Embryology Flashcards
Tissues formed from mesoderm
Muscle
Cardiac muscle
Kidney
Bone
Cartilage
Adipose
Circulatory system
Lymphatics
Dermis
Dentine of teeth
GU system
Testes
Serous membranes
Spleen
Notochord
Tissues formed from ectoderm
The surface ectoderm develops into: epidermis, hair, nails, lens of the eye, sebaceous glands, cornea, tooth enamel, the epithelium of the mouth and nose.
Note: The anterior pituitary develops from the ectodermal tissue of Rathke’s pouch.
The neural crest of the ectoderm develops into: peripheral nervous system, adrenal medulla, melanocytes, facial cartilage.
The neural tube of the ectoderm develops into: brain, spinal cord, posterior pituitary, motor neurons, retina.
Tissues formed from endoderm
Pharynx
Oesophagus
Stomach
SI
Colon
Liver
Pancreas
Bladder
Epithelial trachea and bronco
Lungs - develop from GI tract
Thyroid
Parathyroid
Development of CV system
3rd week- formation of the primitive heart tube
Angiogenic cells
Suspended in pericardial membrane
From superior to inferior, the primitive heart tube is comprised of six regions:
Aortic roots (Arterial poles)
Truncus arteriosus
Bulbus cordis- ventricles
Ventricle
Atrium
Sinus venosus (Venous poles)
Bulbus cordis moves- ventrally, caudally and right
Ventricles- move dorsally, cranially and left
First organ in embryo beginning to function - beating in 4th week
Septum primium forms in 4th week
What does sinus venous form
Atrium and Coronary sinus
What does the bulbs cordis form
Aortic vestibule of left ventricle
Formation of fossa oval
Fusion of septum primum and secundum
Location of fossa ovals
Posteromedial wall
What does urethra develop from
Cloaca
What ducts give male vs female
Wollfian (mesonephric)- male
Connect primitive kidney to cloaca under testosterone
Mullerian - female
Cause of cleft lip
Incomplete fusion between medial nasal process and maxillary
Cause of cleft palate
Failure of fusion between palatine process
Migration of test phases
1st- abdo to internal ring - gubernaculum thickens and shortens anchoring
2nd to scrotum - gubernaculum responds to testosterone - grows migrating through canal
What does the allantois become
Evagination of handout and becomes urachus
What forms the uterus
Mullerian duct
Along with fallopian, cervic, upper vagina
When does gender differentiation occur
Week 8- fully differentiated by 9
Start producing testosterone
What is anencephaly and when does it occur
Failure of cranial neuropore to close around day 25
What forms round ligament
Gubernaculum with is from mesoderm
What tissue origin are the gonads from
Mesoderm
What condition is associated with myelomeningocele
Chiari type 2
Mx of imperforate anus
Sigmoid colostomy then definite repair after 3-6m
Which arch does ductus arteriosus form from
6th
Teenager, well developed breasts and hair, but absence of uterus
Mullerian agenesis
Androgen insensitivity syndrome
X linked
Female genetali
Testes- produce Mullerian inhibiting so no uterus, and Fallopian tubes
If mild- male genetali
When does palate fully form
10w
When does ear form
8w
What makes intubating children more difficult
Larger head
Larger tongue
Cephalic larynx
Shorter trachea
What is hypospadias linked with
Undescended teste
Cleft lip/palate
Congenital heat
Inguinal hernia
% of children not born with fusion of L5/S1 and what they develop
10-15%
Spina bifida occulta
Continuous murmur infraclavicular
PDA
Which structure prevents the ascent of hors how kidney
IMA
When do kidneys develop
6-8w
Partial fusion of Mullerian ducts causes
Bicornate uterus
Cyanotic feet but normal hands
PDA with shunt reversal
As subclavian receives normal O2
External male genitali development depends on
DHT
What happens to foreamen oval at birth
Elevated LA pressure forces septum priumum and secundum together closing it
Where subarachnoid space finishes
S1-3
Hilum terminale continues with Pia mater
Where are vas deferens and prostate developed from
VD- mesonephric
Psostate- ueogenital
When does PDA fully close
2-3 w
Narrows after 12hr
Movement of hindgut on its mesocolon in development
Hinges to the left
Incomplete endocardial cushion fusion defect
AV septal defect
What is associated with oesophageal fistula
Polyhydraminos
What is the embryological equivalent of Batholin glands in men
Bulbourethral - Skenes
When should intervention be considered in undescended teste
6-12m
Which arch is styloid process derived
2nd
Which arch is palatine tonsil derived
2nd
Which arch is the maxilla, zygomatic bone, palatine bone from
1st
Which arch is mallet incus, mockers cartilage and sphenomandibular from
1st
