L9+10: nervous tissue Flashcards
(26 cards)
what is nervous tissue made up of ?
neurons and supporting cells
what are the supporting cells in nervous tissue called?
neuroglia
how many pairs of spinal nerves are there in the peripheral nervous system ?
31
what parts make up the brain stem ?
pons , mid brain , and medulla oblongata
what is the largest part of the brain?
cerebrum
what are the 2 cerebral hemispheres of the cerebrum ?
outer layer of grey matter
inner layer of white matter
what is the outer covering of the grey matter over the hemisphere called ?
cerebral cortex
which cerebral hemisphere of the cerebrum contains myelinated nerve fiber and which one contains unmyelinated nerve fibers?
grey matter contains unmyelinated nerve fibers
white matter contains myelinated nerve fiber
what structure is responsible for basic vital life functions such as breathing , heartbeat ,and blood pressure ?
the brain stem
what part of the brain is responsible for voluntary muscular movement , posture and balance?
the cerebellum
what are the 2 divisions of the peripheral nervous system ?
sensory / afferent division and motor/ efferent division
what are the 2 further divisions of the efferent division ?
autonomic and somatic nervous systems
what nervous system do the sympathetic and parasympathetic divisions belong to ?
autonomic nervous system
Nervous system #2
….
what is the function of neuroglia / supporting cells ?
- Phagocytoses
- Forming myelin sheath
- Forming brain barrier
- Producing cerebral spinal fluid (CSF)
do neurons contain centrioles?
no
what is the difference between dendrites and axons ?
dendrites are highly branched and irregular , contain nissl substancce and impulses travel through them towards the cell body
axons are long cylendrical structures without nissl substance and impulses travel through them away from the cell body
where is the axon hillock present on a neuron ?
just below the cell body
describe the cell body (perikaryon or soma) of a neuron .
they have large roubd nuclei with single prominent neucleous and their cytoplasm is abundantly supplied with golgi bodies and lysosomes
they also contain:
nissl substance , neurofibrils , and pigment granules
what is nissl substance ?
granular material composed of rough endoplasmic reticulum
sensory / afferent neurons are typically ____
unipolar
motor/efferent neurons are always ___
multipolar
what cell is responsible for the myelination of peripheral nervous system neurons ?
schwan cells
what cell is responsible for myelination of central nervous system neurons ?
oligodendrocytes
