Genetics Block I Flashcards
(237 cards)
1
Q
What are the two types of bone developmental processes?
A
- Intramembranous ossification - via mesenchyme w/ pre-existing membrane
- Intracartilagenous ossification via mesenchyme forming a cartilaginous model
2
Q
Which type of bone developmental processes do long bones undergo?
A
Intracartilagenous ossification
3
Q
Which type of bone developmental processes does flat bones of skull, mandible, and clavicle undergo?
A
Intramembranous ossification
4
Q
Skeleton of the face is derived from the neurocranium or viscerocranium?
A
Viscerocranium
5
Q
The protective case around the brain is derived from the neurocranium or viscerocranium?
A
Neurocranium
6
Q
The roof of the neurocranium is formed by which type of bone ossification? (intramembranous or intracartilagenous)
A
Made up of flat bones = Intramembranous
7
Q
The base of the neurocranium (sphenoid, ethmoid, petrous, mastoid, and basilar part of occipital bone) is formed by which type of bone ossification?
A
Intracartilagenous/endochondral ossification
8
Q
The membranous neurocranium (roof/vault) is derived from which embryological structure? (2)
A
- Neural crest cells
2. Paraxial mesoderm
9
Q
Prechordal chondrocranium consists of the ethmoid and sphenoid bone, where do these structures arise from?
A
Neural crest cells
10
Q
Chordal chondrocranium consists of structures that are posterior to the pituitary fossa (petrous bone, base of occipital bone, etc.), where do these structures arise from?
A
Paraxial mesoderm
11
Q
The viscerocranium is derived from which embryological structure?
A
Neural crest cells
Viscerocranium formed mainly via 1st & 2nd pharyngeal arches
12
Q
Craniosynostosis
A
Premature closure of sutures
Scaphocephaly - premature of sagittal
Brachycephaly - coronal
Plagiocephaly - coronal closure on one side only
13
Q
Achondroplasia primarily affects long bones, what type of bone ossification do they undergo?
This is the same for ALL types of skeletal dysplasia (Thanatoporic dysplasia, Hypochondroplasia, Cleidocranial dystosis)
A
Intracartilagenous ossification
14
Q
Cause of hemivertebra
A
Mesenchymal cells from one sclerotome fail to migrate
Absence of 1/2 of vertebra = scoliosis
15
Q
Origin of vertebral arches? Vertebral column and ribs?
A
Sclerotome via paraxial mesoderm
16
Q
Spondylolysis and spondylolisthesis are development processes associated with vertebral arches and the vertebral bodies, where are these derived from?
A
Sclerotome via paraxial mesoderm
17
Q
Bony portion of ribs are derived from where?
A
Sclerotome of the paraxial mesoderm
18
Q
Costal cartilages of the ribs are derived from where?
A
Sclerotome cells that migrate across the lateral somatic frontier into the lateral plate mesoderm
19
Q
Derivation of the sternum?
A
Parietal layer of the lateral plate mesoderm of the paraxial mesoderm
20
Q
Pectus excavatum is when the sternum is sunken posteriorly, where is the sternum derived from?
A
Parietal layer of the lateral plate mesoderm of the paraxial mesoderm
21
Q
Which mesoderm layer is skeletal muscle derived from
A
Paraxial mesoderm
22
Q
Which mesoderm layer is smooth muscle derived from
A
Splanchnic mesoderm surrounding the gut tube
23
Q
Which mesodermal layer is cardiac muscle derived from
A
Splanchnic mesoderm surrounding the heart tube
24
Q
Somitomeres 1,2,3,5 of the mesoderm give rise to what structures?
A
Muscles of the eyeball
25
```
Somitomere 4
Somitomere 6
Somitomere 7
Somites 1,2
Somites 2-5
```
```
4 - muscles of mastication
6 - muscles of facial expression
7 - stylopharyngeus
1,2 - intrinsic laryngeals
2-5 - tongue
```
26
Extensor muscles of the vertebral column are derived from which layer of the myotome?
