Embryology Flashcards
1
Q
What is the time period for a human to be considered a embryo?
A
fertilization to 8 weeks
2
Q
What is the time period for a human to be considered a fetus?
A
Week 8 to birth
3
Q
What is a fertilized egg called?
A
zygote
4
Q
When a cell undergoes mitosis and is 8 to 16 cells what is it called? 1. Are these cell differentiated? 2. Where is this usually located? 3
A
- morula
- no
- stage usually entering uterus
5
Q
What is it called when the embryo stays in the fallopian tube?
A
tubal pregnancy
6
Q
What is it called when the embryo is not in the uterus?
A
Ectopic pregnancy
7
Q
What is it called when the morula begins to cavitate when in the uterus?
A
blastocyst
8
Q
What does the blastocyst differentiate into:
- covers entire outside of blastocyst
- at one pole of embryo
A
- trophoblast
2. inner cell mass
9
Q
Is contact with the endometrium and the blastocyst at the pole or away from the pole?
A
at the pole
10
Q
What does the trophoblast differentiate into? and which of them moves into the uterine wall>
A
- cytotrophoblast
- syncytiotrophoblast
- syncytiotrophoblast
11
Q
What does the embryo start to secrete around day 9?
A
Human Chorionic Gonadotropin (hCG)
12
Q
Without conception, what does the corpus luteum involute into?
A
corpus albicans
13
Q
What hormone causes dozens of follicles to develop?
A
FSH
14
Q
What do follicular cells secrete that has a negative feedback on FSH?
A
estrogen
15
Q
What does luteinizing hormone (LH) do?
A
- Turns follicular cells yellow
2. triggers ovulation
16
Q
What does the corpus luteum secrete that initiates secretory phase?
A
progesterone
17
Q
When estrogen and progesterone decrease what section of the uterus becomes ischemic and sloughs off?
A
zona functionalis
18
Q
What does Human Chorionic Gonadotropin (hCG) do?
A
- maintain uterus in gravid state (missed period)
2. allows embryonic implantation
19
Q
Syncytio and cytotrophoblast continue to develop to form what?
A
placenta
20
Q
After how many months does the placenta release progesterone and what does this progesterone do?
A
2 months and it eliminates the corpus luteum
21
Q
Embryoblast cells differentiate into:
- monolayer ventral layer near blastocyst cavity
- Remaining cells
A
- endoderm
2. epiblast
22
Q
What is the second fluid filled area formed dorsal to the embryo?
A
Amniotic cavity
23
Q
At the end of week two, a group of endoderm cells at one pole of embryo further differentiate to form: 1. Which end of the embryo is this? 2
A
- prochordal plate
2. cranial
24
Q
What is it called when the trophoblast is maintained during pregnancy but inner cell mass fails to develop embryoblast? 1. Why are there no signs and symptoms of this? 2. What is it caused by? 3. What are the options for the mother? 4
A
- Blighted ovum
- hCG is maintained so seems like pregnancy still
- chromosomal abnormalities
- miscarry or D&C
25
What is the formation of a trilaminar embryo called?
gastrulation
26
What is the formation of the central nervous system called?
neurolation
27
What are the two parallel rows of epiblast cells at the caudal axial pole with a trench between them called? 1. What is the morphology of these cells? 2
1. primitive streak cells
| 2. columnar
28
Once the formation of primitive streak cells takes place what are all other cells now called?
ectoderm
29
What is the layer that forms when the primitive streak cells mitose and touch at midline then migrate ventrally making a layer in between two other layers?
mesoderm
30
The primitive knot is located at the 1 end of the 2. It is a circular mass which cells move 3 through its center. Once these cells reach the mesoderm they migrate in an axial pattern towards 4. What structure do these cells from? 5
1. cranial
2. primitive streak
3. radially inward
4. prechordal plate
5. notochord
31
What layer of tissue is most dorsal in a trilaminar embryo?
ectoderm
32
What releases growth factor that causes ectoderm cells to have gene activation and differentiation? 1. What are these differentiated cells called? 2. What are all other cells that did not differentiate now called?
