INTROPSY - Lesson 2: The Biological Perspective

Nervous system

a network of cells that carries information to and from all parts of the body

Neuroscience

is a branch of the life sciences that deals with the structure and functioning of the brain and the neurons, nerves, and nervous tissue that form the nervous system

Biological psychology

or behavioral neuroscience, is the branch of neuroscience that focuses on the biological bases of psychological processes, behavior, and learning, and it is the primary area associated with the biological perspective in psychology.

Neuron

specialized cell in the nervous system that receives and sends messages within that system

Dendrites

• parts of the neuron that receive messages from other cells

• “tree-like” or “branch”

Soma

• where dendrites are attached to

• part of the cell that contains the nucleus and keeps the entire cell alive and functioning

• means “body”

Axon

fiber attached to the soma, and its job is to carry messages out to other cells

Axon terminals

several shorter fibers that have swellings or little knobs on the ends (may also be called presypnatic terminals, terminal buttons, or synaptic knobs), which are responsible for communicating with other nerve cells

Glial cells

• which serve a variety of functions

• Some serves as a sort of structure on which neurons develop and work and that hold neurons in place

• Others are involved in getting nutrients to the neurons, cleaning up remains of neurons that have died, communicating with other ___, and providing insulation for neurons

Glial cells

• affect both the functioning and structure of neurons and specific types have properties similiar to stem cells

• also being investigated for their possible role in a variety of psychiatric disorders, including major depressive disorder and schizophrenia

Myelin

• Two special types of glial cells, called oligodendrocytes and Schwann cells, generate a layer of fatty substances called ____

• wraps around the shaft of the axons, forming an insulating and protective sheath

Oligodendrocytes

produce myelin for the neurons in the brain (central nervous system)

Schwann cells

produce myelin for the neurons of the body (peripheral nervous system)

Tracts

bundles of myelin-coated axons travel together as “cables” in the central nervous system

Nerves

bundles of axons in the peripheral nervous system

Synaptic vesicles

an axon terminal enlarged to giant scale has a presynaptic terminal which is not empty has a number of little sac-like structures in it called ___

Vesicle

latin word meaning a “little blister” or “fluid-filled sac”

Neurotransmitters

inside the synaptic vesicle are chemicals suspended in fluid, which are molecules of substances called ____

Synapse

or the synaptic gap, the fluid-filled space between the axon terminal and the dendrite of another neuron

Presynaptic membrane

contains the molecules of neurotransmitters

Postsynaptic membrane

surface of the dendrite next to the axon contains ion channels that have receptor sites, proteins that allow only particular molecules of a certain shape to fit into it

Excitatory effect

when neurotransmitters found at various synapses around the nervous system turn cells on

Inhibitory effect

when neurotransmitters found at various synapses around the nervous system turn cells off

Acetylcholine (ACh)

• found at the synapses between neurons and muscle cells

• stimulates the skeletal muscles to contract but actually slows contractions in the heart muscle

Dopamine (DA)

• neurotransmitter found in the brain, it can have different effects depending on the exact location of its activity

• too little, Parkinson’s disease

• too much, Schizophrenia

Serotonin (5-HT)

• neurotransmitter originating in the lower part of the brain that can have either an excitatory or inhibitory effect, depending on the particular synapses being affected

• associated with sleep, mood, anxiety, and appetite

• low levels of activity have been linked to depression

Glutamate

• major excitatory neurotransmitter

• plays an important role in learning and memory, and may also be involved in the development of the nervous system and in synaptic plasticity

• excess, results in overactivitation and neuronal damage, may be associated with the cell death that occurs after stroke, head injury or degenerative diseases like Alzheimer’s

Synaptic Plasticity

ability of the brain to change connections among its neurons

Gaba-aminobutyric acid (GABA)

• most common neurotransmitter producing inhibition in the brain

• can help to calm anxiety

Endorphins

• pain controlling chemicals in the body

• neurotransmitter that signals pain is released, binds to receptors that open the ion channels on the axon

• heroin, morphine

Diffusion

process of ions moving from areas of high concentration to low

Action potential

when neurons are working

Resting potential

cell’s electric potential state of rest

Central nervous system

• composed of the brain and the spinal cord

• control the life sustaining functions of the body as well as all thought, emotion, and behavior

Brain

core of the nervous system, the part that makes sense of the information receive from the senses, makes decisions, and sends commands out to the muscles and the rest of the body, if needed

Spinal cord

• long bundle of neurons that serves two vital functions for the nervous system.

