Midterms_Ectodermal Derivatives Flashcards
1
Q
The ectoderm is made up of these three main derivatives
A
Outer Ectoderm
Neural Crest
Neural Tube
2
Q
What are the derivatives of the Outer Ectoderms
A
Lens
Epidermis
Mouth Epithelium
Olfactory Epithelium
Nails
Sebaceous Glands
Hair
3
Q
What are the subderivatives of the mouth epithelium
Clue: CAT
A
Cheek epithelium
Anterior Pituitary
Tooth Enamel
4
Q
What are the derivatives of the Neural Crest?
A
Dentine of Teeth
Adrenal Medulla
Melanocytes
Peripheral Nervous System
Facial Cartilage
5
Q
What are the derivatives of the peripheral nervous system?
PNSS
A
Parasympathetic Nervous System
Neuroglial Cells
Schwann Cells
Sympathetic Nervous System
6
Q
What are the derivatives of the Neural tube?
A
Spinal Cord
Motor Neuron
Brain
Retina
Neural Pituitary
7
Q
True or False
The nervous system is made up of the central nervous system and the peripheral nervous system.
A
True
8
Q
What is the CNS made of?
A
Brain and spinal cord
9
Q
What is the PNS made of?
A
nerves and ganglia
10
Q
The development of the nervous system differentiates from this structure at different organizations.
A
Neural Tube
11
Q
The development of the nervous system differentiates from the neural tube at 3 LEVELS OF ORGANIZATION. Which are?
A
Organ Level
Tissue Level
Cellular Level
12
Q
In the development of the nervous system, what is the level of organization where the neural tube bulges and constricts to form the different regions of the brain and spinal cord
A
Organ Level
13
Q
In the development of the nervous system, what is the level of organization where cells on the walls of the neural tube rearrange themselves to form different functional regions of the brain and spinal cord
A
Tissue Level
14
Q
In the development of the nervous system, what is the level of organization where the neuroepithelial cells differentiate into neurons and glial cells.
A
Cellular Level
15
Q
T or F
In the cellular level of nervous system development, neural crest cells differentiate into neurons and glial cells
A
False: Neural crest, Neuroepithelial
16
Q
T or F: In the development of the nervous system (cellular level), the POSTERIOR portion of the neural tube develops into the brain whereas the ANTERIOR portion develops into the spinal cord
A
False: Interchange posterior and anterior
17
Q
What type of directional differentiation does the brain vesicles and brain flexures undergo?
A
Antero-posterior Differentiation
18
Q
What are the two features that forms in antero-posterior differentiation.
A
Brain vesicles and brain flexures
19
Q
This is a process of expansion (of the neural tube) to form primary vesicles.
A
vesiculation
20
Q
What region does vesiculation occur?
A
Anterior region
21
Q
The brain vesicles have cavities called?
A
ventricles.
22
Q
The secondary ventricles are derived from?
A
primary ventricles.
23
Q
Essay
How does the brain vesicles form?
A
At the anterior region, the neural tube undergoes vesiculation, a process of expansion or ballooning into three primary vesicles, the prosencephalon, mesencephalon, and rhombencephalon.
These primary vesicles eventually form secondary vesicles, which give rise to various adult structures.
The brain vesicles have cavities called ventricles.
The secondary ventricles are derived from the primary
ventricles.
24
Q
What are the ventricles that make up Forebrain, Midbrain, and Hindbrain respectively?
A
Prosocoel, Mesocoel, and Rhombocoel
25
What do you call the smaller compartments of the rhombencephalon?
Rhombomeres
26
This brain structure is formed by the derivatives of the midbrain and hindbrain
Brainstem
27
These are clusters of neuronal cell bodies whose axons form a nerve
Ganglia
28
What forms the ganglia?
Rhombomeres
29
T or F
In Brain Flexures, The brain grows far more slowly than the membranous skull enclosing it, causing the brain to develop flexures.
False; slowly, rapidly
30
In Brain Flexures, the brain develops three flexures namely:
Cephalic
Pontine
Cervical
31
T or F
The Cephalic flexure is found between midbrain and hindbrain
False: Found between Forebrain and Midbrain
32
T or F
The cephalic flexures folds the forebrain dorsally
False: dorsally, ventrally
33
The cephalic flexure pushes the mesencephalon to what direction?
upwards
34
True or False
Pontine Flexures are Dorsal Flexures
True
35
Where are pontine flexures located?
