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Coordinating Movement, etc.! Nerve Systems Electrical Transmission -- Chemical Connection. Released from vesicles input nucleus transmission output.

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Presentation on theme: "Coordinating Movement, etc.! Nerve Systems Electrical Transmission -- Chemical Connection. Released from vesicles input nucleus transmission output."— Presentation transcript:

1 Coordinating Movement, etc.! Nerve Systems Electrical Transmission -- Chemical Connection. Released from vesicles input nucleus transmission output

2 In peripheral nerves, the tissue is mostly axons, tightly packed like the wires in a complex phone cable!

3 Conduction of action potential along neuron A bit slower than electrical wire, but does not need heavy, rigid metal and, for typical organism sizes, is fast enough!

4 Myelin Sheath Increases Rate of Transmission Multiple Sclerosis and Guillain-Barré Syndrome Electrical current passes rapidly (150 vs 30 m/s) down the sheathed axon segments

5 Coordinating Movement, etc.! Nerve Systems Regulation by ACH or NE.

6 Neurotransmitter Roles Opposing Muscles Glands

7 Neurotransmitter diffusion is fast enough… Because the synapse gap is about mm

8 AcetylCholine Stimulates muscle contraction in the neuromuscular junction.Stimulates muscle contraction in the neuromuscular junction. Atropine blocks Ach reception…relaxation of irisAtropine blocks Ach reception…relaxation of iris Slows the pacemaker in the heart.Slows the pacemaker in the heart. Adrenaline (nor-epinephrine) Promotes nutritional release to bloodPromotes nutritional release to blood Speeds the pacemaker in the heart.Speeds the pacemaker in the heart. Higher blood pressure, more oxygenationHigher blood pressure, more oxygenation Fright, Flight, or Fight stimulantFright, Flight, or Fight stimulant

9 Simple Nervous Systems > dendrite O soma axon > synaptic terminal S sensor M muscle cell >O > neuron -->>O>>O--- interneuron >O >M motor neuron S>O > sensory neuron Reflex Arc: S>O >>O>>O M (one of each) tendon spinal cord muscle

10 A neuron can have many synaptic terminals These synaptic terminals are neuromuscular junctions…how can you tell?

11 The spinal cord has cell bodies surrounded by dendrites and axons Reflex arcs connect via interneurons here in the spinal cord!

12 Complex Nervous Systems Cell bodies in ganglia in peripheral nervesCell bodies in ganglia in peripheral nerves Cell bodies in spinal cord and brainCell bodies in spinal cord and brain Much of Central Nerve System are interneuronsMuch of Central Nerve System are interneurons Connect to Sensors, Muscles, Glands, etc.Connect to Sensors, Muscles, Glands, etc. Connect to each other!Connect to each other!

13 Mapping a Portion of the Brain Here you can see where portions of the brain map out to body parts.Here you can see where portions of the brain map out to body parts. You might notice that the body has biases in terms of mapping various areas.You might notice that the body has biases in terms of mapping various areas. The head and face covers as much neural tissue as the rest of the body.The head and face covers as much neural tissue as the rest of the body.

14 The Sensory Inputs Taste sensors have receptors for molecules of interest to the organism.Taste sensors have receptors for molecules of interest to the organism. Taste cells transduce receptor-molecule complex into action potential.Taste cells transduce receptor-molecule complex into action potential. Action potential is transmitted to sensory neuron with soma in a nearby ganglion.Action potential is transmitted to sensory neuron with soma in a nearby ganglion. Sensory neuron may be connected to a reflex arc and/or the central nervous system.Sensory neuron may be connected to a reflex arc and/or the central nervous system.

15 The sensitive tongue of reptiles is for tasting the air!

16 Chemotaxis is Signal Tranduction Too! Bacterium movement haphazard without signalBacterium movement haphazard without signal Straight line movement in signal pathStraight line movement in signal path Haphazard movement when off-targetHaphazard movement when off-target Restored straight line movement on pathRestored straight line movement on path

17 The Largest Organ of the Body has Many Sensors! Dendrites (nerve endings) for pain, and itchDendrites (nerve endings) for pain, and itch Pressure sensorsPressure sensors Stretch receptors to hair shaftsStretch receptors to hair shafts Touch and pressure receptorsTouch and pressure receptors Temperature flow sensors… can be confused!Temperature flow sensors… can be confused! Sensor density varies over the body…face and hands are dense!Sensor density varies over the body…face and hands are dense!

18 Arthropod legs have chemical, pressure, and other sensors

19 Sound Waves Sound travels as pressure wavesSound travels as pressure waves Wavelength (frequency) is pitch (short=fast=high)Wavelength (frequency) is pitch (short=fast=high) Amplitude (height) is intensity (decibels)Amplitude (height) is intensity (decibels) >100 = damaging >100 = damaging

20 The Sound Transducer Sound collected by outer earSound collected by outer ear Pressure waves vibrate eardrumPressure waves vibrate eardrum Former jawbones amplify the vibrationsFormer jawbones amplify the vibrations Tapping on Cochlea (inner ear) vibrates fluid-surrounded ciliated transduction cellsTapping on Cochlea (inner ear) vibrates fluid-surrounded ciliated transduction cells Action potential sent to auditory nervesAction potential sent to auditory nerves Auditory nerves connect to CNSAuditory nerves connect to CNS Perception of sound in CNSPerception of sound in CNS Cultural appreciation based upon experienceCultural appreciation based upon experience Plants cannot do this!Plants cannot do this!

21 The antennae of a moth are for chemical and sonic stimuli


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