[C] 1.67 Main forms of developmental anomalies

Question 1

Groups of the developmental anomalies

Answer 1

• Blocking of development (defect)
• Facilitated development
• Heterotopia

Question 2

Groups of the developmental anomalies:

• Blocking of the development

Answer 2

• Agenesia
• Hypoplasia
• Oligodactylia; oligodontia
• Schisis
• Atresia
• Stenosis
• Nanosomia

Question 3

Agenesia

Answer 3

• Failure of all parts of an organ to develop during embryonic development
• Many forms of agenesis are lethal such as absence entirely of the brain

Question 4

Hypoplasia

Answer 4

• Underdevelopment or incomplete development of a tissue or organ
• Similar to aplasia but less severe
• Radial hypoplasia in cats

Question 5

Oligo-

Answer 5

Deficiency of different organs

E.g oligodactylia (deficiency of digits)

Question 6

Schisis

Answer 6

Splitting of the different organs or tissues

E.g Abdominschisis or cleft palate

Question 7

Atresia

Answer 7

• Body orifice that is abnormally closed/absent
• Imperforate anus
  
  • ​Defect where the rectum is malformed and closed

Question 8

Stenosis

Answer 8

“Stricture”

• Abnormal narrowing in tubular organ or structure
• “Coarctation” used to describe the aorta

Question 9

Nanosomia

Answer 9

Dwarfism

• A person of short stature

Question 10

Facilitated development: Types

Answer 10

• Duplicitas
• Hypersomia
• Heterotopia

Question 11

Facilitated development: Duplicitas

Answer 11

Polydactyly / polydactylism

• Congenital physical anomaly having an increased number of fingers/ toes

Question 12

Facilitated development: Hypersomia

Answer 12

Gigantism

• Being of abnormally large size

Question 13

Facilitated development: Heterotopia

Answer 13

• Normal tissue that is present at an abnormal site

or

• Displacement of an organ/part of an organ from its normal position
• E.g Grey matter heterotopia - Displacement of grey matter into the cerebral white matter*

Question 14

Monsters

Answer 14

• Foetuses with marked morphologic anomalies during intrauterine development
• Either die in utero or shortly after birth

Question 15

Monstra simplicia (Solitary monster)

Answer 15

• Partial/complete agenesis of lumbar, sacral & coccygeal vertebrae
• Spinal cord & ankylosis of the hindlimbs
• Malformation of the musculature

Question 16

Cyclopia

Answer 16

• Characterised by the failure of the embryonic prosencephalon
• Face is either missing or replaced with a non-functioning nose in the form of a proboscis

Question 17

Rhinencephaly/Rhinocephaly

Answer 17

• Proboscis appears above the central eye
• The characteristic form of cyclopia
• One optic lobe, only optic nerve, one olfactory lobe

Question 18

Cyclopia can be caused by…

Answer 18

Cyclopamine

• Found in the plant Vertrum californicum

Question 19

Monstra duplicia (Duplex monsters)

Answer 19

• When zygote doesn’t split properly
• Fetus has some body parts once and others twice

Question 20

Dulicitas completa

Answer 20

Double complete monsters

Question 21

Dulicitas incompleta

Answer 21

Double incomplete monsters

Question 22

Craniophagus

Answer 22

Double complete monsters joined at the head

Question 23

Xiphpagus

Answer 23

Double complete monsters joined at the xyphoid region

Question 24

Thoracopagus

Answer 24

Double complete monsters joined at the thorax

Question 25

Pyopagus

Answer 25

Double complete monsters joined at the sacral region

Question 26

Duplicitas symmetros anterior incompleta

Answer 26

One body with two heads

Question 27

Duplicitas asymmetros

Answer 27

Assymetrical double monsters

• Size not identical
• “Autosita”* = “Host” (Larger)
• “Parasita”* = “Parasite” (Smaller)