Between Metencephalon and Myelencephalon
36
The pontine generates what type of ventricle?
Fourth Ventricle
37
The cervical flexures are found between?
Myelencephalon and spinal cord
38
The cervical flexures folds the brain in what direction relative to the spinal cord?
ventrally
39
Another result of limited space is that, as the cerebral hemispheres continue to grow and expand, they almost completely envelope what secondary vesicles?
Diencephalon and Mesencephalon
40
State all the secondary vesicles
CLUE: Tel Di Mes Met My
Telencephalon
Diencephalon
Mesencephalon
Metencephalon
Myencephalon
41
Under the limited space from rapid brain growth, what structures form, that increase the surface area, allowing more neurons to occupy a limited space.
Convolution
42
Advantage of convolutions?
Increase surface area that allow neurons to occupy a limited space
43
T or F
The dorsoventral differentiation of the neural tube can be best understood by looking at the brain.
False: brain, spinal cord
44
The dorsal region of the neural tube receives input from what cells?
sensory neurons
45
What region of the neural tube receives input from sensory neurons?
dorsal region
46
What region of the neural tube does the motor neurons reside?
Ventral region
47
The region between the dorsal and ventral areas contains what cells?
interneurons
48
Purpose of interneurons?
Relay information between sensory and motor neurons
49
Fill in the Blank
Dorsal differentiation is influenced by __________ while ventral differentiation is induced by the __________.
1. epidermis
2. notochord
50
The epidermis BMP4 and BMP7 induce the dorsal most area of the neural tube to become what identity?
roof plate
51
What is the roof plate for?
It serves as a secondary signalling center
52
The roof plate also expresses what substance?
BMP4
53
What does BMP4 induce?
A cascade of TGF-β superfamily proteins
54
What does TGF-β superfamily proteins do?
Act as a morphogen
55
These signal molecules that diffuse from the source and form a concentration gradient.
morphogens
56
The concentration gradients of the TGF-β superfamily induce different types of what?
Transcription Factors
57
T or F
The concentration gradients of the TGF-β superfamily induce different types of vesicles in cells at different distances from the roof plate, giving them different identities.
False: vesicles, transcription factors
58
List the gradients of the following identities
• roof plate
• D1 interneurons
• D2 interneurons
• D3 interneurons
• BMP4, BMP5, BMP7, Dorsalin, Activin = roof plate
• BMP7, Dorsalin, Activin = D1 interneurons
• Dorsalin, Activin = D2 interneurons
• Activin = D3 interneurons
59
In ventral patterning, what is the substance secreted by the notochord?
sonic hedgehog (shh)
60
What does sonic hedgehog (shh) do?
induces the ventral most area of the neural tube to become the floor plate,
61
What is the function of the floor plate?
secondary signalling center
62
What acts as morphogens in ventral patterning?
sonic hedehog (shh)
63
T or F
The floor plate also expresses shh that acts as a morphogen, forming a gradient highest at the most anterior portion of the neural tube,
False: anterior, ventral
64
What signals the differentiation of different cell identities?
gradients
65
List their identities:
• Highest concentration of shh
• Decreasing concentrations from the floor plate
1. floor plate
2. V3 neurons
motor neurons
V2 interneurons
V1 interneurons
66
The neural tube is initially composed of a single layer called?
Germinal neuroepithelium
67
T or F
The germinal neuroepithelium is single layered
True
68
This is a mitotic neural layer surrounding the cavity (ventricle) of the neural tube
germinal neuroepithelium.
69
The germinal neuroepithelium is also known as?
ventricular layer or ependymal layer.
70
It is a pseudostratified layer whose cells divide vertically (instead of horizontally)
Germinal neuroepithelium, ventricular layer or ependymal layer.
71
In Neural Tissue; the ventricular layer or ependymal layer gives rise to two cells.
One cell remains close to the ventricle and remains as a what?
Stem cell
72
In Neural Tissue; the ventricular layer or ependymal layer gives rise to two cells.
The cells migrates away to become either what?