Epimere of the myotome
27
Anterolateral muscles of the body wall and limbs are derived from which layer of the myotome?
Hypomere of the myotome
28
Poland syndrome is an absence of the pectoral is minor and partial loss of pectoral is major, what are these muscles origins?
Skeletal muscle = Paraxial mesoderm of the myotome
29
Each limb bud contains 3 components, what are they? (ZAS)
Z - Zeugopod --> radius/ulna, tibia/fibula
A - Autopod --> carpals, metacarpals, digits/tarsals, digits/metatarsals
S - Stylopod --> humerus and femur
30
Of the limb mesenchyme, where is the musculature derived from?
Hypomere part of the somite
31
Of the limb mesenchyme, where is the skeleton, blood vessels, and CT derived from?
Parietal layer of lateral plate mesoderm
32
What type of bone ossification occurs for the clavicle?
Intramembranous ossification
33
The skeleton of the upper and lower limbs develop via what bone ossification?
Intracartilagenous ossification via lateral plate mesoderm
34
The earliest arterial supply of the upper limb bud is the ____ and ____
Axis artery and terminal plexus
35
The axis artery gives rise to which upper limb arteries?
First to branch = posterior interosseous, median artery
Last to branch = radial and ulnar arteries
Axis artery persist as the axillary, brachial, anterior interosseous, and deep palmar arch arteries
36
Which UL arteries persist from the axis artery? (4) DAAB on em
Radial artery anastomoses with terminal plexus forming:
1. Deep palmar arch
2. Axillary
3. Anterior interosseus
4. Brachial
37
For LL vasculature, what arteries persist from axis artery? (4) DIPS
1. Distal part of peroneal a.
2. Inferior gluteal artery
3. Proximal part of popliteal
4. Sciatic artery
38
Where does the femoral a. arise from in LL vasculature?
External iliac; femoral a. gives rise to profound femoris a.
39
What initially branches from the axis artery in the LL vasculature?
Anterior and posterior tibial a.
40
What are the 3 derivatives of the dermis?
1. Neural crest cells - dermis in face and neck
2. Paraxial mesoderm - dermis in the back
3. Lateral plate mesoderm - dermis for limbs and body wall
41
Hair is derived from where?
Ectoderm
42
Origin of mammary glands?
Epidermis of the ectoderm
43
Derivation of the epithelial lining and glands of mucosa of the GI tract?
Endoderm; while the remaining is via visceral/splanchnic part of lateral plate mesoderm
44
What are the three divisions of the primitive gut tube?
1. Foregut
2. Midgut
3. Hindgut
45
The ventral mesentery is divided into two parts by the ____ which are ___ and ____
Liver
1. Lesser omentum --> extends from lower esophagus, stomach and upper duodenum to liver
2. Falciform ligament --> to ventral body wall
46
Foregut derivatives? (6)
1. Esophagus
2. Gall bladder
3. Liver
4. Pancreas
5. Stomach
6. Upper duodenum
47
In what rotation does the stomach move?
90 degrees clockwise along the longitudinal axis
48
Liver buds appear as an outgrowth of _______ epithelium at distal end of ______. This also gives rise to what?
endodermal; foregut
Parenchyma of liver and bile capillaries
49
Where does the pancreas develop from?
Endoderm of the foregut tube (duodenum) (both endocrine and exocrine)
50
What are the two pancreatic buds, what do they consist of and where are they located?
1. Dorsal - upper part of head, neck, body, tail - dorsal mesentery
2. Ventral - uncinate process, lower part of head - ventral mesentery close to bile duct
51
The main pancreatic duct of Wirsung is derived from which pancreatic structure?
Distal part of dorsal pancreatic duct and the entire ventral pancreatic duct
52
The accessory pancreatic duct of Santorini is derived from which pancreatic structures?
Proximal part of dorsal pancreatic duct
53
Midgut derivatives
1. Lower duodenum
2. Jejunum, ileum
3. Cecum
4. Vermiform appendix
5. Ascending color
6. Proximal 2/3 transverse colon
54
The primary intestinal loop is divided into what two parts containing what organs?
