EMBRYOLOGY

• Embryological Anatomy
• Embryological Physiology
• Embryological biochemistry

• युग्मज (zygote )
  • द्वि कोशिकीय युग्मज ( क्स 2 celled )
  • 4 celled (4 क्स )
  • 8 celled (8 क्स )
  • 16 celled (16 क्स )
    • जननपूट (blastocyst - क्सः )
    • जननगुहा ( blastoceol - ह,अः)
    • outer cell mass ( क )
      • पोषज ( trophoblast )
        • कोशिकापोषज (cytotrophoblast - क्र )
        • बीजपोषक संकोशिका (synctiotrophoblast - कृ )
    • भ्रूणीय ध्रुव (Emrbyonic pole - किं )
      • अवभ्रूणीय ध्रुव ( Abembryonic pole - कुं )
      • Mural trophoblast (कों )
    • भ्रूणज ( inner cell mass / embryoblast - स)
      • अधिःज ( epiblast - श )
        • उल्वीय गुहा ( amniotic cavity - शः )
        • उलवज ( amnioblast )
          • ectoderm
            • आद्य रेखा ( Primitive streak )
              • आद्य मंडली , आद्य गांठ (Primitive knot / node / hensens node )
                • जनन छिद्र ( blastopore )
                  • आद्य पृष्ठरज्जु नाल ( notochordal process )
                    • आद्य तंत्राशय नली (neurenteric canal )
                    • तंत्रिक शिखर ( neural crest )
                    • development of nervous system
      • अधःज ( hypoblast - ष )
        • पीतक थैली (yolk sac - षः)
        • heuser membrane (पीतकज )
          • endoderm
            • प्ररज्जु पत्तल / आद्य पत्तल ( Prochordal plate / primitive plate )
            • development of digestive system
            • development of respiratory system
      • मध्यत्वक, मध्यज ( mesoderm - स ) derived from ingressing epiblast cells
        • paraxial ( परअक्षीय - )
          • extends from primitive streak to prechordal plate
            • extends to otic vesicle of hind brain
              • post otic part undergoes segmentation in to cubical blocks
                • अनुकाय , कायखंड ( Somites ) or , अनुकायांश ( somitomeres ) , metameres by transverse clefts
                  • 44 pairs develop
                    • first 4 pairs called occipital somites
                      • form skull
                    • 8 cervical
                    • 12 thoracic
                    • 5 lumbar
                    • 5 sacral
                    • 8-10 coccygeal
                    • (sclerotome)
                      • अक्षीय कंकाल ( axial skeleton )
                        • development of skeletal system
                        • vertebral column
                        • ribs
                    • (dermato-myotome)
                      • lateral (dermatome) plate
                        • त्वचा ( dermis of skin )
                      • medial muscle plate
                        • अक्षीय मांस - पेशी (axial muscles)
                        • muscles of tongue
                        • diaphragm
                        • trunk
                        • अंगीय मांस पेशी ( limb muscles )
              • rostral/ beak part remains unsegmented
                • develop base of skull
        • Intermediate ( अंतरामध्य )
          • upper cervical and thoracic regions show segmentation
          • lower segments are unsegmented
            • Nephrogenic cord
              • development of urogenital system
              • development of reproductive system
        • Lateral ( पार्श्व )
          • continuous with pericardial bar cephalic to buccopharyngeal membrane
          • pericardial bar
            • pericardial sac
          • series of clefts appear inside
            • join to form
              • intraembryonic coelom
              • u shaped tubular passage
              • divides mesoderm
                • somatic layer with overlying ectoderm
                  • somatopleure
                    • body wall
                    • parietal layer
                    • skeletal elements
                      • pectoral girdle
                      • pelvic girdle
                • splanchnic layer with underlying endoderm
                • Splanchnic layer
                • gut
            • splanchnic mesoderm
              • development of circulatory system
    • बाह्य भ्रूणगुहा ( extraembryonic coelom )
    • बाह्य मध्यत्वक ( extramebryonic mesoderm )
      • आद्यकायिक मध्यजनस्तर ( Somatopleuric mesoderm )
      • आद्यआशय मध्यजनस्तर ( Splanchnopleuric mesoderm )
      • ग्रसनी चाप
    • PRIMITIVE POSTURE OF EMBRYO
      • the first folding of embryo to reorganize the organ locations
        • cardiogenic area , pericardial sac , septum transversum

• आद्य गर्त ( Primitive pit )
• आद्य खात ( Primitive groove )
• आद्य स्थंभ / पृष्ठरज्जु ( notochord )

• decidua ( माँ )
  • decidua basalis पाती आधार
  • decidua parietalis पाती पार्श्‍व
  • decidua capsularis पाती संपुट

• fertilization

• morula
• blastocyst

CLEAVAGE The two cells formed as described above undergo a series of divisions. One cell divides first so that we have a 3 cell stage of embryo followed by 4 cell stage , a 5 cell stage etc. This process is called cleavage.

Subdivisions of cleavage

• Stage of compaction : at 8 celled stage
• Morula
• Blastocyst : between 4th and 5th day

GERMINAL PERIOD

• Development of cardiovascular system
• Development of respiratory system
• Development of nervous system
• Development of urogenital system
• development of gastrointestinal tract
• development of skeletal system
• Development of face