1. Name the three main parts of the neuron and describe their function.

a. Cell body
b. Dendrites
c. axon

2. Which structure characteristics permit the many possible interconnections among neurons?

a. Each axon may connect with dendritic branches from numerous neurons, making it possible for a single neuron to pass messages to as many as 50,000 neurons.

3. How do glial cells differ from neurons? What three functions do they have in the nervous system?

a. Neurons are the basic building blocks of the nervous system. These nerve cells are linked together in circuits. Neurons carry and transmit electrical signals throughout the nervous system.

b. Glial cells do not send or receive nerve impulses, but they surround neurons and hold them in place.

c. The glial cells manufacture nutrients chemicals that neurons need.

d. The glial cells absorb toxins and waste materials that might damage neurons.

4. What causes the negative resting potential of neurons? When is a neuron said to be in a state of polarization?

a. Neurons are surrounded by high concentrated sodium which carries a positive electrical charge. The inside of the neuron is electrically negative relative to the outside. (-70 millivolts across the membrane) producing a resting potential.

b. When the neuron is in a resting potential, the neuron is said to be polarized.

5. What chemical changes cause the process of depolarization that creates graded and action potentials? How do these potentials differ?

a. Graded potential is when the dendrites or the cell body of a neuron are stimulated by axons from other neurons just enough to cause some depolarization e.g. the electrical charge inside the neuron cell increases slightly but is not severe enough to cause an action potential.

b. Action potential is when the difference between the inside of the neuron cell compared to the outside becomes too small or even equalizes e.g. moves from -70 mv to + 40 mv. (depolarization)

c. The electronic difference between the two liquids is called graded potentials.

d. When the graded potentials becomes large enough, e.g. reaches the action potential threshold, the neuron discharges, letting ions to cross the cell membrane via the ion channels in both ways. The ultimate goal is to reach the resting potential state again.

6. What is the nature and importance of the myelin sheath? Which disorder results from inadequate myelinization?

a. Axons that transmit information throughout the brain and spinal cord are covered by a tube like myelin sheath, a fatty, whitish insulation layer derived from glial cells during development.

b. The myelin sheath is interrupted at regular intervals by the nodes of Ranvier, where the myelin is either extremely thin or totally absent.

c. In myelinated axons, action potential or electrical impulses can skip from node to node thus increasing the conduction rate. (more than 300km/h)

d. In unmyelinated axons, action potential or electrical impulses must travel along axons and can not skip from node to node, thus having a slower conduction rate.

e. Inadequate myelinization results in the disease of Multiple Sclerosis where the myelin sheath is damaged by the immune system causing a disruption of the delicate timing of nerve impulses.

7. How do neurotransmitters achieve the processes of excitation and inhibition of postsynaptic neurons?

a. The binding of a transmitter molecule to the receptor site produces a chemical reaction that can have one or two effects on the postsynaptic neuron.
i. Depolarization (excite) of the postsynaptic cell membrane occurs when the inflow of sodium or other positively charged ion is stimulated.

ii. Hyperpolarize (inhibitory); When neurotransmitters dock (attach) at its receptor site, hyperpolarizing occurs. Ion channels are being stimulated allowing positively charged potassium ions to flow out of the neuron or negatively charged ions.

iii. Cells whose voltage is more negative than typical are said to be hyperpolarized, and those more positive are said to be depolarized. Healthy cells do not naturally hyperpolarize or depolarize except for brief intervals, for example during a nerve impulse or action potential

iv. Excitatory Neurotransmitter > depolarizes neuron’s membrane > Increases likelihood of action potential

Inhibitory Neurotransmitter > Hyperpolarizes neuron’s membrane > Decreases likelihood of action potential

8. Describe two methods by which neurotransmitter molecules are deactivated at the synapse.

a. Some transmitter molecules are deactivated by other chemicals located in the synaptic spaces that break them down into their chemical components.

b. The deactivation mechanism is reuptake, in which the transmitter molecule is vacant, the postsynaptic neuron returns to its former resting state, awaiting the next chemical stimulation.

9. Describe the roles of

(a) acetylcholine; Excitory at synapses. Involved in muscular movement and memory.
(b) Dopamine; Can be inhibitory or excitory. Involved in voluntary movement, emotional arousal, learning, motivation, experiencing pleasure. Neurotransmitter found in the brain and essential for the normal functioning of the central nervous system
(c) Serotonin; Inhibitory at most sites. Involved in mood, sleep, eating, and arousal. Transmitter of pleasure or pain.
(d) Endorphins; reduce pain and increase feeling of well being.

