embryogenesis 7 Flashcards
There are two types of neurulation, what are they
Primary - proliferation and the closure of the tube through separation,
Secondary - condensation of the mesenchyme into a chord which then develops a lumen.
Give an overveiw of the neurulation process
Pulling down of the neural plate till a chasm is formed. This creates the neural folds. The sides then lift up and pinch together forming the neural tubes.
Describe gastrulation in the process of neurulation.
Gastrulation to the neurulation continues in an anterior to posterior gradient.
Neurulation complete in the head, gastrulation just starting in the tail of the chick embryo
describe the primitive streak location
caudally with the node at its most cranial end
describe the head folds
Cranial to the node they elevate and form the basis for the embryo.
Closure of the neural tube is critical for:
Cell proliferation
Cell motility
Cell shape
Cell adhesion (cadherins)
the surface ectoderm does what
Epidermis, hair, Nails, Sebaceous glands, olfactory epithelium, mouth apithelium, lens, cornea.
the mouth epithemilum deviates into what
anterior pituitary, tooth enamel, cheek epithelium
the neural crest deviates into what
Peripheral nervous system, Adrenal medulla, Melanocytes, Facial Cartilage, Dentine of teeth.
the periheral nervous system develops into
Schawann cells, Neuroglial cells, Sympathetic nervous system, parasympathetic nervous sytem.
the nerual tube develops into what
Brain, neural pituitary, spinal cord, motor neurons, retina
describe the three phases of Neurulation
neural plate, neural folds, neural tube
list the three primary vesicles of which develops into the central nervous system
forebrain, midbrain, hindbrain
list the five secondary vesicles of which develops into the central nervous system
Telencephalon, Diencephalon, Mesencephalon, Metencephalon, Myelencephalon
what does the telencephalon derivative into in the adult CNS
Olfactory lobes
Hippocampus
Cerebrum
what does the Diencephalon derivative into in the adult CNS
Optic vesicle, Epithalamus, Thalamus, Hypothalamus
what does the Mesencephalon derivative into in the adult CNS
Midbrain
what does the Metencephalon derivative into in the adult CNS
Cerebellum, Pons
what does the Myelencephalon derivative into in the adult CNS
Medulla
what does the Eye develop from
the eye is an outgrowth of the diencephalon
describe regionalisation in the CNS development
the developing forebrain is defined by the gene expression boundaries
Summary of CNS regionalisation
Summary is the cortical development is produced from a strict pattern, the neurons are born in the Ventricular Zone (VZ) and migrate to their destination along the radial glial processes. The adult cortex is a 6 layered structure which is generated from in ‘inside to outside’ manner (cortical lamination)
describe Pax6 and Emx2 role in CNS regionalisation
Pax6 and Emx2 determine the specific aerial identities.
Pax 6 is rostral
Emx2 is caudal.
The spatial arrangement of these expression determine the borderder in the specific cortical regions
