Cells and tissues of the nervous system Flashcards
where is the CSF produced from?
the choroid plexus in each ventricle
where is the CSF found?
inside the ventricles
between the pia and arachnoid matter
where is the CSF absorbed?
by arachnoid villi and drain into the superior sagittal sinus
what are the different ventricles of the brain?
2 lateral - within each cerebral hemisphere
III -within diencephalon
cerebral aqueduct - within cerebellum
IV - between pons and medulla and cerebellum
is sensory divisions afferent or efferent?
sensory - afferent
motor- efferent
what are th differences between neurones and glial cells?
neurones are excitable - glial cells are non excitable supporting cells
glial cells are much smaller
what does a typical neurone contain in terms of dendrites and axons?
multiple dendrites and 1 axon
what is th difference in the cytoplasm within the cell body of a neurones compared to its axon?
in the cell body = perikaryon
in the axon = axoplasm
cell neurones’ nucleus can divide without mitosis - therefore a neurone is termed as?
amitotic
what increased the conduction speed in axons?
myelin sheath - saltatory conduction
what is the myelin sheath formed by in the PNS and CNS?
PNS = Schwann cell CNS = oligodendrocytes
in what condition is the nerve conduction across axons abnormal and why?
nerve conduction across affected axons are abnormal in multiple sclerosis
nerve conduction is slower in some parts as there is patchy loss/scarring of the myelin sheath
this affects nerve conduction
what does he white matter in the brain consist of?
bundles of myelinated axons called tracts
what does the grey matter in the brain consist of?
neuronal cell bodies
what is a collection of neuronal cell bodies in the CNS and outside the CNS called?
Inside CNS = nucleus
Outside CNS = ganglion
what are the 3 types of neurones and what type of neurones do they carry?
multipolar - motor
bipolar - olfactory mucosa & retinal nerve fibres
pseudo unipolar - sensory
what type of cells are found in abundance in the blood brain barrier and why?
astrocytes
they help in K buffering
what 3 features help make the blood brain barrier a protective mechanism from harmful substances such as amino acids, ions and blood cells?
endothelium has tight junctions
thick basal lamina
foot processes of astrocytes (glial cells)
is the blood brain barrier continuous covering the whole brain?
no
it is absent in a few circumventricular organs such as the thalamus and posterior pituitary
concerning drug delivery the the CNS - what features makes the drugs able to cross the BBB?
drugs have the be lipid soluble or if not use suitable vectors
what part of the brain is responsible for balance and coordination?
cerebellum
what is the brainstem responsible for?
fine tuning of visceral motor innervation -
vital centres such as cardiorespiratory
where do you find ventricle IV ?
posterior of medulla
where do you find the 2 lateral ventricles?
in each hemisphere of the cerebrum
where do you find the cerebral aqueduct?
midbrain
where do you find III ventricle?
cavity within the diencephalon
what is the diencephalon composed of?
the thalamus (80%) and the hypothalamus
what connects the lateral ventricles with the 3rd ventricle?
inter ventricular foramen
what is the CSF absorbed by and how does it circulate?
absorbed by arachnoid vili drains into the superior sagittal sinus
circulates via the venous circulation
what is responsible for maintenance of intracranial pressure?
CSF
What type of cells are oligodendrocytes and schwann cells?
Glial cells
What type of cells surround the blood brain barrier?
Astrocytes (type of glial cell)
What connect the lateral ventricles with the 3rd ventricle?
Interventricular foramen
What is the subdural space?
A potential space which is travelled by blood vessels penetrating into the CNS
What is the function of the arachnoid villi?
They absorb CSF into the superior Sagittal sinus
