Histology of the NS I Flashcards
What is the name of the substance that surrounds the nucleolus of the neuron?
Nissl substance which is chromatophillic
What are sensory neurons?
Afferent neurons that transmit changes in body to the brain
What are interneurons?
They lie between the sensory and motor neurons, process, store and retrieve information
What are motor neurons?
efferent neurones that send signals out to muscles and glands
What kind of neurons do mammals have?
initially bipolar but becomes unipolar as the animal develops
What do multipolar neurons look like?
single axon with many dendrites
they are typically efferent motor neurons
What do multipolar neurons look like?
single axon with many dendrites
they are typically efferent motor neurons
What do multipolar neurons look like?
single axon with many dendrites
they are typically efferent motor neurons
What do neuroglia have an important role in?
important role in neural development, activity, plasticity and recovery from injury
What are the two types of astrocytes?
white matter fibrous astrocytes, long and slender with branched processes
Grey matter protoplamsic astrocytes
What are some of the functions of astrocytes?
They provide support to the neurons via glia fibrils
Immune function
store glycogen and release glucose
What are oligodendrocytes?
small, spherical and densely staining nuclei with few branches
What are microglia?
small, elongated chromophillic nuclei that synthesise and release tropic factors
What makes up the white matter?
Dense accumulation of myelinated axons
/ collection of tracts
What makes up grey matter?
Rich in neuronal bodies, glial cells and neuropil
neuropil= axons
What are the two types of fibres that you may find in the cerebellum?
Climbing fibres and mossy fibres
What makes up the dura matar?
thick collagen bundles and elastic fibres
The inner layer contains flattened fibrocyes
Where is the majority of sensory ganglia located?
located in roots of cranial and spinal nerves
Where do pseudounipolar bifuricate?
They bifuricate into central and peripheral systens
What does neuroglia mean?
‘Brain glue’ they hold all the cells together
What is neuroglia important in?
development, activity, plasticity and recovery from injury
small cells in comparison to neurons- originate from ectoderm
What do the ependymal cells line?
they line the ventricular cavities within the brain and the central canal of the spinal cord
Where is the choroid plexus found?
It is located in the brain ventricles
What is the name of the neuroglia that can transform into macrophages?
Microglia
What is the main role of microglia?
Phagocytic/ autoimmunity
What are pericytes associated with?
Pericytes are associated with capillaries as part of the blood brain barrier
Where are tanycytes found?
In the third ventricle, hence may have a relation to the hypothalamus
Where are neurolemmocytes (Schwann cells) derived from?
They are derived from the neural crest
What part of the brain has a purkinjie cell layer?
The cerebellum
Purkinjie cells are surrounded by basket cells
What is the inner cell layer of the cerebellum?
contains densley packed granule cells
What are the climbing fibres of the cerebellum?
each fibre makes numerous synpases on one dendritic tree
they carry ‘error signals’
What are the mossy fibres of the cerebellum?
connect with the granular cells and feed sensory information to the cerebellum
What part of the brain does not have distinct layers?
The thalamus
What makes up the hippocampus?
Two interlocking sections of grey matter
hippocampus proper, dentate gyrus
How many different sub-regions does the hippocampus have?
It has 4 different sub-regions
What is the function of the brain stem?
cardiovascular and respiratory control (basal body activity)
