Upload
arline-dean
View
225
Download
3
Embed Size (px)
DESCRIPTION
Parts of a Neuron Soma – cell body Dendrite – receive messages Axon – send messages out Myelin – help speed up messages, made up of Schwann cells
Citation preview
Nervous System
BrainSpinal Cord
NervesNeurons
Neurons
Communication between cells through nerve signals.
Parts of a Neuron• Soma – cell body• Dendrite – receive messages• Axon – send messages out• Myelin – help speed up
messages, made up of Schwann cells
Types of Neurons• Sensory – incoming signals• Motor - movement• Interneurons – in brain and
spinal cord only (processors/relay terminals)
Neural Connections• Synapse – space between axon of
neuron A and dendrite of neuron B• Neurotransmitter – chemicals
that diffuse across synapse to change polarity of neuron B’s dendrite membrane
• Nerve cells contain receptor molecules for neurotransmitters
Synapses
Neurotransmitter being released into synapse and attaching to receptors on dendriteBased on Harvard Medical School
Family Health Guide
Central Nervous System• Brain• Spinal Cord
Control center, coordinates body functions
Peripheral Nervous System Carry messages to and from
CNS
Motor and sensory neurons found here.
No interneurons here!
BrainCerebrum
Corpus Callosum
Pituitary Gland
HypothalamusBrain Stem: Pons, Midbrain, Medulla Oblongata
Cerebellum
Thalamus
Autonomic Nervous System• Involuntary• Two divisions
–Sympathetic – fight-or-flight responses
–Parasympathetic – body at rest
Somatic Nervous System• Cranial and spinal nerves• Reflexes – automatic
responses to stimuli
Senses• Chemoreceptors – chemicals• Photoreceptors – light• Mechanoreceptors – pressure,
vibration
Chemoreceptors• Taste – taste buds
–Sweet–Salty–Bitter–Sour
• Olfaction - smell
Photoreceptors• Vision• Retina
–Cones – color–Rods – black & white
Mechanoreceptors• Hearing – vibration in cochlea• Balance – semicircular canals
in ears• Touch – pressure, pain, heat,
cold