How do we control ourselves? Flashcards
What are the functions of the Nervous System?
- Maintaining homeostasis
- Receives sensory input
o Internal
o External - Integrating information
- Motor output
- Establish and maintain mental activity
What are the structural divisions of the nervous system?
-Central nervous system (CNS)
o Brain and spinal cord
-Peripheral nervous system (PNS)
o Spinal nerves and cranial nerves
What is a Neuron, Axon, Nerve & Sensory Receptors?
- Neuron (nerve cell): basic structural unit of the nervous system
- Axon: nerve fibre
- Nerve: bundle of axons (or nerve fibres) and their sheaths (outer covering)
- Sensory receptors: separate specialised cells which detect temperature, pain, touch, pressure, light, sound, odour and other stimuli
What is a Action Potential, Effector organ/cell, Ganglion, Plexus and Synapse?
- Action potential: electrical signal
- Effector organ or effector cell: the organ, tissue or cell in which an effect or an action takes place
- Ganglion: collection of cell bodies located outside the CNS
- Plexus: extensive network of axons or cell bodies
- Synapse: junction of a neuron with another cell e.g. end of a neuron with a muscle cell or another neuron
Describe the Autonomic nervous system.
- Involuntary and under subconscious control
- Action potentials in the motor neurons travel from the CNS to smooth or cardiac muscle, or glands
- Two-neuron system
- Cell bodies of the neurons are located in the CNS and autonomic ganglion
Describe the Somatic nervous system
- Voluntary and under conscious control
- Action potentials in the motor neurons travel from the CNS to skeletal muscles
- Single neuron system
- Cell bodies are located in the CNS
What are the cells of the NS (CNS & PNS)
-Neuron
-Neuroglia
CNS
-Astrocytes
-Ependymal cells
-Microglia
-Oligodendrocytes
PNS
-Schwann cells
-Satellite cells
Describe the structure of a Neuron
-Structural unit of the nervous system
-Dendrites
o Dendritic spines
-Cell body (soma)
-Axon
o Axon hillock
o Initial segment
o Trigger zone
o Axon collaterals
o Axon terminal or presynaptic terminal
o Terminal boutons or synaptic knobs
What are the types of neurons in terms of function?
- Sensory (afferent) neuron – information to the CNS
- Motor (efferent) neuron – information away from the CNS
- Inter-neuron – information from one neuron to another neuron
What are the types of neurons in terms of structure?
- Multipolar
- Bipolar
- Unipolar
What are Astroycyte Cells?
- Forming a supporting framework for blood vessels and neurons
- Assists in the formation of tight junctions between endothelial cells of the capillaries
- Respond to tissue damage in the CNS
What are Ependymal Cells?
-Line the central cavities of the brain and spinal cord
What are Microglial Cells?
- Monitor the health of surrounding neurons
- Phagocytose microorganisms, infection, trauma or inflammation
What are Oligodendrocytes?
-Cover axons which forms an insulating sheath around them → myelin sheath
What are Schwann Cells?
- Also called neurolemmocytes
- Form a myelin sheath around axons
- Insulating
What are Satellite Cells?
- Provide support and nutrition to cell bodies in ganglia
- Protect cell bodies from harmful substances