1. Cephalic/Cranial limb - distal duodenum, jejunum, & upper part of ileum
2. Caudal limb - lower ileum, cecum, appendix, ascending and proximal 2/3 transverse colon
55
Which organ of the midgut is the first to retract into the abdominal cavity?
Jejunum
56
During intestinal looping, which organs lose their mesenteries (pressed against peritoneum of posterior ab wall)? (retroperitoneal)
1. Ascending and descending colon
2. duodenum
3. pancreas
57
During intestinal looping, which organs retain their free mesenteries?
1. Appendix
| 2. Sigmoid colon
58
Hindgut derivatives (6)
1. Distal 3rd t. colon
2. Descending colon
3. Sigmoid colon
4. Rectum
5. Upper anal canal
6. Internal lining of urinary bladder and urethra
59
Derivative of superior 2/3 and inferior 1/3 of anal canal?
1. Superior - endodermal cloaca
| 2. Inferior - ectodermal pit
60
Abnormal process in megacolon (Hirschsprung's disease)?
Abnormal migration of neural crest cells
61
From which mesodermal origin does the urogenital system arise from?
Intermediate mesoderm
62
Which part of the kidney forms the permanent kidney?
Pronephros
Mesonephros
Metanephros
Metanephros
Mesonephros functions for a brief period
63
What structure persists in males to form efferent ductules of testis?
Mesonephric/Wolffian tubules/duct which open into urogenital sinus (cloaca)
-degenerates in females
64
The ureteric bud comes from what kidney structure?
Lower end of mesonephric duct which eventually forms the primitive renal pelvis
65
Describe the formation of the renal pyramids
Renal pelvis via uteric bud (mesonephric duct) splits into 2-3 major calyces
Which divide and form minor calyces and collecting tubules which converge on minor calyx forming renal pyramid
66
List the 4 derivatives of the ureteric bud
Via mesonephros
1. Ureter
2. Renal pelvis
3. Major and minor calyces
4. Collecting tubules
67
List the 4 derivatives of the metanephros
1. DCT
2. PCT
3. LOH
4. Bowman's capsule
68
Renal agenesis occurs in oligohydramnios, what structure fails to develop?
Ureteric bud via mesonephros
69
Renal hypoplasia includes small amounts of renal parenchyma which are derived from which kidney part?
Metanephros
70
Polycystic kidney disease contains cysts that are thought to be caused by:
Failure of union b/w developing convoluted tubules and collecting tubules which arise from the metanephros
71
Horseshoe kidney occurs by fusion of lower poles preventing what process?
Ascent into the abdominal cavity is prevented due to the root of the inferior mesenteric artery where the inferior poles are attached across
72
What are the 3 parts of the urogenital sinus and what do they give rise to?
1. Vesical - urinary bladder (continuous with allantois)
2. Pelvic - prostate, bulbourethral glands & membranous urethra, entire female urethra (paraurethral, urethral glands, vestibular glands)
3. Phallic (definitive urogenital sinus) - penile urethra and vestibule in females
73
Mucosa of the trigone is derived from mesoderm and initially lined with mesoderm, but eventually gets replaced with ______
Endodermal epithelium
74
Where is the muscle and CT of the urinary bladder derived from?
Splanchnic part of lateral plate mesoderm
75
Once the allantois detaches from the bladder, what does it turn into?
Urachus = median umbilical ligament
76
Where is the epithelium of the urethra derived from?
Urogenital sinus - endoderm
77
Female urethra is derived from which germ layer?
Endoderm
78
Exstrophy of the cloaca is caused by a defect of the ____ body wall and occurs from what abnormal function?
Ventral; mesodermal fail to migrate in lower part of abdomen and in perineum (around cloaca)
79
Origin of the cortex of the suprarenal glands
Mesoderm
80
Origin of the medulla of the suprarenal glands
Neural crest cells; eventually get surrounded by the fetal and permanent cortex
81
Once neural crest cells migrate to form suprarenal glands, what do they differentiate into?
