8.3.3 Humans rep Flashcards
What is puberty?
Why doesn’t it happen immediately after birth
The period during adolescence in which the reproductive tissues begin to mature is called puberty
Reproductive maturity is not as essential as general growth in the early stages of life and is hence not a priority.
Puberty in females
Menstruation
Breast size increases
Darkening of niples
Puberty in males
Facial hair
Voice crack
Penis occasionally becomes enlarged and erect
Puberty common to all sexed
Genital hair
Genitals darken
Thinner hair: arms/legs/face
Oily face + pimples
What is the purpose of puberty
For animals to participate in the process of mating, their state of sexual maturity must be identifiable by their specimen
» External features such as new hair growth patterns signal that sexual maturation has occurred
The transfer of germ cells and the subsequent fertilization require certain special organs
»penis capable of being erect to transfer sperms
»breast capable of feeding the newborn
Testes
2 functions + location
> produces testosterone responsible for changes at puberty
> produces sperms
> Located in scrotum outside abdominal cavity as sperm formation requires a temperature lower than normal human body temp
What happens to the sperm after production
> > Delivered via the vas deferens and unites with a tube from urinary bladder. Urethra forms common passage for both urine and sperm.
> > Along the vas deferens, prostate gland and seminal vesicles add secretions so sperm is in a fluid. This fluid facilitates transport and gives nutrition.
Structure of sperm
Tiny bodies
Mainly genetic material
Long tail to help them move towards the female germ-cell
Ovary functions
Egg production
Hormone production
Fertilization in humans
During sexual intercourse, the sperm enters through the vaginal passage
It enters the oviduct/fallopian tube and meets the egg there
The zygote divides to form an embryo
It is implanted in the inner linings of the uterus where it grows and develops to become a foetus
Fertilisation to birth
In the uterus, the linings thicken and are richly supplied with blood to nourish the embryo
A special tissue called placenta is a disc embedded on the uterine wall
1. which gives the embryo nutrition using the mothers blood
- on the embryo’s side, it has villi
- on the mother’s side are blood spaces which surround villi
- this structure increases surface area for glucose and oxygen to reach the embryo
2. Which passes waste material into the mothers blood
After approx 9 months, the baby is born due to rhythmic contractions in the uterus muscles
Menstruation
When the egg is not fertilized, it lives for about a day
SInce the thick and spongy uterus walls are not needed due to the absence of an embryo, the walls break down slowly
It comes out as blood + mucous from the vagina in a process called menstruation
It happens roughly every month for 2-8 days
STD examples
HIV-AIDS, warts (viral)
Syphilis, Gonorohhoea (bacterial)
Types of contraceptives
Mechanical barriers: condoms/similar coverings
Oral pills: change hormonal balance and prevent eggs from being released, have side effects
Loop/Copper T: placed in uterus, can cause irritation to uterus
Surgical: blocking vas deferens and fallopian tube, infections and other problems if not performed properly
