PROCESS OF CONCEPTION AND EARLY FETAL DEVELOPMENT Flashcards
1
Q
- results in the production of diploid body (somatic) cells, which are exact copies of the original cell
- makes growth and development possible, and in mature individuals
- the process by which our body cells continue to divide and replace themselves.
A
mitosis
2
Q
- process of cell division leading to the development of eggs and sperm needed to produce a new organism
- results in a haploid number of chromosomes - 23 each
- 22 autosomes and 1 sex chromosome
A
meiosis
3
Q
process by which germ cells or gametes are produced
A
gametogenesis
4
Q
gamete should have how many chromosomes?
A
23
5
Q
name of the baby during:
ovulation to fertilization
A
ovum
6
Q
name of the baby during:
fertilization to implantation
A
zygote
7
Q
name of the baby during:
implantation to 5-8 weeks
A
embryo
8
Q
name of the baby during:
5-8 weeks until term
A
fetus
9
Q
name of the baby during:
developing embryo or fetus and placental structures
A
conceptus
10
Q
parts of the sperm
A
head, body (midpiece), and tail
11
Q
product of the golgi complex and contains the acrosin enzyme, mannose, hexosmine, and galactose
A
acrosome
12
Q
- responsible for the recognition of the oocyte to be fertilized
- its lysosomal enzymes degrade the thick membrane of the egg
A
acrosome
13
Q
- recognition of the eggs based on molecule composition
- allows the sperm to navigate towards the eggs through chemical signals
A
chemotaxis
14
Q
- the central strand of the tail (flagellum)
- one of the main structures of the flagellum and is commonly known as the motility motor
A
axoneme
15
Q
- has a smooth and oval shape.
- is the most important part of the cell given that it contains the nucleus (genetic material with 23 chromosomes) required to form a new organism.
A
head
16
Q
nucleus takes up ___% of the head
A
65%
17
Q
mitochondria is also suggested to play a role in controlled cell death known as ___
A
apoptosis
18
Q
The midpiece of a sperm carries about ___ mitochondria
A
70
19
Q
- is the central part of the sperm cell between the head and the tail.
- it makes up about 10 percent of the total sperm length.
- it contains tightly packed mitochondria that provide the energy requires for swimming
A
midsection / midpiece
20
Q
part of the sperm cell located between the head and the midpiece.
A
centriole
21
Q
is a thin, elongated structure that makes up about 80 percent of the entire length of the sperm
A
tail
22
Q
part that connects the flagellum to the sperm head
A
connecting piece
23
Q
parts the generate waveform of the sperms and allows movement
A
principal piece (axial fillament) and end piece
24
Q
Sperm cells have been shown to swim at an average rate of ___
A
3 mm/min
25
- This is the type observed in the early stages of motility (in the epididymis as well as freshly ejaculated sperm).
- the sperm's flagella beats gently from one side to another as the cell moves along what may appear to be a straight path.
activated motility
26
- this type of motility occurs is in the female reproductive tract (site of fertilization).
- more erratic, with the flagellum depicting a symmetrical
- serves to prevent the sperm cell from getting trapped, propelling through the reproductive tract (of the female) as well as enhancing sperm penetration into the egg (oocyte).
hyperactivated motility (hyperactivation)
27
sperm converts to a form that can penetrate the cell membrane of the egg
capacitation
28
what does the semen form to protect it from the acidic environment
gel
29
how many minutes until the liquefaction of semen gel so transportation may occur
20-30 minutes
30
after semen transportation, what is left in the vagina
seminal plasma
31
what propels the sperm upward the fallopian tubes
contractions of the uterus
32
how long can sperm survive in the female reproductive tract
5 days
33
tubal transport of the egg usually takes ___ days
3-4 days
34
egg transport phases:
- slow transport in the ampulla (72 hours)
- rapid phase passing through the isthmus and into the uterus (8 hours)
35
is the process by which a sperm fuses with an ovum to form a new diploid cell, or zygote
fertilization
36
where does fertilization occur
ampulla (outer 3rd of fallopian tube)
37
during ovulation, high estrogen levels increase ___ to help move the ovum to the uterus
peristalsis
38
high ___ levels cause thinning of the cervical mucus, facilitating sperm movement
estrogen
39
cell membrane surrounding the ovum
zona pellucida
40
gaseous corona surrounding the ovum
corona radiata
41
Ova are considered fertile for about ___ hours after ovulation
12-24
42
Sperm can survive in the female reproductive tract for 48-72 hours but are believed to be healthy and highly fertile for about ___ hours
24
43
In a single ejaculation, the male deposits approximately ___ million spermatozoa in the vagina
200-300
44
Transit time pf sperm from the cervix into the fallopian tube can be as short as ___ minutes but usually takes an average of ___ hours after ejaculation
5 minutes,
2-7 hours
45
Sperm must undergo two processes before fertilization can occur:
capacitation and acrosomal reaction
46
- Removal of plasma membrane & loss of seminal plasma CHON
- Occurs in female reproductive tract and is thought to take about 7 hours
capacitation
47
Follows capacitation is the process of releasing their enzymes to break down the corona radiata of the ovum
acrosomal reaction
48
- Occurs as nuclei unite
- Zygote contains new combination of genetic material resulting in individual different from either parent and from anyone else
- Sex of zygote is determined
fertilization
49
- begins as the zygote moves through the fallopian tube towards the cavity of the uterus
- this transport takes 3 days or more
cellular multiplication
50
The zygote now enters a period of rapid mitotic divisions called ___, during which it divides into two cells, four cells, eight cells, and so on.