Neural stem cell and glial stem cell
73
Neural stem cells form what type of cells?
Neurons
74
Glial stem cells form what type of cells?
neuroglia
75
As the neuroepithelium divides, migrating cells form a second layer around the neuroepithelium called the?
mantle or intermediate zone.
76
As the neuroepithelium divides, migrating cells form a second layer called the mantle or intermediate zone around the neuroepithelium. The mantle differentiates into what type of cells?
neurons and glial cells
77
Neurons, from the differentiation of the mantle layer, establish connections with each other and send out axons away from the lumen, forming a cell-poor layer called?
the marginal zone
78
In the marginal zone, The glial cells ensheath these axons with myelin sheaths, giving them a whitish appearance thus referred to as?
White matter
79
In the marginal zone, the mantle layer that contains the neuronal cell bodies is then referred to as?
gray matter
80
What do you call neuronal precursors from the neuroepithelium?
Neuroblasts
81
Where do neuroblasts migrate to form neuron clusters?
white matter
82
What do you call clusters of neurons?
Nuclei
83
What is the function of the clusters of neurons (nuclei)?
relay stations between cerebellum and other parts of the brain
84
In the cerebellum, other neuroblasts from the neuroepithelium migrate to the outer layer surrounding the white matter to form a two-layered what?
External Granule Layer
85
What is the function of the external granule layer?
It is where neuroblasts proliferate
86
Neuroblasts of the inner layer of the external granule layer form granule neurons that migrate back to the white matter and form the?
Internal Granule Layer
87
neuroblasts of the inner layer of the external granule layer form what?
Granule neurons
88
As the neuroepithelial layer continues to generate more cells, it gives rise to large and distinctive?
Purkinje neurons
89
what doesthe purkinje neurons do?
migrate between the external granule layer and the internal granule layer forming the Purkinje cell layer
90
The Purkinje neurons have enormous processes called?
dendritic arbor
91
what is the purpose of dendritic arbor?
synapse with the neurons of the external granule layer
92
What part of the Purkinje neurons synapse with the neurons of the internal granule layer?
Long axons
93
Where does vertical and horizontal differentiation occur?
cerebrum
94
In vertical differentiation, neuroblasts from the mantle layer (grey matter) migrate outside the white matter to form the outer layer of the brain called the?
neocortex
95
The neocortex; this layer forms how many layers?
6 distinct layers
96
T or F
The cerebrum is organized vertically into over 40 regions with distinct functions
False: vertically, horizontally
97
Neural crest cells originate at what region of the neural tube?
dorsal
98
What do neural crests do to generate various types of cells?
migrate
99
Nural crest cells give rise to how many functional domains?
4 main functional domains
100
The first group of neural crest cells to separate from the neural tube and undergo epithelial to mesenchyme transition.
Cranial / Cephalic Neural Crest
101
neural crest cells from the forebrain and midbrain give rise to three structures; namely?
1. Skeletal elements of the face
2. Melanocytes
3. Neurons and glial of the cranial ganglia
102
Neural crest cells from the rhombomeres give rise to three streams which are?
Trigeminal
Hyoid
Post-otic
103
FThis stream of neural crest cells fills in the 1st pharyngeal arch (PA1) and gives rise to the jawbones, odontoblasts of the teeth, malleus, and incus of the middle ear
Trigeminal Neural Crest
104
This stream of neural crest fills in the 2nd pharyngeal arch (PA2) and gives rise to the hyoid bone and stapes
Hyoid neural crest
105
This stream of neural crest cells fills in the 3rd pharyngeal arch (PA3) and contributes to the thyroid and parathyroid gland
Post-otic neural crest
106
T or F
Each of the neural crest streams gives rise to the cranial and pharyngeal ganglion
False: pharyngeal, jugular
107
What arises from the neural tube at the level of somites?
Vagal Neural Crest
108
What somite level form the parasympathetic (enteric) nervous system of the foregut?
Somite 1-3
109
In level of somites 1-3, some of the cells migrate to the heart thus called the?
cardiac neural crest
110
T or F
Cardiac neural crests contribute to the formation of the pulmonary semilaminar valves
False: semilaminar, semilunar
111
Level of somite produces this tissue of large arteries of the heart.
musculoconnective tissue
112
The cardiac neural crest populate what Pharyngeal arches?
