Cells And Tissues Of The Nervous System Flashcards
How does the sympathetic signalling reach the head
Through blood vessels (e.g. sweat on head and neck)
What are neurons
Structural and functional unit (multiple dendrites, one axon)
Excitable cells
Impulses carried as action potentials
Travel in one direction, from cell body to synaptic terminal
What are glial cells
Non-excitable supporting cells
Much smaller than neurons
What structures are part of the CNS
Brain and spinal cord
What structures are part of the PNS
Cranial and spinal nerves
What can the PNS be divided into
Sensory (afferent) division
Motor (efferent) division
- motor can be further divided in somatic motor and autonomic
- autonomic can be further divided into sympathetic and parasympathetic
What forms the myelin sheath in PNS and CNS
PNS = Schwann cells
CNS = oligodendrocytes
What is the difference between white matter and grey matter
White matter = myelinated axons
Grey matter = neuronal cell bodies
What are the different types of neurons (3) - give an example of each
Multipolar (interneurons + motor neurons)
Bipolar (olfactory mucosa + retinal nerve fibres)
Psedounipolar (sensory neurons)
What are fibre pathways called
Tracts
What is a collection of neuronal cell bodies called in the brain
Nucleus
What is a collection of neuronal cell bodies called in the PNS
Ganglion
What is the role of the blood brain barrier
Protective mechanism helping to maintain a stable environment for the brain - maintains homeostasis in brain parenchyma
(Prevents harmful amino acids, ions, blood cells from entering the brain)
What do drugs have to be to pass blood brain barrier
Lipid soluble or use suitable vector
Where do the lateral ventricles lie
Cerebral hemispheres
What connects the lateral ventricles with the 3rd ventricle
Interventricular foramen
Where is the 3rd ventricle
Cavity within diencephalon
What connects the 3rd ventricle to the 4th
Cerebral aqueduct (in the midbrain)
Where is the 4th ventricle
Behind the Pons + medulla and infront of cerebellum
What are the 3 meninges from outer to inner
Dura matter
Arachnoid matter
Pia matter
Where is cerebrospinal fluid present
Fluid inside the cavity of the brain (ventricles) and CENTRAL CANAL OF SPINAL CORD
Also present surrounding the brain and spinal cord in between layers of meninges (between pia and arachnoid layers)
Where is CSF formed
By choroid plexus in each ventricle
Where is CSF absorbed (where does it go)
By arachnoid villi into sagittal sinus (venous channel in brain)
How does CSF circulate
Secreted by choroid plexus, enters subarachnoid space, absorbed by arachnoid villa
