pict. of spermatogenesis - 2015 [1]

Dr.Iman Abdel-AalDr.Iman Abdel-Aal


IntroductionIntroduction

Human Development : It is a continuous process that begins when an oocyte

(ovum) from a female is fertilized by a sperm (or spermatozoon) from a male.

Cell division, cell migration, programmed cell death, differentiation, growth, and cell rearrangement transform the fertilized oocyte, a highly specialized, a zygote (totipotent cell ) into a multicellular human being.

Development Periods : It is customary to divide human development into

A. Prenatal (before birth) period.

B. Postnatal (after birth) period.


IntroductionIntroduction

Stages of Prenatal Development :It is divided into three stages:1. Stage 1 : begins at fertilization.2. Embryonic period : from 3-8th week.3. Fetal period : ends when the fetus is completely

outside the mother.

Definition of Embryology : Embryology means the study of embryo however, the

term generally refers to prenatal development (the study of embryos and fetuses).


Mitosis


462n

Mitosis

462n

Single structured

Double structured

Replication

Amount of DNA=2N

4N

462n

462n

Single structured2N


Meiosis


462n

Meiosis

462n

Single structured

Double structured

Replication

Amount of DNA=2N

4N

23n

23n

Single structured

2NDouble structured

23n

23n

23n

23nN

MI

MII

Male Genital System and Male Genital System and Stages of Stages of

SpermatogenesisSpermatogenesis


Spermatogenesis

Type A spermatogonia

Mitosis

Type B spermatogonia

1ry spermatocyte

1st meiosis

2nd spermatocyte 2nd meiosis Spermatids

By spermiogenesis it gives 4 Spermatozoa


44+

XY

44+

XY

44+

XY

22+X

22+Y

22+Y

22+Y

22+X

22+X

SpermiogenesisSpermiogenesis


Abnormal GametesAbnormal Gametes


pict. of spermatogenesis - 2015 [1]

Documents

iman abdelaaldr

iman abdelaalspermiogenesisdr

iman abdelaalmitosisdr

iman abdelaalmeiosisdr

prenatal development

cell migration

birth period

cell rearrangement