|Obstetrics And Gynaecology Reproduction In Man|
Reproduction is the union of the male and female Gamates to form a Zygote. As it is common with other terrestrial animals, man has developed a more certain means of bringing the games together,
The sperm is produced in the numerous seminiferous tubules in the testes. From here it passed through the vasa efferentia and epididymis into the vas deferens. For the sperm to be introduced into the female, it is necessary for the penis to be inserted into the vagina in an act of coitus or copulation. Under conditions of erotic excitement, the arteries in the penis dilate and the veins constrict.
Male and Female Reproduction
- Spermatic cord
- Uterus (Womb)
- Oviduct (Fallo
- pain tube
- Funnel of Oviduct
- Uterus wall
- Prostate gland
- Cooper’s gland
- Sperm duct
- Right testis
- Caput epididymis
- Cauda epididymis
- Scrotal sac
Male Reproductive system
The resultant high blood pressure in the penis causes the penis to become erect. As the penis moves up and down in the vagina, the tactile stimulation of the sensory cells at its tip triggers off a reflex.
This causes the contraction of the vas deferens. The sperm is then swept down into the urethra. Here it is mixed with secretions from both the seminal vesicles and the prostate gland. These secretions keep the sperm in a viable and motile state. The admixture of the sperm and secretion is called semen. The semen is expelled from the penis into the vagina by a powerful contraction of the urethra.
This is called ejaculation. The reflex mechanism that brings about erection and ejaculation inhibits urination The sperm reaches the ovum at the upper part of the fallopian tube where fertilization takes place. Despite the fact that millions of sperm cells are produced, only a few reach the ovum; and of these few, only one sperm cell fertilizes an ovum
After fertilization, the zygote moves down the fallopian tube by peristalsis. It takes about one week for the zygote to reach the uterus embedding of the blastocyst in the uterus is called “Implantation”. and before then it has divided mitotically to form. Blastocyst.
After implantation, the blastocyst continues to develop by cell division. As development continues the blastocyst is called the fetus”. The fetus is enveloped by a protective membrane- the chorion and the amnion.
- Tai or Flagellum
- Male Spermatozoon
- Vitelline membrane
- Yolk granules
- Plasma membrane
The amnion is the inner membrane and it encloses a fluid-filled amniotic cavity which acts as a buffer for the fetus. Later the placenta is formed in association with the walls of the uterus and it is connected to the fetus by the umbilical cord. Within the placenta, fetal and maternal blood vessels come into intimate association with each other, and across their walls exchange respiratory gases, food materials, and nitrogenous waste takes place.
To accommodate the growing fetus, the uterus expands enormously. and this is accompanied by the thickening of its walls and increased vascularisation. When the fetus reaches a certain age, birth or parturition occurs. The time interval from fertilization to parturition is called the gestational period and it is nine months in man.
Actually, for reproduction to occur in men, fertile sperm cells have to be introduced into the vagina of an ovulating woman with patent fallopian. tubes and a uterus. From the above, it is obvious that not all sperm cells can fertilize an ovum. Certain qualities are used to measure the
the potency of the sperm cells:
- Volume – The normal volume ranges from one milliliter to six milliliters (1 – 6 MLS).
- Mortality:- This should be equal to or greater than sixty percent in one hour). hour or seventy percent in two hours (60% in one hour or 70% in two
- Count:- Equal to or greater than twenty million cells per milliliter of sperm produced. (> 20 million cells/ml).
- Morphology-Equal to or less than twenty-five percent of abnormal forms (<25% abnormal forms)
- Pus Cell:- There should be no pus cells in sperm. Two abnormalities are associated with sperm.
Azoospermia And Oligospermia
- Azoospermia means there is no sperm cell at all in the semen.
- Oligospermia denotes the presence of sperm cells less than normal.
Oligospermia:- Mild = 11-19 Millions/ml. Moderate = 6-10 Millions/ml. Severe = Less than or equal to 5 Million/ml. The man as a rule must abstain from sexual intercourse for four days before producing segment for analysis.