The Nervous System

The Lay of the Land

Nervous system

Central nervous system

Peripheral nervous system

Central nervous system

Brain Spinal cord

Peripheral nervous system

Somatic nervous system

Autonomic nervous system

Nervous system

Central nervous system

Peripheral nervous system

Brain Spinal cordSomatic

nervous systemAutonomic

nervous system

Figure 2.2 The human nervous system Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

Nervous system

Central nervous system

Peripheral nervous system

Brain Spinal cordSomatic

nervous systemAutonomic

nervous system

Afferent nerves

Efferent nerves

Afferent nerves

Efferent nerves

Sympathetic nervous system

Parasympathetic nervous system

Generally speaking…

• Sympathetic nervous system– Gets body ready for

“fight or flight”

• Parasympathetic nervous system– Saves energy, slows

things down to normal after danger is over

Protecting the Central Nervous System

Figure 2.12 Structures that protect the CNS Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

Meninges: Layers of protection

• Dura mater (tough mother)

• Arachnoid mater (spiderweblike membrane)

• Pia mater (pious mater)

Cerebrospinal Fluid (CSF)

• Water bed

• Central canal• Cerebral ventricles

Figure 2.14 The ventricular system Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

The Blood-Brain Barrier

• Prevents harmful substances in the blood from entering the brain

• The cells that make up the walls of the blood vessel walls are squeezed close together, so many molecules cannot pass through

The Blood-Brain Barrier

• Substances that are important for brain and body functioning can pass through

• Psychotropic drugs, anti-histamines

Cells of the Nervous System

Cells of the Nervous System

• Neurons

• Glial cells

NeuronsFigure 2.5 A typical neuron and synapse Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

Figure 2.6 The four major types of synapses Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

2. Glial cells

• Oligodendrocytes– Myelin sheath of central nervous system

• Schwann cells– Myelin sheath of peripheral nervous system

Figure 2.9 Types of glial cellsS Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

2. Glial cells• Astrocytes

– Astro = star– Helps maintain the

blood-brain barrier– Provide neurons with

nutrients– Support neurons:

protect and hold neurons in place

– Keep neurons separated to prevent messages from being mistakenly transmitted

2. Glial cells• Microglial

– Micro = small– Clean up neurons that

have died

Central nervous system

Brain Spinal cord

The Spinal Cord

• 31 pairs of spinal nerves– 8 cervical– 12 thoracic– 5 lumbar– 5 sacral– 1 coccygeal

Figure 2.10 The 31 pairs of spinal nerves Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

Figure 2.15 Section of the spinal cord Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

Gray matter: cell bodies

White matter: axons

Figure 1.3 A cross-sectional view of part of the spinal cordKlein/Thorne: Biological Psychology© 2007 by Worth Publishers

• Dorsal, afferent, sensory

• Ventral, efferent, motor

Major Structures of the Brain

Major Structures of the Brain

• Hindbrain

• Midbrain

• Forebrain

Major Structures of the Brain

• Hindbrain

Figure 2.17 The hindbrain Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

Hindbrain

• Medulla

• Pons

• Cerebellum

• Medulla• Vital functions

(heart beat, breathing)

• Swallowing, coughing, sneezing

• Pons• Relays info

between cerebellum and forebrain

• Sleep• Levels of

consciousness

• Cerebellum• Balance• Motor function• Movement• Posture

Major Structures of the Brain

• Midbrain

Figure 2.18 The midbrain Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

Midbrain

• Periaqueductal gray

• Substantia nigra

• Periaqueductal gray– Drugs that reduce pain

• Substantia nigra– Latin for “black

substance”– Dopamine

Major Structures of the Brain

• Forebrain

• Thalamus• Hypothalamus

• Cerebral cortex• Limbic system• Basal ganglia

http://www.msnbc.msn.com/id/10401930

• Thalamus• Relays information

from all senses except smell

• Like a telephone switchboard that conveys information from vision, hearing, touch.

Figure 2.21 The thalamus Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

• Hypothalamus– Controls release of

hormones – that stimulate

growth– when under

stress

• Controls temperature, hunger, thirst

Figure 2.22 The hypothalamus Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

• The cerebral cortex

Figure 2.25 The cerebral cortex Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

• Frontal lobe– Movement – Memory – Decision-making– Emotion– Conscious control of

behavior– Personality

Figure 2.25 The cerebral cortex Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

Damage to the frontal lobe

• Difficulty with responding to the environment– Not following rules– Impaired learning

• Changes in personality

• Temporal lobe– Hearing– Memory– Language

Figure 2.25 The cerebral cortex Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

• Parietal lobe– Information from touch– Making sense of

spatial relationships in the environment

Figure 2.25 The cerebral cortex Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

Damage to the parietal lobe

• Right parietal lobe: neglect of left side

• Occipital lobe– Vision

Figure 2.25 The cerebral cortex Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

• The limbic system

Figure 2.23 The limbic system Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

• Amygdala: fear and escape

• Hippocampus: memory

• The basal ganglia

Figure 2.23 The basal ganglia Klein/Thorne: Biological Psychology© 2007 by Worth Publishers

Basal ganglia

• Voluntary movements– Parkinson’s disease– Huntington’s disease– Tourette’s

Figure 2.4 Anatomical directions and perspectives Klein/Thorne: Biological Psychology© 2007 by Worth Publishers