Exam II Flashcards
(190 cards)
1
Q
What is the principle inductor in neural tube formation?
A
Notochord
2
Q
How are Hox genes arranged from 3’ to 5’?
A
Hox1’s are most anterior and expressed at the 3’ end
Hox13 is most posterior and expressed at the 5’ end
3
Q
What genes’ pattern determines cranial nerves and pharyngeal arch derivatives?
A
Hox genes
4
Q
What type of gradient stimulates and initiates expression of Hox genes?
A
Retinoic acid
5
Q
What hox genes determine the cranial/caudal extend of intermediate mesoderm?
A
Hox4 through Hox11
6
Q
What Hox genes are responsible for refinement and differentiation of gut structures?
A
Hoxa-d9, Hoxa-d13
7
Q
What are chordin, goosecoid, and Fox-2 responsible for?
A
Organizer regions like the notochord and prechordal plate
8
Q
What signaling factor originates in epiblast and establishes the posterior signaling center for the primitive streak?
A
Nodal
9
Q
What 2 signaling factors originate in the hypoblast and target nodal, confining it to the posterior epiblast?
A
Lefty-1
Cer-1
10
Q
What does Wnt-3 do?
A
Signals nodal
11
Q
What are Cerberus-like and DKK-1 for?
A
Posterior structures
12
Q
What 3 signaling factors are responsible for neural induction?
A
Noggin
Chordin
Shh
13
Q
What signaling factor originates in the primitive streak and is responsible for cell movement through the primitive streak?
A
Brachyury
14
Q
What is Cerebrus-related 1 for?
A
Normal head formation
15
Q
What 3 transcription factors are responsible for signaling in the primitive streak because they initiate Hox gene transcription?
A
Retinoic acid
Wnt
FGF
16
Q
What signaling factor is responsible for: neural tube induction, formation of axial structures, intestinal portals, and limb development/polarity?
A
Shh
17
Q
What signaling factor involved in the early primitive streak originates in the primitive node and targets chordin and noggin?
A
Goosecoid
18
Q
What would be the result of a goosecoid gene mutation?
A
Craniofacial defects, short stature, auditory canal atresia, mandibular hypoplasia, skeletal abnormalities
19
Q
What gene involved in the early primitive streak originates in the primitive streak and is responsible for notochord formation, and normal movement of cells through the PS?
A
Brachyury
Aka T gene
20
Q
What would be the result of a mutation in the brachyury gene?
A
Vertebral malformations
21
Q
What is the first sign of asymmetry in early development?
A
Asymmetrical beating of cilia around primitive node - results in directional current and expression of TGF-B
22
Q
What two signaling factors are involved in early asymmetry?
A
Nodal
Lefty-1
23
Q
What term refers to the shaping of the neural plate involving migration of ectodermal cells toward midline as they elongate along anterior-posterior axis?
A
Convergent extension - forms elongated narrow plate
24
Q
What term refers to the cells becoming oriented along an axis in a flat plane?
A
Planar polarity
25
What causes planar polarity?
Asymmetric distribution of planar cell polarity proteins Disheveled and Prickle
26
What would occur in the absence of the planar polarity pathway?
Neural folds would remain far apart and neural tube closure is absent
27
In the anterior notochord, Gbx-2 is expressed in which region of the brain?
Hindbrain
28
In terms of spinal cord segmentation, presomitic mesoderm flanking the posterior regions of neural tube secrete ______ which maintains caudal neural plate cells in a proliferative state
FGF-8
29
In terms of spinal cord segmentation, as the neural tube advances posteriorly, some stem cells will fall out the stem cell zone and differentiate. What causes this differentiation and how does it do this?
Retinoic acid produced by flanking somites
| blocks FGF-8 and Wnt-3a
30
During segmentation of the hindbrain, what signaling molecule is important for rhombomeres 3 and 5?
Krox-20
31
In terms of hindbrain segmentation, what signaling molecules are important in just rhombomere 5?
Kreisler and Hoxa-1
32
In terms of hindbrain segmentation, what is important for rhombomeres 4-7, as well as expression of Hoxa-1 and Hoxb-1?
Retinoic acid gradient
33
What two signaling factors establish the isthmic organizer?