3-6
113
T or F
Cardiac neural crest gives rise to melanocytes, neurons, and connective tissues of Pharyngeal Arches 1-3
False: 3-6
114
What somite level contributes to the enteric nervous system of the stomach?
Level of somites 4-6
115
What somite level contribute to the dorsal root ganglia of the peripheral nervous system and melanocytes
Level of somite 7
116
What neural crest originates posterior to the vagal neural crest.
Trunk neural crest
117
What trunk neural crest pathways is between the neural tube and the somites
ventrolateral
118
What do you call the derivatives of the somite?
ssclerotome
119
Trunk Neural Crest Cells that migrate up to the ___________ give rise to the sensory neurons and glial cells of the dorsal root ganglia of the peripheral nervous system
sclerotome
120
Trunk neural crest cells that migrate towards this pathway form the sympathetic ganglia, the adrenal medulla, and nerve clusters of the aorta. So what is this pathway?
ventrally
121
What Trunk neural crest pathway is between the ectoderm and anterior sclerotome?
dorsolateral
122
Dorsolateral pathway of the Trunk neural crest gives rise to what cells?
melanocytes
123
What arise at the posterior-most region of the neural tube?
Sacral Neural Crest
124
T or F
The sacral neural crest migrates ventrally and colonizes the gut giving rise to the enteric nervous system of the
foregut
False: foregut, hindgut
125
Eye development begins when vesicles bulge from each side of the diencephalon. what are these vesicles?
optic vesicles
126
As the optic vesicles continue to grow outward, it comes in contact with the ectoderm and induces the formation of this structure.
lens placode
127
The induced lens placode then invaginates forming this structure.
Lens pit
128
This invagination pushes against the optic vesicle, causing it to invaginate, too, forming a double-walled?
optic cup
129
What structure is the optic cup attached to?
narrow optic stalk.
130
The walls of the optic cup includes:
Outer and Inner wall
131
At what layer of the optic cup do cells produce melanin pigment?
Outer wall
132
In the outer walls of the optic cup, cells produce melanin pigment and the layer becomes the?
pigmented retina
133
At what layer of the optic cup do cells proliferate rapidly?
Inner wall
134
glial cells, ganglion cells, interneurons, and light-sensitive photoreceptor neurons all form what structure?
neural retina
135
Fill in the blank
In the inner wall of the optic cup, the optic stalk is now called?
optic nerve
136
In the development of the eye, the lens pit closes over itself forming what structure?
lens vesicle
137
In the development of the eye, The closed ectoderm then
differentiates into?
cornea
138
T or F
The optic vesicles arise from the Myelencephalon,
False: Myelencephalon, diencephalon
139
T or F
Since the optic vesicles arise from the diencephalon, the walls are then lined with the same germinal neuroepithelium of the neurologlia.
False: neurologlia, neural tube
140
Differentiation of the Neural Retina give rise to two layers, Which are?
Outer neuroblastic layer
Inner neuroblastic layer
141
What does the outer neuroblastic layer face?
pigmented retina
142
What does the inner neuroblastic layer face?
lens
143
In differentiation of the neural retina, from two layers, three layers of cells are formed, which are?
Outer, middle and inner layers
144
In differentiation of the neural retina, what layer comprises rods and cones phototoreceptors?
Outer layer
145
In differentiation of the neural retina, what layer comprises bipolar neurons?
Middle
146
In differentiation of the neural retina, what layer comprises ganglion cells?
Inner layer
147
In differentiation of the neural retina, point of synapsis between the neurons of each layer form the?
plexiform layers
148
T or F
In differentiation of the Lens, the lens vesicle is made up of a single layer of lens epithelium surrounding a lens cavity.
True
149
What induces the cells of the posterior epithelium
to transform into elongated, slender cells?
neural retina
150
What lens epithelium forms the primary lens fibers and crystallins?
Posterior epithelium
151
What do you call elongated slender cells transformed from the posterior epithelium?
primary lens fibers
152
What is tghe function of primary lens fibers?
fill in the cavity of the lens vesicle.
