Sexual Reproduction in Human | Human Reproduction
In this article we are going to discuss about Human Reproduction or Sexual Reproduction in Humans NOTE:- Male Reproductive System, Female Reproductive System, Gametogenesis, Menstrual Cycle, Pregnancy and Development, Fertilization and Embryonic d Implantation, Parturition and Lactation and we will give it full free pdf format
What is Reproduction
Reproduction is the process in which organisms replicate to produce their young ones
(offspring). It is one of the most important notions in biology. It means to duplicate or make a
copy and therefore providing continued existence of organisms. Human reproduction involves
sexual acts between a man and a woman, resulting in fertilization. When a man and a woman are
having sex, their reproductive systems result in fertilization. The man produces sperms and the
woman produces an egg, also known as the ovum, and so when the man’s sperm meets the
woman’s ovum, fertilization occurs. Gametes are the specialized reproductive cells and are
produced through a process known as meiosis.
To produce an offspring, the male and female reproductive organs have to be present, normally
constructed and functional.
What is Male reproductive systems include;
The male organ used for copulation or sexual activity. When aroused, the erectile tissue on the
penis becomes engorged with blood and that results into a considerable enlargement, and
erection. This erection allows the penis to properly penetrate a vagina.
They are enveloped in a sac-like skin. They produce spermatozoa, the male germ cells
Contributes to secretion of semen
Scrotum-lies below and outside the abdomen
What is Female reproductive system
Its orifice is guarded by the hymen. When a woman engages in sexual intercourse for the first
time, this membrane known as hymen has to be broken to allow the penis to pass through. This
causes a lot of pressure and sometimes may cause bleeding. That’s why it’s always painful for a
lady having sex for the primary time.
It connects the vagina to the uterus and acts a gateway between the two. It dilates to allow the
sperm to pass from the vagina into the uterine cavity. It is sterile and thus protects the uterine
cavity from bacterial invasion.
Also known as the womb. It is hollow and muscular and has very thick walls. Normally, the
uterus is 7.5cm long, 5cm wide and 2.5cm thick. During pregnancy, it enlarges four to five times
its normal size.
Situated in the pelvic cavity, ovaries produce ova, the female germ cells
Also known as the uterine tubes. They carry ova from the ovaries to the uterus. It is this is where
fertilization takes place tube that fertilization takes place.
The ovaries and testicles are responsible for producing gametes. They also cause proper
functioning of the reproductive tracts and produce hormones that cause full development of
secondary sexual characteristics such as pubic hair, enlarged breasts and widened hips in women,
and facial hair and Adam’s apples in men.
During sexual intercourse, the penis is stimulated to erect and penetrate the vagina, then the man
ejaculates seminal fluid containing sperms into the female genital tract. From the vagina the
sperm then passes through the uterus to the fallopian tube where fertilization of the ovum takes
place in the outer part of the tube. At puberty, women experience a period in the activity of their
ovaries, known as menstruation period. The menstrual periods begin at puberty, at around 11
years for girls, and proceeds until menopause. The menstrual periods come in intervals of 28
days although it may be different for some women. During ovulation, the ovaries release an egg
(ovum) which moves through the fallopian tube to the uterus. If a woman engages in sexual
intercourse during that period, they are likely to get pregnant. If no sexual activity occurs, that
means the ovum does not meet a sperm, and so fertilization won’t occur. Instead, the ovum
proceeds to the uterus and then comes out through the vagina as the monthly bleeding known as
menstrual periods. The menstrual periods temporarily stop appearing when a woman is pregnant
or in the early weeks of breast feeding.
Development of the reproductive organs
In the human reproductive system, external and internal organs work together to ensure sexual
reproduction. The development of sexual organs begins very early in the embryo. Let’s look at
when the female and male sex organs.
Gonads are the primary reproductive organs, testes for men and ovaries for female Indifferent
stage of the gonads. During the first stages of gonadal development, you cannot tell or
differentiate between a male and female gonad, which is why. The stage is known as indifferent
stage. The gonads begin as longitudinal ridges that do not contain any gametes. In the fourth
week of gestation, the gamete cells in the yolk sac begin to move to the longitudinal genital
ridges through the dorsal mesentery. In the sixth week of gestation, the gametes reach the genital
ridges. XY chromosomes are present in a male embryo and XX chromosomes in female embryo.
The gonads are tethered to the scrotum in males and labia in female. As the fetus grows, the
testes look more like a tail. In the 28th week, they pass through a pathway known as inguinal
canal, and in the 33rd week, they reach the scrotum. So, the testes descent on the 33rd week. The
ovaries also migrate looking like a tail just like the male testes, however, they don’t go far. The
ovaries reach their destination at the pelvis.
The reproductive organs will have developed and at the right positions at birth but won’t be
functional until puberty. During childhood, the reproductive organs grow gradually. There is
steady growth and gradual development of activity until puberty. When puberty hits, that when
the activity in the se gland increases and secondary sexual characteristics develop steadily.
During this period, the girls begin to have enlarged breasts, pubic hair a soft voice and might
start to grow some hips. Girls become shy at this Point because they start to realize their features
are showing. This also awakens the period of menstruation. In boys, the testes enlarge and
become active, and now they have the capacity to ejaculate. The voice box also known as the
larynx also enlarges resulting to deepening hoarse voice. They start to develop hair on their
armpits and face as well as pubic hair and hair on the chest. They also develop the Adam’s apple
around their necks.