Otx-2 and Gbx-2
34
What is the isthmic organizer for?
Organizing midbrain and cerebellum
35
What does the isthmic organizer release (anteriorly and posteriorly)?
Wnt-1 anteriorly, FGF-8 posteriorly
Induces gradients for anterior En-1 and posterior En-2
36
What are sclerotomes derived from?
Paraxial mesoderm
37
The following is/are derivatives of which part of the sclerotome?
Vertebral bodies and their intervertebral discs
Ventral
38
The following is/are derivatives of which part of the sclerotome?
Distal ribs, some tendons
Lateral
39
The following is/are derivatives of which part of the sclerotome?
Dorsal part of the neural arch, spinous process
Dorsal
40
The following is/are derivatives of which part of the sclerotome?
Pedicles and ventral parts of neural arches, proximal ribs, or transverse processes of vertebrae
Central
41
The following is/are derivatives of which part of the sclerotome?
Meninges and blood vessels of meninges
Medial (meningotome)
42
What type of mesoderm does the cardiogenic plate arise from?
Splanchnic mesoderm
43
What are the 2 derivatives of the lateral plate mesoderm?
2 layers: dorsal, ventral
44
Which layer of the lateral plate mesoderm is made up of splanchnic mesoderm?
Ventral layer
45
Which layer of the lateral plate mesoderm is made up of somatic mesoderm?
Dorsal layer
46
What parts derived from lateral plate mesoderm form the somatopleure?
Somatic mesoderm (from dorsal layer) + ectoderm
47
What parts from the lateral plate mesoderm form the splanchnopleure?
Splanchnic mesoderm (from the ventral layer) + endoderm
48
What is the major derivative of the intermediate mesoderm?
Urogenital system (pronephros -> mesonephros)
49
Does the following describe a somite or somitomere?
Initial pairs of segments of mesenchyme that begin to develop along and on either side of neural plate in paraxial mesoderm
Somitomere
50
__________ are more dense blocks of mesoderm that form along the notochord; in the caudal direction, a pair of somitomeres is transformed into a pair of these every few hours
Somites
51
As pairs of somites are formed, pairs of somitomeres are also forming at the anterior end of the _________ ________
Primitive node
52
New somitomeres are added _________ as the primitive streak regresses and the embryo elongates
Caudally
53
Expression of Pax-3 and Pax-7 (and paraxis) leads to the separation of the __________ into dorsal and ventral
Dermomyotome
54
Early heart formation through the primitive streak:
Anterior PS = ________
Middle PS = _________
Posterior PS = ________
```
Anterior = outflow tract
Middle = ventricles
Posterior = atria
```
55
Endoderm formation requires _______ expression during gastrulation
Nodal
56
What major circulatory arc supplies the yolk sac?
Vitelline arc
57
Is the vitelline arc intraembryonic or extraembryonic?
Extraembryonic
58
What major circulatory arc goes through the body stalk and spreads its network in the placenta and chorionic tissues?
Allantoic arc
59
Is the allantoic arc intraembryonic or extraembryonic?
Extraembryonic
60
What major circulatory arc passes through the pharynx and pharyngeal arches, then collects cephalically paired dorsal aorta that distribute blood throughout the body?
Embryonic arc
61
Is the embryonic arc intraembryonic or extraembryonic?
Intraembryonic
62
What are the 3 main circulatory arcs?
Vitelline
Allantoic
Embryonic
63
Which circulatory arc is made up of dorsal aorta, aortic arches, anterior cardinal vein, common cardinal veins, posterior cardinal veins, atrium, ventricle, and ventral aorta?
Embryonic arc
64
The posterior/hindgut expresses which transcription factor?
Cdx-2
65
The anterior/foregut expresses which 3 transcription factors?
Hex
Sox-2
Foxa-2
66
What are the 4 extraembryonic layers?
Amnion
Yolk sac
Chorion
Allantois
67
What two germ layers make up the amnion?
Ectoderm
| Mesoderm
68
What 2 germ layers make up the yolk sac?
Endoderm
| Mesoderm
69
What 2 germ layers make up the chorion?
Ectoderm
| Mesoderm
70
What 2 germ layers make up the allantois?