Chromaffin cells
82
Sertoli cells originate from?
Mesoderm of seminiferous cords
83
Spermatogonia originate from?
Primordial germ cells - epiblast
84
Leydig cells originate from?
Mesoderm b/w seminiferous cords
85
Follicular cells originate from?
Secondary sex cords; cortical sex cords
86
Oogonia original from?
Primordial germ cells
87
During the dev of paramesonephric/mullerian ducts, the paramesonephric duct crosses mesonephric duct caudally from ventral side, unites at midline forming ______
Uterovaginal primordium which opens into posterior wall of urogenital sinus
88
When the testis secretes Mullerian inhibiting substance (Sertoli cells) what is suppressed?
Paramesonephric ducts
89
What does testosterone (Leydig cells) induce in male genital development?
Mesonephric ducts stimulated
Epididymis, vas deferens, seminal vesicles, external genitalia, penis, scrotum, prostate
90
What are the 2 remnants of the mesonephric ducts in the male?
1. Epididymis
| 2. Vas deferens
91
What are the 2 remnants of the paramesonephric ducts in the male?
1. Appendix testis
| 2. Prostatic utricle
92
Remnant of mesonephric tubules in females
Epoophoron and paroophoron (cranial and caudal tubules) in mesovarium
93
Remnant of mesonephric DUCT in females
Gartner's cyst; a small caudal portion that persist in the wall of uterus or vagina
94
What germ layer covers the tip of the phallus?
Ectoderm; which forms into a solid epithelial cord and forms the external urethral meatus (glandular part of urethra)
95
Where are sperm produced and where do they initially travel to
Seminiferous tubules; epididymis
96
Where does sperm maturation occur?
Epididymis; acquire motility
97
Define capacitation
Occurs in the uterus where the glycoprotein coat is modified and seminal proteins are removed from the surface of the sperm
Only these guys can get to the egg
98
Ovarian cycle is controlled by which two hormones?
FSH and LH
99
Uterine cycle is controlled by which two hormones?
Est & Progesterone
100
If pregnancy occurs, what hormone prevents the degeneration of corpus luteum?
hCG
101
Acrosomal reaction vs. cortical reaction
A - the release of acrosomal enzymes
C - the release of cortical granules from oocyte cytoplasm thus making ZP and oocyte membrane impermeable; keep the multiple sperm bastards out (prevent polyspermy)
102
Where does normal implantation occur?
Posterosuperior wall of uterus by day 7 after fertilization
103
Define placenta previa
abnormal implantation within the lower part of uterus
104
Ectopic pregnancy; which is most common?
What hormone contributes to this?
Implantation outside the uterus; tubal most common
hCG
105
Which trophoblastic layer produces/secretes hCG?
Syncytiotrophoblast = outer layer
| Cytotrophoblast = inner layer
106
Holoprosencephaly and Sirenomelia birth defects can occur as a result of:
Abnormal gastrulation
107
Sacrococcygeal teratoma usually contains tissues derived from all three germ layers, which important process is defected?
Persistence of primitive streak
108
Neural crest cell derivatives
1. DRG
2. Autonomic ganglia
3. Adrenal medulla
4. Schwann cells
5. Pia-arachnoid sheath
6. Skin melanocytes
7. Thyroid parafollicular cells
8. Craniofacial skeleton
9. Teeth odontoblasts
10. Aorticopulmonary septum
109
In the paraxial mesoderm segmentation, which day does the first somite arise and in what region?
Day 20 = occipital region
Day 25 = 17-20 somites
110
In the paraxial mesoderm segmentation, what somitomeres make up the mesenchyme of the head?
Upper 7
111
Fate of somatic layer of the lateral plate mesoderm
Parietal pericardium + pleura + peritoneum
112
Fate of visceral/splanchnic layer of the lateral plate mesoderm
Visceral pericardium + pleura + peritoneum
113
Fate of intraembryonic coelom of the lateral plate mesoderm
Pericardial + pleura + peritoneal cavities
114
What are the two ways in which blood vessels are formed?
