Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anatomy 2 Module 1 > Lecture 2: embryogeneses > Flashcards

Lecture 2: embryogeneses Flashcards

1
Q

time it takes for a oocyte to degenerate

A

24 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

time it takes for a sperm to degenerate

A

48 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

structures released during ovulation

A
  • secondary oocyte
  • corona radiata
  • zona pellicida
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

sequence of events involved in fertilization (5)

A
  1. penetration of corona radiata
  2. penetration of zona pellicida
  3. fusion of plasma membranes
    - zona reaction: doesn’t allow another sperm to fertilize the oocyte
  4. meiosis 2
  5. nuclei fuse –> zygote forms (~12 hours later)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

cleavage division

A

mitotic division of the zygote

daughter cells called blastomers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

2 systems for dating pregnancies

A
  • fertilization age

- menstrual age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

fetilization age

A

dates pregnancy from the time of fertilization, thus a six week embryo is six weeks (42 days) from the day of fertilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

menstrual age

A

Used by clinicians and dates the pregnancy from the woman’s last normal menstrual period (menstrual age). (divided in trimesters) The menstrual age of a human embryo is two weeks greater than the fertilization age because usually two weeks elapse between the start of the last menstrual period and fertilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

embryonic stages of development

A
  • embryonic stage
  • fetal stage
  • postnatal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

embryonic stage

A

first 8 weeks

  • zygote formation
  • cell division
  • implantation
  • organ formation
  • teratogen sensitivity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

fetal stage

A

week 9 to birth

  • rapid fetal growth
  • sex organ formation
  • organ system function
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

postnatal

A

emotional, physical, and social growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

outer cell mass/ trophoblast

A

gives rise to the extra-embryonic tissues that form the placenta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

inner cell mass/ embryoblast

A

gives rise to the embryonic cells and layers that form all of the tissues and organs of the body (intra-embryonic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

stages in human implantation

A

5-maturation of blastocyst
5-loss of zone pellucida
6-attachment of blastocyst to uterine epithelium
6-7- epithelial penetration
7-9-trophoblastic plate formation and invasion of uterine storm by blastocyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the usual site of implantation

A

the posterior, superior wall of the uterus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

ectopic pregnancy ?

A

“out of place”

happens ~ 0.25 to 1% of the time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

where do most ectopic pregnancies occur?

A

ampulla of the uterine tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

rick factors for ectopic pregnancies

A

pelvic inflammatory disease, endometriosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

clinical signs for ectopic pregnancies

A

abnormal bleeding, abdominal pain, positive pregnancy test, intraperitoneal blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

decidua

A

name for endometrium after implantation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

after implantation trophoblast proliferates into 2 layers

A

cytotropoblast layer

syncytiotropoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

cytotropoblast layer

A

mitotically active inner layer of cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

syncytiotropoblast

A

produces human chorionic gonadotropin (hCG)- feedback to the ovary to the corpus luteum (hormones maintain the pregnancy until the placenta is fully functioning)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

after implantation the cells of the embryoblast reorganize into 2 epithelial layers

A

epiblast layer

hypoblast layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

epiblast layer

A
  • form a membrane that lines the amniotic cavity
  • dorsal aspect of the disc
  • gives rise to the embryo
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

hypoblast layer

A
  • form a membrane that lines the yolk sac
  • also called the primitive endoderm
  • does NOT contribute to the cells developing embryo
  • ventral aspect of the disc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

2 cavities that form

A
  • amniotic cavity

- yolk sac/ umbilical vesicle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

amniotic cavity

A

• The amniotic membrane surrounds the embryo
following body folding
• Prevents mechanical injury to the fetus
• Allows normal fetal movements
• Cavity expands until fluid content reaches nearly one L by 33 weeks
• Sources of amniotic fluid:
o Amnion cells
o Maternal tissue (diffusion across chorionic plate)
o Fetal urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

extraembryonic mesoderm

A

forms between the yolk sac and cytotrophoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

chorionic cavity divides the extraemrbyonic mesoderm into the

A
  • extraembryonic somatic mesoderm

- extraembryonic splanchnic mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

extraembryonic somatic mesoderm

A

lining cytotrophoblast and amnion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

extraembryonic splanchnic mesoderm

A

lines the yolk sac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

the chorion forms the wall of the chorionic cavity and has 3 layers

A
  • extraembryonic somatic mesoderm
  • cytotrophoblast
  • syncytiotrophoblast
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

connecting stalk

A

suspends the amniotic cavity and the yolk sac in the chorionic cavity
-future umbilical cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

contact to the maternal blood

A

ALL urfaces of chorion and villi in contact with maternal blood are lined with syncytiotrophoblast**

