EMBRYONIC DEVELOPMENT OF THE UMBILICAL CORD

 EMBRYONIC DEVELOPMENT OF THE UMBILICAL CORD

At 3 weeks’ gestation, the developing embryo is connected to the chorion by a connective stalk, which contains the developing umbilical vessels and allantois. The primitive gut develops from the yolk sac and is connected, along with vitelline vessels, to the extracoelomic part via the vitelline duct.

As the embryo grows, the amniotic cavity expands, drawing the connective stalk and vitelline duct together with proteoglycan-rich Wharton jelly to form the primitive umbilical cord.

By the 9th week of gestation, the vitelline duct involutes, whereas the allantois obliterates by the 5th month into the urachus, a fibrous structure that connects the urinary bladder to the umbilicus, to leave behind the umbilical cord composed of 2 umbilical arteries and a single umbilical vein supported by Wharton jelly.

Failure of obliteration of allantois and/or the omphalomesenteric duct (OMD) or vessels either completely or partially can lead to congenital disorders of the umbilical cord.

- Lung Function Abnormalities in Bronchial Asthma.

Lung Function Abnormalities in Bronchial Asthma.

Spirometry (in clinic):

• Airflow limitation
• Low FEV1 (relative to percentage of predicted norms)
• FEV1:FVC ratio< 0.80

Bronchodilator response (to inhaled β-agonist):
o Improvement in FEV1 ≥12% and ≥200 mL
Exercise challenge: Worsening in FEV1 ≥15%
Daily peak flow or FEV1 monitoring: day to day and/or A.M.-to-P.M .variation ≥20%.

Ibrahim Samaha

- Understanding Bronchial Asthma Triggers.

 Understanding Bronchial Asthma Triggers.

1. Allergens: 

• Allergen exposures in sensitized individuals can initiate airways inflammation and hypersensitivity to other irritant exposures, and are strongly linked to disease severity and persistence. 
• Consequently, eliminating the offending allergen(s) can lead to resolution of asthma symptoms and can sometimes cure asthma.

- Infantile Colic.

Infantile Colic

• The conventional definition of colic is the Wessel’s "Rule of three" which mandates an otherwise healthy baby "important word" with crying spells that occur for at least 3 h a day, 3 times a wk for 3 consecutive weeks and These infants are typically healthy and thriving well.
• The recently modified definition includes all of the following:

1.  Paroxysms of irritability, fussing or crying that occur without a cause
2. Episodes lasting 3 or more hours per day and occurring at least 3 d per week for at least 1 wk.
3. Absence of failure to thrive.

- Organic Causes of Excessive Crying in infancy.

Organic Causes of Excessive Crying in infancy

Organic diseases account for 5 to 10% of infants presenting with incessant crying.
1.CNS:
– CNS abnormality (Chiari type 1)
– Infantile migraine
– ↑ICP (trauma, hydrocephalus, intracranial hemorrhage, Mass)
– Seizure
– Meningitis
– Encephalitis
2. Eyes, Ears, Nose, Throat:
– Choanal atresia
– Otitis externa
– Otitis media
– Corneal abrasion
– Glaucoma
– Teething
– Gingivostomatitis
– Thrush
– Foreign body
3.Cardiac:
– Tachyarrhythmia e.g SVT
– myocarditis,
– congestive cardiac failure
4.GI:
– Constipation
– Cow’s milk protein intolerance
– GERD
– Lactose intolerance
– Gastrointestinal obstruction (intussusception, volvulus, pyloric stenosis, Hirschsprung disease)
– Anal fissure
– Strangulated Hernia
– Abdominal trauma
– Peritonitis 
5.Respiratory:
– Airway obstruction (croup, foreign body)
– Upper respiratory tract infection
– Lower respiratory tract infection (pneumonia, bronchiolitis)
6. Genitourinary System:
– Testicular torsion
– Ovarian torsion
– Urinary tract infection
– Tight phimosis
7.Musculoskeletal system:
– Infection ( septic arthritis, Osteomyelitis)
– Fracture limbs.
– Others—pulled elbow, caffey’s disease
8.Skin:
– Cellulitis
– Impetigo
– Tourniquet syndrome (extremities, penis, clitoris)
– Dermatitis (e.g Napkin)
– Insect bites
– Minor injury
9.Other causes:
– Narcotic Withdrawal Syndrome
– Drugs (ephedrine, amphetamine, clonezepam, antihistaminics)
– Vaccine reaction
– Inborn error of metabolism
– Sepsis
– Sickle cell crisis
– Physical abuse

- Clinical grades of stridor.

Clinical grades of stridor.

1.Grade 1 (Exertional stridor) :
Stridor appears during crying or exercise.
2.Grade 2 (Continuous stridor or stridor at rest) : 
Stridor is present at rest & become worse with exertion.
 3.Grade 3 (Stridor with retractions) : 
Stridor is continuous & accompanied with suprasternal& supraclavicular retractions. The patient looks anxious, irritable, struggling for breathing.
4.Grade 4 (Stridor with cyanosis) :
 In addition to continuous stridor & retractions, cyanosis& altered consciousness occur denoting severe respiratory failure. ET intubation may be considered.

- Newborn with Focal colonic fits.

Newborn aged 3 days delivered by Caesarean section with history of perinatal asphyxia and prolonged resuscitation and need intubation in delivery room admitted into our NICU on mechanical ventilator and show right upper limb colonic fits.