10. What are the three major types of neurons? What are their functions?

a. Sensory neurons > Carry input messages from the sense organs to the spinal cord and brain.
b. Motor neurons > Transmit output impulses from the brain and spinal cord to the body’s muscles and organs.
c. Interneuron > Outnumber sensory and motor neurons. Perform connective or associate functions within the nervous system.

11. Differentiate between the central nervous system and the peripheral nervous system. What are the two divisions of the peripheral nervous system?

a. Peripheral nervous system contains all the neural structures that lie outside of the brain and spinal cord.

b. Central nervous system consists of all the neurons in the brain and spinal cord.

12. Describe the two divisions of the autonomic nervous system, as well as their roles in maintaining homeostasis.

a. The sympathetic nervous system has an activation function.

b. The parasympathetic nervous system slows down body processes and maintains a state of tranquility.

13. How do spinal reflexes occur?

a. Spinal reflexes can be triggered at the level of the spinal cord without any involvement of the brain.

i. If one touches something hot, sensory receptors in the skin trigger nerve impulses in sensory nerves that flash into the spinal cord and synapse inside with interneurons. The interneurons then excite motor neurons that send impulses to the hand, so that it pulls away.

14. Describe four methods used to study brain-behaviour function.

a. Neuropsychological tests; Measures verbal and non-verbal behaviours.

b. Destruction and stimulation techniques: Experimental studies where brain damage is induced under careful controlled conditions. E.g. brain lesions.

c. Electrical recording: Brain activities are recorded and or stimulated and then measured.

d. Brain imaging:
i. Computed axial tomography (CAT)
ii. Magnetic Resonance Imaging (MRI)
iii. Electroencephalography (EEG)
iv. Positron Emission Tomography (PET)
v. Computerized axial tomography (CT)

15. How are CT scan, PET scans, and MRIs produced, and how is each used in brain research?

a. CT (computer axial tomography) uses X-ray technology to study brain structures.
b. PET (Positron Emission tomography) measures brain activity including blood flow and metabolism. A harmless form of radioactive glucose is injected in the body and its traveling through the body is measured.
c. MRI (Magnetic Resonance Imaging) combines the functions of CT and PET. Is used to study both brain structures, and brain activity.
i. To obtain two-dimensional views of an internal organ or structure, especially the brain and spinal cord.
ii. To assess response to treatment, especially cancer chemotherapy or radiation therapy.

16. In what sense might the structure of the human brain mirror evolutionary development?

a. Represents 500 million years of evolutionary development and fine tuning.
b. More recently developed structures build atop structures from the distant evolutionary past.
c. Basic animal instinct is at the bottom; more civilized division is ‘higher’.

17. Which behavioural functions are controlled by the hindbrain structures, namely;
Medulla > plays important role in vital body functions such as heart rate and respiration.
Pons > serves as a bridge carrying nerve impulses between higher and lower levels of the nervous system.
Cerebellum > concerned mainly with muscular movement coordination. Also plays a role in certain types of learning and memory.

What occurs with damage to these structures?
Damage to the cerebellum results in severe motor disturbance characterized by jerky, uncoordinated movements.

18. Describe the roles played by the ascending and descending reticular formation. Why is it called the “brain’s gatekeeper”?

a. Ascending reticular formation > sends input to higher regions of the brain to alert it
b. Descending reticular formation > higher brain centres can either admit or block out sensory input.

c. Reticular formation > acts as a kind of guard, both alerting higher centres of the brain that messages are coming and then either blocking those messages or allowing them to go forward.

19. What is the role of the thalamus in sensory input, and possibly in thought and perceptual disorders?

a. Important sensory relay station that organizes inputs from sense organs and routes them to the appropriate areas of the brain.
b. Disrupted thalamic functioning can produce a highly confusing world for its victims. E.g. schizophrenia.

20. What role does the hypothalamus have in motivated behaviour, hunger, pleasure-pain, and hormonal functions?

a. It is thought to be involved in the expression of emotions, such as fear, rage, and aggression, and in sexual behavior.

b. The hypothalamus has important connections with the endocrine system, the body’s collection of hormone-producing glands.

