Embryology Flashcards
(88 cards)
1
Q
What structures are derived from endoderm?
A
Epithelial lini of digestive and respiratory tract
Lining of urethra, bladder reproductive system
Liver
Pancreas
2
Q
Which structures are derived from mesoderm?
A
Notochord
Musculoskeletal system
Muscular layer of viscera
Circulatory system
3
Q
Which structures are derived from ectoderm?
A
Epidermis of skin
Cornea and lens
Nervous system
4
Q
When does granulation occur?
A
Week 3
5
Q
Which embryological structure forms the paired spinal nerves?
A
Somites
6
Q
How many pairs of spinal nerves are there?
A
31
7
Q
Which structure do the ribs and vertebrae form from?
A
Sclerotome
8
Q
Which structure are somites formed from?
A
Paraxial mesoderm
9
Q
Which structure is formed from the dorsal portion of the somite?
A
Dermomyotomes
10
Q
C5 myotome
A
Shoulder abduction
11
Q
Elbow extension myotome
A
C7
12
Q
Finger abduction myotome
A
T1
13
Q
C8 myotome
A
Finger flexion
14
Q
C6 myotome
A
Elbow flexion
15
Q
L2 myotome
A
Hip flexion
16
Q
L3 myotome
A
Knee extension
17
Q
Ankle dorsiflexion myotome
A
L4
18
Q
L5 myotome
A
Great toe extension
19
Q
S1 myotome
A
Ankle plantarflexion
20
Q
By which day has the trimlaminar disc formed?
A
20
21
Q
Do upper or lower limbs develop first?
A
Upper
22
Q
When are the limbs well differentiated?
A
Week 8
23
Q
What is amelia?
A
Congenital absence of one or more limbs
24
Q
What is meromelia?
A
Partial absence of one or more limb structures
25
What is syndactyly?
Fusion of digits
26
What is polydactyly?
Increased number of digits
27
When is development of the face complete?
6 weeks
28
When are the nasal and oral cavities distinct from one another?
12th week
29
How many pharyngeal arches are there?
6
30
Which three structures are associated with each pharyngeal arch?
Branch of aorta
Cranial nerve
Cartilage bar
31
What causes cleft lip?
Failure of the medial nasal prominence to fuse with the maxillary prominence
32
What causes cleft palate?
Failure of the palatal shelves to fuse in the midline
33
What is the primitive mouth called?
Stomatodeum
34
Name the six regions of the primitive heart tube
Aortic roots
Truncus arteriosus
Bulbus cordis
Ventricle
Atrium
Sinus Venosus
35
1st and 2nd aortic arch
Maxillary, hyoid and stapedial arteries
36
3rd aortic arch
Common carotid artery
Part of the proximal internal carotid artery
37
4th aortic arch
Right - right subclavian
Left - arch of aorta
38
5th aortic arch
Never forms or incompletely forms and regresses
39
6th aortic arch
Right - right pulmonary artery
Left - left pulmonary artery and ductus arteriosus
40
Which arches do the left and right RLNs hook under?
Right - 4th arch - right subclavian artery
Left - 6th arch - ductus arteriosum
41
Which structures are connected by the ductus venosus?
Umbilical vein and IVC
42
Which substance causes the ductus venosus to close at birth?
Bradykinin
43
What is the adult remnant of the umbilical vein?
Ligamentum teres
44
Which primitive structure gives rise to the kidneys?
Urogenital ridge
45
Which structure is the collecting system of the kidney derived from?
Ureteric bud
46
Which structure is the excretory system of the kidney derived from?
Metanephric blastema
47
Where are accessory renal arteries found?
Pelvis
48
Which vessel would a horseshoe kidney be found underneath?
Inferior mesenteric artery
49
Which structure originally drains the urinary bladder in the foetus?
Allantois
50
What is the remnant of the allantois called?
Urachus
51
In adults, what is the name given to the remnant of the urachus?
Median umbilical ligament
52
What structure is formed by the mesonephric (Wolffian) ducts in men?
Ejaculatory ducts
53
What causes the mesonephric ducts to degenerate in women?
Lack of testicular androgens
54
Which structure arises from the 1st pharyngeal cleft?
External auditory meatus
55
What does the first pharyngeal arch form?
All the muscles innervated by the trigeminal nerve
Maxilla, zygoma, temoral bone
Maxillary artery
Malleus, incus
56
Which embryological arteries are associated with the second pharyngeal arch?
Stapedial artery
Hyoid artery
57
Which structures are formed by the cartilage of the second pharyngeal arch? (Reicherts cartilage)
Stapes
Styloid process
Stylohypoid ligament
Upper bost and lessor horns of hyoid
58
Which nerve is associated with the second pharyngeal arch?
Facial
59
Which artery is formed from the third pharyngeal arch?
Common carotid artery
60
What is formed from the cartilage of the 3rd pharyngeal arch?
Lower bodt and greater horn of hyoid
61
Which nerve is associated with the third pharyngeal arch?
Glossopharyngeal
62
Which muscle is formed from the third pharyngeal arch?
Stylopharyngeus
63
Which arteries are formed from the 4th pharyngeal arch?
Right - proximal portion of subclavian artery
Left - aortic arch
64
Which structured are formed from the cartilage of the 4th pharyngeal arch?
Laryngeal cartilages
65
Which nerve is associated with the 4th pharyngeal arch?
Superior laryngeal branch of the vagus
66
Which arteries are formed by the 6th pharyngeal arch?
Right - proximal pulmonary arteries
Left - ductus arteriosus
67
Which nerve is associated with the 6th pharyngeal arch?
Recurrent laryngeal branch of the vagus
68
Which structures are derived from the 1st pharyngeal pouch?
Eustachion tube
Middle ear cavity
69
Which structures are derived from the 2nd pharyngeal pouch?
Lining of the palatine tonsils
70
Which structures are derived from the 3rd pharyngeal pouch?
Dorsal - inferior parathyroid glands
Ventral - thymus
71
Which structures are derived from the 4th pharyngeal pouch?
Dorsal - superior parathyroid glands
Ventral - C cells of thyroid
72
Where are brachial/pharyngeal cysts found?
Anterior border of SCM
73
Which structure in the embryo becomes the anterior pituitary?
Rathke's pouch
74
Which structure in the embryo becomes the posterior pituitary?
Infundibulum
75
Which cells in the alveoli produce surfactant?
Type II pneumocytes
76
Which gene stimulates the primitive sex cords to form testis cords?
SRY gene on Y chromosome
77
Which structure is formed from the testis cords in puberty?
Seminiferous tubules
78
Which cells in the testis cords produce testosterone?
Leydig cells
79
What do the mesonephric ducts become in males?
Efferent ductules
Epididymis
Vas deferens
Seminal vesicles
80
What happens to the paramesonephric ducts in males and why?
Degenerate due to anti-Mullerian hormone produced by sertoli cells in the testes
81
What is the appendix testes a remnant of?
Paramesonephric ducts (Mullerian)
82
What is the remnant of the mesonephric ducts in females?
Gartner's duct
83
What do the paramesonephric ducts form in females?
Fallopian tubes
Uterus
Cervix
Upper portion of vagina
84
What causes bicornuate uterus?
Incomplete fusion of the paramesonephric ducts
85
What causes hypospadias?
Incomplete closure of the urethral folds
86
What is the remnant of the gubernaculum in males?
Scrotal ligament
87
What is the remnant of the gubernaculum in females?
Ovarian ligament
Round ligament of uterus
88
