The NERVOUS SYSTEM Flashcards
master all mntanami (128 cards)
what makes up the CNS
The spinal cord and the brain
what makes up the peripheral nervous system
nerves
what are neurons and how do they function
cells responsible for nervous system signaling
they are specialized for communication.
what are dendrites
be able to identify these Mnumzana
cytoplasmic extensions of the body
they receive information from other neurons and receptors
define an axon and its function
tube of the cell membrane
enclosed with the myelin sheath
it transmits Action Potential away from the cell body
what is the function of Schwann cells
to create fatty myelin sheath in PNS
produce myelin
what are oligodendrocytes
myelinating cells in the CNS
demyelination definition
loss of myelin sheath in the axons
caused by neurodegenerative autoimmune diseases
diseases caused by demyelination of the axons
multiple sclerosis
Guillain Barre Syndrome
Acute encephalomyelitis
what is multiple sclerosis
an autoimmune disease that involves the loss of oligodendrocytes
the immune system attacks the nervous system leading to demyelination
disrupts the CNS from communicating
how is Ms diagnosed?
based on signs and symptoms
supporting imaging and laboratory testing
(neuroimaging is used– which is the analysis of the cerebrospinal fluid and action potentials)
during MS diagnosis using neuroimaging, what is the cerebrospinal fluid tested for
the cerebrospinal fluid is tested for Oligoclonal bands of IgG on electrophoresis( which are inflammation markers found in 75% to 85% of people with MS)
what are the 3 stages of information processing?
- Input( sensory input) gathering of information
- Integration- processing of information
- Motor output- response to the information transmitted
what are the 2 cells that make up the nervous system
neurons(20% of the nervous system)
A-N-D
glia cells
what are the 3 types of neurons
- sensory( afferent) neurons
- Interneurons- connect neurons to specific regions of the CNS
- motor ( efferent) neurons
What are the 4 types of Glia cells
- Microglia
- Astrocytes
- Oligodendrocytes and Schwann cells
- Ependymal cells
Who is ONE person on Earth that you believe in the Most?
NKANYISO NELSON ZULU
THE GUY IS AMAZING AND CAPABLE OF ACHIEVING ANYTHING
HE MUST REMEMBER TO REMAIN DISCIPLINED AND BE CONSI
BE ABLE TO IDENTIFY ALL GLIA CELLS IN A DIAGRAM
LET’S SEE DR. ZULU
YOU CAN DO IT. NEVER DOUBT YOURSELF
what are glia cells?
glia means glue, and hence these cells can be understood to support the structure of the nervous system
maintain homeostasis
do not generate impulses
neurons initiate action potentials
what is ACTION POTENTIAL?
transient (only lasting for a short time) alteration of the transmembrane voltage across an excitable membrane in an excitable cell
Generated by the activity of voltage-gated ion channels embedded in the membrane.
definition of the resting/membrane potential
the difference in charge between the cell’s membrane and extracellular fluid when the cell is not electrically charged.
it results from ionic gradients
what is the function of the sodium/potassium pump
prevents leaking of ions and also prevents the cell gradients from running down.
the resting potential of neurons is -70mV. the pump maintains this PUMP.
what happens if the resting potential of -70mV changes?
a neuron is triggered to fire and send electrical impulses.
there are two types of ion channels. What are these?
active channels
passive channels