1. Vasculogenesis = vessels arise from blood islands
| 2. Angiogenesis = vessels arise from existing vessels
115
What are the two components of the placenta?
1. Decidua basalis = maternal part
| 2. Chorion frondosum = fetal part
116
List the 3 types of decidua
1. basalis = where placenta is to be formed
2. capsularis = separates embryo from uterine lumen
3. parietalis/vera = lining the rest of uterine cavity
117
At what three stages can the zygote split?
1. Two cell = 2 placentas, 2 chorionic sacs, 2 amniotic sacs
2. Early blastocyst (ICM) stage = 1 placenta, 1 chorionic sac, 2 amniotic sac
3. Bilaminar germ disc stage (just before primitive streak) = incomplete ICM division; 1 placenta, 1 chorionic sac, 1 amniotic sac (embryo/fetus remains united)
118
Which cell stage of zygote splitting can cause conjoined twins?
Blaminar germ disc stage = inner cell mass doesn't completely split
119
Derivative of heart endocardium
Endothelial heart tube; blood islands/progenitor heart cells
120
Derivative of heart myocardium
Visceral/splanchnic part of lateral plate mesoderm
121
Derivative of heart epicardium (visceral pericardium)
Visceral/splanchnic mesoderm
122
Left or right bending occurs in dextrocardia?
Left; may coincide with situs inversus (complete reversal of all organs)
123
List the 5 primitive heart tube dilations
1. Truncus arteriosus - aorta & pul trunk
2. Bulbus cordis - smooth part of LV & RV
3. Ventricle - Rough part of LV & RV
4. Atrium - Rough/trabeculated part of LA & RA
5. Sinus venosus - right horn = smooth part RA; left horn = coronary sinus, oblique vein of LA
124
Truncus arteriosus turns into
Aorta and Pulmonary trunk
125
Bulbus cordis turns into
Smooth part of LV and RV
126
Primitive ventricle turns into
Rough/trabeculated part of LV and RV
127
Primitive atrium turn into
Rough/trabeculated part of LA and RA
128
Sinus venosus turn into...
Right horn = smooth part of RA
| Left horn = coronary sinus, oblique vein of LA
129
Derivative of AV valves?
Endocardial cushions of AV canal
While muscular tissue forms cusps, chordae tendineae, and papillary muscles
130
Persistent common AV canal is due to failure of what
Formation/fusion of endocardial AV cushion
Both atrium communicates with both ventricle
131
Foramen primum defect is due to failure of what
AV septum to fuse with septum primum
132
Tricuspid atresia is due to
Insufficient amount of AV endocardial cushion
133
Sinuatrial orific/right venous valve forms
Crista terminalis, IVC valves, and coronary sinus
Eventually fuses with septum secundum, becoming incorporated into interatrial septum
134
Dorsal wall of primitive LA gives rise to
Pulmonary veins
Distal part of pul veins invade developing lung, proximal part gets absorbed into LA and forms its smooth part
135
Primitive atrium persists as?
Left auricle (rough part of LA)
136
Derivative of interatrial septum
Septum primum
| Septum secundum
137
Foramen secundum defect is usually due to?
Excessive resorption of septum primum
Opening b/w RA and LA
138
Muscular derivative of IV septum
Floor of ventricle (bulbo-ventricular cavity)
139
Membranous derivative of IV septum (3)
1. Endocardial cushion of AV septum
2. Right bulbar ridge
3. Left bulbar ridge
140
Persistent truncus arteriosus is primarily due to
Partial/non-development of spiral septum, due to abnormal or non neural crest cell migration
141
Tetralogy of Fallot and transposition of great arteries arise from which abnormal function?
Abnormal neural crest cell migration
142
Right and left umbilical arteries becomes...
Medial umbilical ligament
143
Left umbilical vein becomes...
ligamentum teres
144
Ductus venous becomes...
Ligamentum venosum
145
Foramen ovale becomes...
Fossa ovale
146
Ducuts arteriosus becomes....
