Nerves 1-3 Flashcards
What are the dendrites on a nerve cell?
Where the nerve cell receives information
What is the name given to the body of a nerve cell?
Soma
What are the 4 different types of glial cell?
Astrocytes, oligodendrocytes, microglia and ependymal cells
What is the function of astrocytes?
Maintains chemical concentrations and gradients
Removes waste Repair
Important contribution in the BLOOD BRAIN BARRIER
What are the glial cells in the PNS?
Satellite cells and schwann cells
What do satellite cells surround?
They surround the sensory and autonomic ganglia
What is the function of satellite cells?
They regulate the microenvironment of the ganglia in the peripheral nervous system
Which glial cells are responsible for providing the myelin sheath around the axons?
Oligodendrocytes and schwann cells
What is the function of microglial cells?
Immune role, Ingest cells and pathogens
What is the function of ependymal glial cells?
Filters blood to make CSF
What portion of the nervous system is responsible for gut activity?
The enteric system
The cortex contains grooves, what is the name given to a groove that surrounds a gyrus?
A sulcus
What is the cortex?
The outer layer of the cerebrum consisting of folded grey matter
What is the cerebellum responsible for?
Coordinates and regulates muscular activity
What is the function of the cerebrum?
It is associated with higher brain power such as thought and action
What is the name given to the 4 lobes of the cerebrum?
Occipital, frontal, temporal and parietal
What does the brain stem contain?
Midbrain, pons and the medulla oblongata
What does the diencephalon contain?
It is the posterior part of the brain and it contains the epithalamus, thalamus and the hypothalamus
Which part of a nerve cell triggers the action potential?
Axon hillock
Where can you find interneurones?
In the CNS
What is depolarization?
When the cell membrane potential becomes more positively charged
Why is a cell normally electronegative?
Because of a higher portion of positive ions outside the cell
What causes the cell to hyperpolarise?
The movement of potassium ions out of the cell via potassium channels
Give examples of graded potentials
Generator potentials,
post synaptic potentials,
end plate potentials
Why are graded potentials described as decremental?
Current leaks out the membrane as you travel away from the source
How can you create an IPSP?
Opening chloride ion channels (fast)
Opening more chlorine channels (slow - acts via G protein)
How can you create an EPSP?
Opening more sodium channels or closing potassium channels
Why is the sodium channel described as a mono-valent non-specific cation channel?
Some potassium can travel as well
What is the summation of EPSP’s?
EPSP can accumulate from many inputs
What is temporal summation?
When you get two EPSP’s from the same synapse in close succession
What is spatial summation?
When there is an accumulation of EPSP’s from different synapses
Which synapses will suffer less decay?
Those closer to the axon hillock
Label as many as possible (Ignore 3&10)
- frontal lobe
- corpus callosum
- parieatel lobe
- Diencephalon
- Occipital lobe
- Cerebullum
- Medulla oblongata
- Pons
- Midbrain
What are meninges?
The folds of the brain
How many pairs of cervical nerves are there?
8
How many thoracic and lumbar nerve pairs are there
12 and 5
Have many sacral and coccygeal nerve pairs are there
5 & 1
What is the function of the axon?
Bridge between dendrites and axon terminals that allow signals to travel across
What is the proper name for a sensory nerouns?
Afferent nerouns
What is the proper name for motor neurons?
Efferent nerouns
What morphology would be used to describe afferent neurons in the dorsal root ganglia?
pseudounipolar
What defines an anaxonic neuron
Neurons where axons are undifferentiable from dendrites (e.g. in the brain)
What morphological shape describes efferent neurons?
Multipolar
What 4 types of Glia are present in the CNS?
What 2 types of Glia are present in the PNS?
Astrocytes, Oligodendrocytes, Epedymal cells, Microglia
What 2 types of Glia are present in the PNS?
Shwann cells and satellite cells
Function of astrocytes?
Maintain water, ion concentration levels in ECF and blood brain barrier
Function of Ependymal cells?
Produces Cerebrospinal fluid
Function of Microglia?
phagocytes in the CNS
Function of oligodendrites?
Myelinates multiple axons in CNS
Function of Schwann cells?
fully wrap around PNS axons (myelination)
Function of Satellite cells?
attach around neuron cell bodies supporting them
What are the functions of Potentials in neurons
Allow a signal to travel the distance to/from peripheral
Allow neuron to be specifically ‘activated’
Resting potential means neurons are always ready with some energy to send electrical signal
Describe: Action, Graded & Resting potentials
Action - Potential used to transport signal from axon hillock to dendrites
Graded - Potential needed to activate action
Resting - baseline potential existing in dormant cells (not neutral)
What is the resting potential in a typical neuron?
-70mV
What is the function of Na+/K+ ATPase for membrane potential?
pumps 3 Pumps 3 Na+ out of cell & 2 K+ into cell (creating slightly negative charge)
However, main function is to move K+ into cell (for leaky membrane proteins)
What is the function of the leaky potassium pump on a membrane of a neuron?
Allows K+ ions to diffuse down concentration gradient, so more positive charges on outside of cell, creating negative charge inside
when will K+ ions stop leaving through leaky protein channels?
when Force of diffusion of different K+ concentration = electrical repulsion of positive charges outside cell
What are the typical concentration values of sodium, chlorine and potassium ions in the ICF and ECF of cells?
mMol/l
K+ - 150 ICF 5 ECF
Na+ - 15 ICF 150 ECF
Cl- - 10ICF 110 ECF
