Cells of the Epidermis: Keratinocytes: Origin and Location: Derived from ectoderm, present in all layers of the epidermis (90-95% of all epidermal cells). Characteristic Features: Rich in intermediate filaments called…
Layers of the Cerebellar Cortex
Layers of the Cerebellar Cortex: Molecular Layer: Outermost layer. Contains stellate cells and basket cells. Functions: Receive excitatory input from parallel fibers. Form inhibitory synapses on Purkinje cells. Appearance: Pale…
DiGeorge Syndrome
DiGeorge Syndrome: Cellular immunodeficiency disorder caused by deletion of a segment of chromosome 22 (22q11), affecting endodermal derivatives of the third and fourth pharyngeal pouches. Clinical Features (Remembered by CATCH):…
Remnants of Embryonic Parts
Embryonic Part: Ductus arteriosus Remnant: Ligamentum arteriosum. Embryonic Part: Umbilical artery Remnant: Proximal part becomes the superior vesical artery; Distal part forms the medial umbilical ligament. Embryonic Part: Umbilical vein…
Derivatives of Aortic Arches
First Aortic Arches: Arterial Structures: Part of maxillary arteries bilaterally. Second Aortic Arches: Arterial Structures: Stapedial and hyoid arteries bilaterally. Third Aortic Arches: Arterial Structures: Common carotid arteries and proximal…
Gastroschisis & Omphalocele
Gastroschisis: Characteristic: Defect typically located on the right side. Defect Size: 2-3 cm. Sac: Never present. Gestational Age: Prematurity. Umbilical Cord: Adjacent to the defect. Herniated Viscera: Small bowel, stomach,…
Embryology of the ear
Derived from 1st Pharyngeal Groove: External Auditory Meatus Derived from 1st Pharyngeal Arch: Auricle or Pinna Malleus and Incus Derived from 2nd Pharyngeal Arch: Stapes Suprastructure Stapes Footplate and Annular…