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Biological-Psychology Lecture- Notes for BS PSYCHOLOGY

STUDENTS
BS Psychology (Rizal Technological University)

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BIOLOGICAL/PHYSIOLOGICAL PSYCHOLOGY - call attention to behavioral similarities among related - moral imperative is that people have no right to
species use animals at all, even if the research is highly
LESSON 1: THE FIELD OF BIOLOGICAL PSYCHOLOGY useful and totally painless
4. Functional Explanation
Biological Psychology - describes why a structure or behavior evolved as it did
- the study of the physiological, evolutionary, and - within a small, isolated population, a gene can spread LESSON 2: THE CELLS OF THE NERVOUS SYSTEM
developmental mechanisms of behavior and by accident through a process called genetic drift.
experience Ψ Two scientists of the late 1800s and early 1900s are
- is approximately synonymous with the terms The Use of Animals in Research widely recognized as the main founders of neuroscience
biopsychology, psychobiology, physiological - ethical dispute on the use of animals in research Charles Sherrington, and the Spanish investigator
psychology, and behavioral neuroscience - still insist however because of the position that it is Santiago Ramón y Cajal (1852–1934).
- emphasizes that the goal is to relate biology to issues of proper and ethical
psychology - four reasons why psychologists and neuroscientists Charles Sherrington
- It holds that we think and act as we do because of study nonhumans: - best known for providing us with the term synapse
brain mechanisms, and that we evolved those brain  The underlying mechanisms of behavior are similar - also studied reflexes, proprioception, spinal nerves,
mechanisms because ancient animals built this way across species and sometimes easier to study in a muscle action, and movement
survived and reproduce nonhuman species
- deals mostly with brain activity  We are interested in animals for their own sake. Camillo Golgi
 What we learn about animals sheds light on human - an Italian investigator that found a way to stain nerve
Neuroscience evolution cells with silver salts
- includes much that is relevant to behavior but also  Legal or ethical restrictions prevent certain kinds of - this method, which completely stains some cells without
includes more detail about anatomy and chemistry research on humans. affecting others at all, enabled researchers to examine
the structure of a single cell
Three Main Facts to Remember in Biological Psychology Degree of Opposition - theorized that all nerve cells merge directly into one
1. Perception occurs in your brain - legal standard emphasizes “the three R’s”: reduction of another
2. Mental activity and certain types of brain activity are, animal numbers (using fewer animals), replacement
so far as we can tell, inseparable (using computer models or other substitutes for animals, Santiago Ramón y Cajal
3. We should be cautious about what is an explanation when possible), and refinement (modifying the - used Golgi’s methods but applied them to infant brains,
and what is not. procedures to reduce pain and discomfort) in which the cells are smaller and therefore easier to
- has two positions: examine on a single slide
Biological Explanations of Behavior a. Minimalist - his research demonstrated that nerve cells remain
1. Physiological Explanation - tolerate certain types of animal research but wish separate instead of merging into one another
- behavior is related to the activity of the brain and other to limit or prohibit others depending on the
organs probable value of the research, the amount of Neuron
- deals with the machinery of the body — such as the distress to the animal, and the type of animal - also called the nerve cell
chemical reactions that enable hormones to influence - favor firm regulations on research - convey messages to one another (other neurons) and
brain activity and the routes by which brain activity to muscles and glands
controls muscle contractions b. Abolitionist - vary enormously in size, shape, and functions
- see no room for compromise - have long branching extensions
2. Ontological Explanation - maintain that all animals have the same rights as - the adult human brain contains approximately 86
- comes from Greek roots meaning the origin (or genesis) humans billion neurons on average however, exact number
of being - regard killing an animal as murder, regardless of varies from person to person
- describes how a behavior develops, including the whether the intention is to eat it, use its fur, or gain - all neurons include a soma (cell body), and most also
influences of genes, nutrition, experiences, and their scientific knowledge have dendrites, an axon, and presynaptic terminals
interactions. - keeping an animal in a cage (presumably even - tiniest neurons lack axons, and some lack well-defined
a pet) is, in their view, slavery. dendrites
3. Evolutionary Explanation - insist it is wrong to use them in any way, regardless - three types of neurons:
- reconstructs the evolutionary history of a structure or of the circumstances because animals cannot a. Afferent Neurons/Sensory Neurons
behavior. give informed consent to research. - is specialized at one end to be highly sensitive to
- the characteristic features of an animal are almost - claim that most animal research is painful and a particular type of stimulation, such as light,
always modifications of something found in ancestral that it never leads to important results. sound, or touch
species. - located and spread out to the five sensory organs
of the body