Endoderm
| Mesoderm
71
What extraembryonic layer is derived from epiblast?
Amnion (inner cell mass)
72
What extraembryonic layer is derived from hypoblast?
Yolk sac
73
What extraembryonic layer interfaces with the placenta via the umbilical cord?
Allantois
74
What extraembryonic layer forms the maternal/fetal interface?
Chorion
75
In the mature placenta, the ____________ directly interfaces with maternal uterine connective tissue
Cytotrophoblast
76
The __________ ________ faces away from the chorionic villi and towards the chorionic cavity
Chorionic plate
77
Most embryonic tissues are derived from epiblast or hypoblast, but the chorion is derived from ___________
Trophoblast
78
What term refers to too little amniotic fluid (less than 500 mL) leading to potential renal agenesis?
Oligohydramnios
79
What term refers to excessive amniotic fluid (500-1000mL) leading to possible esophageal atresia and anencephaly
Hydramnios
80
What term refers to a condition, related to erythroblastosis fetalis, when bilirubin released from lysed RBCs causes water accumulation in the fetus?
Hydrops
81
What term refers to the condition of extremely high blood pressure in pregnancy that may lead to grand mal seizures or coma?
Eclampsia
82
What are Hofbauer cells?
Fetal macrophages
83
What maternal/fetal membrane overlies the embryo and its chorionic vesicle?
Decidua capsularis
84
What maternal/fetal membrane is the smooth part of the chorion next to the decidua basalis?
Chorion laevae
85
What maternal/fetal membrane originates with ectoderm of the inner cell mass in implanting embryo?
Amnion
86
What is the only maternal/fetal membrane that DOES NOT rupture during childbirth?
Decidua parietalis
87
The lecithin-to-sphingomyelin ratio is a reflection of what?
Fetal lung maturity -- used to assess overall fetal development
Creatinine does the same
88
If you found excess alpha-fetoprotein in the amniotic fluid, what would you conclude?
Alpha-fetoprotein is a protein of the CNS, and it would indicate a neural tube defect
89
This condition is characterized by jaundice due to excess bile production leading to yellowing of internal and external structures
Kernicturus
90
What condition is Kernicturus related to?
Immune hydrops - blood incompatibility between mother and fetus
91
What secretes HCG?
Syncyciotrophoblast cells
92
When is HCG at its maximum secretion?
10-12th week
93
Prevention of involution of corpus luteum, as well as the growth of the CL is due to what hormone?
HCG
94
What hormone is 30x its normal level in the mother toward the end of pregnancy?
Estrogen
95
What secretes this estrogen during pregnancy?
The placenta, almost entirely from androgenic steroid (from mom and baby's adrenal glands)
96
What converts placental estrogen into estriol, estradiol, and estrone?
The trophoblast
97
What hormone is responsible for relaxing the pelvic ligaments during pregnancy?
Estrogen
98
What hormone is secreted by the corpus luteum and later in large quantities by the placenta?
Progesterone
99
What hormone causes decreased insulin sensitivity and decreased insulin utilization by pregnant mom?
Human chorionic somatomammotropin
100
What secretes human chorionic somatomammotropin?
Placenta beginning in 5th week
101
What hormone causes decidual cells to develop in the endometrium, as well as decreases the contractility of the pregnant uterus, and increase the secretions of the fallopian tubes and uterus
Progesterone
102
Are the following characteristics of the early or late placenta?
Thin
Highly permeable
Large surface area
High diffusion rate
Late
103
How would you describe the early placenta in terms of thickness, permeability, surface area, and diffusion rate?
Thick
Low permeability
Small surface area
Minimal diffusion
104
What is the double Bohr effect?
Double shift in oxygen carrying capacity in maternal and fetal blood
105
What condition characterized by absent limbs likely due to the drug Thalidomide?
phocomelia
106
Neonatal respiratory distress syndrome is characterized by lung immaturity at birth, likely due to lack of surfactant. This leads to a glassy coating of the alveoli referred to as what?
Hyaline membrane disease
107
What hemolytic disease is caused by an Rh+ baby being attacked by mom's Rh-Antibodies leading to hemolysis of fetal RBCs? What can this condition lead to?