153
The cells of the posterior epithelium synthesize transparent, lens-specific proteins and lose their nuclei. What do you call these proteins?
crystallins
154
In the anterior epithelium, Cells at the equatorial region elongate towards the anterior and posterior areas and form the?
secondary lens fibers
155
What section of the len epithelium do secondary lens fibers form?
Anterior epithelium
156
This process begins when the mesenchyme that surrounds the external surface of the optic cup condenses.
Corneal differentiation
157
In corneal differentiation, the mesenchyme condenses into two layers, which are?
Choroid and sclera
158
This is the inner, pigmented, vascular layer of the mesenchyme
choroid
159
This is the outer, fibrous layer of the mesenchyme.
Sclera
160
In mesenchyme at the anterior of the developing lens, this is the inner layer that is continuous with the choroid.
Iridopupillay membrane
161
True or False
The Iridopupillay membrane will eventualy disappear.
162
What happens if Iridopupillay membrane dissappears?
allowing communication between the anterior and posterior
chambers of the eye
163
In the mesenchyme at the anterior of the developing lens, what do you call the outer layer that is continuous with the sclera?
Corneal stroma
164
This is a corneal layer that develops from the surface ectoderm.
Corneal epithelium
165
This is a corneal layer that is derived from the surrounding mesenchyme.
Corneal Stroma
166
This is a corneal layer that forms from neural crest cells that migrate from the rim of the optic cup
Corneal endothelium
167
T or F
The epidermis develops from the ectoderm after gastrulation.
False: gastrulation, neurulation
168
In the development of the epidermis, this is the outer layer that serves as a temporary covering
Periderm
169
T or F
The periderm merges once the true epidermis is formed.
False: merges, shed
170
In the development of the epidermis, this is the inner layer that is mitotic.
Basal layer/ Stratum germinativum
171
This strata gives rise to all the cells of the epidermis
stratum germinativum
172
The basal layer/stratum germinativum divides to form?
an intermediate layer
173
In the development of the epidermal cells the intermediate layer is between what?
periderm and basal layer
174
The intermediate layer forms numerous tonofilaments that connect adjacent cells making the layer look “spiny” thus called?
stratum spinosum
175
stratum germinativum and stratum spinosum are mitotic layers and collectively known as the?
Malphigian Layer
176
In the development of Epidermal Cells, Cells of the
Malphigian layer divide to produce what strata?
stratum granulosum
177
stratum granulosum is a layer that contains what granules?
keratohyalin
178
What are the precursor of keratin?
keratohyalin granules
179
The non-mitotic granular cells differentiate into
keratinized cells called?
keratinocytes
180
Keratinocytes comprises what strata?
stratum corneum
181
T or F
Stratum granulosum is a layer of flat cells
False: granulosum, corneum
182
Melanocytes from the neural crest invade the Malphigian layer and transfer their pigment sacs to developing keratinocytes. What do you call these pigment sacs?
melanosomes
183
T or F
When epidermal derivatives form, they grow downward and penetrate the fatty tissues.
False: fatty tissues, dermis
184
What do you call the derivative of the mesoderm?
dermis
185
The development of hair occurs in how many stages?
3
186
What are the three stages of hair develoment?
Clue: IOC
Induction
Organogenesis
Cytodifferentiation
187
What induces the epidermal cells of the of the basal layer to become columnar and bulge slightly into the dermis?
fibroblast cells,
188
The epidermal cells of the of the basal layer to become columnar and bulge slightly into the dermis as?
hair placode
189
In Organogenesis (Hair Development), the cells continue to proliferate and form clusters which enlarge and elongate to
generate the?
hair germ
190
In organogenesis, the dermal fibroblasts respond to the “sinking” of the hair germ and form a small node beneath the hair germ forming the?
dermal papilla
191
T or F
The dermal papilla pushes against the “sinking” hair germ, stimulating the hair germ further to divide and envelope the dermal papilla
True
192
In cytodifferentiation, the hair germ cells give rise to post-mitotic cells that will differentiate into what keratinized structure?
hair shaft
193
In Cytodifferentiation, two epithelial swellings or bulges grow on the sides of the hair germ which are?
Lower and Upper Swelling
194
This epithelial bulge retains the population of stem cells and will generate the hair shaft periodically
lower swelling
195
This epithelial bulge forms the sebaceous gland
uper swelling