cleavage
51
dividing cells, called ___, are so small that the developing cell mass is only slightly larger than the original zygote.
blastomeres
52
blastomeres are held together by the ___, which is under the corona radiata
zona pellucida
53
blastomeres eventually form a solid ball of 12-16 cells called the ___
morula
54
after entering the uterus:
The inner solid mass of cells is called the ___. The outer layer of cells that surrounds the cavity and replaces the zona pellucida is the ___
blastocyst,
trophoblast
55
Eventually, the trophoblast develops into one of the two embryonic membranes, the ___
chorion
56
The blastocyst develops into a double layer of cells called the ___, from which the embryo will develop, and the other embryonic membrane (the amnion).
embryonic disc
57
- an immunosuppressant protein is secreted by the trophoblastic cells.
- appears in the maternal serum within 24-48 hours after fertilization and forms the basis of pregnancy test during the first 10 days of development
EPF - early pregnancy factor
58
tubal pregnancy where the fetus implants in the fallopian tube
ectopic pregnancy
59
- The process involving the attachment, penetration, and embedding of the blastocyst in the lining of the uterine wall
- occurs 7-10 days after fertilization
implantation
60
other name for attachment
apposition
61
other name for penetration
adhesion
62
other name for embedding
invasion
63
frequent site of attachment
upper part of posterior uterine wall
64
Under the influence of progesterone, the endometrium increases in thickness and vascularity and is called the ___
dedicua
65
3 layers of dedicua
- dedicua basalis
- dedicua capsularis
- dedicua vera/parietalis
66
portion of the decidua that covers the blastocyst
dedicua capsularis
67
portion of dedicua directly under the implanted blastocyst
dedicua basalis
68
portion of dedicua that lines the rest of the uterine cavity
dedicua vera
69
About the ___ day after conception, the homogeneous mass of blastocyst cell differentiates into the primary germ layers
10-14th day
70
3 primary germ layers
ectoderm, mesoderm, endoderm
71
Implantation is completed by day ___, and ___ is beginning to form a discrete layer beneath the cytotrophoblast
day 9,
extraembyronic mesoderm
72
By day ___ the embryo shows all three germ layers, a yolk sac, and an allantois
day 16
73
on day 16 - cytotrophoblast and associated mesoderm have become the ___, and chorionic villi are developing
chorion
74
what germ layer
Epidermis
Sweat glands
Sebaceous glands
ectoderm
75
what germ layer
Nails
Hair follicles
Lens of eye
ectoderm
76
what germ layer
Sensory epithelium
Central and peripheral nervous systems
Nasal cavity
ectoderm
77
what germ layer
Oral glands and tooth enamel
Pituitary gland
Mammary glands
ectoderm
78
what germ layer
Dermis
Wall of digestive tract
Kidneys and ureter
mesoderm
79
what germ layer
Reproductive organs
Connective tissue
Skeleton
mesoderm
80
what germ layer
Muscles
Cardiovascular system
Pleura
mesoderm
81
what germ layer
Lymphatic tissue and cells
Spleen
mesoderm
82
what germ layer
Respiratory tract epithelium
Epithelium (except nasal)
Lining of the digestive tract
endoderm
83
what germ layer
Primary tissue of liver and pancreas
Urethra and associated glands
Urinary bladder
Vagina
endoderm
84
- begin to form at the time of implantation.
- protect and support the embryo as it grows and develops inside the uterus
embryonic membranes
85
- First and outermost membrane that encircles the amnion, embryo and yolk sac
- Develops from the trophoblast, and has many fingerlike projections called chorionic villi
chorion
86
as the pregnancy progresses the chorionic villi will degenerate.