Erythroblastosis fetalis - can lead to fetal hydrops
108
What disease is known as Trisomy 21 and is likely due to advanced maternal age?
Down syndrome
109
What inborn error of metabolism leads to a buildup of phenylalanine in the body?
Phenylketonuria
110
Lack of what major component of prenatal vitamins leads to neural tube defects like anencephaly?
Folic acid
111
What term refers to primary errors of morphogenesis that are likely multifactorial with both environmental and genetic components?
Malformations
112
What term refers to disturbances in otherwise normal morphogenesis - i.e., amniotic bands?
Disruptions
113
What term refers to constellations of congenital anomalies that are thought to be pathological but cannot be traced to a single event (these are often caused by viral infections)
Syndromes
114
What term refers to the series of events triggered by one factor (i.e. Oligohydramnios)
Sequences
115
What is the origin and function of melanoblasts?
Origin = neural crest
Function = produce pigment
116
What is the origin and function of Langerhan's cells?
Origin = bone marrow
Function = APC
117
What is the origin and function of Merkel cells?
Origin = neural crest
Function = slow-adapting mechanoreceptors
118
Activation of _______ leads to a 3-layered epidermis by the end of the 3rd month of pregnancy
p63
119
What are the 3 layers of the multilayered epidermis initiated by p63?
Basal (germinative) layer
Intermediate layer
Superficial peridermal layer
120
In forming the intermediate layer of the epidermis, p63 is inactivated by _______
miR203
121
The intermediate layer of the epidermis consists of what two sub-layers?
Stratum spinosum
| Stratum granulosum
122
Which sublayer of the intermediate layer of the epidermis is characterized by its interconnections with fillagrin?
Stratum granulosum
123
What sub-layer of the intermediate layer of the epidermis is characterized by the loss of integrins and the appearance of granules (keratohyalin)?
Stratum spinosum
124
When do epidermal ridges first appear?
Between 11-17 weeks (1 week later in feet/toes)
125
What is the source of dorsal mesenchyme?
Dermatome
126
What is the source of ventral and lateral mesenchyme?
Lateral plate mesoderm
127
What is the source of limb mesenchyme?
Lateral plate mesoderm
128
What is the source of cranial and anterior neck mesenchyme?
Neural crest
129
What signaling factor is important in the development of dermal cells from mesenchymal cells?
Wnt
130
What is the term for when one germ layer instructs another how to differentiate?
Instructive induction
131
What are the stages of hair development/growth?
1. Anagen
2. Catagen
3. Telogen
4. Exogen
132
What stage of hair growth lasts 5-6 weeks and is characterized by hair that stops growing?
Telogen
133
What stage of hair growth lasts 1-2 weeks and is characterized by regression of hair follicles?
Catagen
134
What stage of hair growth is characterized by the shedding of hair?
Exogen
135
What stage of hair growth lasts 5-6 weeks and is characterized by hair that is actively growing?
Anagen
136
What hormones are important for mammary gland development?
Estrogen
Progesterone
Prolactin
Oxytocin
137
What hormone involved in mammary gland development acts on the base of growth hormone to stimulate proliferation of fatty tissue?
Estrogen
138
What hormone involved in mammary gland development leads to the milk let-down for lactation?
Oxytocin
139
What are the skeletal derivatives of mesodermal sclerotomes?
Vertebral column, ribs, sternum
140
What are the skeletal derivatives of the lateral plate mesoderm?
Limb bones, girdles
141
What are the skeletal derivatives of head mesoderm?
Calvaria and base of skull
142
What are the skeletal derivatives of the neural crest?
Facial bones
143
What are the 2 transcription factors required for membranous bone development?
Runx-2 and Osx
144
What transcription factor causes chondroblasts to secrete collagen II and cartilage matrix during permanent cartilage development?
Sox-9
145
Runx-2, ihh, and BMP-6 are used to induce cartilage hypertrophy during what type of bone development?
Endochondral
146
What Hox gene is responsible for the occipital/cervical boundary?
Hox3
147
What Hox gene is responsible for the cervical/thoracic boundary?
Hox-6
148
What Hox gene is responsible for the attached/floating ribs boundary?
Hox-9
149
What Hox gene is responsible for the thoracic lumbar boundary?
