Embryology Flashcards
16 cell morula what day
3
hatches what day
5
- what establishes the Dorsal/Ventral Axis?
- what establishes the Cranial/Caudal Axis?
- BILAMINAR DISC formation
- PRIMITIVE STREAK formation
Notochord serves as the basis for the development of what?
the AXIAL SKELETON
(paraxial mesoderm)
when is Primitive Utero-Placental Circulatory system formed?
- what forms Primary Chorionic Villi?
- what forms Secondary Chorionic Villi?
- what forms Tertiary Chorionic Villi?
DAY 13
- PRIMARY Chorionic Villi: CYTOTROPHOBLAST grows into the SYNCYTIOTROPHOBLAST
- SECONDARY Chorionic Villi: EXTRAEMBRYONIC MESODERM grows into primary villus
- TERTIARY Chorionic Villi: EMBRYONIC BLOOD VESSELS FORM in villus
when is the Placenta formed with materno-embryonic exchanges taking place?
end of 4TH WEEK
when is Gastrulation
WEEK 3
when is Neurulation
WEEK 3 & 4
when does the Cranial Neuropore close?
when does the Caudal Neuropore close?
CRANIAL: DAY 25
CAUDAL: DAY 28
Epidermis is derived from which layer?
Dermis is derived from which layer?
- EPIDERMIS: SURFACE ECTODERM
- DERMIS: PARAXIAL MESODERM
(dermis of back)
Somites (paraxial mesoderm) determine the Migration pattern of what
NEURAL CREST CELLS & SPINAL NERVE AXONS
when is Folding of the Embryo
WEEK 4
Hepatocytes origin:
Kupffer and Haematopoietic cells origin:
Hepatocytes: ENDODERM (FOREGUT)
- induced by Cardiogenic mesoderm
Kupffer and Haematopoietic cells: MESODERM
MOST OF LIVER FROM ENDODERM
but some parts from MESODERM
when does INSULIN secretion begin
5TH MONTH
(but Islets of Langerhans formed at 3 Months)
Lung Bud / Respiratory Diverticulum is an outgrowth of what
FOREGUT ventral wall
(4 weeks)
Cartilaginous, Muscular and Connective Tissue components of the Lungs, Trachea and Ovaries are derived from what?
SPLANCHNIC MESODERM
when do Pharyngeal Arches appear
DAY 24
Pharyngeal Arch 1
cranial nerve:
artery:
derivative:
- MANDIBULAR ARCH
TRIGEMINAL NERVE
MAXILLARY ARTERY
Muscles of mastication, skull bones etc
Pharyngeal Arch 2
cranial nerve:
artery:
derivative:
- HYOID ARCH
FACIAL NERVE
HYOID & STAPEIDAL ARTERY
Muscles of Facial expression, Reichert’s cartilage, lesser horn of hyoid
(most of hyoid)
Pharyngeal Arch 3
cranial nerve:
artery:
derivative:
GLOSSOPHARYNGEAL NERVE
COMMON & INTERNAL CAROTID ARTERIES
NECK STRUCTURES
GREATER HORN, INFERIOR BODY of HYOID BONE
Pharyngeal Arch 4
cranial nerve:
artery:
derivative:
VAGUS NERVE
AORTIC ARCH & RIGHT SUBCLAVIAN ARTERY
THYROID CARTILAGE
(NECK STRUCTURES)
Pharyngeal Arch 6
cranial nerve:
artery:
derivative:
VAGUS NERVE
PULMONARY ARTERIES
CRICOID CARTILAGE
(NECK STRUCTURES)
when do you have 42-44 pairs of Somites by
END 5TH WEEK
- when is Primordial Heart present and pumping Blood?
- when does it separate into Atria and Ventricles?
- DAY 26
- DAY 28
