Nervous Systems

Nervous Systems

Functions:

1. Sensory input

2. Integration

3. Motor output

Nervous Systems

Functions:

1. Sensory input

2. Integration

3. Motor output

Nervous SystemsComponents:

1. Peripheral

2. Central

3. Peripheral.

Nervous Systems

Nervous Systems

Nervous Systems

Simple neural circuit (reflex arc)

Nervous Systems

More complex neural circuit

Nervous Systems

More complex neural circuit

Nervous Systems

Vocabulary:

•PNS

•CNS

•effector cells

•axon

•dendrite

•myelin sheath

•Schwann cell

Nervous Systems•synapse

•reflex arc

•interneuron

•ganglion

•glia

•astrocyte

•oligodendrocyte

•blood-brain barrier.

Nerve Signals

Nerve Signals

Nerve Signals

Nerve Signals

dendrite

den

drite

dendritedendrite

dendrited

end

riteaxon

Nerve Signals

axon

Nerve Signals

axon

Nerve Signals

axon

Nerve Signals

Nerve Signals

The same neurotransmitter can produce different effects on different cells.

Neurotransmitters can be fast and local or slow and diffuse.

Nerve Signals

Acetylcholine

Epinephrine

Norepinephrine

Dopamine

Serotonin

Endorphins

Nitric oxide (gas).

Nerve Signals

Vocabulary:

•membrane potential

•resting potential

•threshold potential

•action potential

•chemically-gated ion channels

•voltage-gated ion channels

•synaptic cleft.

Nerve Signals

Vocabulary:

•hyperpolarization

•depolarization

•refractory period

•saltatory conduction

•EPSP

•IPSP

•summation.

Cephalization

Cephalization

Cephalization

Cephalization

Cephalization

Cephalization

Vertebrate Nervous Systems

Vertebrate Nervous Systems

Cerebrospinal fluid

Vertebrate Nervous Systems

Vertebrate Nervous SystemsPeripheral

nervous system

Sensory (afferent) division

Sensing external

environment

Sensing internal

environment

Motor (efferent) division

Autonomic nervous system

Somatic

nervous system

Parasympathetic division

Sympathetic division

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.

Vertebrate Nervous Systems

Medulla oblongata and pons

•attention

•alertness

•appetite

•motivation.

Vertebrate Nervous Systems

Midbrain

•integration of sensory input.

Vertebrate Nervous Systems

Reticular formation

•reticular activating system (RAS)

•sleep and wakefulness.

Vertebrate Nervous Systems

Cerebellum

•coordination and error checking

•learning motor tasks.

Vertebrate Nervous Systems

Thalamus

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

Vertebrate Nervous Systems

Hypothalamus

•circadian rhythms (biological clock).

Vertebrate Nervous Systems

Cerebrum

•basal nuclei – planning and learning movement sequences

•neocortex – cognition

•corpus callosum – communication between hemispheres

•limbic system (hippocampus) – emotions.

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.

Vertebrate Nervous Systems

Vocabulary:•Basal nuclei

•neocortex

•corpus callosum

•hippocampus

•limbic system.

Memory

Memory

Short-term memory

•Held in the frontal lobes

•Released when no longer needed

•Involves rapid changes in strength of existing nerve connections.

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.

Memory

Long-term memory

•Difficulty of unlearning motor tasks

•Dreaming

•PTSD and state-specific memory.

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