chapter 1: development, composition & evolution of the nervous system Flashcards
neurons
transfer information rapidly from one part of the body to another
nervous system =
all neurons + their supporting cells
communicative function of neuron
- conduction of a signal from one part of the cell to another
- synaptic transmission: communication between adjecent cells
impulse =
actionpotential
wave of electrical depolarization that is propagated within the surface of te membrane
CNS =
brain stem + spinal cord
gray matter =
cell bodies of neurons
inside spinal cord and outside brain
white matter =
region that contains axons but not neural cell bodies
outside spinal cord and inside brain
development of the meninges
3 layers
pia mater
–> subarachnoid space with CSF
arachnoid
dura mater
main regions of the CNS
- spinal cord
- medulla oblongata
- pons
- midbrain
- cerebellum
- diencephalon
- telencephalon (= cerebral hemispheres)
development of the nervous system
neurulation
(3indications)
1st indication: neuroectoderm consisting of neural plate
2nd indication: neural plate -> neural groove & neural fold
3rd indication: neural groove -> neural tube
development of the nervous system
neural crest =
cells at junction between neural plate and ectodermal cells
will form dorsal root ganglia of spinal cord
development of the nervous system
formation of the brain and spinal cord during 4th and 5th week after fertilazation
end of 4th week: primary brain vesicles: - prosencephalon = forebrain - mesencephalon = midbrain - rhombencephalon = hindbrain during 5th week: secondary brain vesicles: - telencephalon - diencephalon - mesencephalon - metencephalon - myelencephalon
development of the nervous system
further development of the brain
telencephalon --> cerebral hemispheres diencephalon --> thalamus mesencephalon --> midbrain metencephalon --> pons and cerebellum myelencephalon --> medulla oblongata
development of the nervous system
the ventricular system
rises from lumen of neural tube
- lateral ventricle
- third ventricle
- fourth ventricle
- cerebral aqueduct (connects 3rd and 4th ventricle)
development of the nervous system
flexures in the neural tube
help to accomodate the brain to become a round head
- cevical flexure
- mesencephalic flexure
- pontine flexure
