Brainscape's Knowledge GenomeTM

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


See full index

Embryo Exam III > Exam III Review > Flashcards

Exam III Review Flashcards

1
Q

Weaver mutation

A

Specific behavioral defects related to abnormal function of the cerebellum; abnormally of the radial glial cells in cerebrum and consequent abnormal migration of the cells that normally form the granular layer of the cerebellar cortex.

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

Reeler mutation

A

Abnormal behavior and absence of normal cortical layers

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

What is the relation of reelin to reeler?

A

Reelin is defective in the reeler mutant; it is a stop signal for radial neuronal migration

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

What are the major derivatives of the diencephalon?

A

Epi thalamus, thalamus, hypothalamus

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

What are the 3 patterning centers in the forebrain and what signaling molecules do they use?

A

Rostral patterning center (FGF-8)
Dorsal patterning center (BMPs and Wnts)
Ventral patterning center (Shh)

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

The topographical arrangement of the myelencephalon is almost identical to the spinal cord. What is the major topographical change?

A

Pronounced expansion of the roof plate to from the thin roof over the 4th ventricle

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

Expression of which set of genes seems to be responsible for the differentiation of specific nuclei in the myelencephalon?

A

Hox genes

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

What type of transformation do the nueral crest cells undergo when they break free from the neural tube?

A

Epithelial - mesenchymal transformation

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

What factors are involved in the breaking free of neural crest to the neural tube?

A

Snail-1, snail-2 and Foxd3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Neural crest cells form many components of the nervous system, but they do NOT form what?

A

Motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Explain what happened in the following experiment: Transplant thoracic neural crest cells to the head region and vice versa

A

Neural crest cells from the trunk transplanted into head form most neural crest derivates, BUT cannot from cartilage or skeletal elements** even though this is normal for neural crest.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Circumpharyngeal neural crest arise from where?

A

The area of somites 1-7

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

What is the circumpharyngeal ridge?

A

And arc-shaped aggregation of cells passing behind the 6th pharyngeal arch which migrate ventrally and then cranially to provide a pathway for CN XII and related musculature

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

Where do most neural crest cells from somites 1-3 pass ?

A

Into pharyngeal arches 4 and 6 or form cardiac crescent

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

Neural crest cells from R4-7 make up what?

A

Make up the Vagal crest and form parasympathetic innervation for digestive tract

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

Vagal neural crest arises from ?

A

Circumpharyngeal crest and exit from levels of somites 1-7

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

Vagal neural crest cells are mostly associated with what?

A

Gut enteric system (parasympathetics)

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

What factor maintains the competence of neural crest cells to differentiate into autonomic neurons?

A

Mash-1

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

Waardenburg’s Syndrome - neurocristopathy of trunk and cranial NC

A

Caused by Pax3 mutations. Involves various combinations of pigmentation defects (commonly a white strip of hair), deafness, cleft palate, ocular hypertelorism. 1 type has hypoplasia of limb muscles.

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

CHARGE - neurocristopathy of trunk and cranial NC

A

Colomba, heart disease, atresia of nasal choanae, retardation of development, genital hypoplasia in males and anomalies of the ear.

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

DiGeorges’ syndrome - neurocristopathy of cranial NC

A

Associated w/ a deletion on chromosome 22; characterized by hypoplasia and reduced function of the thymus, thyroid, and parathyroid glands and cardiovascular defects, including persistent truncus arteriosis and abnormalities of the aortic arch

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

Neurofibromas - neurocristopathy tumor and proliferation defect

A

Neurofibromas are peripheral nerve tumors. A disease associated w/ them is Neurofibromatosis aka Von Recklinghausens which is a common genetic disease manifested by multiple tumors of NC origin. Occasional gigantism of limb/digit and various other conditions

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

The preplacodal region encircles what?

A

The cranial plate

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

The preplacodal region is induced by what?

A

Cranial mesoderm (and neural tube); involves activation of FGF pathway and inhibition of Wnt and BMP

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

As BMP concentration progresses, what is the order of differentiation?

A

Placodes –> neural crest –> neural plate

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

Review major inductive events chart **

A

.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

The optic stalk is a lateral evagination of the what?

A

Diencephalon - it enlarges distally to from the optic vesicle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The optic vesicle asymmetrically invaginates to from a cup-like structure with a groove along one side of it, what is the groove?

A

The choroid fissure - it is continuous w/ the groove in the optic stalk which is continuous with the posterior chamber of the eye

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

What artery uses the choroid fissure and optic stalk to pass into the posterior chamber of the eye?