Ligamentum arteriosum
147
Derivatives of aortic arches:
| 1,2,3,4,5,6
Make Sure (you) CumIn AndPlay Down (LPADA, RPA)
1 - maxillary artery
2- stapedial artery
3 - proximal = common carotid; distal = internal carotid
4 - left = part of aortic arch; right = proximal part of right subclavian artery
5 - degenerates
6 - left = left pul artery and ductus arteriosus; right = right pulmonary artery
148
Manifestation of abnormal right subclavian artery
Caudal right dorsal aorta and 7th intersegmental artery persist
This artery will cross the midline behind the esophagus to reach the right arm
149
List the branches of primitive dorsal aorta:
Anterior/ventral branch
Lateral branch
Posterior/posterolateral branch
Anterior/ventral = vitelline = celiac, SMA, IMA, umbilical
Lateral = renal, suprarenal, gonadal
Posterior = arteries of UL, LL, intercostal, lumbar, lateral sacral arteries
150
```
List the blood drainage of the following veins:
VUC = YPE
Vitelline
Umbilical
Cardinal
```
Vitelline - blood from yolk
Umbilical - placenta
Cardinal - body wall of embryo
151
Which of the three VUC veins disappears?
Umbilical; becoming the ligament teres hepatic and ductus venosus
152
Derivative of left brachiocephalic vein
Right and left anterior cardinal veins
153
Derivative of SVC
Part of right anterior cardinal vein and right common cardinal vein
154
Left superior vena cava is a result of which two veins being obliterated?
Right common cardinal and anterior cardinal veins
left SVC drains into RA by way of coronary sinus
155
List the drainage of the following veins:
Supracardinal veins
Subcardinal veins
Sacrocardinal v
Supracardinal - body wall via intercostal veins
Subcardinal - developing kidneys (& suprarenal gland and gonads)
Sacrocardinal - lower limb (becomes left common iliac and right common iliac vein)
156
List the 3 derivatives of the IVC
Hepatic segment
Prerenal/renal segment
Postrenal segment
157
Derivative of the hepatic segment of IVC
Proximal part of right vitelline vein
158
Derivative of the pre renal/renal segment of IVC
Right sub cardinal vein
159
Derivative of the post renal segment of IVC
Right sacrocardinal vein
160
Double IVC is caused by what
Persistence of the left sacrocardinal vein
161
What causes the absence of the hepatic segment of IVC?
Right sub cardinal vein fails to make its connection with the liver and shunts blood directly into supra cardinal vein
Blood from inferior part of body drains into RA thru azygous vein
162
Originally there are 6 lymph sacs, what connects them?
Right and left lymphatic ducts creating an anastomosis
163
What eventually occurs with the left and right lymphatic ducts?
Right - most cranial part persists
Left - distal portion = anastomosis, cranial portion = thoracic duct
164
Parietal/somatic layer
adjacent to surface ectoderm
165
Visceral/splanchnic layer
adjacent to endoderm
166
Somatopleure
Parietal layer + overlying ectoderm
167
Splanchnopleure
Visceral layer + underlying endoderm
168
What occurs during ventral body wall defects? What's different w/ omphalocoele?
Ectopia cordis
Gastroschisis
Bladder/cloacal exstophy
Lateral body folds fail to close
Omphalocoele - failure of midgut to return to abdominal cavity
169
What are the contents of the splanchnopleuric mesoderm? (respiratory) CMVC
1. Cartilage
2. Muscle
3. Vasculature
4. CT
170
What is the derivative of the epithelium of the respiratory tree down to the alveolar epithelium, glands?
Endoderm
171
What do the proximal and distal ends of the respiratory diverticulum (from the ventral wall of primitive foregut) turn into?
Proximal - larynx and trachea
Distal - 2 lung buds
Tracheoesophageal ridge separates the respiratory diverticulum from the foregut
172
What are the 4 stages of lung maturation
1. Pseudoglandular (simple columnar)
2. Canalicular (simple cuboidal)
3. Saccular**
4. Alveolar (well developed epithelial endothelial contacts)
173
During which stage of lung development do Type I and Type II pneumocytes develop (i.e. surfactant produced)?
