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TOPIC: REPRODUCTIVE SYSTEMS AND REPRODUCTION IN HUMANS
CONTENTSS
Reproductive system in males and female
- Function of various parts
- Structure of a male sperm and ovum
Fertilization
- Fusion of gametes
- Implantation
Development of embryo
- Selective exchange between mother and child and removal of excretory product from foetus; survival conditions like food, oxygen, ammotic fluid, placenta and umbilical cord
SUB-TOPIC 1: REPRODUCTIVE SYSTEM IN HUMANS
The reproductive system in human are the most highly developed among the animals. Basically, the male and the female reproductive system consist of the gonad where the sex cell or gametes, as well as glands that are involved in secretion of hormones and fluids essential for development and sexual process.
The reproductive system consist of the internal genitalia which are contained within the abdominal cavity and the external genitalia which is found outside the body in the groin region
THE REPRODUCTIVE SYSTEM IN A MALE HUMAN
The male reproductive system consists of the following organs
- The testes: these are two ovoid structure situated in the scrotal sac. They are external and suspended in the posterior end of the abdominal cavity. They have descended into the scrotum at birth. They require temperature range of below 350C to function effectively. The testes contain coiled tubules called seminiferous tubes. This contains actively dividing cells that produce sperm cells. The seminiferous tubes continue and emerge into a spongy structure called epididymis atop the testes. This structure stores sperms produced in the testes. The cells of these tubules divide repeatedly to form sperm cells in a process called spermatogenesis. The testes produce the sperm-the male gametes. It also secretes the hormones testosterone, which is responsible for producing secondary sex characteristics in males as well as stimulating sperm production
- Vas deferens: this is called the sperm duct. It is a continuation of the epididymis. It serves as the pathway through which sperm cell run from the epididymis and opens into the urethra. e
- Penis: this is a sensitive organ of copulation transverse by urethra. The urethra is a common duct for sperms and urine in the male, thus the penis is described as a urinogenital organ. It consists of spongy erectile tissue. Blood flows into the dilated erectile tissue when stimulated. The flow of blood into the tissue contributes to its turgidity; hence the erection of the penis is no stimulation. The penis is covered with a sensitive skin called glans penis and retractable foreskin called the prepuce. This can be surgically removed during circumcision,
- Epididymis: A set of profusely coiled tubule known as epididymis connects each testis to the vas deferens, which conveys the sperm cells to the seminal vesicle for storage until there is the need for ejaculation.
- Other accessories and glands: the male reproductive system also consists of certain other accessories and glands whose secretions play important roles in reproduction. This includes the prostate gland whose secretion helps to energise and transport the sperm; the concentration of the sperm so as to normalize acidic matters along the wall of the urethra. The mixture of sperm and those secretions is known as semen. Seminal fluid secreted by the prostate gland provides a medium for sperm cells to swim and be nourished. On ejaculation, the sperms are discharged to the outside through the urethra.
THE REPRODUCTIVE SYSTEM IN FEMALE HUMAN
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