21. What is the possible relation between the hypothalamus and the limbic system regarding emotion and motivation? What roles do the hippocampus and amygdale play in psychological functions?

a. The limbic system is a set of structures lying deep within the cerebral hemisphere.

b. The limbic system helps to coordinate behaviours needed to satisfy motivational and emotional urges. Also involved in memory

c. The hippocampus is involved in forming and retrieving memories. Damage to the hippocampus can result in severe memory impairment for recent events, and an inability to transfer information from short term memory to long term memory.

d. The amygdale organizes emotional response patterns, particularly those linked to aggression and fear.

22. What are the four lobes of the brain, and where are they located?

a. Frontal Lobe > top/front of brain
b. Parietal Lobe > top/rear of brain
c. Occipital Lobe > back of brain
d. Temporal Lobe > above the brain stem

23. Differentiate between sensory, motor, and association cortex.

a. Sensory systems send information to specific regions of the cerebral cortex.

b. Motor cortex control 600 or more muscles involved in voluntary body movements.

c. Somatic sensory cortex receives sensory input that gives rise to our sensations of heat, touch, cold, and our senses of balance and body movement.

24. How are the somatic sensory and motor cortexes organized?

a. The somatic sensory cortex lies in the parietal lobe just behind the motor cortex, separated from it by the large fissure that divides the frontal lobe from the motor cortex.

b. The motor cortex lies at the rear of the frontal lobe.

25. Where are Wernickes’s and Broca’s areas? How are they involved in speech?

a. Wernickes’s area is located in the temporal lobe and is involved in speech comprehension.

b. Broca’s area is located in the frontal lobe and is involved in the production of speech through its connection with the motor cortex region that controls the muscles used in speech.

26. What is the role of association cortex, the “silent areas”?

a. Involved in the highest level of mental functions, including perception, language and thought.

27. Describe the role of the frontal cortex in higher mental (including “executive”) functions.

a. The frontal cortex plays a role in self-awareness, planning, initiative, and responsibility

b. The prefrontal cortex is located just behind the forehead and is the seat of the so-called executive functions e.g. mental abilities involving goal setting, judgment, strategic planning, and impulse control which allows people to direct their behaviour in an adaptive fashion

28. What is hemispheric lateralization, and what do we know about the functions that are concentrated in the left and right hemispheres?

a. Localization of function attributed to either the right or left side of the brain.

b. The right hemisphere controls mental imagery, musical and artistic abilities, and the ability to control spatial abilities.

c. In most people, the left hemisphere of the human brain dominates, and specializes (in very broad terms) in speech, writing, language and calculation.

29. What roles have (a) the corpus collosum and (b) the optic chiasma played in “split-brain” research? Is it reasonable to speak of separate “right” and “left” brains in normal people?

a. The corpus collosum is a bridge of nervous tissue that connects the two cerebral hemispheres, allowing communication between the right and left sides of the brain.

b. The optic chiasma is a structure in the brain formed by the partial intersection or crossing of the optic nerve fibers on the underside of the hypothalamus.

c. The brain is an integrated system, not a collection of localized functions.

30. How is language lateralized in the brain? Are there sex difference?

a. Language is primarily a left-hemisphere function

b. Male and female may differ to the extent to which certain language functions are lateralized, or located, on one side of the brain.

31. What is neural plasticity? How do age, environment, and behaviour affect plasticity?

a. Neural plasticity refers to the ability of neurons to change in structure and function

b. Brain damage suffered early in life is less devastating than damage received later in life. Neural reorganization enables other neurons to take over the functions of those that have either been destroyed or have died.

c. A caring environment to a newborn e.g. caressing and massaging on a regular basis showed a faster neurological development.

32. Why do children typically show better recovery of function after brain injury?

a. The brain is capable of greater plasticity early in life as it has about 50% more synapses than mature adults do.

33. How are axon repair, brain grafts, and neural stem cell injections being used to improve the functioning of damaged brains? What kinds of ethical issues arise in the use of these procedures?

a. Through either current stimulation or chemical methods, axon development can occur. Implantation of cells has also shown new nerve growth which attached them to the damaged nerve area, repairing itself.

b. Since fetal tissue is best suited for re-growing nervous tissue, is a production and ‘harvesting’ of unborn life the result? Does it result in artificial insemination and the aborting of the resulting embryo e.g. creating life and then destroying it for the sake of ‘harvesting’ tissue that in turn can improve and save life? Very hard question to answer.