A

Hyaloid artery

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

In mammals, absence of what gene results in early optic vesicle formation but then no more eye formation?

A

Pax6

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

High concentrations what what inhibit the expression of Pax6?

A

Shh

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

Low concentrations of Shh in distal optic stalk has what effect?

A

Permits expression of Pax6 and development of optic vesicle which will lead to formation of the retina

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

High concentrations of Shh in proximal optic stalk has what effect on eye formation?

A

Decreases expression of Pax6 and induces expression of Pax2

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

Function of Pax2

A

Will provide guidance of axons of ganglion cells from retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Review Lens chart

A

.

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

What factor is necessary for corneal induction?

A

Pax6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

In cornea formation, the underlying lens vesicle induces the overlying ectoderm to do what?

A

Transfrom from bilayered epithelium (simple cuboidal basal layer + flattened periderm) to transparent multi-layered cornea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What forms the retina?

A

The invaginated optic cup forms both the pigmented and the neural retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Pigmented retina

A

Outer thin layer of the optic cup after invagination occurs - this is the only pigmented part of the body that doesn’t need neural crest cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What factors are necessary for the differentiation of the pigmented retina?

A

Otx2 stimulated by Shh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

In the fixation of retinal polarity, what is fixed first?

A

The nasotemporal (anterior-posterior) axis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

How is the nasotemporal axis established ?

A

By gradients composed of ephrins and receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is fixed second in the fixation of retinal polarity?

A

The dorsoventral axis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

The dorsoventral axis is established by what?

A

Antagonistic actions of Shh and BMP, along w/ ventropin, Tbx-5, Pax2, and Vax2.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Anopthalmos

A

Absence of an eye resulting from a mutation in RAX; very rare and can normally be attributed to lack of formation of the optics vesicle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Microphthalamos

A

Can range from an eyeball that is slightly smaller than normal to one that is almost vestigial; can be associated w/ a large # of genetic defects and various other causes including intrauterine infections. One of the most common components of rubella syndrome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Colomba

A

Nonclosure of the choroid fissure of the iris during the 6th or 7th week results in its persistence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Rathke’s pouch

A

Evagination from the roof of the stomodeal ectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Rathke’s pouch is the primordium for the ?

A

Anterior pituitary (adenohypophysis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What cranial nerves arise from what arches?

A

Arch I: CN V - trigeminal
Arch II: CN VII - facial
Arch III: CN IX - Glossopharyngeal
Arch IV: CN X - vagus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Why does the first arch develop into jaws?

A

Because of the lack of Hox gene expression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What factor is necessary to keep arch 2 from differentiating into arch 1 and forming the jaws?

A

Hoxa-2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

The neural tube is the basic signaling center in craniofacial development. It’s segmentation occurs as a result of what?

A

Hox gene expression - segmentation is carried over onto the neural crest cells giving rise to neural crest tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Pharyngeal arch derived musculature arises from?

A

Mesoderm from somitomeres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Pharyngeal arch mesenchyme that doesn’t consist of pharyngeal arch derived musculature is derived from?

A

Neural crest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Except for _______________, mesodermal structures of the pharyngeal arches are derived from neural crest.

A

Pharyngeal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

The Frontonasal ectodermal zone is induced by. ?

A

Shh from forebrain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What is the Frontonasal ectodermal zone?

A

An ectodermal signal center involving the establishment of a dorsoventral gradient of FGF-8 (more dorsal) and Shh (more ventral)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What factors are involved in the shaping of the tip of the snout?

A

Shh and FGF-8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What are the 3 facial primordia?

A
  1. Frontonasal prominence - unpaired
  2. Nasomedial processes
  3. Nasolateral processes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What are the primordia for the jaws and from which arch do they arise?

A

Maxillary processes
Mandibular processes
Meckel’s cartilage

Pharyngeal arch 1*

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Maxillary processes consist of ?

A

Neural crest derived from forebraine and midbrain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Mandibular processes consists of ?

A

Neural crest derived from midbrain and hindbrain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Meckel’s cartilage

A

Slender, elongated cartilagenous rod that develops w/I the 1st arch. Derived from neural crest cells. The mandible forms around it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What type of bone is the mandible?

A

Membrane bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What are the derivatives of Meckel’s cartilage?

A

Articular and Quadrate bones

They’re cartilagenous bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

TMJ

A

Synovial joint w/ an articular disk. Articular surfaces are the temporal bone and the mandibular condyle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Formation of the TMJ involved early expression of what?

