1. Biology & Behavior
Chapter 2

2. Section 1: The Nervous System

3. It’s almost like running is this great friend we both share…Anyway, that’s what I’d like to talk to you about… running as a friend, as a companion, a lover even…in other words, the relationship of running. “WHAT!?” many of you will be saying. “I thought that I was going to learn how to improve my 10k time.” GO read Runner’s World for that. You see, I don’t view running as what I DO or who I AM, but as this thing, this force, that changes me over time.
From “Running and Me: A love Story” by Joan Nesbit, 1999

4. Neurons
Nerve cells that run through our entire body and communicate with one another
100 billion neurons, most found in brain

5. The Nervous System Central Nervous System Peripheral Nervous System
Brain & Spinal Cord
Nerve cells that send messages between the central nervous system and all parts of the body

7. Parts of a Neuron
Cell body – produces energy that fuels the activity of the cell
Dendrites –receive information from other neurons and pass the message through the cell body
Axons –carries messages away from cell body

8. Myelin – white fatty substance that insulates and protects the axon; also speeds up transmission of messages
Axon terminals – small fibers at the end of the axon

9. The Communication Process
Messages sent from the axon terminals of one neuron to dendrites of other neurons
Crosses synapse (junction between the axon terminals of one neuron and the dendrites of another neuron)
Messages travel in only one direction

10. Neurotransmitters: Chemical Messengers
Neurotransmitters (the message)are chemicals that are stored in axon terminals
Neurons can fire hundreds of times every second
Several types of neurotransmitters, each with their own structure

11. The Central Nervous System
Transmits messages between the brain and the muscles and glands throughout the body
Also involved in spinal reflexes

12. The Peripheral Nervous System
Made up of the Somatic Nervous System & the Autonomic Nervous System

13. The Somatic Nervous System
AKA the skeletal nervous system
Transmits sensory messages to the CNS
Activated by touch, pain, changes in temperature, changes in body position
Enables us to experience hot and cold and to feel pain and pressure
Helps us maintain posture and balance

14. The Autonomic Nervous System
Regulates body’s vital functions (heartbeat, breathing, digestion, blood pressure)
Don’t have to think about these activities...happen automatically
Made up of the Sympathetic & Parasympathetic nervous systems

15. Sympathetic Nervous System
Prepares body for action
To either run away or confront situation
“Fight or Flight” response
Suppresses digestion, increases heart & respiration rates, elevates blood pressure

16. Parasympathetic Nervous System
Restores the body’s reserves of energy after an action has occurred
Heart rate & blood pressure are normalized, breathing slowed, digestion returns to normal

17. CNS PNS Nervous System Spinal Cord Brain
Autonomic System (involuntary muscles & internal organs)
Parasympathetic System
(Calms body after emergencies
Sympathetic System
Prepares body for action
Somatic System (voluntary muscles & sense organs)

18. For homework:
On a half sheet of paper… explain how a neuron works using the metaphor of a relay race. Be sure to be specific and detailed in your description.

19. Section 2: The Brain

20. The Brain Mind, or consciousness, dwells within the brain
Divided into 3 sections
Hindbrain
Midbrain
Forebrain

22. Hindbrain
Medulla oblangata – Involved in vital functions (heart rate, blood pressure, and breathing)
Pons –regulates body movement, attention, sleep, and alertness
Cerebellum – “little brain” – balance and coordination

23. Midbrain Vision & hearing Contains part of reticular activating system
Important for attention, sleep, and arousal
Increases heart rate & blood pressure

24. Forebrain Four major areas Thalamus Hypothalamus Limbic System
Cerebrum

25. Thalamus
A relay station for sensory stimulation

26. Hypothalamus
Regulates body temperature, storage of nutrients, & various aspects of motivation & emotion
Involved in hunger, thirst, sexual behavior, caring for offspring, & aggression
Disturbances within the hypothalamus can lead to unusual drinking & eating behaviors

27. Limbic System
Involved in learning and memory, emotion, hunger, sex, and aggression
If damaged, people can recall old memories but not create new ones

28. Cerebrum
Surface of cerebrum known as the cerebral cortex (outer layer of brain)
Part that makes us uniquely human – the part that thinks
Also deals with memory, language, emotions, complex motor functions, perception

30. Cerebral Cortex Divided into two hemispheres
Corpus Callosum connects two hemispheres
Information received by one side of the body is transmitted to the opposite hemisphere
Each hemisphere is divided into four lobes
Frontal Lobe
Parietal Lobe
Temporal Lobe
Occipital Lobe

32. Senses and Motor Behavior
Occipital lobe contains primary visual area
Damage creates unusual conditions: may be able to recognize an object but unable to differentiate it from another similar object
Temporal lobe contains hearing or auditory area
If damaged a person may not be able to recognize common sounds

33. Parietal lobe – receives messages from skin senses (warmth, touch, cold, pain)
Frontal lobe – home to the motor cortex (neurons fire when we move certain parts of our body)

34. Association Areas Shape information into something meaningful
Frontal lobe association areas where we solve problems, make plans and decisions

35. Left vs. Right Hemispheres
Left Hemisphere
Right Hemisphere
Language functions, logic, problem-solving, math
imagination, art, feelings, spatial relations
For nearly all right-handed people, language functions are based in left hemisphere
Language functions also based in left hemisphere for 2/3rds of left-handed people
Although differences exist between two hemispheres, they don’t act independently of each other

36. How do we study the brain?
Accidents
Electrical Stimulation of the Brain – shows that specific areas are associated with specific types of sensations
EEG – device that records electrical activity in the brain
Scans
MRI – lie in a magnetic field – brain gives off extra energy from radio waves and creates visual images
Good for small injuries
CAT – X-ray beams passed through head and form 3-d images of brain
fMRI – fast kind of MRI that shows the brain at work
PET – radioactive sugar injected into body – as it reaches the brain – more is used in areas of greater activity – images show this activity

37. Section 3: The Endocrine System

38. The Endocrine System Glands that secrete hormones into the bloodstream
Pituitary Gland – The “master gland”
Secretes growth hormone, hormone to stimulate labor in pregnant women
Thyroid Gland – controls metabolism
Pineal Gland – produces melatonin & affects sexual development
Adrenal Gland – produce adrenaline & nonadrenaline
Testes & Ovaries – produce testosterone, estrogen, progesterone

43. Section 4: Heredity

44. Heredity Transmission of characteristics from parents to offspring
Genes – basic building blocks of heredity
46 chromosomes divided into 23 pairs
23rd chromosome – boys xy and girls xx
Dad determines sex of offspring

45. Nature-Nurture Debate
What people inherit
Inherited characteristics determine the kind of people we are
Nurture
Environmental factors
Family, education, culture, living conditions, everyday experiences
Today, most psychologists believe both are involved

46. Kinship Studies Common way to study nature vs. nurture
Twin studies – to determine which traits are genetically inherited
Adoption studies – do kids act more like biological or adopted parents?
Twins reared apart – still share many traits