1. The Biology of Behavior
Unit 2: Biopsychology

2. The Nervous System
Central nervous system  consists of the brain and the spinal cord
Brain  an organ of soft nervous tissue contained in the skull; functions as the coordinating center of sensation, intellect, and nervous activity
Spinal Cord  cylindrical bundle of nerve fibers and associated tissue that is enclosed in the spine; connects nearly all parts of the body to brain
Peripheral nervous system  made up of nerve cells that send messages between the central nervous system and all of the other parts of the body

4. Spinal Cord

5. Spinal cord

6. Spinal cord anatomy

7. Neurons
Neurons  nerve cells that run through the whole body and communicate with each other.
30,000 neurons can fit on a pinhead
Each neuron contains:
Cell body with nucleus
Dendrites : fibers that receive messages from other neurons
Axons : fibers that send messages to other neurons
Neurons do NOT touch; there is a gap between them called a synapse
Messages are sent across the synapses by special chemicals called neurotransmitters

10. Communication Between Neurons
The use of neurotransmitters causes an electrical current
There is enough electrical current in the brain to power a flashlight

11. Major Neurotransmitters
Serotonin
Dopamine
Achetylcholine
Norephinephrine
Endorphins

12. Peripheral Nervous System
Nerves : visible bundles of axons and dendrites that extend from the brain and spinal cord to all other parts of the body
Responsibilities:
Sensory nerves - carry messages from body to brain (pain, pressure, temperature)
Motor nerves – carry messages from brain to body to respond

13. Somatic Nervous System
Voluntary Actions!!!
Transmits sensory messages to the central nervous system
It is activated by touch, pain, changes in temperature, and changes in body position
The somatic nervous system allows the body to move or change position
It also sends messages to the muscles and the glands and helps to maintain posture and balance

14. Automatic Nervous System
Involuntary Actions!!!
Regulates the body’s vital functions, such as heartbeat, breathing, digestion, and blood pressure
We generally do not have to think about these activities – they occur automatically and are essential for keeping us alive
Two divisions:
Sympathetic  activated when a person is going into action (“fight or flight”)
Parasympathetic  restores the body’s reserves of energy after an action has occurred

15. Anatomy of the Brain The Hindbrain:
Medulla  involved in vital functions such as heart rate, blood pressure, and breathing
Pons  located in front of the medulla; involved in regulating body movement, attention, sleep, and alertness
Cerebellum  rests under the larger part of the brain (cerebrum); involved in balance and coordination

16. Anatomy of the Brain The Midbrain:
Located between the hindbrain and the forebrain
Involved in vision and hearing
Reticular activating system  begins in the hindbrain, rises through the midbrain, continues into the lower part of the forebrain
Important for attention, sleep, and arousal

17. Anatomy of the Brain The Forebrain:
Thalamus  serves as a relay point for sensory stimulation; most of the messages coming from the sense organs go through the thalamus on the way to the higher levels of the brain
Hypothalamus  located below the thalamus; vital to regulation of body temperature, storage of nutrients, and various aspects of motivation and emotion

18. Anatomy of the Brain The Forebrain:
Limbic system  forms a fringe along the inner edge of the cerebrum; involved in learning and memory, emotion, hunger, sex, and aggression
Hippocampus  involved in memory processing
Amygdala  involved in aggressive and fear based responses (fight or flight)

19. Anatomy of the Brain The Forebrain:
Cerebrum  accounts for 70% of the weight of the human brain; surface is wrinkled with ridges and valleys, known as the cerebral cortex
Cerebral cortex is involved with thinking, memory, language, emotions, complex motor functions, perception, and more

20. Lobes of the Brain (4)
Frontal
Parietal
Occipital
Temporal

21. Lobes of the Brain - Frontal
The Frontal Lobe of the brain is located deep to the Frontal Bone of the skull.
It plays an integral role in the following functions/actions:
- Memory Formation
- Emotions
- Decision Making/Reasoning
- Personality

22. Lobes of the Brain - Parietal Lobe
It plays a major role in the following functions/actions:
- Senses and integrates sensation(s)
Spatial awareness and perception

23. Lobes of the Brain – Occipital Lobe
The Occipital Lobe of the Brain is located at the back of the head
Its primary function is the processing, integration, interpretation, etc. of VISION and visual stimuli.

24. Lobes of the Brain – Temporal Lobe
The Temporal Lobes are located on the sides of the brain
They play an integral role in the following functions:
Hearing
Organization/Comprehension of language