A

Barx-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Fate of the articular and Quadrate bones

A

Quadrate: moves to middle ear and becomes incus
Articular: moves to middle ear and become malleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Stapes is another middle ear bone that is derived from which arch?

A

Arch II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

When does the palate form?

A

Between 6 and 10 weeks of development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What does the palate divide?

A

The common oronasal cavity into nasal and oral cavity - they remain connection together in the adult as the pharynx (Oro and naso)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What are the primordia for the palate?

A

Median palatine process (unpaired) and

Lateral palatine process (paired)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What forms the primary palate aka the premaxilla

A

Median palatine process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What forms the secondary palate?

A

The lateral palatine process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Dental lamina

A

C-shaped bands of oral ectoderm overlying neural crest mesenchyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Tooth bud

A

Epithelial downgrowth overlying neural crest mesenchyme and marking position of a single tooth

78
Q

Cap stage

A

Inverted cup-shaped layer of ectoderm (ameleoblast layer) capped by stellate reticulum and covering a mass of mesenchyme = dental papilla

79
Q

Bell stage

A

Cone-shaped primordium covered by stellate reticulum overlying the enamel organ

Enamel organ: ameloblasts make up outermost layer of the 2 layered covering
Dental papilla: odontoblasts form the outermost layer of the pulpy mass and lie under and adjacent to the ameloblasts (dentine)

80
Q

What stage do the ameloblasts and odontoblasts come together for the first time?

A

Bell stage

81
Q

Dental sac

A

A condensation of mesenchymal cells around the developing tooth which will form the cementum and periodontal ligament

82
Q

What factor is necessary for tooth development to continue past the bud stage?

A

Pax-9

83
Q

What factors creat non-tooth-forming spaces?

A

BMP-4 inhibits FGF-8 to do so

84
Q

What establishes the cusps on tri/bi cuspid teeth?

A

Enamel knots

85
Q

What does salivary gland development depend on?

A

Interaction b/w the epithelium and the underlying mesenchyme

86
Q

Branching pattern of salivary glands depends heavily on what?

A

Shh

87
Q

Describe the signaling in salivary gland development

A

Signaling between Shh and FGF occurs within the epithelium rather that between the epithelium and the mesenchyme as occurs in other types of glandular development
entirely in epithelium

88
Q

Cleft lip

A

Lack of fusion of the maxillary and nasomedial processes. In the most complete form of the defect, the entire pre maxillary segment is separated from both maxillae, w/ resulting bilateral clefts that run through the lip and upper jaw b/w lateral incisors and canine teeth. Mechanism frequently underlying cleft lip is hypoplasia of the maxillary process that prevents contact b/w the maxillary and nasomedial processes from being established

89
Q

Cleft palate

A

Results from incomplete/absent fusion of the palatal shelves. Usually multifactorial. Some chromosomal syndromes (trisomy 13) are characterized by increased incidence of clefts. other cases can be linked to the action of a chemical teratogen.

90
Q

Holoprosencephaly

A

Includes a broad specutrm of defects, all based on defective formation of the forebrain (prosencephalon) and structures whose normal formation depends on influences from forebrain. Arises early in pregnancy and brain defects usually involve archencephalic structures (olfactory system). B/c of the influence of the brain on surrounding structures, esp cranial base, primary defects of forebraine often manifest externally as facial malformations, typically a reduction in tissue of the Frontonasal process. In extreme cases, it can take form of Cyclopia. Also reduction defects of the nose (proboscis). Root cause of holoprosencephaly occurs very early in embryonic development w/ disturbances in the ability of the prechordal palate and anterior ectoderm to secrete Shh

91
Q

Dentinogenesis imperfecta

A

Teeth appear with blue-gray or Amber-brown and are opalescent. Can be nonsyndromic or associate w/ osteogenesis imperfecta

92
Q

Amelogenesis imperfecta

A

Group of clinically and genetically heterogeneous disorders that affect the development of enamel and result in abnormalities of the amount, composition, and or structure of the enamel. Caused by mutations in a variety of genes important in enamel formation. Enamel may be hypoplasia, hypo mature or hypo calcified

93
Q

What is the main organizer for pharyngeal arch development?

A

Foregut endoderm

94
Q

The craniocaudal segmentation of the pharyngeal arches is determined by what?

A

Hox genes

95
Q

Pharyngeal arches II and III require expression of what?

