Nervous system Flashcards
CNS
brain + spinal cord
Sensory neurons
signals from receptors to CNS
PNS
peripheral nerves
motor neurons
signals from CNS to effectors
Autonomic nervous system
Automatic functions (like heartbeat and breathing).
Somatic nervous system
Voluntary actions (things you decide to do).
Sympathetic division
Controls “Fight or Flight” response (stress response).
Parasympathetic division
Conserves energy
Rest + Digest
medulla oblongata
connects spinal cord to brain
involuntary movement
pons
brain to spinal cord
sleeping breathing
cerebellum
balance, limb movement etc,
motor movements
mid brain
eye and ear reflexes
activates forebrain
cerebrum
learning, memory and emotions
frontal lobe
motor, personality, intelligence
Parietal lobe
touch taste temperature, pain
temporal lobe
hearing, smell, memory
occipital lobe
vision
hypothalamus
bodies control center, controls basic needs, behaviour emotion, hunger, thirst etc
SNS
controls voluntary actions
ANS
works automatically without doing it on porpose
sympathetic division
fight or flight prepares body for action in stressful situations
parasympathetic division
rest and digest
white matter
myelinated, sends signals quickly inside the brain and outside the spinal cord.
gray matter
unmyelinated, outside the brain and inside the spinal cord; slower signals.
function of spinal cord
Sends messages between the brain and body and controls reflexes.
spinal cord has
sensory neurons
motor neurons
Interneurons
reflex pathway acronym
SSIMMR
dendrites
bring info to neauron
role of body cell in neuron
holds main part of cell
Axon
sends signal to next cell
myelin sheath
covers axon and helps signals move faster
synapse
gap between neurons where signals pass
motor neuron
sends signals from CNS to muscle or glands
sensory neuron
Brings signals from body sensors to the CNS.
interneuron
neuron that connects other neurons within the CNS.
neuron
sends electrical signals in the body
glial cell
supports and keeps neurons healthy
sensory (afferent) neuron
carries information from sensory receptors in the PNS to the CNS.
motor (efferent) neuron
carries info from the CNS to muscles or glands (effectors) to cause a response.
effector
A muscle or gland that responds to signals from motor neurons.
action potential
nerve impulse caused by changes in electrical charge inside the neuron.
phases of an action potential?
Resting potential, depolarization, repolarization, hyperpolarization, and return to resting potential. RDRHR
depolarization
Sodium (Na+) channels open, allowing Na+ to enter the cell, making the inside more positive.
repolarization
Potassium (K+) channels open, allowing K+ to leave the cell, which makes the inside more negative again.
hyperpolarization
cell becomes more negative than the resting potential due to excess K+ leaving.
What restores the neuron to resting potential?
sodium-potassium pump, which moves Na+ out and K+ in.
What is the “All or None” response?
Neurons either fully respond with an action potential or not at all, depending on whether they reach the threshold.
refractory period?
short time after an action potential when a neuron cannot respond to another stimulus.
How does an action potential move along a neuron?
goes along the axon as a wave of depolarization, jumping between nodes of Ranvier in myelinated neurons
What makes nerve impulses travel faster?
Myelination, which allows impulses to jump between nodes of Ranvier, speeding up conduction.