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- the sensory neuron conducts information or - surface is lined with specialized synaptic receptors, at 8. Synaptic Cleft/Gap
message from the sensory organs to the spinal which the dendrite receives information from other - a microscopic fluid-filled gap where the
cord and brain neurons neurotransmitters are released by the sending neuron to
the receiving neuron
b. Efferent Neurons/Motor Neurons 2. Soma/Cell Body
- with its soma in the spinal cord, receives - Greek for “body”; plural: somata 9. Receptor Sites
excitation through its dendrites and conducts - the cell's life support center - receives neurotransmitters
impulses along its axon to a muscle. - contains the nucleus, ribosomes, and mitochondria
- carries information away from brain and spinal - most of a neuron’s metabolic work occurs here Neurotransmitters – are often referred to as the body's
cord - cell bodies of neurons range in diameter from 0.005 mm chemical messengers.
to 0.1 mm in mammals and up to a millimeter in certain
c. Interneurons/Intrinsic Neurons invertebrates Two Types of Neurotransmitters
- located entirely within the central nervous system 1. Excitatory – keeps neurons from firing (booster ganon).
that conducts signals between other nerve cells 3 Axon 2. Inhibitory – prevents neurons from firing (pang-kalma).
- acts as a “middle-man” between afferent or - comes from a Greek word meaning “axis”
sensory neurons and efferent or motor neurons - thin fiber of constant diameter that passes messages or Examples of Neurotransmitters
- also connects to other interneurons, allowing impulse away from the cell body towards other neurons, 1. Adrenaline
them to communicate with one another muscles or glands - produced in stressful or exciting situations
- can be more than a meter in length, as in the case of - increases heart-rate and blood flow, leading to a
Glia/Glial Cells axons from your spinal cord to your feet physical boost and heightened awareness
- derived from a Greek word “glial” meaning “glue” - its length is enormous in comparison to its width, and in - involved in fight-or-flight response
- generally smaller than neurons comparison to the length of dendrites. - can either be excitatory or inhibitory neurotransmitter
- have many functions but do not convey information - many vertebrate axons are covered with an insulating
over great distances material called “myelin sheath” with interruptions known 2. Noradrenaline/Norepinephrine
- activities of neurons and glia somehow produce an as nodes of Ranvier while invertebrate axons do not - affects attention and responding actions in the brain
enormous wealth of behavior and experience have myelin sheaths. and is also involved in fight-or-flight response
- binds or holds the neurons together - may have branches at the end of it that has a swelling - contracts blood vessels, increasing blood flow and
- nourishes the neurons and manages the waste called “presynaptic terminal” in which the axon releases concentration
materials eliminated by the nerve cells chemicals that cross through the junction between that - excitatory neurotransmitter
- has five types: neuron and another cell.
a. Schwann Cells – surround axons of all peripheral 3. Dopamine
nerve fibers and form the myelin sheath 4. Myelin Sheath - feelings of pleasure, and also addiction, movement
- fatty substance that covers the axon of some neurons and motivation
b. Oligodendrocytes – form myelin sheath around and helps speed neural impulses - released when people repeat behaviors
central axons producing the white matter of CNS - excitatory neurotransmitter
5. Axon Terminals/Terminal Buttons
c. Astrocytes – cover capillaries of brain to form the - branches at the end of the neurons that form junctions 4. Serotonin
blood brain barrier and help regulate passage of with other cells - contributes to mood, well-being, and happiness
molecules from blood to brain - helps sleep cycle and digestive system regulation
6. Synapse - affected by exercise and light exposure
d. Ependymal – line the ventricles or brain cavities - sac or bulb-like structures located at the end of the - inhibitory neurotransmitter
and central canal of spinal cord axon terminals where chemicals or neurotransmitters are
encased and released once the neural impulse pass 5. Gamma-Aminobutyric Acid (GABA)
e. Microglia – phagocytic amoeboid cells in CNS through this part of the neuron - calms firing nerves in Central Nervous System (CNS)
that remove foreign and degenerate material from - high levels improve focus; low levels cause anxiety
the brain 7. Synaptic Vesicles - also contributes to motor control and vision
- is located in the axon terminal that is responsible for - inhibitory neurotransmitter
Parts of Neuron storing the neurotransmitters
1. Dendrites - vesicle is often described as a bubble made of liquid 6. Acetylcholine
- comes from a Greek root word meaning “tree” sitting inside of a different liquid - involved in thought, learning, and memory
- are branching fibers that get narrower near their ends - activates muscle action in the body
that receives messages from other cells - also associated with attention and awakening
- excitatory neurotransmitter

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7. Glutamate Resting Potential Sodium Channel/Gate

