Transcript The Nervous System

The Nervous System
The Neuron
• The neuron is the
basic unit of the
nervous system
• Central Neurons in
CNS
• Peripheral Neurons in
PNS
The Peripheral and Central
Nervous Systems
The peripheral nervous system carries
information to and from the nervous
system
The somatic nervous system is the
part of the peripheral nervous system
that carries information to skeletal
muscles
The Peripheral and Central
Nervous Systems
• The sympathetic nervous system is the
part of the autonomic nervous system that
becomes most active during emergency
situations
The Peripheral and Central
Nervous Systems
• The parasympathetic nervous system is
the part of the autonomic nervous system
that controls the ongoing maintenance
processes of the body
Figure 2.8 The Basic Divisions of the Nervous System
Five Principles of Brain
Organization
1. The hindbrain, midbrain, and forebrain
each involve several brain regions that
carry out different types of information
processing
2. There are identifiable neural pathways
projecting from one area to the next
Five Principles of Brain
Organization
3. Each part of the brain projects to the next
in an orderly fashion creating organized
regions that can be mapped
4. The brain is hierarchically organized
5. The brain systems are organized so that
one side of the brain controls the other
side of the body
Figure 2.11 The Hindbrain
The Midbrain
• The midbrain receives afferent signals
from other parts of the brain and relays the
information to a more complex part of the
brain
The Forebrain
• The forebrain is the most complicated and
advanced of the three divisions of the
brain
• The thalamus sends information to other
parts of the brain
• The hypothalamus affects many complex
behaviours
Figure 2.12 The Forebrain
The Forebrain
• The limbic system is an interconnected
group of structures that influences
emotions and memory
• The hippocampus is involved in new
learning
• The amygdala is involved in emotional
control
Figure 2.13 Principal Structures of the Limbic System
The Forebrain
• The basal ganglia controls movement and
posture
• The corpus callosum provides crosshemisphere connections
The Cortex
• The cortex is divided into a series of
lobes
The Cortex
• The frontal lobe is concerned with
directing thought processes
• The parietal lobe integrates visual input
• The occipital lobe processes visual
input
• The temporal lobe is important for
language comprehension
Figure 2.14 The Cortex and the Lobes of the Brain
Monitoring Neural Activity
• Single-unit recording measures activity
in individual neurons
• Electroencephalography (EEG)
measures electrical activity in the
nervous system
Monitoring Neural Activity
• CT scans are computer-enhanced X-
rays
• PET tracks radioactive markers that
have been injected into the bloodstream
Monitoring Neural Activity
• MRI uses magnetic fields
• fMRI measures brain activity as it
takes place