Introduction to Brain and Behavior Dr. Hakan Psychology 256 Introduction to Brain and Behavior Dr. Hakan
What is the Brain? Billions of nerve cells
What is the Brain? Thousands of connections where one neuron may interact (communicate) with other neurons. As many as 10,000 connections 40+ neurochemicals ( neurotransmitters)
Why Study the Brain? Sensation Motion Internal Regulation Reproduction Adaptation EVERYTHING WE DO!
Overarching Principles of Brain function Hierarchically organized Redundant control Inhibition Automaticity Conscious vs Unconscious processes
The Scientific Method Empiricism Objectivity Measurement and testing replication
NUTS AND BOLTS to get started
Planes of orientation
Confusing terms (Particularly where the CNS makes its’ 90 degree bend) Anterior-Posterior/Rostral-Caudal Dorsal-ventral/ Superior-inferior
Dorsal fins
The basic unit of the nervous system
Myelin gives a whitish appearance because its adipose content Shwann cells myelinate the PNS
Oligodendrocytes myelinate the CNS
White matter and gray matter reflect organization
Staining for myelin in the brain coronal section
Myelin Staining in the Spinal cord Dorsal Horizontal plane ventral
Organizational schemes always have shortcomings: The PNS can not be truly separated from the CNS
To consider the PNS we first must consider the spinal cord The vertebral column
Each vertebra houses a spinal cord segment Midsaggital view
Each segment is similar: Central gray and surrounding white matter
Central gray: Dorsal = sensory Ventral = motor
Each segment gives rise to nerve pairs: i.e. The PNS
31 peripheral nerve pairs
Each nerve pair contains thousands of incoming and outgoing axons
The PNS:All neural tissue outside of the cranium and vertebral column ( with one exception)
Major divisions of the PNS
motor output to skeletal muscles
And somatosensory input
The somatic division of the PNS gives rise to segmental organiztion: Dermatomes and myotomes
The autonomic division
The other subdivision of the PNS-the ANS
The sympathetic chain
Sympathetic activation may be magnified by adrenal gland
Some functional differences between the somatic branch and the ANS
THE CNS
Exception- The cranial nerves