vesicle

prostate

Male Reproductive SystemHormonal control of male reproduction

FSH stimulates the Sertoli to facilitate sperm development.

LH stimulates Leydig cells to secrete testosterone.Principle negative feedback inhibition applies

to FSH and LH secretion.

UTERUS and OVARY

Ovari

Oogenesis

Ovum production processOccurs in ovaryOocyte develop simultaneously with

the development of follicle.

Female Reproductive System

Menstrual and estrous cycles At birth, a female’s ovaries contain

approximately 2 million follicles.Some follicles are stimulated to

develop each cycle.Human menstrual cycle lasts

approximately one month, and is commonly divided into a follicular phase and a luteal phase.

I want to learn to some more Please …..

Oogenesis

Oogonium

Oocyte primer

Secondary oocyte + polar body

mitosis

Meiosis I

Ovum + polar body

Sperm Meiosis II

Graafian follicle

Inside the fallopian tube

Secondary Oocyte

MENSTRUAL CYCLE

NOTES

QUIZ

Ovum and sperm

Mitosis

Oooh… overdosed already

5 weeks 6 weeks 7 weeks

8 weeks 9 weeks 12 weeks

24 weeks20 weeks

18 weeks16 weeks14 weeks

Baby grow?

Before birth After birth

Placenta

Substances that able to diffuse across the placenta from mother to fetus:

OxygenAmino AcidGlucoseFatty acid and glycerolVitaminAntibodyAny virus, drugs, alchohol.

Substances that able to diffuse across the placenta from fets to mother blood:Carbon dioxideUric acidUrea

Milk production

Normal delivery

Problems in reproduction

Infertility in male and female

----find the causes

Ectopic pregnancy

Family planning

Ectopic pregnancy

Procidentia

Placenta abnormal position

Hormone involve

Pituitary secretes: FSH [Follicle Stimulating Hormone] stimulate the

development of follicle in the ovary LH [Luteinizing – stimulate ovulation

From ovary: Follicle cells produce Estrogen- – stimulate the endometrial wall (uterine lining) after

menstrual Corpus luteum produces Progestrone - – stimulate and maintain the thickness of endometrial.

Compilation of graph

Identical twin

Produce after fertilization of an ovum by a sperm Membentuk satu zigot Diperingkat morula berlaku pemisahan tisu kepada dua – dua fetus

berkembang serentak Berkongsi plasenta Ciri-ciri:

Jantina sama Rupa paras sama

Fraternal / non-identical twin

Fraternal twin

Two ovum produce at a time Fertilezed by two sperm Two zigotes formed Not sharing the plasenta Developed into two babies with:

Same or different gender Different feature

Siamese twin

Group discussion:

1 Male and female infertility 2 Sperm bank3 Invitro fertilization4 GIFT5 IVF6 Surrogate mother7 Family planning

Natural way….

Infertility has been defined as the inability of a couple to conceive after one year of regular intercourse without the use of contraceptives. The definition has also come to include couples who are able to conceive but, due to repeated miscarriages, are unable to carry a pregnancy to term.

causes of infertility

>>>In men, these include environmental and hormonal factors that affect the production of healthy, motile sperm and normal semen, as well asblockages that affect the delivery of sperm

>>>In women, the causes are more varied since she plays a greater role in reproduction. First, one of the organs involved in reproduction may be absent, mal-formed or non-functional. Second, the organs may be normal, but the complex hormonal feedback system that is necessary to support follicular development, ovulation and implantation of the fertilized egg may be disrupted

If there are enough sperms ?

>>less than 20 million sperm per ml, this is considered to be a low sperm count. >>Less than 10 million is very low.

# Whether the sperms are moving well or not

Grade a ( fast progressive) sperms are thosewhich swim forward fast in a straight line

Grade b ( slow progressive) sperms swim forward, but either in a curved or crooked line,

Grade c ( nonprogressive) sperms move their tails, but do not move forward ( local motility only).

Grade d ( immotile ) sperms do not move at all

Whether the sperms are normally shaped or not >> a good sperm should have a regular oval head, with a connecting mid-piece and a long straight tail.

>> abnormal

* round heads; * pin heads; * very large heads; * double heads; * absent tails