Biology 3202 Chapter 13 test Flashcards
the union of a sperm cell and an egg cell will result in a
zygote
after fertilization, the zygote travels to the to implant itself
uterus
during the stage, major organs and systems form in the developing fetus
fetal
the stage begins when the blastocyst implants into the uterine wall
embryonic stage
the process of delivering a baby through the birth canal is called
labor
what is the main function of the placenta during pregnancy?
to provide oxygen and nutrients to the developing fetus
what hormone is primarily responsible for maintaining pregnancy
progesterone
what term describes the developing human from the ninth week of pregnancy until birth?
fetus
how long is the typical gestation period for humans?
40 weeks
at which stage does the zygote implant into the uterine wall
blastocyst
how long is the menstrual cycle?
28 days
what event occurs as the levels of LH peaks in the bloodstream?
ovulation
which hormone levels are at their highest in the blood when the uterine lining is the thickest
progesterone and estrogen
what is the biology term to describe the period?
menstruation
the 3 structures which add secretions to the semen to compose seminal fluid are
the prostate, cowpers and seminal vesicle
the testes are located in a pouch called the
. the temperature is lower than the rest of the body. Sperm production is best at a lower temp.
scrotum
what structure stores and cools the sperm cells is called the
epididymis
the structure which produces the sperm cells is called the
seminiferous tubules
where are the seminiferous tubules located?
in the testes
the tubes which lead from each testes to the ureter are called the
vas deferens
what is the vas deferens function?
to transport sperm
a male is first able to produce sperm after going through the stage of
puberty
what is semen composed of?
sugar (fructose), sperm, alkaline fluids, mucus, lubricant
semen contains the sugar which sperm cells absorb by diffusion for energy
fructose
the nucleus of a sperm has a genetic state called
. which means it contains half the number of chromosomes.
haploid
the process of spermatogenesis is stimulated by the production of an anterior pituitary hormone called
FSH (Follicle-stimulating hormone)
the seminiferous tubules release what hormone which forms a negative feedback loop with the hormone FSH for the production of sperm
infibin
what is the male sex hormone
testosterone
the anterior hormone stimulates the interstital cells of the seminiferous tubules to produce the male sex hormone.
LH (Luteinizing hormone)
the two female gonads are called the
ovaries
the fist-sized female organ with thick, muscular walls inside of which embryo of a placental mammal will develop is called the
uterus
the egg develops inside of a chamber in the ovary called a
follicle
the muscular, narrow end of the uterus separating it from the vagina is called the
cervix
the female birth canal and receiving area for sperm is called the . the environment of the vagina is naturally , protecting it from bacteria and other pathogens
vagina, acidic
what is the function of the oviduct?
transports the egg/zygote towards uterus
what is the function of the uterus?
holds the developing baby/zygote
what is the function of the bladder?
container to collect urine
what is the function of the cervix?
the end/beginning of the uterus - entrance of sperm/ exit of fetus
what is the function of the fimbriae?
massage ovary + aids movement of the egg into the oviduct
what is the function of the ovary?
contains follicles which contain eggs. only 1 egg will mature in one follicle per month
what is gonorrhea? is it a virus or bacteria? is it curable or treatable?, what are some distinct features/facts
it’s a bacteria, curable, and it’s one of the most common sti’s. it can make babies go blind during child birth.
what is syphilis? is it a virus or bacteria? is it curable or treatable?, what are some distinct features/facts
it’s a bacteria, curable, and it can cause mental illness
What is AID/HIV is it a virus or bacteria? is it curable or treatable?, what are some distinct features/facts
it’s a virus, treatable, and you don’t die from aids. it weakens your immune system to the point where you die from a common cold, flu etc
what is the Endometrium
membrane that lines the uterus; provides nutrients to the fetus
One cycle takes place in the ovaries and is known as the
ovarian cycle
The other cycle takes place in the uterus and is known as the
uterine cycle
what is the morula?
(a mass of cells which are exactly the same) results from cleavage.
what is the follicular stage?
-1st show of blood
days 1-13
-The initial stage of the menstrual cycle.
FSH is rising + a follicle develops and forms an egg
-Egg produces estrogen, as estrogen levels rise, FSH levels fall (1st negative feedback loop
-since FSH is low, that means no other follicle will develop
-estrogen will also feed the endometrium
Estrogen will reach a max, causing a spike in LH- this will cause the follicle to burst
what is ovulation?
day 14 (midpoint)
-due to the spike in LH, the egg is released from the follicle. The fimbriae then massages the ovary, Leading the egg towards the oviduct
what is the luteal phase
days (15-24)
- the follicle that remains becomes a corpus luteum
-the corpus luteum produces progesterone, as progesterone levels rise, LH levels fall (2nd negative feedback loop)
-the progesterone and estrogen continue to feed the endometrium to prepare for pregnancy
what is the menstrual stage?
