BIO UGHUGHUGH Flashcards
How is the placenta adapted?
The placenta is adapted for nutrient and gas exchange between the mother and fetus through its extensive network of blood vessels.
what causes puberty
sex hormones
physical changes for girls
-breast development
-hips widen
-pubic hair
-release of egg cells by the ovaries
physical changes for boys
-sperm produced
-shoulders broaden
-body becomes more muscular
-body hair (chest, face, pubic)
adolescence vs puberty
adolescence is the period between childhood and adulthood and puberty is the physical changes that occur during this period
how do sperm cells reach the egg cell
- During sexual intercourse, sperm travels up from the testes through the sperm duct
- receives nutrients and fluids from glands becoming semen
-and through the urethra semen is released into the vagina.
-sperm travels through vagina through cervix - into the uterus
-enters fallopian tube where fertilisation happens - fuses with egg cell and is wafted down to the uterus to be implanted.
what happens during implantation?
The embryo that has been wafted down by the cilia cells in the oviduct, attaches to the lining of the uterus and begins to develop into a baby.
define gestation
the periood between fertilisation and birth is
when is an embryo called a fetus
after 8 weeks
placenta
An organ which allows the transfusion of substances pass between the mother;s blood and the fetus’s blood, It acts as a barrier, which stops infections and harmful substances from reaching the fetus.
umbilical chord
connects fetus to placenta
fluid sac
acts as shock absorber protecting fetus from any bumps
at 4 weeks an embryo forms ___
spine and brain
at 9 weeks a fetus
tiny movements happen and cheeks and lips can sense
at 12 weeks a fetus
uses its muscles to kick, suck, swallow and practice breathing
to grow, a fetus needs oxygen and _____ diffused from the mothers _____.
nutrients, blood
what happens during birth
-after 40 weeks a baby is ready to be born.
-The mother’s cervix relaxes
- muscles in the uterus contract which pushes the baby through the vagina.
day 1 of the menstrual cycle
blood from the uterus lining leaves the body through the vagina
female sex hormones
estrogen and progesterone
male sex hormone
testosterone
what do male and female sex hormones do?
trigger different processes such as egg release and pubic hair growth.
day 14 of the menstrual cycle
an egg cell is released from one of the ovaries.This is called ovulation
fertilisation
when the male and female gametes fuse
gametes
female and male sex cells (egg, sperm)
