Lecture 19 Nervous Tissue I Flashcards
The neural plate is composed of what type of epithelium?
Simple columnar epithelium
In the neural plate, cell shape is maintained by:
Microtubules
In the neural folds, columnar cell shape changes to:
wedge cell shape
In the neural folds, the shape change is due to:
actin filaments
The wedge shape of cells in the neural fold causes:
Flattened neural plate to bend
Neuroepithelial cells from embryonic neuroectoderm give rise to _____.
neuroblasts
Neuroblasts give rise to _____ of the central nervous system (brain and spinal cord).
Neurons
______ _______ cells are derived from the neuroectoderm and give rise to neurons and neuroglial cells of the peripheral nervous system
Neural Crest Cells
Pseudostratified epithelium
Ventricular zone
Intermediate zone
Ventricular zone
made up of ventricular cells
Intermediate zone
Area of destruction of excess neurons via apoptosis
Cortical plate (mantle layer)
Postmitotic neurons
Future gray matter (cell bodies, dendrites, and unmyelinated axons)
Marginal Layer
Axons
Future white matter (myelinated axons
Characteristics of Nerve Tissue
Irritability
Conductibility
Irritability
Specialized to receive stimuli
Conductibility
Specialized to transmit impulses
Cellular components of Nerve Tissue
Neurons
Neuroglial cells
Neurons
Conduct impulses
Fundamental structural and functional unit of the nervous system
Neuroglial Cells
Nonconductive cells that support and protect the neurons
Parts of the neuron
Cell body (soma)
Dendrites
Axon
Characteristics of the cell body of a neuron
Contains nucleus
Nissl bodies
Extensive RER and elaborate Golgi structures
Abundant mitochondria
Abundant microtubules and intermediate filaments
Lipofucsin granules formed from lysosomes & accumulate with age of neuron
Ligand-gated channels and local potentials