Nervous system I Flashcards
(45 cards)
Complete the following:
The nervous system is a ________________ of fibres which span the body co-ordinating a diverse range and voluntary and ________________ actions. It transmits ________________ between parts of the body. It responds rapidly to changes within the internal and external ________________ It works alongside the ________________ system to maintain ________________.
network involuntary signals environment endocrine homeostasis
Describe the difference between the central nervous system and the peripheral nervous system.
Central nervous system is the brain and spinal cord
Peripheral nervous system is made up of the peripheral nerves, not in the CNS
Describe the role of the somatic nervous system.
Part of the peripheral nervous system, controls voluntary muscles and transmits sensory information to the CNS
With regards to neuron function, complete the following table:
Complete the following
With regards to the effects of the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS), complete the following table:
- Name the specific body location of the following:
a. Sympathetic nervous system
b. Parasympathetic nervous system
a - central nervous system - spinal cord.
b - within the brain and sacral portion of the spinal cord.
Explain how the enteric nervous system is linked to the CNS.
Links with the CNS via the sympathetic and parasympathetic nerve fibres. Vagus nerve - involuntary.
Describe the role of the following in the enteric nervous system:
a. Sensory neurons
b. Motor neurons
c. Interneurons
a. Sensory - monitor chemical changes via chemo-receptors in the GI tract and stretching (stretch receptors) of its walls
b. Motor - govern motility and secretions of the GIT and associated glands
c. interneurons - connect the 2 plexus
Define the following terms:
a. Action potential
b. Nerve stimulus
c. Nuclei
d. Ganglia
e. Tracts
a. Action potential - ability of neurons to create a nerve impulse
b. Nerve stimulus - anything able to generate an action potential
c. Nuclei - collections of cell bodies in the CNS form structural and functional groups in the brain.
d. Ganglia - collections of cell bodies in the PNS
e. Tracts - axon bundles are called tracts in the CNS
Describe the main role of dendrites.
Dendrites are the receiving portion of the cell. They communicate with other neurons/dendrites.
Can axons regenerate? Explain.
Yes, if injured they can regenerate at a rate of 1-2mm per day
Describe TWO roles of the myelin sheath.
Increases the speed of nerve conduction
Electrically insulates the axon
State which vitamin is required as a co-factor in myelin production?
B12
Describe ONE key difference between ‘grey matter’ and ‘white matter’
Grey matter is mostly composed of cell bodies. White matter is composed of myelinated axons
Describe THREE key differences between ‘neurons’ and ‘neuroglial cells’.
Glial cells are smaller
Glial cells are 50x more prevalent
Glial cells can multiply and divide
List TWO key functions of neuroglial cells.
Fill spaces left by damaged neurons after trauma
Match the nervous system CNS or PNS to the neuroglial cell:
a. Schwann cell
b. Astrocytes
c. Microglia
d. Ependymal cells
e. Satellite cells
f. Oligodendrocytes
a. Schwann cell PNS
b. Astrocytes CNS
c. Microglia CNS
d. Ependymal cells CNS
e. Satellite cells PNS
f. Oligodendrocytes CNS
Name the neuroglial cell that:
a. Contributes to the blood brain barrier
b. Is phagocytic and is mobile in the brain
c. Provides structural support in PNS ganglia
d. Myelinates axons in the CNS
e. Produces cerebrospinal fluid
f. Myelinates axons in the PNS
a. Contributes to the blood brain barrier ASTROCYTES
b. Is phagocytic and is mobile in the brain MICROGLIA
c. Provides structural support in PNS ganglia SATELLITE CELLS
d. Myelinates axons in the CNS OLIGODENDROCYTES
e. Produces cerebrospinal fluid EPENDYMAL CELLS
f. Myelinates axons in the PNS SCHWANN CELLS
Describe TWO key differences between ‘graded potential’ and ‘action potential’.
Graded potential for short distance communication. Longer duration.
Action potential for long distance communication, Shorter duration.
Name TWO characteristics that facilitate graded and action potentials.
1 - Specific ion channels can open and close when stimulated
2- Electrical difference across the cell membrane (resting potential)
Name TWO stimuli that trigger ion channels.
Changes in voltage, chemicals (hormones)
Complete the following:
Neurons at rest process an _____________ gradient across the cell membrane. This is created by the build-up of ________________ ions on the inside of the cell membrane relative to the extracellular fluid which contains more ___________ ions The separation of charges create ________________ energy. The resting potential is approximately_________ mV. Cells exhibiting a membrane potential are said to be ________________ or charged.
Neurons at rest process an ELECTROCHEMICAL gradient across the cell membrane. This is created by the build-up of NEGATIVE ions on the inside of the cell membrane relative to the extracellular fluid which contains more POSITIVE ions The separation of charges create POTENTIAL energy. The resting potential is approximately -70 mV. Cells exhibiting a membrane potential are said to be POLARISED or charged.
Describe in detail the resting potential (think sodium, chloride, potassium, proteins and the sodium-potassium pump).
The extracellular fluid is rich in Na+and Cl–ions and carries a positive charge.
• The intracellular fluid is rich in K+and large negatively charged proteins and phosphates which cannot leave the cell. Thus carries a negative charge inside the cell.
• As the Na+ and Cl– try to move back to equalise the charge, the separation of charges is maintained by the sodium-potassium pump which pumps 3Na+ out for every 2K+it pumps back in (using ATP).