37
Q

villi

A

numerous , minute, elongated projections

38
Q

primary villi

A

made up of syncytiotrophoblast and cytotrophoblast

39
Q

secondary villi

A

made up of syncytiotrophoblast, cytotrophoblast, mesoderm core

40
Q

tertiary villi

A

made up of syncytiotrophoblast, cytotrophoblast, mesoderm core, and villous capillary

41
Q

the placenta

A

is formed by both maternal and fetal contributions:
Fetal -the structures of the chorion
Maternal - the decidua

42
Q

Week two = “rule of two’s”:

A
  • Embryoblast splits into two layers (epiblast, hypoblast)
  • Trophoblast gives rise to two tissues (cytotrophoblast, syncytiotrophoblast)
  • Two yolk sacs form (primary, secondary)
  • Two new cavities form (amnionic, chorionic)
  • Extraembryonic mesoderm splits into two layers (somatic, splanchnic)
43
Q

week three

A

(15-16 days post fertilization) gastrulation occurs producing 3 main germ layers

44
Q

primitive streak

A

represents site of cell migration
CAUDAL to CRANIAL
disappears at the end of the 4 week

45
Q

primitive node

A

elevated area at the cephalic end of the primitive streak

46
Q

epiblast cells along the primitive streak

A

epiblast cells proliferate, lose their adhesion molecules(E-cadherin), detach from their neighboring cells and migrate toward the median plane of the embryonic disc

47
Q

epiblast layer gives rise to

A

all 3 germ layers

48
Q

endoderm

A

forms by epiblast cells that replace the entire hypoblast

49
Q

mesoderm forms..

A

by epiblast cells that migrate between the existing layers

50
Q

ectoderm forms..

A

by cells that remain in the epiblast after gastrulation is complete

51
Q

Sacrococcygeal teratoma

A

remnants of the primitive streak remain in the sacral region and cells proliferate and form a tumor
most common newborn tumor

52
Q

notochord

A

axial mesoderm that forms a long chord along the cranial- caudal axis

53
Q

Ectoderm and endoderm are adhered together at the

A

oropharyngeal and cloacal membranes

-but two membranes will break down completely as development continues

54
Q

prechordal plate

A
  • mesoderm structure

- may act as a signaling center to stimulate the development of the forebrain and contribute to head and neck mesenchyme

55
Q

importance of the notochord

A

-vertebral column and base of skull develop around it
-inductive signals (induction-when one population of cells influences the development of another population of cells) stimulate:
o the conversion of overlying surface ectoderm into neural tissue.
o the transformation of mesodermal cells of the somites into vertebral bodies.

the adult remnant: nucleus pulposus of the intervertebral disc.

56
Q

neural plate

A

thickened region composed of columnar epithelial cells–> neuroectoderm
develops into the primordial central nervous system

57
Q

bending of the neural plate

A
  • the edges thicken and move up to form the neural folds

- U shaped neural groove forms in the center

58
Q

closure of the neural tube

A
  • neural folds migrate to the midline and fuse
  • neural crest dissociates to become the neural crest cells
  • the remaining ectoderm differentiates into the epidermis layer (of skin)
59
Q

day 22

A

lateral edges of the neural folds first begin to fuse in the occipitocervical region

60
Q

day 24

A

cranial neuropore of the neural tube closes

61
Q

day 26

A

caudal neuropore of the neural tube closes

62
Q

Spina bifida with meningocele

A

-sac contains meninges and CSF, may be spinal anomalies if nerve roots extend into sac