A

Hoxa-2 and Hoxa-3

96
Q

Adult derivative of pharyngeal groove I

A

External auditory meatus

97
Q

Adult derivative of pharyngeal pouch I

A

Middle ear auditory tube

98
Q

Derivative of pharyngeal pouch II

A

Supratonsilar fossa

99
Q

Derivative of pharyngeal pouch III

A

Thymus, inferior parathyroid gland

100
Q

Derivative of pharyngeal pouch IV

A

Superior parathyroid gland, post-branchial body

101
Q

Arch I

A

Aka mandibular
Aortic arch: I - maxillary artery
N: V - trigeminal
Muscles: of mastication, tensor tympani, mylohyoid, tensor veli palatini, anterior belly digastric
Skeletal derivatives: malleus, incus, sphenomandibular ligament, Meckel’s cartilage, tympanic ring

102
Q

Arch II

A

Aka hyoid
Aortic arch: II - hyoid and stapedial artery
N: VII - Facial
Muscles: of facial expression, stapedius, stylohyoid, posterior belly digastric
Skeletal derivatives: stapes, styloid process, lesser horn of hyoid, part of hyoid body

103
Q

Arch III

A

Aortic arch: III - internal carotid
N: IX - Glossopharyngeal
Muscles: stylopharyngeus
Skeletal derivatives: greater horn of hyoid, part of hyoid body

104
Q

Arch IV

A

Aortic arch: IV - r. Subclavian and aorta
N: X - Vagus
Muscles: pharyngeal and laryngeal musculature
Skeletal derivatives: laryngeal cartilages

105
Q

Describe the development of the 1st pharyngeal arch

A

NC derived from rhombomeres 1 and 2 and midbrain. Differentiation associated w/ Otx-2

106
Q

What cartilage is found in the second pharyngeal arch ?

A

Reichert’s -body and lesser horn of hyoid, stapes, and styloid process and ligament

107
Q

The development of the second pharyngeal arch is influenced by ?

A

Hoxa2

108
Q

The cervical sinus (temporary) is composed of what pharyngeal grooves?

A

2nd and 3rd

109
Q

What is the relationship of the cervical sinus and the overlying enlargement of the second arch?

A

As development progresses, the posterior ectoderm of the second arch fuses w/ the ectoderm of a swelling (Cardiac swelling) just posterior to the 4th arch, thus causing the cervical sinus to disappear and the external contours of the neck to become smooth

110
Q

Where is the external auditory meatus derived from?

A

1st groove

111
Q

Derivatives of the first pouch?

A

Tympanic cavity of middle ear and auditory tube

112
Q

Derivative of second pouch

A

Fossa for palatine tonsils

113
Q

Derivative of third pouch

A

Inferior parathyroids and thymus

114
Q

The inferior parathyroid from the 3rd pouch respond to what?

A

High concentrations of Shh

115
Q

The thymus in the 3rd pouch responds to what?

A

High concentrations of BMP-4

116
Q

Derivatives of the 4th pouch

A

Superior parathyroids and postbranchial body

117
Q

What does the postbranchial body in the 4th pouch become?

A

Becomes incorporated into the thyroid as para follicular (C) cells with secrete calcitonin

118
Q

What does the thyroid gland begin as?

A

A node (anlage) of cells located on the ventral surface of the pharynx b/w the 1st and 2nd pairs of pharyngeal arches then grows down into underlying mesenchyme as thyroid Diverticulum

119
Q

The thyroid Diverticulum remains connected temporarily where and how?

A

To the floor of the pharynx via the throglossal duct

120
Q

What is the foramen cecum?

A

Opening of the thyroglossal duct persists as a small pit at the base of the tongue = foramen cecum

121
Q

Infundibular process

A

Ventral downgrowth from floor of Diencephalon that forms the neurohypophysis (posterior pituitary)

122
Q

Rathkes’ pouch

A

Midline up growth from roof of stomodeum - forms a cup like extension distally that attaches to the infundibular process

123
Q

What does the inner layer of the cup of rathke’s pouch adhere to and form?

A

Neurohypophysis and forms pars intermedia

124
Q

What does the outer layer of the cup of rathke’s pouch do?

A

It is separated from pars intermedia by a narrow lumen called the residual lumen - will form the anterior pituitary (adenohypophysis)

125
Q

In all vertebrate embryos, the first kidneys to develop are what?