- most common brain neurotransmitter - the difference in voltage of a cell - a protein that allows sodium to cross
- involved in learning and memory - a negative electrical potential in which the cell is at rest - at resting potential, the sodium channels are fully
- regulates development and creation of nerve contacts because of negatively charged proteins inside it closed
- excitatory neurotransmitter - body invests much energy to operate the sodium– - as depolarizing happens, sodium channels begin to
potassium pump, which maintains the resting potential open allowing freer flow; however it snaps shut at the
8. Endorphins - prepares the neuron to respond rapidly but remains peak of the action potential
- released during exercise, excitement and sex stable until the neuron is stimulated
- produces well-being and euphoria; reduces pain
- biologically active section shown Action Potential Potassium Channel
- excitatory neurotransmitter - occurs when resting potential is disturbed by a neural - allows potassium to cross
impulse or depolarization - at resting potential, potassium channels are almost
Blood-Brain Barrier - an electrical potential in which the cell is in action closed, allowing only a little flow of potassium; begins to
- mechanism that excludes most chemicals from the - messages sent by axons open when depolarized
vertebrate because once a virus enters a neuron and - stimulation beyond the threshold of excitation
becomes damaged, it can no longer be replaced produces a massive depolarization of the membrane Process of Action Potential
- to minimize the risk of irreparable brain damage, the - when the potential reaches the threshold, the 1. When an area of the axon membrane reaches its
body lines the brain’s blood vessels with tightly packed membrane opens its sodium channels and lets sodium threshold of excitation, sodium channels and potassium
cells that keep out most viruses, bacteria, and harmful ions flow into the cell channels open.
chemicals - shoots up far beyond the strength that the stimulus 2. At first, the opening of potassium channels produces
- outside the brain, such cells are separated by small provided little effect.
gaps, but in the brain, they are joined so tightly that they - the peak varies from one axon to another 3. Opening sodium channels lets sodium ions rush into
block viruses, bacteria, and other harmful chemicals - require the flow of sodium and potassium. the axon.
from passage. 4. Positive charge flows down the axon and opens
All-or-None-Law voltage-gated sodium channels at the next point.
- any depolarization that reaches or passes the threshold 5. At the peak of the action potential, the sodium gates
LESSON 3: THE NERVE IMPULSE produces an action potential snap shut. They remain closed for the next millisecond or
- for a given neuron, all action potentials are so, despite the depolarization of the membrane.
Nerve/Neural Impulse approximately equal in amplitude (intensity) and 6. Because voltage-gated potassium channels remain
- is the electrical message that is transmitted down the velocity. open, potassium ions flow out of the axon, returning the
axon of a neuron - the intensity of the stimulus cannot cause a neuron to membrane toward its original depolarization.
- impulse is regenerated at points along the axon produce a bigger or smaller action potential, or a faster 7. A few milliseconds later, the voltage-dependent
- speed ranges from approximately 1 m/s to 100 m/s or slower one. (slight variations can occur at random, potassium channels close.
but not because of the stimulus.)
Membrane - states that the amplitude and velocity of an action Refractory Period
- covers all parts of a neuron and is about 8 nanometers potential are independent of the intensity of the stimulus - the period in which the sodium channel snap shut
(nm) thick that initiated it, provided that the stimulus reaches the wherein it resists the production of further action
- composed of two layers (free to float relative to each threshold potentials
other) of phospholipid molecules (containing chains of - puts constraints on how an axon can send a message - depends on two facts: the sodium channels are closed,
fatty acids and a phosphate group) - to signal the difference between a weak stimulus and and potassium is flowing out of the cell at a faster-than-
- when at rest, it maintains an electrical gradient, also a strong stimulus, the axon cannot send bigger or faster usual rate.
known as polarization—a difference in electrical charge action potentials, all it can change is the timing - has two parts:
between the inside and outside of the cell a. Absolute Refractory Period – the membrane
Three Chemical Events Principles behind the Action cannot produce another action potential,
Phospholipids Potential regardless of the stimulation
- embeds cylindrical protein molecules through which 1. At the start, sodium ions are mostly outside the neuron,
certain chemicals can pass by opening (the size and and potassium ions are mostly inside. b. Relative Refractory Period – a stronger-than-usual
shape of the opening determines which ion or chemical 2. When the membrane is depolarized, sodium and stimulus is necessary to initiate an action potential.
passes) potassium channels in the membrane open.
3. At the peak of the action potential, the sodium
channels close.

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Myelin Sheath
- an insulating material composed of fats and proteins
that vertebrate axons use to increase the travel speed
of action potential
- as the action potential occurs at the first myelin
segment, it cannot regenerate along the membrane
due to the virtual absence of sodium channels between
nodes called Ranvier
- after an action potential occurs at a node, sodium ions
enter the axon and diffuse, pushing a chain of positive
charge along the axon to the next node, where they
regenerate the action potential

Saltatory Conduction
- from the Latin word “saltare” meaning “to jump”
- the jumping of action potentials from node to node
- provides rapid conduction of impulses and conserves
energy

References:

Kalat, J.W. (2018). Biological Psychology (13th

ed.). Boston, MA: Cengage Learning.

Metal, I. (2020). Module and Syllabus on

Biological/Physiological Psychology

Barnes, S. J., & Pinel, J. P. (2018). Biopsychology. Pearson.

Compiled by: Bryle Zyver R. Pineda | @brylezyver

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