Nervous Systems

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Nervous Systems
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Nervous Systems
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Nervous Systems

• Functions
• 1. Sensory input
• 2. Integration
• 3. Motor output

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Nervous Systems

• Functions
• 1. Sensory input
• 2. Integration
• 3. Motor output

• Components
• 1. Peripheral
• 2. Central
• 3. Peripheral.

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Nervous Systems
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Nervous Systems
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Nervous Systems
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Nervous Systems

• Simple neural circuit (reflex arc)

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Nervous Systems

• More complex neural circuit

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Nervous Systems

• Vocabulary
• PNS
• CNS
• effector cells
• axon
• dendrite
• myelin sheath
• Schwann cell

• synapse
• reflex arc
• interneuron
• ganglion
• glia
• astrocyte
• oligodendrocyte
• blood-brain barrier.

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Nerve Signals
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Nerve Signals
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Nerve Signals
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Nerve Signals
dendrite
dendrite
dendrite
dendrite
axon
dendrite
dendrite
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Nerve Signals
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Nerve Signals
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Nerve Signals
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Nerve Signals
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Nerve Signals
The same neurotransmitter can produce different
effects on different cells. Neurotransmitters can
be fast and local or slow and diffuse.
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Nerve Signals
Acetylcholine Epinephrine Norepinephrine Dopamine
Serotonin Endorphins Nitric oxide (gas).
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Nerve Signals

• Vocabulary
• membrane potential
• resting potential
• threshold potential
• action potential
• chemically-gated ion channels
• voltage-gated ion channels
• synaptic cleft.

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Nerve Signals

• Vocabulary
• hyperpolarization
• depolarization
• refractory period
• saltatory conduction
• EPSP
• IPSP
• summation.

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Cephalization
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Cephalization
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Cephalization
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Cephalization
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Cephalization
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Cephalization
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Cephalization
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Vertebrate Nervous Systems
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Vertebrate Nervous Systems
Cerebrospinal fluid
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Vertebrate Nervous Systems
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Vertebrate Nervous Systems
Peripheral nervous system
Motor (efferent) division
Sensory (afferent) division
Sensing external environment
Sensing internal environment
Autonomic nervous system
Somatic nervous system
Parasympathetic division
Sympathetic division
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• Parasympathetic
• Constrict pupils
• Stimulate saliva
• Slow heart
• Constrict bronchi
• Stimulate digestion
• Promote urination
• Promote erection

• Sympathetic
• Dilate pupils
• Inhibit saliva
• Relax bronchi
• Accelerate heart
• Inhibit digestion
• Stimulate glucose release from liver
• Stimulate adrenalin
• Inhibit urination
• Promote orgasm.

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Vertebrate Nervous Systems

• Medulla oblongata and pons
• attention
• alertness
• appetite
• motivation.

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Vertebrate Nervous Systems

• Midbrain
• integration of sensory input.

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Vertebrate Nervous Systems

• Reticular formation
• reticular activating system (RAS)
• sleep and wakefulness.

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Vertebrate Nervous Systems

• Cerebellum
• coordination and error checking
• learning motor tasks.

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Vertebrate Nervous Systems

• Thalamus
• main input and output center for sensory and
  motor signals.

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Vertebrate Nervous Systems

• Hypothalamus
• circadian rhythms (biological clock).

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Vertebrate Nervous Systems

• Cerebrum
• basal nuclei planning and learning movement
  sequences
• neocortex cognition
• corpus callosum communication between
  hemispheres
• limbic system (hippocampus) emotions.

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Vertebrate Nervous Systems

• Vocabulary
• gray matter
• white matter
• afferent
• efferent
• autonomic
• somatic
• parasympathetic
• sympathetic

• medulla oblongata
• pons
• midbrain
• reticular formation
• ras
• cerebellum
• thalamus
• hypothalamus
• cerebrum.

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Vertebrate Nervous Systems

• Vocabulary
• Basal nuclei
• neocortex
• corpus callosum
• hippocampus
• limbic system.

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Memory
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Memory

• Short-term memory
• Held in the frontal lobes
• Released when no longer needed
• Involves rapid changes in strength of existing
  nerve connections.

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Memory

• Long-term memory
• Involves hippocampus
• Enhanced by rehearsal, emotional states, and
  previous experience
• Nerve cells actually grow new connections
• Long-term depression or potentiation of synaptic
  connections.

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Memory

• Long-term memory
• Difficulty of unlearning motor tasks
• Dreaming
• PTSD and state-specific memory.