The Nervous System Flashcards
What are the 4 cell types found in the adult CNS?
Pericytes, Ependymal cells, oligodendrocytes, Microglia
What does the white matter of the CNS contain? (3 things)
Myelinated axons. descending and ascending fibre tracts.
What does the grey matter of the CNS contains? (5 things)
Interneurons, cell bodies, dendrites (of efferent neurons), synapses and glia.
What are the three types of glial cells in the CNS?
Astrocytes, oligodendorcytes, and microglial cells.
What is the choroid plexus?
It is a plexus (network) of cells that produces the cerebrospinal fluid in the ventricles of the brain.
What does the choroid plexus consist of?
Modified ependymal cells.
What two pieces of information about the health status of the nervous system does the cerebrospinal fluid provide (CSF)?
1) It detects and provides information about the presences of lymphocytes of bacteria as indicative of infection or an autoimmune disease (e.g. multiple sclerosis)
2) it detects and provides information about the levels of protein as indicative of a ‘leaky’ choroid plexus.
How many pairs of nerve does the PNS contain and what are they sub-divided into?
The PNS contains 43 pairs of nerves.
Sub-divided into: 12 pairs of cranial nerves and 31 pairs of spinal nerves.
What is the enteric nervous system and what is its function?
It is a meshwork of neurones that innervates gut muscles.
It plays a role in peristalsis, and infection and hyperactivity of the autonomic nervous system.
What are the 4 types of spinal nerves?
Cervical nerves, thoracic nerves, lumbar nerves and Sacral Nerves.
What type of neurons are pre-ganglionic and post-ganglionic sympathetic neurones?
Pre-ganglionic - cholinergic (release acetylcholine).
Post-ganglionic - noradrenergic (releases adrenaline).
What effect does the release of acetylcholine towards the adrenal medulla have?
It causes the release of adrenaline from the adrenal medulla.
How is the human brain formed?
It is formed from disproportionate growth and flexure of the neural tube during embryonic development.
i.e. the forebrain (cerebral cortex) becomes the largest part of the CNS and ‘obscures’ other parts of the brain.
What are the 4 main subdivisions of the brain?
The medulla oblongata, Cerebellum, Thalamus and Hypothalamus.
What is the function of the Medulla Oblongata, cerebellum, Thalamus and Hypothalamus.
MO = controls involuntary function (e.g. breathing, blood pressure) Cerebellum = controls the coordination of movement and balance. Thalamus = controls awareness and states of arousal. Hypothalamus = controls homeostasis.
What is the function of the Limbic System?
It function to control basic emotion, olfaction and the processing of memories (via the hippocampus)
What are the two hemispheres of the brain connected by?
The are connected by the corpus callosum.
What is the function of the cerebral cortex?
It plays roles in sensory analysis, motor coordination, language and intellect.
Where is the Somatosensory Cortex located at what is its function?
It is located in the parietal lobe of the cerebral cortex.
It function the analyse inputs from mechanoreceptors, thermoreceptors and nocireceptors (pain).
Which part of the cerebral cortex in involved in the articulation of speech?
Broca’s area.
Which part of the cerebral cortex in involved interpretation of spoken language?
Wernicke’s area.
What is the major neurotransmittor of the CNS?
Glutamate.
What are the effects of the neurotransmitters GABA and Glycine?
They cause the opening of Chlorine ion channels, which results in hyperpolarisation of the membrane potential (generation of IPSPs).
Which drug acts as a sedative by modulation the effects of GABA and how?
Benzodiazepines act by enhancing chlorine ion conductance.
Which amino acid is serotonin derived from?
Tryptophan.