by which month will the surface of the chorion be smooth except at the attachment place to the uterine wall
4th month
87
- second membrane to form
- Originates from the ectoderm
- Thin protective membrane that contains amniotic fluid
- As the embryo grows, this expands until it comes into contact with the chorion forming the bag of water
amnion
88
- Protect embryo against mechanical injury
- Control the embryo’s temperature
- Permits symmetrical external growth
- Prevents adherence of the amnion to the embryo-fetus
- Allows freedom of movement
amniotic fluid
89
- slightly alkaline
- contains albumin, uric acid, creatinine, lecithin, sphingomyelin, bilirubin, vernix, leukocytes, epithelial cells, enzymes, and fine hair called lanugo
amniotic fluid
90
amount of amniotic fluid at 10 weeks
30 ml
91
amount of amniotic fluid at 20 weeks
350 ml
92
after 20 weeks, the volume of amniotic fluid ranges from
700-1000 ml
93
fetus swallow amniotic fluid up to ___ every 24 hours
600 ml
94
about ___ of amniotic fluid flows out to the fetal lungs each day
400 ml
95
- Develops as a second cavity in the blastocyst on about day 8 or 9 after conception
- Provides source of RBCs until the embryo’s hematopoietic system is mature
yolk sac
96
The yolk sac ___ & remains as a thin white streak discernible in the cord at birth
atrophies
97
- 55 cm in length
- 2 cm in diameter
- contains wharton's jelly that prevent pressure
umbilical cord
98
- has no sensory or motor innervations
- can attach itself to the placenta in various sites
umbilical cord
99
said to exist when the umbilical cord encircles the fetal neck
muchal cord
100
It is the means of metabolic and nutrient exchange between the embryonic and maternal circulation.
placenta
101
what is the diameter of the placenta after 20 weeks
15-20 cm
102
what is the thickness of placenta after 20 weeks
2.5-3 cm
103
what is the weight of placenta after 20 weeks
400-600 grams
104
placenta portion:
consists of decidua basalis and its circulation; surface is red and flesh like.
maternal portion
105
placenta portion:
consists of chorionic villi and their circulation, with shiny and gray appearance due to amnion
fetal portion
106
development of the placenta begins with the ___
chorionic villi
107
trophoblastic layers of placenta:
Functional layer of the placenta & secretes the placental hormones of pregnancy
syncytium (outer layer)
108
trophoblastic layers of placenta:
Thins out & disappears about the 5th month, leaving only a single layer of syncytium covering the chronic villi
cytotrophoblast (inner layer)
109
trophoblastic layer of placenta:
- connecting mesoderm that forms anchoring villi
- eventually forms the septa that divides the placenta into 15-20 segments
third layer (wala siyang name ate!)
110
placental segments
cotyledons
111
by what week does the placenta begin to function as a means of metabolic exchange
week 4
112
by what week does the the placenta become a discrete organ
week 14
113
- heard over the symphysis pubis
- timed precisely with the mother's pulse
- caused by the augmented blood flow entering the dilated uterine arteries
uterine souffle
114
- can be heard over the area of the umbilical cord
- maternal blood spurts from the spiral uterine arteries into the intervillous spaces
funic souffle
115
contractions are believed to facilitate placental circulation
braxton hicks
116
- Produces glycogen, cholesterol, & fatty acids (for fetal use and hormone production).
- Breaks down epinephrine & histamine
- Stores glycogen & iron
placenta
117
placental transport:
- moves substances from an area of higher concentration to an area of lower concentration
- water, oxygen, carbon dioxide, electrolytes (sodium and chloride), anesthetic gases, and drugs
- insulin and steroid hormones (but slower rate)
simple diffusion
118
placental transport:
- involves a carrier system to move molecules from an area of greater concentration to an area of lower concentration
- glucose, galactose, and some oxygen
facilitated transport
119
the glucose level in the fetal blood is ___% lower than in the maternal blood
20-30%
120
placental transport:
- can work against a concentration gradient and allow molecules to move from areas of lower concentration to areas of higher concentration
- Amino acids, calcium, iron, iodine, water-soluble vitamins, and glucose
active transport
121
what content occur in greater concentration in fetal blood than maternal blood?
- amino acids
- calcium
- inorganic phosphate
122
important for transferring large molecules such as albumin and gamma globulin
pinocytosis
123
The placenta produces hormones that are vital to the survival of the fetus, these include (4)
- hCG
- progesterone
- estrogen
- hPL
124
similar to the luteinizing hormone (LH) and prevents the normal involution of the corpus luteum at the end of the menstrual cycle
hCG
125
If the corpus luteum stops functioning before the 11th week of pregnancy, what happens?
spontaneous abortion
126
causes the corpus luteum to secrete increased amounts of estrogen and progesterone
hCG
127
Human chronic gonadotropin is present in maternal blood serum 8-___ days after fertilization
10
128
After reaching the maximum level of ___ days gestation, hCG begins to decrease as placental hormone production increases.
50-70
129
At 16 days after ovulation, ___ reaches a level between 25-50mg per day and continues to rise slowly in subsequent weeks
progesterone
130
what week does the placenta take over the production of progesterone
week 10
131
quantity of progesterone per day late in pregnancy, as secreted by the placenta
250 mg
132
By 7 weeks, the placenta produces more than 50% of the ___ in the maternal circulation
estrogen
133
The ___ assumes the function of the fetal lungs by supplying oxygen and allowing the fetus to excrete carbon dioxide into the maternal blood stream
placenta
134
___ divides into two branches, one of which circulates a small amount of blood through the fetal liver and empties into the inferior vena cava through the hepatic vein.
umbilical cord
135
- second umbilical cord branch
- empties into the fetal vena cava
ductus venosus
136
fetal blood then enters the right atrium, passes through the ___ into the left atrium and pours into the left ventricle, which pumps it into the aorta
foramen ovale
