Lectures Embryo

Front 1

Imperforate hymen

Back 1

failure of inferior end of vaginal plate to perforate [hematocolpos -accumulation of menstrual blood in the vagina]

Front 2

Double Uterus (uterus didelphys)

Back 2

failure of fusion of lower parts of the paramesonephric ducts

Front 3

Bicornuate uterus with rudimentary horn

Back 3

[growth of one paramesonephric duct is retarded]

Front 4

Unicornuate uterus

Back 4

one paramesonephric duct fails to develop

Front 5

Female Hermaphroditism

Back 5

exposure of female fetus to excessive androgens e.g. congenital adrenal hyperplasia -androgens from the adrenal gland

Front 6

Androgen insensitivity syndrome

Back 6

[1 in 20,000] –lack of androgen receptors [androgens are ineffective in inducing growth of male genitalia]
•MIS is present [mullerian duct degenerates],
•Usually 46XY, external appearance of female,
•X linked disorder

Front 7

Hypospadias

Back 7

-Abnormal urethral orifices on the ventral surface of penis
-Failure of URETHRAL FOLDS to unite results in abnormal urethral orifices on the ventral surface of penis

Front 8

Epispadias

Back 8

-urethra opens on the dorsal surface of penis
-delelopmental defect in the spongy urethra

Front 9

Rickets

Back 9

•Vitamin D deficiency leads to impaired calcium absorption by the intestine
•The resulting calcium deficiency causes disturbance in ossification of epiphysial plates
–Short & deformed limbs

Front 10

Achondroplasia

Back 10

•Premature fusion of epiphyses
–Short stature
–Bowed limbs
–Short trunk
–Enlarged head
•Mutation of the complementary DNA in the fibroblast growth factor receptor 3(FGFR-3) gene on chromosome 4p

Front 11

Syndactyly

Back 11

•Cutaneous syndactyly
–Webbing of the digits
•Osseous syndactyly
–Fusion of the bones

Front 12

Polydactyly

Back 12

•Supernumerary digits
•Common anomaly
–1:1000
•Disruption of the anteroposterior pattern

Front 13

Congenital Club Foot

Back 13

•Talipes equinovarus
•Foot is turned medially and inverted

Front 14

Amelia

Back 14

–Complete absence of limbs
–Suppression of limb bud development in the 4thweek

Front 15

Meromelia

Back 15

–Partial absence of limbs
–Disturbance of limb development during 5th week
-Inhibits FGFsat the AER
-Thalidomide causes this
-Thalidomide still used as a sedative and antinauseant.

Front 16

Cleft Hand & Cleft Foot

Back 16

•Absence of one or more central digits
–Failure of development of one or more digital rays
•Remaining digits are partially or completely fused
•Rare anomaly
–Lobster-claw deformities

Front 17

Amniotic Band Syndrome

Back 17

•Tears in the amnion result in amniotic bands
•May encircle fetal limbs & digits
–Ring constrictions
–Amputations
•Cause unknown
–May be due to infection

Front 18

Congenital detached retina

Back 18

Abnormal development of the Optic cup

Front 19

Coloboma

Back 19

-keyhole pupil
-Results due to a failure of closure of the retinal fissure

Front 20

Congenital aniridia

Back 20

(absence of iris) It is a rare anomaly due to an arrest of development at the rim of the optic cup.

Front 21

Congenital aphakia

Back 21

(absence of lens) is a rare anomaly due to failure of lens placode to form.

Front 22

Congenital cataract

Back 22

Lens appears white and opaque at birth.
Maternal rubella infections cause this anomaly.

Front 23

Persistent hyaloid artery

Back 23

Sometimes remnants of the hyaloid canal or artery can be seen as floats which may interfere with vision.

Front 24

Microphthalmia

Back 24

Small eye due to arrested development. May be caused by rubella infection.

Front 25

Anophthalmia

Back 25

Complete absence of eye. Eyelids are present.
May be associated with other craniocerebral defects.

Front 26

Cryptophthalmos

Back 26

Hidden eye occurs due to a failure of development of palpebral fissure. The eye ball is smaller defective and lies beneath the skin.

Front 27

Branchial Cyst (lateral cervical cyst)

Back 27

Failure of the second pharyngeal groove and the cervical sinus to obliterate.

Front 28

Branchial Sinus

Back 28

Failure of the second pharyngeal groove and the cervical sinus to obliterate resulting in an opening in the outside neck or into the pharynx.

