Developmental Diseases: Morphology Flashcards
Failure of closure of Fetal Grooves and Fissures
A defect in closure of the neural tube. Resulting conditions can include anencephaly, encephalocele, and spina bifida resulting in failure of formation of the overlying dorsal portion of the vertebra.
Types include meylomenigeocele, meningocele, spina bifida occulta
Failure of Closure of Fetal Grooves and Fissures:
Spina Bifida
A neural tube defect resulting in spinal cord malformation and failure of formation of the overlying dorsal portion of the vertebra.
Spina Bifida occulta:
there is a bony change in one or more vertebra, but it does not affect nerves withing the spinal column.
Severe Microencephaly with Meningoencephalocele
This is one manifestation of a neural tube defect
Hard Patale, Cleft
“Cleft palate”
“Palatoschisis”
Ectopic cordis
Duplications:
Diphagus
Two jaws
Polydactyly
Additional Digits
Con-joined Twins (-pagus)
-pagus = suffic for con-joined twins, idicating fixed or united
Cephalothoracopagus
Fusion of hte head and thorax of conjoined twins
Parapagus
Con-joined twins taht lie side-by-side with ventrolateral fusion
Dicephalic parapagus
Lack of coordination of growth and dfferentiation
Development is a highly corrdinated process where cells must grow, undergo apoptosis, and differentiate n an orchestration and well defined sequence
Holoprosencephaly
Failure of proper differentiation of the embryonic forebrain(prosencephalon)
Features vary widely from microencephaly, hydrocephalus, facial anomalies, and clefts, cyclopia, single upper incisor
Schistosomus reflexus
A syndrome with multiple malformations including:
- Spinal inversion
- Ventral midline abdominal viscera
- arthrogryposis/ankylosis
- Hypoplasia of the diapragham and lungs
Variable features include cleft sternum and exposure of thoracic viscera, scoliosis, and digestive urogenital defects
Amorphous Globosus
A spherical fetus that lacks differentiation of phenotypic body parts.
Inner part of the mass consists of various degrees of differentiation of mesodermal and ectodermal tissues
Developmental Disease: Morphology
Musculoskeletal system examples:
Amelia
Hemimelia
Arthrogryposis
Chondrodysplasia
Osteopetrosis
Limb Aplasia (Amelia)
Absence or near absence of a limb or limbs
Hemimelia
The absence of all or part of the distal part of the limb
Hemivertebra
Half of the vertebral body fails to form, often resulting in a wedge-shaped vertebra.
Common cause of scoliosis
Scoliosis
Lateral deviation of the spine
Sideways curvature
Kyphosis
Dorsal/ventral deviation of the spine - Hunchback
Arthrogryposis
Flexure or contrature of a joint
Syndactyly
Conjoined digits
Brachygnathia
Shortening of the mandible relative to the maxilla
Prognathia
Lengthening fo the mandible relative to the maxilla
Chondrodysplasia
Abnormal development of cartilage.
This results in short long bones and spine (dwarfism)
It is a normal phenotypic trait in certain dog breeds.
Osteopetrosis
A disorder characterized by increased bone density and abnormal bone remodeling (Due to decreased osteoclast dysfunction)
Although thickened, the bone is fragile and predisposed to fractures
Excess bone can compress normal structures and tissues
Developmental Diseases:
Morphology:
Nervous system examples
Anencephaly
Microencephaly
Hydrocephalus
Hydranencephaly
Anencephaly
A neural tube defect where all or part of the brain and skull are absent
Microcephaly
The head is smaller than normal, often a smaller incompletely developed brain
Hydrocephalus
Excessive fluid in the ventricles of the brain.
Gyri and sulci are still present on the cerebrum.
Hydranencephaly
Failure of formation of parts of the cerebrum
Gyri and Sulci are typically not present
Developmental Diseases:
Morphology:
Cardiovascular System
Patent Ductus arteriosus
Septal defects
Aortic/pulmonic stenosis
Tetralogy of Fallot
Aortic and Pulmonary Stenosis
A narrowing of the aortic or pulmonary valves which restricts blood flow.
Ventricular hypertrophy will be a secondary event.
Patent Ductus Arteriosus
The ductus arteriosus, connecting the aorta and pulmonary artery, doesnt close after birth, allowing oxygenated blood in the aorta to flow back into the pulmonary artery/lungs, creating excessive blood flow into the lungs
Truncus Arteriosus
Failure of separation of the aorta and pulmonary artery, resulting in a single common vessel, with a single common valve
Tetralogy of Fallot
4 defects
A combination of pulmonic stenosis, ventricular septal defect, orverriding aorta and right ventricular hypertrophy
Overriding Aorta the aorta is shifted slightly to the right and lies directly above the ventricular septal defect, receiving blood from both the right and left ventricles
Ventricular Septal defects
Incomplete formation of the interventricular septum.
Resulting in holes that allow communication between the right and left ventricles
Developmental Disease:
Morphology:
Reproductive System
Intersex conditions
Segmental hypoplasia or aplasia
Freemartins
Hermaphrodites
Individuals with both ovarian and testicular tissue and ambiguous external genitalia.
Chromosomes have both male and female components.
Pseudohermaphrodites
individuals with mismatched reproductive organs and external genitalia
Named for the reproductive parts the have, not on external genitalia
Freemartinism
Twining of a heifer and a bull calf, in which there has been sharing of a common bood supply.
The male hormones inhibit female reproductive tract development.
Uterus, Segmental aplasia/hypoplasia
Developmental Disease:
Morphology:
Integumentary System
Epitheliogenesis imperfecta
Ichthyosis
Hypotrichosis
collagen dysplasia
Epitheliogenesis imperfecta
Absence of epithelium is discrete areas of the skin and mucosa, most often present over the distal extermities.
These defects can also occur in the oral cavity and tongue
Hypotrichosis
A reduction in the amount of hair
Collagen Dysplasia
A group of diseases of the connective tissue that results in reduced strenght of the affected structures.
Cutaneous asthenia
Ehlers-danlos-like syndrom
Osteogenesis imperfecta
Ichthyosis
A term for a group of conditions characterized by thick, dry scaling skin, which sometimes resembles “fish scales”
