highlights of fetal period Flashcards
……….produces a large ventral
prominence and pumps
blood
The early heart
the
neural tube is open at
the rostral and caudal
…………….
neuropores
At 26 days, the ………….produces a
prominent elevation of the head and the
long, curved caudal eminence (tail-like
structure) is present.
forebrain
At 26 days, the ………. (primordia of
internal ears) are also visible.
otic pits
Ectodermal thickenings called …………., indicating the future lenses of
the eyes, are visible on the sides of the
head.
lens
placodes
At 28 days, which limb buds are
recognizable as small swellings on the
ventrolateral body walls?
upper limb buds
which structures are recognizable by the end of the fourth week?
-The fourth pair of pharyngeal arches and the lower limb buds
-the caudal neuropore is usually closed.
-cardiovascular system is established
when does the Growth of the head
exceeds that of other
regions?
during fifth week
The mesonephric ridges
indicate the site of the
mesonephric kidney
which are the primordia
of the permanent
kidneys during which week?
fifth week
when does the embryo show
reflex
responses to touch and spontaneous movements, such as
twitching of the trunk and limbs?
during Sixth Week
when do the digital rays(primordia of the digits (fingers)) —begin to develop in
the hand plates?
during Sixth Week
when do the —auricular
hillocks—develop and contribute to
the formation of the auricle of the
external ear?
during Sixth Week
when does the umbilical herniation occur?
during the sixth ween
Communication
between the primordial
gut and the umbilical
vesicle is
…………..
omphaloenteric duct.
when do Notches appear
between the digital rays
in the hand plates (to separate the future fingers)?
during the seventh week
when does the the scalp vascular plexus(skull) has
appeared and forms a
characteristic band around
the head?
during the eighth week
Coordinated limb
movements first occur during which week
during the eighth week
At the end of which week does the
embryo have visually distinct
human characteristics?
At the end of the eighth week
The external genitalia of
males and females are not
fully developed until the
end of which week?
12th week.
Urine formation begins
between the …………….
weeks, and urine is
discharged through the
urethra into the amniotic
fluid. The fetus reabsorbs
some of this fluid after
swallowing it.
9th and 12th
weeks
Slow eye
movements occur at which week?
14 weeks (3.5 month)
By ……….weeks, the
ovaries are
differentiated and
contain primordial
ovarian follicles that
have oogonia
(primordial germ
cells)
16
Fetal movements—
quickening—are
commonly felt by the
mother during which period?
17-20 weeks
during which period is the skin of the embryo
covered with a greasy
material—vernix
caseosa. (It consists of
dead epidermal cells
and a fatty secretion
from the fetal
sebaceous glands.)
17-20 weeks
Brown fat forms
during weeks ………and is
the site of heat
production,
particularly in the
neonate.( produces
heat by oxidizing
fatty acids.)
17 to 20
when does the
fetal uterus
formation and
canalization of
the vagina begins?
18th week
when does the testes
begin to
descend?
20 week
At 21 weeks ………..
rapid eye movements begin
Fingernails are present by
24 weeks.
when does the secretion of surfactants(from type II pneumocytes in the
interalveolar walls of the lung ) begin?
24 weeks
during which period does the
fetus usually survive if
born prematurely?
26-29 weeks (bcz during this period the lungs have
developed sufficiently to
provide adequate gas
exchange.)
at 30 weeks :
The pupillary light reflex of the eyes can be elicited