1. notochord
2. neuroectoderm
3. surface ectoderm
33
Neuroectoderm cells form a groove which eventually form into a 1. This is then covered over dorsally by 2
1. neural tube
| 2. surface ectoderm
34
What ate the openings at the end of the neural tube called? 1-2. Which end closes quicker? 3
1. anterior neuropore
2. posterior neuropore
3. cranial closure (anterior neuropore)
35
When do neural crest cells form? 1. What type of cells give rise to the crest cells? 2
1. during formation of the neural tube
| 2. neuroectoderm
36
What forms the placenta?
syncytio and cytotrophoblast
37
While the neural groove and tube formation is occuring, the lateral aspects of the embryo move ventrally make the embryo into:
a tube
38
What does the neural tube ultimately differentiate into?
CNS (brain and spinal cord)
39
What does the neural crest ultimately differentiate into?
PNS (ganglia)
40
What does the notochord ultimately differentiate into?
part of nucleus pulposus of intervertebral disc
41
What is linked to neural tube deformity?
low folic acid levels in mother
42
What is it called when the neural tube does not fuse fully?
Spina bifida
43
What type of spina bifida is it if you cannot tell when looking at the person (ephoria)?
Occulta
44
What type of spina bifida is it if you can tell when looking at the person (strabismus)? 1. What are the two types of these? 2-3
1. manifesta
2. meningocele
3. meningomyelocele (most severe)
45
What is the condition of the embryo forming a brain stem but usually not a cerebrum and hemisphere?
Anencephaly
46
What protein is tested for in embryo, increases with paternal age, and if elevated increases the chance for a neural defect?
Alpha fetal protein
47
What does the mesoderm differentiate into?
1. paraxial plate
2. intermediate plate
3. lateral plate
48
What does the intermediate plate of the mesoderm ultimately give rise to?
urogenital system including gonads, ducts and accessory glands
49
What does the lateral plate of the mesoderm ultimately give rise to?
1. CT and muscle of viscera
2. Serous membranes of pleura, pericardium, and peritoneum
3. Blood and lymph cells
4. cardio and lymph systems
5. spleen
6. adrenal cortex
50
What does the paraxial mesoderm form?
Somites
51
How old is an embryo that has 10 somites? 1. 19 somites? 2. 26-28 somites? 3
1. 23 days
2. 25 days
3. 4 weeks
52
How many somite pairs ultimately develop?
32
53
What is the breakdown of the names and numbers of pairs of somites?
1. 8 cervical (C1-C8)
2. 12 thoracic (T1-T12)
3. 5 lumbar (L1-L5)
4. 5 sacral (S1-S5)
5. 2/3 coccygeal (Co 1/2)
54
What three parts does each somite differentiate into/ what will each of these give rise to?
1. sclerotome / bone
2. myotome / skeletal muscle
3. dermatome / dermis
55
From where is each somite innervated?
1. Ventral half of neural tube
| 2. neural crest column
56
Where does the innervation from the ventral half of the neural tube to the somite enter into?
myotome (will be motor nerves)
57
Where does the innervation from the neural crest column to the somite enter into?
1. dermatome and myotome
| 2. dorsal half of neural tube
58
Which somite only has motor processes?
C1
59
Where are motor fibers located in the spinal cord?
ventral aspect
60
Where are sensory fibers located in the spinal cord?
dorsal root ganglion (dorsolateral to spinal cord)
61
If the ventral aspect of a spinal nerve gets fully cut what is the result? 1. If is is just altered called? 2
1. flaccid paralysis
| 2. paresis
62
If the dorsal root ganglion of a spinal nerve gets fully cut what is the result? 1. If is is just altered called? 2
1. anesthesia
| 2. paraesthesia
63
What is the rule called that states that once a somite is innervated, wherever it migrates and differentiates it brings the original nerve processes with it?
Law of Integrity of Nerve Supply
64
In the thoracic region, where do myotomes and dermatomes migrate to (1) and what form do they do this in (2)?
1. back to ventral midline
| 2. parallel ribbons
65
While wrapping around the chest the sclerotome forms what?
the ribs
66
While wrapping around the chest the myotome forms what?
intercostal muscles
67
While wrapping around the chest the dermatome forms what?
skin of thoracic region
68
If fully cut a spinal nerve in thoracic region what is the result?
anesthesia of dermatome and paralysis of intervertebral muscle below rib associated
69
What is each vertebrae formed by?
fusion of half of two separate somites
70
Each vertebrae has 1 from the upper somite and 2 from the lower somite
1. dense scleratome
| 2. loose scleratome
71
Are there more, less, or the same amount of vertebra as somites?
one less vertebra
72
What vertebra does the C1 nerve pass over?