A

The pronephric kidneys

126
Q

Pronephric kidneys

A

Differentiate in humans from the anterior intermediate mesoderm at about 22 days gestation

127
Q

Are the pronephric kidneys in mammals functional or non-functional ?

A

Non-functional - but required in order for the rest of the excretory system to develop

128
Q

What is the functional kidney in most embryos ?

A

Mesonephros

129
Q

Describe the mesonephros in a salamander

A

The cranial part of the mesonephros does not function as a kidney in the adult. The functional caudal part is usually referred to as the opisthonephros (tail kidney)

130
Q

Mesonephric tubules

A

Longer than pronephric tubules (solid cords) and are often sigmoid or convoluted in shape

131
Q

Causally, each mesonephric duct forms an evagination called the ?

A

Ureteric bud or metanephric Diverticulum

132
Q

Metanephric Diverticulum/ureteric bud

A

Pocket-like expansion grows into the surrounding mesenchyme of the mesonephric ridge during week 5 of gestation. It will give rise to the adult ureter, renal pelvis, and collecting tubules

133
Q

As the metanephric diverticula expand, they induce the surrounding mesenchyme to condense into the what?

A

Metanephrogenic blastemata / blastema

134
Q

Metanephrogenic blastema form what?

A

Renal tubules of the adult kidney

135
Q

What is the effect of the metanephrogenic blastema on the ureteric diverticula?

A

The metanephrogenic blastemata have a reverse
inductive effect on the ureteric diverticula - Neither one can continue to develop in the absence
of the other. The metanephric tubules will not form in the
absence of the mesonephric duct.

136
Q

Effect of europlakins

A

Make ureter epithelium impermeable to water

137
Q

What factors repress GDNF in the anterior regions?

A

Slit-2 and robo-2

138
Q

Potters sequence

A

Flattened nose, wide interpupillary space, receding chin, tapering fingers, low-set ears, hip dislocation, and pulmonary hypoplasia often resulting in respiratory failure and death. Classified as a set of malformations secondary to a primary disturbance in development (bilateral renal agenesis for example).

139
Q

Horseshoe kidney

A

1 in 400. Kidneys are typically fused at their inferior poles. They cannon migrate out of the pelvic cavity b/c the inferior mes. Artery blocks them. Most cases are asymmtomatic but can obstruct ureters.

140
Q

Polycystic kidney disease

A

1 in 800. Manifested by the presence of 100s-1000s of cysts of different sizes w/I the parenchyma of the kidney.

141
Q

Extrophy of the bladder

A

Major defect in which the urinary bladder opens broadly onto the abdominal wall. Most commonly attributed to an insufficiency of mesodermal tissue of the ventral abdominal wall.

142
Q

What are the first part of the reproductive system to develop?

A

Gonads - after the embryonic kidneys have been established

143
Q

What is the “default” condition of the gonads when they are indifferentiated?

A

Female

144
Q

What is the switch that determines whether the indifferent gonad will develop into an ovary or switch to testis?

A

SRY on the Y chromosome

145
Q

What is within the medulla of the indifferent gonad?

A

Solid cords of cells called sex cords which have the potential to give rise to the seminiferous tubules containing Sertoli cells and interstitial cells in the event of a genetic male

146
Q

What anastomoses with the sex cord in a genetic male?

A

Rete cords

147
Q

In the genetic female, what is the outcome of the medulla of the gonads?

A

It regresses and the cortex forms the ovary

148
Q

What separates the cortex from the medulla in the gonad?

A

The tunica albuginea - in adult gonad it will lie on the external suface of the testis but will be internalized in the ovary

149
Q

The mesonephric tubules in the vicinity of the developing gonads will anastomose with what?

A

Rete cords

150
Q

What is the fate of the rete cords in females?

A

Will later degenerate along with the rest of the medulla but some vestigial mesonephric tubules may be retained

151
Q

In males, the mesonephric tubules will be retained as what?

A

Part of the closed duct system that converts sperm to the exterior = efferent ductules **

152
Q

The external genitalia begin as what kind of structure?

A

Bipotential

153
Q

What are three primordia that essentially give rise to the external genetalia in both sexes?

A

Genital tubercle - Genital folds - Genital swellings

154
Q

Genital tubercle

A

Unpaired - will form either the glans penis or clitoris

155
Q

Genital folds

A

More medial paired genital folds will fuse in the male to form the shaft of the penis but will remain infused in the female to form the labia minora

156
Q

Genital swellings

A

Paired - most lateral of the primordia. They will fuse and form the scrotum in males or remain infused and form the labia majora in females

157
Q

Primary heart field aka heart cresent forms what?