Front 29

Branchial Fistula

Back 29

Persistence of the second pharyngeal groove and second pouch, causing a canal between the tonsillar sinus and the outside neck

Front 30

Treacher Collins Syndrome

Back 30

-A First arch syndrome
Failure of neural crest migration into the first arch
Micrognathia
~50% cleft palate
Underdeveloped zygoma
Conductive hearing loss
Malformed pinna
“Drooping” lateral part of lower eyelid

Front 31

Robin Sequence

Back 31

-A First arch syndrome
1) Micrognathia or retrognathia (variable etiology)
2) Glossoptosis (tongue in pharynx -causes airway obstruction and blocks palatal shelves)
3) Cleft palate
Problems with feeding and respiratory distress
May “outgrow” in some cases (cleft palate remains)

Front 32

DiGeorge anomaly –CATCH 22

Back 32

•Cardiac anomalies: conotruncal
•Abnormal face
•Thymichypoplasia/aplasia
•Cleft palate
•Hypocalcemia (parathyroid)
•Psychiatric disorders Catch 22
•Deletion in long arm of chromosome 22
•Faulty migration of neural crest
•Mainly 3rd and 4th pouch
•Exposure to retinoids, alcohol & maternal diabetes mellitus

Front 33

Lingual cyst

Back 33

Failure of closure of the proximal part of the thyroglossal duct

Front 34

thyroglossal fistula

Back 34

-Cystic remnant of the thyroglossal duct, may open to the exterior
-Usually in the midline, 50% close to the hyoid bone

Front 35

Anencephaly/Meroanencephaly

Back 35

-Only a rudimentary brain develops.
•Skull is not formed
•Brain tissue is disorganized and exposed to the amniotic fluid which causes necrosis / degeneration
•Rudimentary brain stem is usually present
•Meroanencephaly is a milder form of anencephaly
Etiology: Failure of rostral neuropore to close.
Tests: Ultrasound or elevated alpha-fetoprotein
Prevention: Folic acid

Front 36

Cranium Bifidum

Back 36

•Defect in the formation of cranial vault usually in the midline
•Often in the occipital bone including foramen magnum but can occur in the frontal and nasal bones
•Approximately 1 in 2000 births

Front 37

Cranium Bifidumwith Meningocoele

Back 37

Swelling contains meninges & CSF

Front 38

Cranium Bifida with Meningoencephalocoele

Back 38

Swelling contains meninges, CSF & brain

Front 39

Cranium Bifidum with Meningohydroencephalocoele

Back 39

Swelling contains extensions of meninges, CSF, brain and ventricle

Front 40

Holoprosencephaly

Back 40

-Failure of forebrain cleavage
-small forebrain, lateral ventricles may merge to form one.
-Other midline structure abnormalities –facial anomalies due to smaller frontonasal prominence [ e.g. single eye, single nasal cavity, single incisor teeth]
Etiology: Defect in Sonic Hedgehog gene.
-Alcohol, maternal diabetes, genetic factors etc.

Front 41

Hypotelorism

Back 41

Absent nose (associated with Holoprosencephaly)

Front 42

Cyclops

Back 42

One eye (associated with Holoprosencephaly))

Front 43

Microcephaly

Back 43

•Abnormally small calvaria and brain but normal size face.
•Underdeveloped brain leads to severe neurological defects
•Genetic and environmental factors
–Viruses
–Ionizing radiation
–Drugs: Fetal Alcohol Syndrome

Front 44

Arnold-Chiari Malformation

Back 44

Inferior displacement of the cerebellum though the foramen magnum
Presentation: Headache, fatigue, difficulty swallowing, dizziness, nausea, difficulty in speech, and/or a diminished gag reflex.
Complication: Obstructive hydrencephaly. Damage to CN IX, X, and XII.

Front 45

Craniopharyngiomas

Back 45

usually benign and sometimes functional tumors may develop from remnants of the hypophysial diverticulum (pouch).

Front 46

Hydrocephaly`

Back 46

Excessive CSF in the brain causing enlargement of the ventricles.
Obstructive-block in CSF flow.
Communicating- no obstruction, overproduction or under absorption of CSF
Presentation: Enlarged head, downward gaze, vomiting, and/or seizures

Front 47

Diseases associated with Sonic Hedgehog

Back 47

-HOLOPROSENCEPHALY
-medulloblastoma: cancer in the cerebellar granule neuron precursors
-basal cell carcinoma: skin cancer

Front 48

Diseases associated with Uncontrolled maternal diabetes mellitus

Back 48

•Macrosomia (big baby syndrome)
•CNS
•Heart
•Skeletal

Front 49

Diseases associated with Mechanical Factors Mechanical (Oligohydramnios, amniotic band formation, etc)