Saccular
174
Derivative of central tendon of diaphragm
Septum transversum via cranial most part of lateral plate mesoderm
175
Derivative of muscular components of the diaphragm
3-5 cervical somites
176
Derivative of crura of diaphragm
Mesentery of esophagus
177
List the 4 components of the diaphragm
1. Central tendon of diaphragm
2. Two pleuroperitoneal folds = diaphragmatic hernias
3. Muscular components = parasternal hernia
4. Crura
178
What days and somites cause closure of the cranial neuropore and caudal neuropore?
Cranial (brain) - 25th day - 18-20 somite stage
Caudal (spinal cord) - 27th day - 25 somite stage
179
List the 3 dilations (primary brain vesicles) PMR
1. Prosencephalon - midbrain
2. Mesencephalon - midbrain
3. Rhombencephalon - hindbrain
180
Prosencephalon divides into what two structures forming what part of the brain?
Telencephalon and Diencephalon = forebrain
181
Rhombencephalon divides into what two structures forming what part of the brain?
Metencephalon and Myelencephalon = hindbrain
182
List the parts of brains where the following ventricles arise from:
1. Lateral ventricle
2. 3rd ventricle
3. Cerebral aqueduct
4. 4th ventricle
1. lateral ventricle = telencephalon
2. 3rd ventricle = diencephalon
3. Cerebral aqueduct = mesencephalon
4. 4th ventricle = Rhombencephalon
183
List circulation of CSF; L34S
Lateral ventricle --> (foramen of Monro) 3rd ventricle ---> (cerebral aqueduct) 4th ventricle --> (foramina of Magendie and Luschka) Subarachnoid space
184
Derivation of Schwann cells
Neural crest cells
185
Derivation of Oligodendrocytes
Neuroepithleial cells
186
Where does the spinal cord terminate in adults?
L1-L2
187
Derivative of pituitary gland
Ectoderm; adenohypophysis = Rathke's pouch = surface ectoderm (upgrowth into oral cavity)
neurohypophysis = down growth from diencephalon
188
Exencephaly
Failure of cranial neuropore to close
189
Derivation of sympathetic and parasympathetic system
1. basal plate of neural tube - preganglioinc fibers
| 2. neural crest cells - ganglion and post ganglionic fibers
190
Derivation of pharyngeal arches
Mesenchyme ventral to cranial end of foregut tube condense and form arches which are covered internally by endoderm and externally by surface ectoderm
Pouches lined by endoderm
191
Which pharyngeal arch degenerates?
V
192
List formations of the pharyngeal arches: 1-6
Make Sure (you) CumIn AndPlay Down
1. maxillary artery
2. stapedial a.
3. common carotid, root of internal carotid
4. left - arch of aorta (middle part) right - rt subclavian a. (proximal part)
5. degenerate
6. pulmonary artery, ductus arteriosus
193
List components of 1st pharyngeal arch
Cartilage - maxillary (part of temporal, zygomatic bone & maxilla) and mandibular process (Meckel's cartilage), malleus and incus
Muscles - mastication, anterior digastric, mylohyoid, tensor tympanic, tensor palatini
194
List components of 2nd pharyngeal arch
Cartilage - stapes, styloid process, stylohyoid ligament, lesser horn and upper part of body of hyoid bone
Muscles - stapedius, stylohyoid, posterior digastric, auricular, facial expression
195
List components of 3rd pharyngeal arch
Cartilage - lower part of the body and greater horn of hyoid bone
Muscle - stylopharyngeus
196
List components of 4th and 6th pharyngeal arch
Cartilage - larynx
Muscle - 4th = pharynx constrictors, cricothyroid, elevator palatine, 6th = intrinsic muscles of larynx
197
Treacher collins syndrome occurs due to under developed zygomatic bones, where does this originate?
1st pharyngeal arch
198
Mesenchyme of craniofacial region and aorticopulmonary septa (spiral septa) originate from what structure?