A

Left ventricle and the atria

158
Q

What is phylogenetically the most primitive component of the mammalian heart?

A

The primary heart field aka heart cresent

159
Q

Within the primary heart field, what are the most posterior cells exposed to and what does that cause?

A

Exposed to high gradient of RA and assume an atrial identity.
The more anterior cells are not exposed to RA and assume the default ventricular identity

160
Q

Anterior cells of the primary heart field that form the ventricles express what factor?

A

Hand-1 ** - it’s absence results in defective left ventricle

161
Q

What does the secondary heart field form?

A

Right ventricle and proximal outflow tract

162
Q

Where are cells from the secondary heart field derived from?

A

The pharyngeal mesoderm - can either for cardiac or skeletal muscle

163
Q

Cells in the secondary heart field express what factor?

A

Hand-2

164
Q

Proepicardium forms what?

A

The epicardium; the interstitial cells and vasculature smooth muscle; and gives rise to the coronary vasculature

165
Q

When does the cardiac tube form?

A

Late in the 3rd week - called primary myocardium

166
Q

The forming of the cardiac tube late in the 3rd week is guided by what factor?

A

Tbx-2

167
Q

What is the cardiac tube composed of?

A

Mostly of cells from primary heart field but incorporates cells from the secondary heart field - it undergoes dextral looping which makes it the first asymmetrical embryonic structure to appear

168
Q

What is the role of Hand-1 and Hand-2 in establishing asymmetry in the looping of the heart?

A

First, there is a shift in the expression of Hand-1 from both sides to the left side of the caudal heart tube. Hand-2 is expressed predominantly in the primordium of the right ventricle.

169
Q

When atrial and ventricular bulges appear on the outer suface of the loop and at inflow end, what structure is formed?

A

Chamber myocardium

170
Q

What guides the formation of the chamber myocardium?

A

Tbx-5

171
Q

What are the results of cardiac looping?

A

S-shaped heart; original caudal inflow (atrium) is now dorsal to outflow part of the heart;

Outflow part of the heart = bulbous cordis**; leads to aortic sac and arch system; internal septum begins to divide ventricle; later an internal septum will divide atrium

172
Q

What is the broader part of the bulbus cordis called?

A

Conus arteriosis

173
Q

What is the narrow distal part of the bulbus cordis called?

A

Trunus arteriosis

174
Q

When does partitioning of the single atrium into a left and right chamber being?

A

During the 5th week

175
Q

Interatrial septum primum

A

Downward growth from cephalic wall of single atrium to endo cardinal cushion. Separates the atrium into left and right chambers

176
Q

Interatrial septum secundum

A

Forms to the right of the septum primum and grows from dorsal to the ventral part of the atrium

177
Q

Interatrial foramen primum

A

Space b/w the leading edge of the septum primum and the endo cardinal cushion. Right to left atrial shunt

178
Q

Interatrial foramen secundum

A

Forms at the cephalic end of the septum primum through apoptosis. continues the right to left atrial shunt after the foramen primum closes w/ the funtion of the septum primum w/ the endocardial cushion

179
Q

Foramen ovale

A

Space formed w/i the septum secundum. Right to left atrial shunt.

180
Q

What is the fate of the first and second pairs of aortic arches?

A

They form but later degenerate

181
Q

What do the 3rd pair of aortic arches form ?

A

Internal carotids (along w/ the dorsal aortae cranial to 3rd arches)

182
Q

External carotids are the cranial extensions of what?

A

The paired ventral aortae cranial to the third arches

183
Q

The common carotids are derived from what?

A

Ventral aortae b/w the 3rd and 4th aortic arches

184
Q

The right subclavian artery is formed by . . .

A

The right 4th aortic arch

185
Q

The left 4th aortic arch forms the .. .

A

Aortic arch

186
Q

The 5th pair of aortic arches . . .

A

Degenerate

187
Q

The 6th pair of aortic arches become .. . .

A

Associated w/ the pulmonary system - dorsal portion becomes the ductules arteriosis shunt in the fetus and later the ligamentum arteriosus

188
Q

** function of the ductus venosus

A

Permits oxygenated placental blood to bypass the capillary network of the liver

189
Q

The left umbilical vein becomes the ?

A

***hepatic portal vein

190
Q

The Right vitelline vein becomes the . . .

A

Right hepatic vein

Embryo Exam III (1 decks)

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