34. How does the endocrine system differ from the nervous system as a communications network?

a. The endocrine system consists of numerous glands distributed throughout the body. This system is much slower than the nervous system as the delivery of messages depends on the speed of the blood flow.

b. The nervous system transmits information rapidly, with the speed of nerve impulses

35. What are some ways in which the nervous and endocrine systems affect each another?

a. Endocrine messages can affect the nervous system, and mental process within the brain can, in turn, affect endocrine functioning.

b. Negative thoughts about a stressful situation can trigger stress hormones within the blood.

36. What physiological explanation did Cannon offer for death by “black magic”?

a. The victim’s belief triggered a profound stress response that included an uncontrolled flow of stress hormones, released by the endocrine system causing a fatal drop in blood pressure.

37. In what ways does the immune system have sensory, response, and memory capabilities?

a. Once the immune system has encountered on of the millions of different antigens that enter the body, it will recognize (remember) the antigen immediately in the future and will produce the biochemical weapons, or antibodies needed to destroy it.

38. How does under-or over activity to internal or external antigens give rise to four varieties of immune dysfunction?

a. Under activity; AIDS, HIV
b. Over activity; Allergy, rheumatoid arthritis

39. What evidence exists that the immune and nervous system communicate with and affect each another?

a. The nervous, endocrine, and immune system are all parts of a communication network.

b. Changes in either the hypothalamus or cerebral cortex result in instantaneous increase or decrease of immune-system activity.

40. Which psychological factors have been shown to influence immune functioning?

a. Stress has show to reduce the immune systems effectiveness because of hormones are released in the blood stream by the adrenal glands which in turn suppresses the effectiveness of the immune system cells.

41. What can be done to enhance immune functioning?

a. Develop a good sense of humor as it can balance out stressful situations which in turn prevent prevents the production and oversupply of stress hormones as these suppress the effectiveness of the immune system cells.

42. Differentiate between genotype and phenotype.

a. Genotype is the specific genetic makeup of the individual

b. Phenotype is the observable characteristics produced by that genetic endowment.

43. How does genetic transmission occur from parents to offspring?

a. At conception, the 23 chromosomes from the egg combine with the 23 from the sperm to form a new cell containing 46 chromosomes.

b. The genes within each chromosome also occur in pairs, so that the offspring receives one of each gene pair from each parent.

44. Compare dominant, recessive, and polygenic influences on phenotypic characteristics.

a. Dominant influences results in the display of the particular characteristic

b. Recessive influences results in the absence of a particular characteristics unless the partner gene inherited from the other parent is also recessive.

c. Polygenic transmission occurs when a number of gene pairs combine their influences to create a single phenotypic trait.

45. Describe the methods used in recombinant DNA research.

a. Recombinant DNA procedures are when genes either duplicated or modified. This is accomplished by using certain enzymes and cut the long threadlike molecules of genetic DNA into pieces, combining them with DNA from another organism, and insert them into a host organism. Inside the host, the new DNA combination continues to divide and produce many copies of itself.

46. What is the knockout procedure and how is it used by psychologists to study behaviour?

a. A knockout procedure is when a particular function of a gene is eliminated e.g. is prevented from carrying out its normal function.

b. After genetic material which prevents neurons from responding to a particular neurotransmitter is introduced to a test carrier (mouse) the ability of the mouse to learn or remember is measured.

47. What is the percentage of genetic resemblance between parents and children, identical and fraternal twins, brothers and sisters, and grandparents and grandchildren?

a. Resemblance: Parent > Child = 50%
Resemblance: Identical > Fraternal twins = 100% - 50%
Resemblance: Brother > Sister = 50%
Resemblance: Grandparents > Grandchild = 25%

48. How are adoption and twin studies used to achieve heritability estimates? What have such studies shown?

a. A person who was adopted early in life is compared on some characteristic with both the biological parents. No characteristics to the adoptive parents were observed.

b. Since identical twins look alike, they may be treated alike and therefore display the same traits, behaviours, and idiosyncrasies.

49. Why are studies of twins raised together and apart especially informative? What findings have occurred in such studies?

a. Both adoption and twin studies have shown that many psychological characteristics; including intelligence, personality traits, and certain psychological disorder, have a remarkable genetic contribution.