Neural crest cells
199
DiGeorge syndrome occurs with an absence of the thymus and parathyroid gland, why does this occur?
Failure of differentiation of 3rd and 4th pharyngeal pouches into thymus and parathyroid glands
200
Pharyngeal pouches and clefts are lined by what epithelial tissue?
Pouches - endoderm
Clefts - ectoderm
201
Tongue dev.
What forms medially to 1st arch?
2 lateral lingual swellings (anterior 2/3)
202
Tongue dev.
What separates the lateral lingual swellings?
Tuberculum impar (median tongue bud)
203
Tongue dev.
What forms medial to 2,3, and cranial part of 4th pharyngeal arches?
Copula (posterior 1/3)
204
Tongue dev.
What forms median to the caudal part of 4th arch?
Epiglotic swelling
205
What folds of the tongue develop the anterior 2/3 of it?
Tuberculum impar
| 2 lateral lingual swellings
206
What part of tongue dev. forms the posterior 1/3 of tongue?
Copula
207
What structure separates the anterior and posterior portions of the tongue?
Terminal sulcus
208
Occipital myotomes form what muscular structure?
Muscles of the tongue; 2-5 somites
209
What two prominences make up the upper lip?
Maxillary and medial nasal prominences
210
What prominences make up the lower lip?
Mandibular prominences
211
What prominences make up the nose? FML
1. Frontonasal prominence (bridge)
2. Merged medial nasal prominence (septum & tip)
3. Lateral nasal prominences (alae)
212
How does the primary palate form
When the medial nasal prominences of each side fuse forming the intermaxillary segment
anterior to incisive foramen
213
How does the secondary palate form
Palatine shelves (outgrowths from maxillary prominences) grow medially and fuse
posterior to incisive foramen
214
Define definitive plate
the fusion of primary and secondary palates at the incisive foramen
215
Cleft palate and cleft uvula occur as a result of?
Lack of fusion of the palatine shelves
216
Pigmented and nervous layer of retina are within which layers?
Outer layer - pigmented
Inner - nervous layer
217
Ciliary muscles of the eye are derived from
Neural crest cells
218
Dilator and sphincter papillae muscles of the iris are derived from
Neuroectoderm
219
Inner choroid layer and outer sclera layer are derived from
Mesenchyme surrounding the optic cup
220
External corneal epithelium derived from
Surface ectoderm
221
Substantia propria and corneal endothelium derived from
outer mesenchymal layer
222
Eyelids form by fusion of which two layers
mesenchyme and overlying surface ectoderm with conjunctival sac (ectoderm) in between
223
Coloboma occurs due to what abnormal process
Non closure of choroid/retinal fissure (usually in iris)
224
What makes up the external ear
Auricle
EAM - external acoustic meatus
Tympanic membrane
225
What makes up the middle ear
MIS
| Muscles
226
What makes up the internal ear?
Membranous and bony labyrinthq
227
What epithelial layer does the internal ear derive from
Surface ectoderm
Myelencephalon
228
What two parts does the otic vesicles divide into?
(surface ectoderm)
Dorsal utricular
Ventral saccular
229
What does the dorsal utricular of the ear form?
| SUE
Semicircular canals
Utricle
Endolymphatic duct
230
What does the ventral saccular of the ear form?
| SC
Saccule
| Cochlear duct
231
What tissue epithelium is the middle ear derived from?
Endoderm
232
Which pharyngeal cleft does the external ear arise from?
1st
Epithelial cells at bottom of cleft proliferate and form solid epithelial plate = meatal plug
233
Outer layer of eardrum/tympanic membrane derived from
Ectoderm of 1st pharyngeal cleft
234
Middle layer of eardrum/tympanic membrane derived from
Mesenchymal tissues b/w 1st and 2nd pharyngeal arches
235
Inner layer of eardrum/tympanic membrane derived from
Endoderm of 1st pharyngeal pouch
236
Congenital deafness occurs from damage to inner ear, which is derived from which tissue epithelium?
Surface ectoderm
237
Auricle is derived from which pharyngeal cleft?
1st
