Nervous System Flashcards
what are the two major divisions of the nervous system?
Central and Peripheral Nervous System
What is myelin made from in the brain and spinal cord?
Oligodendrocytes
What is the name of the pathway that goes towards the CNS?
Afferent
What is the name of the pathway that goes away from the CNS, to effectors?
Efferent
what are glial cells?
cells which surround the soma, axon and dendrites, providing physical and metabolic support
What are different types of glial cells?
- Astrocytes
- Microglial cells
- Ependymal cells
What are Astrocytes?
Cells that regulate extracellular fluid by removing potassium and neurotransmitters
What is myelin made by in the PNS?
Schwann cells
What are microglial cells?
Specialised macrophage like cells
What are Ependymal cells?
Regulate the flow of cerebrospinal fluid in fluid filled cavities
What is the name of a group of axons which link the right and left halves of the CNS
A commissure
What are the cell bodies of neurons with similar functions in the PNS called?
Ganglia
What are the cell bodies of neurons with similar functions in the CNS called?
Nuclei
What are the 4 regions of the CNS in the brain?
Cerebrum, diencephalon, brainstem and cerebellum
What is gray matter composed of?
- Interneurons
- Cell bodies and dendrites of efferent neurons
- Axons of afferent neurones
- glial cells
From what side of the spinal cord do afferent fibres enter the spinal cord?
Dorsal side
On what side of the spinal cord do efferent neurons leave the spinal cord?
Ventral side
How many pairs of nerves does the PNS have?
43
What are the 43 pairs of nerves in the PNS broken down into?
12 pairs of cranial nerves
31 pairs that connect with the spinal cord as spinal nerves
What are the 31 spinal nerves of the PNS broken down into?
- 8 Cervical
- 12 Thoracic
- 5 Lumbar
- 5 Sacral
- 1 Coccygeal
What is the efferent division of the PNS divided into?
Somatic and Autonomic branches
What is the autonomic nervous system responsible for?
Innervation of tissues other than skeletal muscle, like smooth or cardiac muscle
Explain how the autonomic nervous system pathway is made of 2 neurons instead of 1.
Preganglionic Neuron synapses with Autonomic Ganglion, which synapses with postganglionic neuron
What is the autonomic nervous system divided into?
Sympathetic and Parasympathetic
Which neurotransmitter is released between the post-ganglionic neuron and the effector cell in the parasympathetic pathway?
Acetylcholine
Which neurotransmitter is released between the post-ganglionic neuron and the effector cell in the sympathetic pathway?
Norepinephrine
What is a short phrase used to summarise the type of responses controlled by the sympathetic nervous system?
Fight or Flight Response
What is a short phrase used to summarise the type of responses controlled by the parasympathetic nervous system?
Rest or Digest (Mostly Homeostatic responses)
What is the difference in distribution of charged particles either side of a membrane referred to as?
Electrochemical gradient
What is the term used to describe the movement of electrical charge?
Current
What is the resting membrane potential of a cell?
-70mV
What difference is there between graded and action potentials in terms of the distance they can signal/
AP = long GP = short
What is the magnitude of change of membrane potential in an action potential?
100mV, from -70 to +30
What is the main difference between an action potential and a graded potential?
Graded potentials vary in magnitude and only signal over short distances. Action potentials are ‘all or nothing’ and signal over long distance
if a synapse is a gap junction what kind of synapse is it?
Eletrical Synapse
If a synapse is a synaptic cleft, what kind of synapse is it?
Chemical synapse
How does release of neurotransmitter work in synapses?
Neurotransmitter stored in vesicles are released into the synaptic cleft from active zones due to influx of calcium ions
What are the two kinds of post synaptic potential that Chemical synapses can generate?
excitatory and inhibitory
What are the two types of synaptic summation?
Temporal and Spatial
What is temporal summation?
Summation of potentials from the same axon that come shortly after one another which results in depolarisation past the AP threshold
What is spatial summation?
Summation of potentials from 2 or more axons that collectively result in depolarisation past the AP threshold
