QUESTIONS WITH 100% CORRECT ANSWERS
Functions of the nervous system (4) - - Detecting, analysing and transmitting information
o Provides foundation for intelligence, anticipation, and judgment
o Controls skeletal muscle movement
o Helps to regulate cardiac and visceral smooth activity
Definition of Neurons - functional cells that conduct impulses to other nerve cells, muscles, or gland
cells
Three parts of a neuron - cell body, dendrites, axon
What does the cell body do? - - Soma- nucleus- DNA and genetic codes
- Cell activity
- Metabolic activities
What do dendrites do? - conduct info to cell body
§ Extension of cell body that brings info into the cell body
What does the axon do? - Long projections from the cell body (normally only one) that pass nerve
impulses
Function of neuroglial cells - - provide protection, regulate blood flow and metabolic support for the
neurons
o Form the myelin sheath from oligodendrocytes and Schwan cells
§ Helps with the transmission of electrical impulses along the nerve cells
Neuroglial cells of the central nervous system - oligodendrocytes
Neuroglial cells of the peripheral nervous system - Satellite
,What do astrocytes do? - help to form the blood-brain barrier, which prevents the entrance of toxic
materials from the blood to the brain
Major fuel source for the brain? - Glucose
Afferent - sensory- transmit information to the CNS
Efferent - Motor carry information away from the CNS
Retrograde - axon to cell body
Anterograde - cell body to axon
Resting membrane potential - polarized (no electrical activity occurs = -70 mV)
§ Positive outside/ negative inside
Depolarization - sodium channels open- generate electrical impulse= +30 mV)
§ Negative outside/ positive inside
Repolarization - permeable to potassium- exit of K-return to resting membrane potential)
- Na close and K open
Absolute refractory - The minimum length of time after an action potential during which another
action potential cannot begin.
relative refractory period - a stronger than usual stimulus is necessary to initiate an action potential
electrical synaptic transmission - gap junctions- action potentials move rapidlY
Pathway of chemical synaptic transmission - presynaptic release of chemical messenger
(neurotransmitters) -> placed in vesicle within the synaptic cleft-> postsynaptic structures ->
neurotransmitter removal
,Two amino acid neurotransmitters - Glutamate and GABA
Function of GABA - main inhibitory messenger (vision/motor/anxiety)
function of glutamate - -Most plentiful
- controls cognitive function- memory/learning
Excessive glutamate leads to what disorders? - Alzheimers
Stroke
epileptic seizures
A node of Ranvier - small gap between myelinated segments where axonal membrane is exposed;
increase speed of nerve impulses
Two kinds of neuropeptides - endorphins and enkephalins
function of endorphins and enkephalins - inhibit transmission of pain signals/ promotes euphoria
Monoamines - epinephrine, norepinephrine, serotonin, dopamine
function of epinephrine - stress hormone- helps neurons communicate with one another
function of norepinephrine - alertness and arousal (fight or flight)
function of dopamine - reward and motivation, motor control over voluntary movement, addiction
main neurotransmitter associated with parkinsons - dopamine
function of serotonin - mood/sleep/anxiety/sexuality/appetite
, How do SSRIs work? - Antidepressant- balance serotonin reuptake which helps to relieve anxiety
function of acetacholine - motor neurons, memory, and learning
only neurotransmitter in both the cns and pns - acetylcholine
excitatory neurotransmitters - cause the electrical signal to be transmitted down the cell (EPI and
Norepinephrine)
inhibitory neurotransmitter - block the signal from continuing, preventing the message from being
carried (serotonin and GABA)
neuromodulators - chemical messengers that react with receptors to produce slower and longer
acting changes
neurotrophic factors - Proteins that encourage the growth, development, and survival of neurons
CNS is composed of what - brain and spinal cord
PNS is composed of what - cranial and spinal nerves
voltage- dependent gates - guard ion channels
embryonic development contains what two structures - ectoderm and neural crest cells
Function of ectoderm - hallow tube that the CNS develops from- differentiates into the tissues of the
brain and nerves, and the epidermis of the skin
function of neural crest cells - PNS cell development
dorsal root ganglia - at the sides of each spinal cord segment, coveys stimuli like pain, touch,
vibration, and temperature