The Neurological System Flashcards
Describe the classification of the nervous system
Central nervous system
Peripheral nervous system
- Somatic
- Autonomic
What are the 3 functions of the nervous sytem?
Sensory (sensory neurons)
Integrative (interneurons)
Motor (motor neurons)
What’s the difference between the autonomic and somatic NS? Give an example of each
Autonomic
- involuntary
- e.g. detection of blood pressure
Somatic
- voluntary
- e.g. walking
Describe the basic structure of a nerve cell: (4)
Dendrite
Cell body
Axon
Axon terminal
What is the function of dendrites?
Receive signals from surrounding area
What is the function of the cell body?
Contain all organelles
Neurons can also be categorised by the number of processes extending from the cell body. What are the 3 types of neuron classification?
Bipolar
Unipolar
Multipolar
What is the function of the axon?
Carry nerve signals away from cell body to axon terminal
Clusters of neuronal cell bodies are called:
___ in PNS
___ in CNS
Ganglions in PNS
Nucleus in CNS
Bundles of axons are called:
___ in PNS
___ in CNS
Nerve in PNS
Tract in CNS
What is the difference between white and grey matter?
White - primarily myelinated axons
Grey - neuronal cell bodies, un-myelinated axons and neuroglia
What is the function of Glial Cells (neuroglia)?
Type of cell that provides physical and chemical support to neurons and maintain their environment
What are 2 differences between glial cells and neurons?
- Glial cells don’t generate or propagate action potential
- Glial cells can multiply divide. Nerve cells can’t
What is the structure and function of astrocytes?
- Star shaped, branched.
- Found between neurons and blood vessels (anchor them together)
- maintain blood brain barrier
- create framework on CNS
- repairing neural tissue
- control interstitial environment
What is the structure and function of oligodendrocytes?
- found aligned along thick nerve fibres
- provide the myelin sheath around axons within brain and spinal cord
- form internodes
- small gaps in between (nodes of ranvier)
What is the structure and function of microglial cells?
- phagocytize bacterial cells and cellular debris
- transform into specialised macrophages
- lengthy thorn-like processes which touch neurons to monitor their health
- move towards injured or abnormal neurons
What are the the 4 types of CNS neuroglia?
- Astrocytes
- Ependymal cells
- Microglial cells
- Oligodendrocytes
What are the two types of PNS neuroglia?
- Satellite cells
- Schwann cells
What is the structure and function of Schwann cells?
- from a myelin sheath around axons
- repair damaged nerves (through Wallerian generation)
What is the structure and function of Satellite cells?
- similar function to astrocytes in CNS
- surround neuronal cell bodies
- assist in regulating the external chemical environment (through material exchange between cell bodies and interstitial fluid)
Plasticity of the nervous system describes it’s ability to:
Change based on experience
PNS neurogenesis is possible if: (2)
- cell body remains intact
- schwann cells remain active
CNS neurogenesis is almost-non existent due to (2):
- the inhibitory influence of oligodendrocytes
- absence of growth stimulating cues
Describe function of the blood-brain-barrier?
- acts to selectively allow certain molecules to pass and keep others from reaching brain
- maintain constant internal environment of brain
Describe structure of blood brain barrier
- three layers:
1. capillary wall endothelium
2. thick basal lamina
3. bulb-like feet of astrocytes
What is saltatory conduction?
The way an electrical impulse skips between nodes of ranvier
What is the function of the myelin sheath? (2)
- increases axonal conduction velocity
- reduces capacitance of axonal membrane (amount of charge that can be stored)