UNIT 2 BIOLOGICAL BASES OF BEHAVIOR

Transcription

1 UNIT 2 BIOLOGICAL BASES OF BEHAVIOR

2 An Early History of Biopsychology l Plato: the mind is located in the brain l Franz Gall and Phrenology Early 1800s Read bumps on skull to understand traits

3 If I was to take your brain out of your body, place it into patient needing brain surgery, where would the new self call home? Are you simply the end product of a biological and chemical reaction?

4 Biopsychology Today l Everything we do is ulfmately controlled by our body and brain Body/brain composed of cells Brain cells called neurons communicate electrically and chemically Different parts of the brain have specific funcfons Our brains create meaningful experiences from sensory informafon Brain structure and funcfon is influenced by experience

5 AGENDA 1) Review Text Book Reading 2) Quiz 3) Todays Theme: Hemisphere Dominance 4) VIDEO: Split Brain Patients 5) Hand back & Discuss Test (I WILL NEED 5-7 minutes)

6 The Cortex l Each hemisphere is divided into 4 lobes Frontal lobe Temporal lobe Parietal lobe Occipital lobe l The lobes are separated by deep convolufons known as fissures

7 Cortex Breakdown l Occipital Lobes Visual cortex Damage? l Temporal Lobes Auditory cortex Auditory hallucinafons? l Parietal Lobes Primary sensory or somatosensory cortex AllocaFon of space? l Frontal Lobes Most evolved Motor cortex, which allows us to move AllocaFon of space?

8 Some Hemispheric Strengths LeU Hemisphere Language Logic Right side of body Right Hemisphere PercepFon Sense of self Inferences LeU side of body

9 Split- Brain Epilepsy, seizures and the corpus callosum ReducFon in epilepfc seizures Different abilifes in each hemisphere hyps:// watch?v=lfgwsads9dc

10 AGENDA: 1.Map the Brain with the Truine Model 2.COLLABORATION: Map brains parts together 3.VIDEO: Secrets of the Mind

11 TRUINE MODEL: REPTILIAN BRAIN Primary focus is survival Instinct Internal Functions OLDEST STRUCTURE

12 TRUE STORY:

13 TRUINE MODEL: MAMALIAN BRAIN Contains the Limbic System (Seat of EMOTION) In charge of appetite, sex drives and some vision.

14 TRUINE MODEL: HUMAN BRAIN Youngest Part Counteracts Emotions Information Processing Abstract Complex Thoughts & Behaviors

15 THE MORE CREATIVE YOU ARE, THE MORE YOU WILL REMEMBER INTERNAL EXTERNAL STEP 1: RESEARCH YOUR BRAIN FEATURE (You need to explain it to other students WITHOUT NOTES. STEP 2: Create a creaove catch phrase or slogan which will help people remember what your funcoon does. STEP 3: Come up with a visual image that illustrates its funcoon. STEP 4: LOCATE THE BRAIN PART AND PUT YOUR INFO ON THE BOARD

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17 PrimiOve Brain Structures AUTOPILOT Brainstem Oldest part of brain Contains medulla, controlling heartbeat, blood pressure and breathing Also contains pons, which helps regulate sensory informafon and facial expressions Contains ReOcular FormaOon (RF) for alertness/arousal, sleep/wakefulness Thalamus Pair of egg- shaped structures on top of brainstem Routes all incoming sensory informafon except for smell to appropriate areas of brain Cerebellum liyle brain at read of brainstem Controls coordinafon, balance, and muscle tone These parts of the brain are our autopilot so other regions can deal with higher- level human funcfons

18 The Limbic System Hippocampus processes new memories Amygdala controls emofons such as aggression and fear in animals, the ayack response Hypothalamus regulates hunger, thirst, body temperature and sex drive also controls pituitary gland Located in between the primifve parts of the brain and the cerebral hemispheres PRIMARILY, the limbic system processes drives, smell and various emooonal responses

19 The Cortex Most highly evolved part of the human brain Body s ulfmate control and informafon- processing center Reasoning Center Limbic System vs. Cortex hyps:// v=u76jbk59rfk

20 AGENDA: 1.QUIZ (Be ready to go at the bell) 2.GET FIRED UP ABOUT NEUROSCIENCE! 3.How does our body communicate with itself? 4.Labeling the Neuron 5.ACTING OUT NEURAL COMMUNICATION!

