NERVOUS SYSTEM &

THE BRAIN

Fact or Fiction

• Everything psychological is simultaneously biological

– Your every idea, every mood, every urge is a biological happening

– You think, feel and act with your body

– You relate to the world through your body

What do we Know?

• The body is composed of cells

• Among these are nerve cells that conduct electricity and “talk” to one another by sending chemical messages across a tiny gap that separates them – the synapse

• Specific brain systems serve specific functions

• From info processed in these brain systems, we construct our experience of sights, sounds, meanings, memories, pain and passion

Nervous System

Nervous System

Central Nervous System Peripheral Nervous System CNS PNS

(All nerves housed (All nerves not encased

in bone – skull & in bone. Connects

vertebrate) periphery of body with

Central Nervous System)

Nervous System

Nervous System

Central Nervous System Peripheral Nervous System

CNS PNS

Brain Spinal Cord Autonomic Somatic

Sympathetic Parasympathetic

Central Nervous System

Brain

Hind Brain Mid Brain Fore Brain

HIND BRAIN

•Top part of spinal cord

•Our “life support” system

•Controls basic biological functions

•Includes: Medulla, pons, cerebellum

MID BRAIN

•Just above the spinal cord

•In general, co-ordinates simple movements with sensory info

(integrates sensory info & muscle movement)

•Includes: Reticular Formation

Central Nervous System

Brain

Hind Brain Mid Brain Fore Brain

Fore Brain

•Controls thought and reason

•Includes: Cerebral Cortex & Subcortical structures

•Subcortical Structures: Thalamus, Hypothalamus, Amygdala,

Hippocampus

•Thalamus, Hypothalamus, Amygdala, Hippocampus together

are known as the Limbic System

•Limbic System deals with aspects of emotion and memory

Central Nervous System

Spinal Cord

Ascending Inter Descending Pathways Neurons Pathways (sensory) once info reaches (Motor) (afferent) brain or spinal cord (efferent) inter-neurons take messages & send them elsewhere in brain or on to the efferent (motor) neurons

Peripheral Nervous System

Peripheral Nervous System

Somatic Division Autonomic Division

Sensory Motor Sympathetic Parasympathetic

Nerves Nerves System System

(arousing) (calming)

Somatic Division

Somatic Division (involved in sensing & responding; Controls voluntary movements of skeletal

muscles)

Sensory Nerves Motor Nerves

Afferent – info from senses Efferent – info from brain to

to brain rest of the body

Afferent nerves as taking Efferent nerves carry info

info at the brain that exits the body

* Follows ascending pathways * Follows descending pathway

Autonomic Division (involuntary; controls self-regulating action of internal organs & glands. Eg.

Lungs,heart)

Sympathetic System Parasympathetic System (arousing) (calming)

Mobilizes body to deal with slows body after stress response Stress ‘alert system’ ‘brake system’ Carries msgs to control systems slows down body’s autonomic of organs, glands, muscles nervous system Increases heart rate, blood pressure & respiration Conserves resources by

Decreasing digestion NOTE: homeostasis = balanced state