Hox-10
150
What Hox gene is responsible for the sacral-coccygeal boundary?
Hox-13
151
Retinoic acid can cause shifts cranially/caudally. If administered early, retinoic acid will cause a __________ shift
Cranial
152
Retinoic acid can cause shifts cranially/caudally. If administered late, retinoic acid will cause a __________ shift
Caudal
153
The cranial/caudal shifts caused by retinoic acid are called ___________ ____________
Homeotic transformations
154
A single Hox gene knockout or mutation would lead to what?
Minor changes only, paralogues would compensate
155
If you had a knockout of all Hox-10 genes, what would happen?
Ribs form on all sacral and lumbar vertebrae
This suggests that Hox-10 represses influence of anterior Hox genes where they shouldn't be acting
156
What would happen if all Hox-11 genes were knocked out?
Hox-10 would not be suppressed, there would be deformation of the sacrum
157
What is the primordia of the atlas?
Somites 1 and 2
158
What is the primordia of the axis?
Somites 2 and 3
159
The odontoid process or dens of which cervical vertebrae extends is essentially the primordia of for the centrum of which vertebrae?
Atlas
[the dens is a process on the axis, which has taken over the primordia of the centrum of the atlas]
160
The sternum is derived from what type of mesoderm?
Lateral plate mesoderm
161
The clavicle arises from ________ _________ via the intramembranous path
Neural crest
162
The ________ is one of the first bones to become ossified
Clavicle
163
What bone originates as cartilaginous beads that later fuse and subdivide into craniocaudal elements?
Sternum
164
What are the two components of the cartilaginous portion of the viscerocranium?
Pharyngeal arch I (Meckel's cartilage, malleus, incus)
Pharyngeal arch II (Reichert's cartilage, stapes, styloid)
165
What are the 4 general components of a pharyngeal arch?
Skeletal element
Muscles
Branch of specific cranial nerve
Artery
166
In terms of the neurocranium vs. viscerocranium, which one surrounds the oral cavity and pharynx?
Viscerocranium
167
In terms of the neurocranium vs. viscerocranium, which one surrounds the brain?
Neurocranium
168
What is derived from the parachordal cartilages?
Basiooccipital portion of chondrocranium
169
What part of the viscerocranium involves the temporal, zygomatic, maxillary, nasal, lacrimal, palatine, vomer, pterygoids, mandible, and tympanic ring?
Membranous portion
170
The elongation of primary ossification centers is due to ________
Shh
171
What term refers to the structure formed by the intersection of more than 2 bones?
Fontanelle
172
Describe fontanelle formation
FGF inhibits Noggin inhibits BMP causes closure of sutures
173
What type of myotubes are formed by fusion of the earliest embryonic myoblasts?
Primary
174
What type of myotubes are smaller and are formed along the primary from later (fetal) myoblasts?
Secondary
175
___________ cells are mitotic and myogenic. They are located between the sarcolemma and basal lamina of a myofiber. They are able to fuse with the muscle fiber and provide for growth.
Satellite
176
Can satellite cells form new muscle fibers?
No, they can only fuse to existing muscle fibers and provide for growth
177
What is the origin of epaxial trunk musculature?
Dorsal myotome
178
What is the origin of trunk epaxial tendons?
Syndetome layer within somites
179
what is the origin of trunk hypaxial musculature?
Ventral buds of myotome
180
What is the origin of trunk hypaxial tendons?
Lateral plate mesoderm
181
What is the origin of limb musculature?
Ventrolateral dermomyotome
182
What is the origin of limb tendons?
Lateral plate mesoderm
183
What is the origin of most head and neck musculature?
Paraxial somitomeres
184
What is the origin of the extraocular muscles?
Prechordal plate
185
What is the origin of the cranial musculature?
Unsegmented paraxial mesoderm
186
What is the origin of the lower jaw musculature?
Splanchnic mesoderm
187
What is the origin of cardiac muscle?
Splanchnic mesoderm
188
Does early cardiac muscle express MyoD?
No
189
Describe early cardiac musculature
Begins contraction early and maintains mitotic ability by partially disassembling contractile apparatus prior to cell division
190
Early cardiac cells remain ___________ and are attached via ______________ ________
Mononucleated
| Intercalated discs
