● Unit 1 Review:
(1.2) Nervous system:
CNS: brain and spinal cord
PNS: different nerves that branch off from the brain and spine
2 types of nerves that deliver info:
● Afferent nerves (sensory)
● Send signals from the sensory receptors to the CNS
● Efferent nerves (motor)
● Send signals from the CNS to PNS
●
Peripheral nervous system:
Somatic nervous system (skeletal nervous system):
● Skeletal muscle movement and 5 senses
● Conscious and voluntary
●
Autonomic nervous system
● Involuntary activities
● Breathing, heart rate, digestion
●
● Sympathetic nervous system:
● Fight or flight response
● Mobilizes your body and gets it ready for action
● Heart beats faster, eyes dilate, increased breathing rate
●
● Parasympathetic nervous system:
● Relaxes your body
● Slows heart rate, increased digestion
● Focuses on slowing body and storing energy
, ●
Different parts of a neuron and neural firing (1.3):
2 common neural cells:
● Glial cells:
● Most abundant in nervous system
● Provides structure, nutrients, insulation and communication,
waster transportation
● Building blocks for all behavior and mental processes
● Do NOT process info
● Neurons:
● Basic functional units of the nervous system
● Communicate with other neurons through electrical impulses and
chemical signals to send info through the nervous system
Reflex arc: nervous pathway that allows the body to respond to stimulus without
thinking
● Involves sensory, motor, and interneurons
(e.g) if you touch something very hot, skin receptors detect heat and send signals
through the sensory neuron to the spine. Signal then goes through interneurons
in the brain and spinal cord and the neurons communicate internally and connect
the sensory neurons to motor neurons. Signal goes to motor neurons and goes
back to the muscles in the hand, resulting in your hand to move.
● Autonomic response
● Allows the body to respond to a threat before processing what's going on
Neural transmission:
● For neurons to send a message they need to receive enough stimulation
that causes an action potential
Action potential: When a neuron fires and sends an impulse down the axon
● Must be positively and negatively charged ions present for action potential
to occur
● Cell membrane separates the ions and creates an environment in and out
the barrier
, ● Some ions pass through the membrane easier (permeability)
Resting potential: more negative ions in the inside than outside
● To trigger an action potential, a neuron must depolarize, which happens
when an outside stimulus is strong enough to meet the threshold that
causes depolarization to occur, and then it triggers an action potential
All or nothing response: if the stimulus does not meet the threshold, there is no
firing and the neuron will return to its resting state
After an action potential goes through an axon, repolarization happens
● Brings neuron back to resting potential
● Rebalances charges by letting more positive ions back outside
Refractory period: neuron cannot respond to any other stimuli while signal is
moving down a neuron's axon
● Time when cell can not fire and has to wait till repolarization occurs and go
back to resting potential
Synapse: pocket of space between axon terminal of one cell and dendrites of
another
Chemical and electrical synapses:
Chemical: use neurotransmitters (slower, through bloodstream)
● Diffuse through synaptic gap to deliver messages
Electrical: send messages quickly and immediately
Presynaptic terminal: where neurotransmitters are accepted in the dendrite of
the receiving cell
● After message is sent they unbind with the receptors
● Some neurotransmitters get destroyed or reabsorbed
● Reuptake: taking excess neurotransmitters in the gap
(1.2) Nervous system:
CNS: brain and spinal cord
PNS: different nerves that branch off from the brain and spine
2 types of nerves that deliver info:
● Afferent nerves (sensory)
● Send signals from the sensory receptors to the CNS
● Efferent nerves (motor)
● Send signals from the CNS to PNS
●
Peripheral nervous system:
Somatic nervous system (skeletal nervous system):
● Skeletal muscle movement and 5 senses
● Conscious and voluntary
●
Autonomic nervous system
● Involuntary activities
● Breathing, heart rate, digestion
●
● Sympathetic nervous system:
● Fight or flight response
● Mobilizes your body and gets it ready for action
● Heart beats faster, eyes dilate, increased breathing rate
●
● Parasympathetic nervous system:
● Relaxes your body
● Slows heart rate, increased digestion
● Focuses on slowing body and storing energy
, ●
Different parts of a neuron and neural firing (1.3):
2 common neural cells:
● Glial cells:
● Most abundant in nervous system
● Provides structure, nutrients, insulation and communication,
waster transportation
● Building blocks for all behavior and mental processes
● Do NOT process info
● Neurons:
● Basic functional units of the nervous system
● Communicate with other neurons through electrical impulses and
chemical signals to send info through the nervous system
Reflex arc: nervous pathway that allows the body to respond to stimulus without
thinking
● Involves sensory, motor, and interneurons
(e.g) if you touch something very hot, skin receptors detect heat and send signals
through the sensory neuron to the spine. Signal then goes through interneurons
in the brain and spinal cord and the neurons communicate internally and connect
the sensory neurons to motor neurons. Signal goes to motor neurons and goes
back to the muscles in the hand, resulting in your hand to move.
● Autonomic response
● Allows the body to respond to a threat before processing what's going on
Neural transmission:
● For neurons to send a message they need to receive enough stimulation
that causes an action potential
Action potential: When a neuron fires and sends an impulse down the axon
● Must be positively and negatively charged ions present for action potential
to occur
● Cell membrane separates the ions and creates an environment in and out
the barrier
, ● Some ions pass through the membrane easier (permeability)
Resting potential: more negative ions in the inside than outside
● To trigger an action potential, a neuron must depolarize, which happens
when an outside stimulus is strong enough to meet the threshold that
causes depolarization to occur, and then it triggers an action potential
All or nothing response: if the stimulus does not meet the threshold, there is no
firing and the neuron will return to its resting state
After an action potential goes through an axon, repolarization happens
● Brings neuron back to resting potential
● Rebalances charges by letting more positive ions back outside
Refractory period: neuron cannot respond to any other stimuli while signal is
moving down a neuron's axon
● Time when cell can not fire and has to wait till repolarization occurs and go
back to resting potential
Synapse: pocket of space between axon terminal of one cell and dendrites of
another
Chemical and electrical synapses:
Chemical: use neurotransmitters (slower, through bloodstream)
● Diffuse through synaptic gap to deliver messages
Electrical: send messages quickly and immediately
Presynaptic terminal: where neurotransmitters are accepted in the dendrite of
the receiving cell
● After message is sent they unbind with the receptors
● Some neurotransmitters get destroyed or reabsorbed
● Reuptake: taking excess neurotransmitters in the gap