63
Q

Spina bifida with meningomyelocele

A

-severe with neurological defects below the level of the lesion

64
Q

Spina bifida with myeloschisis (rachischisis)

A

-neurofolds fail to fuse

65
Q

Meroanencephaly

A 
• Failure of the rostral neuropore to
close during the fourth week
• Forebrain development is abnormal
• Some, or all of the brain stem is intact
• Overlying bone is defective (calvaria)
66
Q

neural crest cells

A
  • neural crest cells give rise to the cells and tissues of the peripheral nervous system as well as many other critically important structures
  • derived from ectoderm related to the neural tube
  • often called fourth germ layer
  • must migrate from their site of origin undergo ectodermal to mesenchymal differentiation (migrate into the mesenchyme on each side of the tube)
  • very vulnerable cells
  • ectomesenchyme
67
Q

derivatives of surface ectoderm

A
  • epidermis
  • nails
  • hair
  • subcutaneous glands
  • mammary glands
  • anterior pituitary
  • enamel
  • lens of eye
68
Q

derivatives of neural ectoderm

A
  • central nervous system
  • retina
  • posterior pituitary gland
  • pineal body
69
Q

regions of mesoderm

A

paraxial, intermediate, lateral mesoderm

70
Q

Paraxial mesoderm

A

• Bilateral- next to (para) axial mesoderm
• Organizes into segments called somitomeres in
the head region
• From occipital region caudally somitomeres organize into somites
• The age of the embryo can be correlated to the number of somites

71
Q

each somite gives rise to…

A

its own sclerotome, myotome and dermatome

72
Q

sclerotome

A

segmental bone (axial skeleton)

73
Q

myotome

A

skeletal muscle

74
Q

dermatome

A

dermis/ connective tissue of the back

75
Q

each myotome and dermatome…

A

has its own segmental nerve component that migrates with the cells

76
Q

intermediate mesoderm

A

• Gives rise to the urogenital system
• Functionally divided into urinary
system and genital system

77
Q

lateral mesoderm

A

the lateral (plate) mesoderm will develop cavities that coalesce and separate the lateral mesoderm into the:

  • somatic (parietal) mesoderm layer
  • splanchnic (visceral) mesoderm
78
Q

The somatic mesoderm and overlying ectoderm will form

A

the body wall

79
Q

The splanchnic mesoderm and underlying endoderm form

A

the gut wall

80
Q

the body cavity is formed by…

A

splitting of the lateral plate mesoderm

81
Q

mesothelium

A

differentiated specialized simple squamous epithelium of cells lining the parietal and visceral layers
-lines the intraembryonic cavities

82
Q

The space between the two layers of lateral plate mesoderm is the primitive body cavity which gives rise to the:

A
  • Peritioneal cavity
  • Pleural cavities
  • Pericardial cavity
83
Q

Folding occurs in simultaneously in two planes:

A
  • longitudinal or median plane(cranial to caudal) occurs due to brain development
  • horizontal plane (lateral body fold) occurs due to growth of the somite
84
Q

cranial fold/ head fold

A

involves:
- septum transversum (the primordial diaphragm)
- primordial heart
- pericardial cavity
- oropharyngeal membrane

endoderm is incorporated into the embryo and forms the foregut

85
Q

tail fold

A

involves:
- primitive streak
- cloacal membrane
- connecting stalk

endoderm lining the yolk sac is incorporated as the hindgut

86
Q

lateral folding

A

growth of somites forms the body wall

endoderm is incorporated as the midgut

87
Q

endoderm gives rise to

A
  • epithelium of the gut tube
  • liver, gallbladder, pancreas
  • epithelium ofrespiratory system
  • epithelial lining of the urinary bladder and urethra
  • epithelium of some of the glands and structures of the head and neck
88
Q

Omphalocele

A

o Failure of the intestines to return to the body cavity
o Covered by amnion
o Often associated with other malformations

89
Q

Gastroschisis

A

o Protrusion of the viscera into the amniotic cavity due to abnormal closure of the body wall
o Viscera are not covered by amnion

Anatomy 2 Module 1 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions