Chapter 15 Flashcards
(67 cards)
1
Q
trimesters
A
3 three-month periods in a pregnancy
2
Q
what are the 2 main periods of prenatal development
A
Embryonic development - first 8 weeks
Fetal development - 9th week and onwards
3
Q
embryonic development
A
cells divide and become redistributed forming tissues and organs and the structures that support and nourish the embryo
4
Q
fetal development
A
rabidly body growth and organs function and coordinate to form organ systems
5
Q
is zygote haploid or diploid
A
- a diploid
- when egg (haploid) and sperm (haploid) join together they form a diploid
6
Q
When should fertilization occur in order for it to work
A
12-24 hours after ovulation
7
Q
Zona Pellucida
A
Inner plasma membrane of the egg
- clear layer of protein and carbohydrates
8
Q
Corona Radiata
A
- Outer layer of the egg
- are follicle cells
9
Q
How does the sperm fertilize the egg
A
- Sperm meets and enters the egg and the acrosomes releases contents
10
Q
Can more than one sperm enter the egg to fertilize it
A
No
- Once a sperm enters the egg the plasma membrane DEPOLARIZES
- preventing other sperm from entering
- After 12 hours the sperm and egg nucleus disappear and completes fertilization
11
Q
first cell of new life
A
- zygote
- single cell
- has 23 chromosomes
12
Q
Cleavage and mitosis
A
- process of cell division without enlargement of the cells
- The inside of the cell goes through MITOSIS
- The inside of the zygote does mitosis till its 16
13
Q
Zygote at 16 cells is called
A
Morula
14
Q
where does the morula go
A
reaches the uterus within 3-5 days
15
Q
blastocyst
A
- hollow structure from which new cellular structures can develop
16
Q
Trophoblast and embryoblast
A
trophoblast
- outer layer of blastocyst
- eventually develops into a chorion (which develops in the placenta)
embryoblast
- inner mass - develops into the embryo
17
Q
chorion
A
- develops into the placenta
18
Q
placenta
A
- structure that provides nutrients and oxygen
- remove wastes from developing offspring
- site of metabolic exchange
- placenta is formed from the chorion
- placenta does not filter alcohol, drugs, nicotine
19
Q
blastocyst cycle
A
- attaches to the endometrium
- then blastocyst sinks into the uterine wall (IMPLANTATION)
- while implantation begins trophoblasts secretes hormones called hCG
20
Q
hCG
A
- human chorionic gonadotropin
- hormone released from trophoblast
- same as LH. maintains corpus luteum - continues to secrete estrogen and progesterone which maintains the endometrium which then stops menstruation from happening
21
Q
umbilical cord
A
- rope like structure
- from the navel of the fetus to the center of the placenta
- contains 2 arteries for the oxygen rich and poor blood to move in and out of the
22
Q
does the corpus luteum remain intact throughout pregnancy
A
yes
- hCG is high for the first 2 months to keep providing estrogen and progesterone which maintains
- but after that the placenta takes over secretion of progesterone and estrogen
23
Q
Week 2
A
- blastocyst implants, the inner cell mass changes
- a space between the inner cell mass and the trophoblast and fills with fluid becoming the AMNIOTIC CAVITY
- The inner cell mass flattens into a disk shape - the embryonic disk
24
Q
Amniotic and Amnion
A
- amniotic is the fluid formed within the blastocyst and is carried in a sac called Amnion
25
embryonic disc
inner cell mass flattens into a disk shape
26
Octoderm and Endoderm and Mesoderm
- 2 layers of the Embryonic Disk
- Ecto = outside Endo= inside
- then mesoderm = between the 2 layers
27
what are the Germ layers
- 3 layers
- endoderm - nervous system, epidermis (skin)
- mesoderm - skeleton, muscle, reproductive structures
- ectoderm - lining of the digestive and respiratory systems, endocrine glands
28
gastrulation and Grastula
- a series of tissue and cell movements in which blastula stage embryo folds inward forming 3 layers called Gastrula
29
differentiation
- cellular process that enables a cell to develop into a particular shape and perform specific functions different from other cells.
30
week 3
- organs are forming
- thickened band of mesoderm develops along back of embryonic disk
- forms NOTOCHORD
31
Notochord - ectoderm
- rod-like structure which forms the basic framework for the skeleton
- nervous system develops from ectoderm above the notochord
32
neurolation
- the process of which neural tubes which develops into the brain and spinal cord
- soon after, the heart will start beating
33
week 4
- rapid growth and differentiation
- blood cells form and fill blood vessels
- lungs, kidneys, take their shape
- small buds for arms and legs
- distinct head, eyes, ears, and nose
34
week 5
- embryo’s head is very large, eyes are open, brain cells differentiate
35
week 6
- brain continues rapid development
- limbs lengthen and flex
- gonads start producing hormones for the development of external genitalia
36
week 7,8
- embryo has distinct human characteristics, organs have formed, nervous system coordinates body activity, skeleton has formed
37
by week 8 the embryo is now called a
fetus
- eyes and nostrils are developed, mucus surrounds them
- and external genitalia forms/grows more (by this time the gender is fixated)
38
structures that support the embryo
- allantois
- amnion
- chorion
- yolk sac
39
amnion
protects the embryo in a fluid filled cavity
- prevents dehydration and cushions
40
yolk sac
- first site of blood cells formation and forms part of the digestive tract
41
allantois
- becomes the umbilical cord, blood vessels, and urinary bladder
42
chorion
outermost membrane develops into the fetal half of the placenta
43
functions of the placenta
1. Nutritional - provides food for fetus
2. Excretory - transports waste out
3. Respiration - transports O2
4. Endocrine - allows hormones to come in and out
5. Immune - transports antibodies
44
Tetratogen
- any agent that causes a structural abnormality due to exposure during pregnancy
ex)
- cigarettes
- alcohol
45
FASD
fetal alcohol spectrum disorder
- described the disorders related to alcohol consumption during pregnancy
46
parturition
- delivery of the baby
- labour
- uterus experiences contractions throughout pregnancy
47
caesarean section
- surgical procedure where there is an incision in the mothers abdomen and uterus to let the baby out
- this can be due to the baby not turned around (feet first when it should actually be head first)
48
Partition feedback loop
Birth
- Posterior Pituitary Gland releases OXYTOCIN
- Uterine Contractions get triggered
- Triggers prostaglandis (placenta) and cervix stretches
*high levels of estrogen begin labouring
49
lactation
- secretion and formation of breast milk
50
prolactin
- hormone for milk production
- During pregnancy it is suppressed due to the high levels of hormone estrogen and progesterone
- Though after it finishes it starts to produce milk
51
colostrum
- yellow fluid similar to milk
- more protein and less fat
52
suckling
- stimulates milk secretion and production
53
Suckling loop
1. suckling stimulates nerve endings in nipples and areola of breast
2. stimuli gets carried to hypothalamus
3. hypothalamus PRODUCES OXYTOCIN but is released by the posterior pituitary gland
4. oxytocin causes mammary lobules to contract
5. milk letdown occurs
54
sterile vs infertile
- sterile - men and women who can NEVER have kids
- infertile - men and women who have DIFFICULTIES making kids but it is possible
55
Artificial Insemination
- sperm is collected and is injected to the womans vagina
56
In Vitro Fetilization
- eggs and sperm are fertilized in a lab then later on placed in the uterus
57
Gamete Intrafallopian transfer
- eggs and sperm are brought together in the oviduct than in vitro
58
surrogate mothers
- infertile couples have another woman carry the baby
- baby is formed through AI or IVF
59
Superovulation
- production of multiple eggs - result of hormone treatment
- hormones stimulate the follicle developments and ovulation
60
contraceptives or birth control
- prevents having a baby
61
abstinence
not having sexual intercourse
62
tubal ligation vs vasectomy
tubal = cutting oviducts/tying off cut ends so egg does not travel
vasec = cutting ductus deferens so sperm cannot meet egg
63
Hormone Treatment
- mimic effect of progesterone which stops the release of FSH and LH
64
morning after pill
- high doses of estrogen and progesterone within few days of intercourse to prevent ovulation or implantation
65
physical or chemical barriers
- preventing the sperm from reaching ovum
- condoms
66
folic acid
vitamin added to pregnancy medicines
- its for development of the bones and spinal cord of the baby as it develops
67
put in order
baby blastocyst morula fetus embryo gastulla zygote
zygote -> morila -> blastocyst -> gastulla -> embryo -> fetus -> baby