C1
73
What vertebra does the C7 nerve pass over?
C7
74
What vertebra does the C8 nerve pass over?
T1
75
What vertebra does the T1 nerve pass over?
T2
76
At what vertebra does the solid spinal cord end? 1. What is the structure called that extends the fibers to go through their appropriate vertebral gaps? 2
1. Around L2
| 2. Cuada Equina
77
Muscles in the limbs are innervated by more than one spinal nerve. These are called:
Plurisegmental muscles
78
What muscles does the median nerve innervate? 1. What does the nerve pass through? 2. What would be the results if the nerve were cut? 3
1. flexors of the arm
2. carpel tunnel
3. paralysis of flexors of forearm and anesthesia of innervated area of hand
79
What spinal nerves do you have to damage to cause paralysis of flexor of forearm?
C5, C6, C7, C8, T1
80
What muscle runs below the 12th ribs?
Diaphragm
81
What innervates the diaphragm? 1. What somites gave rise to the diaphragm? 2
1. Phrenic nerve
| 2. Mostly C4 and pieces of C3 and C5
82
If the spinal cord is damaged above C3 is the diaphragm affected? 1. Below? 2
1. paralyzed
| 2. unaffected
83
What makes up the cranial somites?
1. 4 pair occipital
2. 1st preotic
3. 2nd preotic
4. 3rd preotic
84
What is the thickening of ectoderm in area forming the pinna?
Otic placode
85
What type of tissue do cranial somites differentiate into?
myotome tissue
86
What type of tissue do occipital somites differentiate into?
myotome tissue
87
What muscles do occipital somites differentiate into?
intrinsic and extrinsic muscles of tongue
88
Types of extrinsic muscles of tongue:
1. primary to protrude tongue. Main muscle
2. Tongue to hyoid. Pulls tongue down
3. Pulls tongue up and back
1. Genioglossus
2. Hyoglossus
3. Styloglossus
89
Types of intrinsic muscles of tongue: 1-3
Transverse, Longitudinal, and Lateral
90
How many total somites make up the muscles of the tongue?
8 somites
91
Before differentiation and migration of occipital somites into myotomes, cell bodies in 1 of future medulla oblongata sends axons into occipital somites. What do these nerve processes form? 2
1. neural tube
| 2. Hypoglossal nerve (XII)
92
Where are the cell bodies of the preotic somites located in the 1st somite? 2nd? 3rd?
1. Mesencephalon
2. Mesencephalon (ventral end but come out dorsally)
3. Pons (ventral half)
93
What cranial nerve innervates the 1st preotic somite? 1. What muscles do these differentiate into? 2
1. Oculomotor (III)
| 2. MR, IR, IO, SR, LPS
94
What cranial nerve innervates the 2nd preotic somite? 1. What muscles do these differentiate into? 2. If there is paralysis of this what is the resulting condition called? 3
1. Trochlear (IV)
2. SO
3. hypertropia
95
What cranial nerve innervates the 3rd preotic somite? 1. What muscles do these differentiate into? 2. If there is paralysis of this what is the resulting condition called? 3
1. Abducens (VI)
2. LR
3. esotropia
96
What type of tissue do preotic somites differentiate into?
myotomes
97
What are the paired pouches that form on the anterolateral surface of the developing head of embryo and are associated with the arterial arches of developing heart and vasculature? 1. How many of these develop? 2
1. Branchial arches
| 2. five
98
What embryonic tissue does the branchial arches come from? 1. Is it a part of the CNS? 2
1. Neural crest
| 2. No
99
How many arteries goes into each branchial arch?
one
100
What type of muscle do the branchial arches give rise to?
visceral muscle
101
What are the innervations of each of the branchial arches? 1-5
1. Trigeminal (V)
2. Facial (VII)
3. Glossopharyngeal (IX)
4. Vagus (X)
5. Spinal Accessory (XI)
102
What is the protective mechanism found in the branchial arches to prevent full paralysis with injury to one arch?