- fertilization did not occur!
-corpus luteum breaks down
-progesterone and estrogen levels drop
-FSH + LH levels rise
-endometrium sheds
Embryonic stages of mammals
chorion
amnion
allantios
yolk/yolk sac
placenta
umbilical cord
chorion- develops into the placenta
amnion-contains amniotic fluid which cushions the developing embryo
allantios-used to collect waste
yolk/yolk sac- the site of first blood cell formation. in many species it provides a nutrient source for the embryo
Placenta- in most pregnant animals, a blood vessel rich organ that develops inside the uterus to supply food and oxygen to the fetus through an umbilical cord.
Umbilical cord- twisted tube that connects the
abdomen of a fetus to the mother’s placenta in the uterus, and through
which nutrients are derived and wastes are expelled
Embryonic stages of birds/reptiles
chorion
amnion
allantios
yolk/yolk sac
placenta
umbilical cord
chorion- becomes the shell (protective/air exchange)
amnion- much smaller(maintains temp, is gel like for lubricant/space to move)
allantois- waste remains in shell- storage container
yolk sac-much larger- nutrients need to be in the shell since no more can be added
think about the place in which human development occurs. based on the place in which the following animals develop, predict whether they form a placenta and give reason to justify your prediction.
-frog
-turtle
-sea star
-crow
All of these animals lay eggs, so there’s no need to develop a placenta. there’s no need for the development of a placenta because there isn’t a need for a connection of the mom and the fetus.
identify the extra embryonic membranes from which the placenta forms and explain how their function, modified in humans, relates to their function for chick embryos
placenta in humans, chorion layer outer layer chicks (shell)
At the end of 3 weeks, the embryo is called a
neurula
At 8 to 9 weeks, the first bone cells begin to
form. The organism is known as a
fetus
at 12 weeks all major organs form such as
liver, stomach, brain, and heart
in the first trimester, the fetus is how many mm long
100 mm
what weeks are the first trimester
1-12
in the 2nd trimester, the fetus develops
audible heartbeat, most organs at 24 weeks, brain and NS develops further, and skeleton begins to form
how big is the fetus in the second trimester
300 mm
what weeks are the second trimester
13-24
what increase quickly in the third trimester
fetus size
what develops in the third tri
the brain continues to develop, and the immune system
what can a fetus do at the end of the eighth month?
open its eyes
how big is the fetus in the third trimester
525mm long
how much does a fetus weigh at the end of the third trimester/ 9 months
3.38 kg
what weeks does the third trimester occur
25-38
identical twins
form from one
fertilized egg.
the single zygote splits into two halves
during the early stages of its
development.
Since they were both
formed from a single cell, the
offspring are genetically identical.
what percent of twins are identical
30%
fraternal twins
Two eggs are released from the ovaries and each egg is fertilized by the sperm
although twins, offspring are genetically different from each other
70% of tins are feternal
birth process is triggered by a number of hormones such as
Progesterone
Estrogen
Prostaglandins
Oxytocin
3 stages of birth
1.Dilation stage
2.Expulsion stage
3.Placental stage
dilation stage
uterine contractions and oxytocin cause the cervix to open up or dilate. The
amnion breaks and the amniotic fluid is released through the vagina
Expulsion stage
Forceful contractions push the baby through the cervix to the birth canal
As the baby moves through the canal the head rotates, making it easier for
the body to pass through the canal
Placental stage
Placental stage
about 10-15 minutes after the baby is born, the placenta and umbilical cord
are expelled from the uterus
Couples who are unable to have any children are called
sterile
couples who have fewer children than they want are called
infertile
A woman may be sterile or
infertile for a number of
reasons including:
Blocked oviducts
Failure to ovulate
Endometriosis, a
condition in which the
endometrium grows
outside the uterus.
Damaged eggs
what hormone triggers puberty
GnRH
what organs create negative feedback loops in women
what is the ovarian cycle?
ovaries-fimbraie-oviduct-cilia-uterus
what is clevage?
it’s when the cells split
secretes a milky fluid
prostate glad
organs that reproduce reproductive cells
gonads