Back 49

•Clubfoot
•Cong. Dislocation of hip
•Constrictions
•Amputations

Front 50

Trisomy21 (Down syndrome)

Back 50

-Major cause of mental retardation
-Linked to advanced maternal age
-No treatment for CNS impairment

Front 51

Trisomy 13 (Patau syndrome)

Back 51

• Severely malformed and mentally retarded
• Poor prognosis

Front 52

Congenital rubella syndrome

Back 52

Cataracts, cardiac defect and loss of hearing

Front 53

Syphilis

Back 53

-hydrocephalus, deafness, mental retardation, malformed teeth, sabnormalities in mild cases
-Prevention : antenatal serological screening and treatment with penicillin

Front 54

Toxoplasmosis (Toxoplasma gondii)

Back 54

-an intracellular parasite.
-Transmission: eating raw or undercooked meat or contaminated vegetables and fruits; from contaminated cat feces; transplacental infection.
-Chorioretinitis, hydrocephalus, intracranial calcifications, convulsions.

Front 55

Cytomegalovirus

Back 55

microcephaly, hydrocephalus, microphthalmia, hearing loss, mental retardation, intrauterine growth retardation

Front 56

Herpes simplex virus

Back 56

skin vesicles and scarring, chorioretinitis, hepatomegaly, thrombocytopenia,"", hemolytic anemia, hydranencephaly

Front 57

Varicella(chickenpox)

Back 57

cutaneous vesicles and scars, neurological anomalies, ocular and urogenital defects , microcephaly

Front 58

ISOTRETINOIN (Accutane- Vit. A –retinoic acid )

Back 58

•Birth defects (high risk)
•Miscarriage
•Premature birth
•Neonatal death

Front 59

FAS (Fetal alcohol spectrum disorder)

Back 59

Indistinct philtrum, thin upper lip, depressed nasal bridge, short nose, mental retardation

Front 60

Cocaine

Back 60

Neurodevelopmental problems, cardiac anomalies, preterm birth, placental abruption.

Front 61

Sacrococcygeal teratoma

Back 61

•Primitive streak remnants(pluripotent cells)
•Contains tissues from all three germ layers
•Prenatal diagnosis (ultrasound,AFP)

Front 62

Auricular sinuses / pits /

Back 62

Common and nonpathological. May indicate other anomalies.
Etiology: Remnants of the 1st pharyngeal grooves.

Front 63

Rudimentary auricle (MICROTIA)

Back 63

-Ear is small and mal-formed.
- results from suppressed development of the auricular hillocks.

Front 64

Preauricular appendages (skin tags)

Back 64

-Results from the development of accessory hillocks

Front 65

Atresia or Absence of the External Auditory Meatus

Back 65

Failure of central cells of meatal plug to canalize]

Front 66

Median cleft upper lip

Back 66

-Failure of fusion of the two medial nasal processes to form the intermaxillary segment
•Rare
•Usually associated with varying degree of loss of midline structures e.g. holoprosencephaly, single incisor teeth, nasal septum absent, single eye

Front 67

Unilateral cleft upper lip

Back 67

Failure of fusion of left maxillary prominence with the intermaxillary segment [medial nasal prominences

Front 68

Bilateral cleft upper lip

Back 68

Failure of both maxillary prominences to fuse with the intermaxillay segment

Front 69

Oblique facial cleft

Back 69

-Failure of maxillary prominence to fuse with lateral nasal process
-Nasolacrimal duct is visible.

Front 70

Anterior Cleft Palate

Back 70

Failure of fusion between secondary and primary plate.
May also include upper lip and gum clefts.

Front 71

Posterior Cleft Palate

Back 71

Failure of fusion of the secondary plates and the nasal septum.
Cleft goes from incisive fossa to the soft palate.
Can be unilateral or bilateral to the nasal septum.

Front 72

Trigonocephaly

Back 72

Symptoms: metopic ridge, depressed temporal regions and orbital hypotelorism (eyes closer together than usual).
-Occurs when METOPIC SUTURE closes early

Front 73

Scaphocephaly

Back 73

-Elongated and wedge-shaped cranium
-Occurs when SAGITTAL SUTURE closes early

Front 74

Brachycephaly

Back 74

-High, tower-like cranium
-Occurs when CORONAL SUTURE ON BOTH SIDES closes early

Front 75

Plagiocephaly

Back 75

-Cranium is twisted and asymmetrical
-Occurs when CORONAL SUTURE ON ONE SIDE closes early