Embryology Flashcards
What process causes a unilateral cleft lip
Incomplete fusion of the nasolabial muscle rings (maxillary and medial nasal processes)
Describe Brown sequard syndrome
Hemisection of the cord producing ipsilateral loss of proprioception and upper motor neurone signs, plus contralateral loss of pain and temperature sensation. The explanation of this is that the fibres decussate at different levels.
At which level will spinal cord lesions present with lower motor neuron signs
Below L1
What is the function of spinothalamic tract
Pain and temprature of contralateral side of body (decussates at level of spine root)
Describe the dorsal column medial lemniscus pathway function
- fine touch, vibration and propriocpetion ispsilaterally as it decussates in medulla
How does cleft palate occur?
Cleft palate occurs as a result of non fusion of the two palatine shelves.
Complete cases are associated with complete separation of the nasal septum and vomer from the palatine processes.
Describe the features spinal shock
- Areflexia
- Flaccid paralysis
- Loss of all sensation
- Bladder and bowel dysfunction
- Autonomic dysfunction: hypotension, bradycardia, temperature dysregulation
Where does the meckel’s diverticulum originate from?
Meckels diverticulum is a persistence of the vitello-intestinal duct.
How does an annular pancreas develop
Annular pancreas develops due to failure of the ventral bud to rotate with the duodenum, causing encasement of the duodenum.
What is the most common embryological origin of atrioventricular septal defect
- Endocardial cushion
Failure of which process allows for congenital diaphragmatic hernias to occur?
- Incomplete fusion of the pleuroperitoneal membrane
What is the function of the umbilical arteries
Carry deoxygenated blood from the foetus to the placenta
- Becomes the two medial umbilical ligaments in adults
What are the borders of the triangular space and which structure passes through it?
basically between teres minor and major
- Superior: Teres minor
- Lateral: Long head of triceps
- Inferior: Teres major inferior border
- Circumflex scapular artery + vein
What are the borders of the triangular interval and which structure passes through it?
- Medial border: Long head of the triceps
- Lateral border: Lateral head of the triceps
- Superior border: Teres Major
- Contents: Radial nerve + Profunda brachii artery
When does the gut move back into abdomen during intrauterine development
- 6-10 weeks
