31.01.25 Flashcards
(19 cards)
What is the mesoderm formed from during gastrulation?
Epiblast cells
Mesoderm is formed during the process of gastrulation, which is a critical stage in embryonic development.
What are the two places of signalling during mesoderm formation?
AVE and node
AVE stands for Anterior Visceral Endoderm, and the node refers to the organizer region in the embryo.
What role do FGF4 and FGF8 play in mesoderm formation?
FGF4 repulses mesoderm cells; FGF8 attracts mesoderm cells back to midline
These fibroblast growth factors are crucial in regulating cell movements during early development.
What does the axial mesoderm consist of?
Notochord
The notochord is an embryonic structure that serves as an important signalling center.
What does the intermediate mesoderm give rise to?
Urogenital system
The intermediate mesoderm is crucial for developing structures related to the urinary and reproductive systems.
List the components derived from the lateral plate mesoderm.
- Heart
- Blood vessels
- Blood cells
- Lining of body cavities
- Mesoderm components of limbs except muscles
The lateral plate mesoderm contributes to various structures, including the circulatory system and body cavity linings.
What are the two divisions of the lateral plate mesoderm?
Splanchnic and somatic mesoderm
Splanchnic mesoderm forms the heart while somatic mesoderm contributes to the body wall.
What are somites?
Transient periodical structures
Somites are formed from paraxial mesoderm and play a vital role in segmenting the developing embryo.
What is somitogenesis?
Formation of somites
Somitogenesis involves periodicity, fissure formation, and epithelialization of somites.
What is the significance of periodicity in somitogenesis?
Cyclic expression of gene products, molecular oscillator
The segmentation clock regulates the timing of somite formation.
What is the role of homeobox genes?
Encode homeodomain that binds to DNA and regulates transcription
Homeobox genes are crucial transcription factors influencing developmental processes.
What do Hox genes determine?
Anterior-posterior identity
Hox genes are essential for establishing the body plan along the anterior-posterior axis.
What does the endoderm give rise to during development?
Gut tube
The endoderm is responsible for forming the inner lining of the gut and associated organs.
What is the impact of longitudinal folding on the gut?
Brings regions of the gut into juxtaposition with other tissues and organs
This folding allows for inductive events that stimulate the development of gut-associated organs.
What is neurulation?
Production of the central nervous system
Neurulation involves the formation of the neural tube, which will develop into the brain and spinal cord.
What do neural crest cells give rise to?
Peripheral nervous system, Schwann cells, and melanocytes
Neural crest cells migrate from the neuroepithelium and differentiate into various cell types.
What are the components of early brain development?
- Forebrain (telencephalon + diencephalon)
- Midbrain
- Hindbrain (cerebellum, pons + medulla)
- Spinal cord
These regions develop from the neural tube and are essential for proper brain function.
What determines the identity of hindbrain segments on the AP axis?
Hox clusters expression
Hox gene expression patterns are crucial for the correct segmentation and identity of hindbrain structures.
What factors contribute to dorsoventral patterning in the spinal cord?
- Shh from notochord and floor plate
- Wnts and Bmps from roof plate and surface ectoderm
- Retinoic acid from adjacent somites
These signaling molecules play vital roles in establishing the dorsal and ventral regions of the spinal cord.
