Organization
of the Animal Nervous System (Fig.
34.1)
3
kinds of neurons
(Fig. 34.2)
peripheral nervous system
sensory neurons
motor neurons
central
nervous system (CNS)
association neurons (interneurons)
Invertebrate
Nervous Systems (Fig. 34.3)
nerve net and no brain.
nerves and ganglia or brains.
vertebrates
more complex sensory mechanisms
differentiation into
central and peripheral nervous systems (Fig. 34.16)
differentiation of
sensory and motor neurons
elaboration of the brain. (Image)
Neurons (Fig. 34.4)
dendrites
cell body
axon
neuroglia
Schwann cell
myelin sheath.
normal neuron, affected neuron, affected CNS, muscle atrophy, diagnosis MRI and lumbar puncture
The Synapse (Fig. 34.7)
presynaptic neuron
postsynaptic neuron.
neurotransmitter
specific
receptors
Kinds of Synapses
excitatory
action potential
inhibitory
inhibits the impulse
integration
(Fig. 34.8)
Neuromodulators and Drug Addiction
Neuromodulators
prolonging or inhibiting it
mood and emotion (Fig. 34.9)
Drug
Addiction
physiological dependence (Fig. 34.10)
Is Addiction
to Smoking Cigarettes Drug Addiction?
nicotine
Divisions of the
vertebrate nervous system (Fig. 34.20)
The Central Nervous
System
How the Brain Works (Fig.
34.11 and 34.12)
cerebrum
cerebral
hemispheres.
thin cerebral cortex
myelinated nerve
fibers
tracts
stroke
(Movie)
The
Thalamus and Hypothalamus Process Information
thalamus: sensory
information
hypothalamus:
internal
functions
limbic
system (Fig. 34.13)
The
Cerebellum Coordinates Muscle Movements
muscular coordination,
balance, and posture
The
Brain Stem Controls Vital Body Processes
medulla oblongata controls breathing rate, heartbeat, and blood vessel diameter.
reticular formation:
sleep
and waking
Language and Other
Higher Functions (Fig. 34.14)
The left hemisphere
is the dominant
one for language
in 90% of right-handed people and two-thirds of left-handers.
The dominant hemisphere is adept at sequential reasoning while the nondominant hemisphere is adept at spatial reasoning.
Short-term
memories are transient and are stored electrically.
Long-term
memories involve structural changes within certain neural connections in the brain.
Alzheimer disease: aged brain
The Spinal Cord (Fig. 34.15)
Spinal cord regeneration
fibroblast
growth factor
The
Peripheral Nervous System
Voluntary
nervous system and the autonomic nervous system.
Voluntary Nervous
System
skeletal muscles.
reflexes. (Fig. 34.18)
Autonomic Nervous
System: smooth
muscles and glands: no conscious control. (Fig. 34.19)
sympathetic nervous system
ganglia
parasympathetic
nervous system
internal
organs and
smooth muscles
homeostasis
The Sensory Nervous
System
Sensory Receptors (Fig. 34.20)
sensory organs.
Path of sensory
information
Stimulation
Transduction
Transmission
Sensing the Internal
Environment
changes in blood
chemistry, pain and tissue damage, muscle contraction and posture (Fig. 34.21), blood pressure (Fig. 34.22), and touch below the skin's surface.
Sensing Gravity:
Balance (Fig. 34.23)
Balance (Fig. 34.23b)
Utricle: horizontal changes
Saccule: vertical changes
Otoliths
Hair cells
inner ear.
Motion
semicircular canals (Fig. 34.23a)
cilia
cupula (Fig 34.23c)
hair cells
Sensing Chemicals:
Taste and Smell
Taste
Tongue with papillae containing taste buds
sour, sweet, bitter, salty,
and umami (meaty)
(Fig. 34.24)
Smell
nasal passages (Fig. 34.25) Olfactory
area, receptor
cells
Sensing Sounds:
Hearing (Fig. 34.26) (Movie)
air pressure waves
eardrum
middle ear
hammer, anvil, stirrup.
cochlea of the inner ear.
hair cells
membrane
different
pitches
volume
Problems
- earwax,
earwax
plug, Q tips,
perforated
eardrum, middle
ear infection, head phones,
permanent
hearing loss.
Lateral line system
(Fig. 34.27)
Sonar and echolocation (Fig. 34.28)
Sensing Light:
Vision (the perception of light)
Eye
structure in other animals (Fig. 34.30) and (Fig. 34.29)
Structure
of the vertebrate eye (Fig. 34.31)
cornea
lens
ciliary muscles
pupil
iris
retina (Fig. 34.36)
rods and cones (Fig. 34.32)
color vision (Fig. 34.34)
fovea
special pigments
Binocular
vision (Fig. 34.37)
Vision
problems - Snellen chart - chart for children
or non-readers
20/20 - normal -
can read at 20 feet the letters which could be read by
a person with "normal" vision.
20/10 -
better than normal vision - can read letters at 20 feet that would be read by a
person with "normal" vision at 10 feet
20/50 - worse
than normal vision - can read letters at 20 feet that would be read by a person
with "normal" vision at 50 feet
Nearsightedness
or myopia
Correction
with glasses
Presbyopia looks like this