Has pretrematic nerve branches that go to the arch cranial to it
103
If a motor nerve is from a somite then what is its classification? 1. If it is from a branchial arch and is to a skeletal muscle what is its classification? 2
1. general somatic efferent n (GSE)
| 2. special visceral efferent n (SVE)
104
What are the two subarches of the 1st branchial arch and what do they become?
1. Cranial arch (Maxillary Arch)
| 2. Caudal Arch (Mandibular Arch)
105
Where does the pretrematic branch of the 1st branchial arch go into? 1. What does it become? 2
1. head mesenchyme
| 2. ophthalmic nerve
106
What are the three branches of CN V and are they sensory or motor?
1. Ophthalmic (sensory)
2. Maxillary (sensory)
3. Mandibular (sensory and motor)
107
Where are the sensory cell bodies of the Mandibular nerve (V3)? 1. Motor cell bodies? 2
1. trigeminal ganglion
| 2. pons
108
What sensory nerve innervates the body of the tongue for touch and temperature?
Lingual branch of mandibular
109
What muscles are innervated by the mandibular nerve?
1. temporalis (mastication)
2. masseter (mastication)
3. lateral pterygoid (mastication)
4. medial pterygoid (mastication)
5. tensor palatine (tensor)
6. tensor tympani (tensor)
7. mylohyoid (floor of mouth)
8. anterior belly digastric (floor of mouth)
110
What nerve and branchial arch give rise to the muscles of facial expression?
facial nerve (VII); 2nd arch
111
Which nerves (and branchial arches) are associated with innervating the ear canal? And which one gives a gag reaction when touched in ear?
1. facial nerve (VII); 2nd arch
2. glossopharyngeal nerve (IX); 3rd arch
3. IX makes gagging
112
What sensory nerve innervates the body of the tongue for taste?
Chorda tympani of facial nerve that is a pretrematic branch
113
What muscle is responsible for keeping food on the tongue while eating so when affected in Bell's Palsy results in food being in vestibule when eating on that side?
Buccinator muscle (innervated by VII)
114
What are the motor branches of VII?
1. Temporal
2. Zygomatic
3. Buccal
4. Mandibular
5. Cervical
115
What disease is associated with flaccid paralysis of one side of the face, without the ability to close their lid? And where is the inflammation occurring?
1. Bell's Palsy
| 2. internal acoustic meatus (CN VII)
116
What disease is associated with flaccid paralysis of one side of the face and a vesicular ear infection due to herpes?
Ramsey-Hunt Syndrome
117
What disease is associated with spastic paralysis that affects the lower quadrant of the face, not including the eyelids?
Internal capsular stroke
118
Which branchial (and nerve) arch gives rise to the stylopharyngeus muscle that pulls the tongue up to close the epiglottis?
3rd arch; glossopharyngeal nerve
119
What sensory nerve innervates the root of the tongue for general sensory and taste?
glossopharyngeal nerve
120
Which branchial arches have autonomic fibers associated with them?
2nd and 3rd
121
Which branchial (and nerve) arch gives rise to the pharyngeal constrictors and muscles of soft palate?
4th arch; vagus nerve
122
Which branchial (and nerve) arch gives rise to the taste buds of the pharynx?
4th arch; vagus nerve
123
Which branchial (and nerve) arch gives rise to the major autonomic to internal organs?
4th arch; vagus nerve
124
What muscle of palate pulls the root of the tongue up?
Palatoglossus
125
What muscle of the palate are your tonsils between?
Palatoglossus and Palatophyngeus
126
What are the muscles of the palate (and what are they innervated by)?
1. Palatoglossus (X)
2. Palatophyngeus (X)
3. Levator Palatine (X)
4. Musculus Uvulae (X)
5. Tensor Palatine (V3)
127
What muscle of the palate keeps food from going up nose when swallowing? 1. Which side does the tongue deviate to if there is a lack of innervation of this muscle (healthy or unhealthy side)? 2
1. Musculus Uvulae
| 2. healthy
128
Which branchial (and nerve) arch gives rise to the trapezius and sternocleidomastoid?
6th arch; spinal accessory nerve
129
What cervical sections of the spinal cord have important contributions to the spinal accessory nerve?
C1, C2, C3
130
What disease is associated with damage and contracture to sternocleidomastoid? 1. What palsy is associated with this disease? 2
1. Torticollis
| 2. Superior Oblique Palsy
