Nervous System Flashcards
What are the two types of cells in the nervous system?
- Neurone
- Neuroglial, also known as supporting cells
What is a neurone?
Excitable cells which transmit electrical signals (conductivity)
What is a cell process?
Axons and Dendrites
What is an Axon?
Nerve Fibre
Where are action potentials created?
Axon Hillock
What part of a neurone receives sensory input?
Dendrites
Define irritability
the ability to initiate nerve impulses in response to stimuli
Define Conductivity
The ability to transmit an impulse
Where do axons conduct nerve impulses to?
- Dendrites of another neuron
- An effector organ/tissue of the body
What is a Synapse?
The junction that mediates information transfer from one neurone to another neurone/effector cell
What is an Electrical Synapse?
- Ionic currents spread to next cell through gap junctions
- Two-way transmission
- Capable of synthesising groups of neurones
What is a Chemical Synapse?
- only allows one-way transmission
What is another name for Axon Terminal?
Synaptic Knob
What are some features of Neurotransmitters?
- Can be excitatory or inhibitory
- Present in the CNS and PNS
*
What is the function of an interneuron?
To connect afferent neurons with efferent neurons
True or false: Interneurons are found in both the CNS and PNS
False - they are only found in the CNS
True or false: Afferent and Efferent neurones are only found in the PNS
True
What is a Multipolar Neurone?
- Several Dendrites
- One Axon
- Most common cell type
What is a Bipolar Neuron?
- 1 Main dendrite
- 1 Axon
- Found in retina, inner ear, and olfactory areas
What is a Unipolar Neurone?
- 1 Processor
- Are always sensory neurones
What are characteristics of Neuroglial cells?
- Smaller than Neurones
- Can divide
- 4 types in CNS
- 2 types in PNS
What are the four types of neuroglial cell in the CNS?
- Astrocytes
- Oligodendrocytes
- Microglia
- Ependymal
What are the two types of Neuroglial cell in the PNS?
- Schwann cells
- Satellite Cells
What are five functions of Neuroglial cells?
- Provides a supporting scaffolding for neurons
- Isolate Neurones
- Insulate neurones
- Provide nutrients
- Remove waste
What is Myelination?
- The myelinated sheath is a mulitlayerered lipid and protein covering, produced by schwann cells in the PNS and oligodendrocytes in the CNS, and surrounds the Axon.
What is the function of Myelination?
- Protect the axon
- Electircally insulate/isolte the axons from each other
- Increase speed of nerve impulse transmission
What are and is the purpose of the Nodes of Ranvier?
- Gaps in myelin sheath between adjacent swann cells
- Nerve impulses jump from node to node, meaning an increase in the transmission of the nerve impulse
What is a motor unit?
One motor neurone, and all the skeletal muscle fibres connected to it
What is a neuromuscular junction?
The point where a motor neurone (axon terminal branch) meets the muscle fibre
Why are there fold in the cerebral cortex?
the brain grows faster than it has room for, allows for more information to be stored in the folds
What is the function of the corpus callosum?
It is the bridge which joins the left and right hemispheres of the brain
True or false: The Insula is involved with the limbic system
True
True or false: the Insula is a lobe of the brain
False - it is not a lobe
What are the four different lobes in the brain
- Frontal
- Parietal
- Temporal (x2)
- Occipital
Which lobe contains Motor areas that generate impulses for Voluntary Movement?
Frontal Lobe
Which lobe contains the general sensory areas that generate touch, and cutaneous sensations?
Parietal Lobe
What does the Central sulcus do?
Seperates the Frontal lobe from the Parietal Lobe
Which lobe is the precentral gyrus in?
Frontal
What lobe is the postcentral gyrus in?
Parietal