21 NEURONS and SYNAPSES Types of Neurons Sensory Motor Interneurons

22 Sensory Neurons From sensory organs to the brain and spinal cord. Drawing shows a somatosensory neuron Vision, hearing, taste and smell nerves are cranial, not spinal Sensory Neuron Brain Spinal Cord

23 Motor Neurons From the brain and spinal cord to the muscles and glands. Sensory Neuron Brain Spinal Cord Motor Neuron

24 Interneurons Interneurons carry information between other neurons only found in the brain and spinal cord.

25 HOW LONG DOES THIS TAKE WITH NORMAL STIMULI?

26 BUT HOW EXACTLY DO THESE CELLS COMMUNICATE??!?!?!

27 AcFon potenfals Brief Electrical charge that travels down an axon (Myelin Sheath helps speed things up!) NeurotransmiYers: Chemicals that transmit messages between neurons

28 STRUCTURES OF THE NEURON PLEASE DRAW THIS ON A BLANK SHEET OF PAPER

29 THE CELL BODY CONTAINS THE CELL S NUCLEUS Round, centrally located structure Contains DNA Controls protein manufacturing Directs metabolism No role in neural signaling

30 InformaFon collectors Receive inputs from neighboring neurons Inputs may number in thousands If enough inputs the cell s AXON may generate output. DENDRITES

31 DENDRITIC GROWH Mature neurons generally can t divide. BUT new dendrites can grow. Provides room for more connecfons to other neurons. NEW CONNECTIONS ARE THE BASIS FOR LEARNING

32 AXON The cell s output structure One axon per cell, 2 disfnct parts: AXON AXON TERMINAL

33 Myelin Sheath White fayy casing on axon Acts as an electrical insulator Not present on all cells When present increases the speed of neural signals Myelin Sheath

34 Neuron on Neuron Axons branch out and end near dendrites of neighboring cells. Axon terminals are the Fps of the axon s branches Gap is the Synapse Axon Cell Body Dendrite

35 Synapse Axon terminals contain small storage sacks called synapfc vesicles Vesicles contain neurotransmiyer molecules Axon Terminal Sending Neuron Synapse

36 THE MESSAGE IS SENT DOWN THE AXON IN WHAT WE CALL AN: ACTION POTENTIAL Domino Effect of electrical current.

37 TIME TO APPLY! LAB TIME! LETS MAKE IT VISUAL!

38 A. ResFng State 1. Outside of the neuron membrane is posiove 2. Inside of the membrane is negaove (- 70 mv) 3. More Na+ outside, more K+ inside Why don t the charges escape? 4. The membrane is selecovely permeable

39 Cell membrane is Semi-Permeable K+ Na+ Cl- Outside of Cell Cell Membrane at rest Na+ K+ A- Cl- Inside of Cell - 70 mv Potassium (K+) can pass through to equalize its concentraoon Sodium and Chlorine cannot pass through Result - inside is negaove relaove to outside

40 RESTING POTENTIAL At rest inside of the cell is at - 70 microvolts With inputs to dendrites inside becomes more posifve If resfng potenfal rises above threshold and acfon potenfal starts to travel from cell body down the axon. Figure shows resfng axon being approached by an AP

41 Depolarization ahead of AP AP opens cell membrane to allow sodium (NA+) in Inside of cell rapidly becomes more posifve than outside This depolarizafon travels down the axon as leading edge of the AP.

42 B. DepolarizaFon (Rising Phase) Causes the inside of the membrane to become posifvely charged (depolarized)

43 2) RepolarizaFon (Falling Phase of AcFon PotenFal)

44 3) Refractory Period Short amount of Fme when no new acfon potenfals can be fired ResFng potenfal (- 70 mv) must Be restored

45 Nerve Cell Membrane Each level contains about 10% o the energy in the previous level.

46 ResFng State hyp:// v=90cj4nx87yk&feature=related

47 Neurotransmitter Release AcFon PotenFal Causes vesicle to open NeurotransmiYer released into synapse Locks onto receptor molecule in postsynapfc membrane. NeurotransmiYer molecules have specific shapes Binding sites for NT s When NT binds to receptor, ions enter Starts AP again

48 What happens when the acfon potenfal reaches the terminal branch? Vesicles containing neurotransmiyers are released into the synapse NeurotransmiYers bind to postsynapfc receptors Cause excitatory or inhibitory effects hyp:// v=ntenaz7sf4k

49 Neuron Firing: Electro Chemical Process 1. Neuron at rest is polarized 2. Neuron receives signals from neighboring neurons 3. Total excitatory input exceeds absolute threshold 4. Neuron fires according to all or none principle acfon potenfal shoots down the axon 5. NeurotransmiYers are released across synapse. 6. Refractory period

50 NeurotransmiYers bind receptors in a lock- and- key model