• It is called a message “pipeline”

Outer part

composed mainly of myelinated axons and nerves, which appear white

Inner part

mainly composed of cell bodies of neurons, which appear gray

Afferent

• sensory

• neurons that carry messages from the senses to the spinal cord

Efferent

• motor

• neurons that carry messages from the spinal cord to the muscles and glands

Interneurons

connect the afferent neurons to the motor neurons

Neuroplasticity

the ability to constantly change both the structure and function of many cells in the brain in response to experience and even trauma

Peripheral nervous system

• made up of all nerves and neurons that are not contained in the brain and spinal cord

• the system that allows the brain and spinal cord to communicate with the sensory systems and allows the brain and spinal cord to control the muscles and glands in the body

Somatic nervous system

which consists of nerves that control the voluntary muscles of the body

Sensory pathway

comprises all the nerves carrying messages from the senses to the central nervous system

Motor pathway

all of the nerves carrying messages from the central nervous system to the voluntary, or skeletal, muscles of the body—muscles that allow people to move their bodies

Autonomic nervous system

consists of nerves that control the involuntary muscles, organs, and glands

Sympathetic division

• is in sympathy with one’s emotions

• usually called “fight-or-flight system” because it allows people and animals to deal with all kinds of stressful events

Parasympathetic division

• “eat-drink-and-rest” system

• refers to the neurons located on either side of the sympathetic division neurons

Hormones

endocrine glands, have no ducts and secrete their chemicals directly onto the bloodstream. The chemicals secreted are called ___

Hypothalamus

controls the glandular system by influencing the pituitary

Pituitary gland

is the master gland, the one that controls or influences all of the other endocrine glands

Oxytocin

• hormone that controls aspects of pregnancy and is involved in a variety of ways with both reproduction and parental behavior

• “rapid” and “childbirth”, injections frequently used to induce or speed up labor and delivery

Vasopressin

• hormone that controls levels of water in our body

• essentially acts an antidiuretic, helping the body conserve water

Growth hormone

controls and regulates the increase in size as children grow from infancy to adulthood

Gonads

• sex glands

• secrete hormones that regulate sexual behavior and reproduction

Pineal gland

• also located in the brain, near the back, directly above the brain stem

• plays an important role in several biological rhythms

Melatonin

• secretes by the pineal gland

• helps track day length, influential in regulating sleep-wake cycle

Thyroid gland

regulate growth and metabolism

Thyroxin

regulates metabolism (how fast the body burns its available energy)

Pancreas

• controls the level of blood sugar in the body by secreting insulin and glucagon

• too little insulin, diabetes

• too much insulin, hypoglycemia, or low blood sugar

Adrenal

meaning “to or on the kidney”

Adrenal medulla

releases epinephrine and norepinephrine, when people are under stress, and aids in sympathetic arousal

Adrenal cortex

• produces over 30 different hormones called corticoids (or steroids), regulate salt intake, help initiate and control stress reactions, and provide a source of sex hormones

Cortisol

• one of the most important adrenal hormones

• released when the body experiences stress, both physical and psychological

The Hindbrain

• Medulla

• The Pons

• The Reticular Formation

• The Cerebellum

Medulla

• controls life sustaining functions such as heartbeat, breathing, and swallowing

• it is where the sensory nerves coming from the left and right sides of the body cross over

Pons

• “bridge”

• bridge between the lower parts of the brain and the upper sections

• motor nerves carrying messages from the brain to the body

Reticular Formation

• network of neurons through the middle of the medulla and the pons slightly beyond

• allows people to ignore constant, unchanging information and become alert to changes in information

• helps keep people alert and aroused

Cerebellum

• “little brain”

• part of lower brain that controls involuntary, rapid, fine motor movement

• also coordinates voluntary movements that have to happen in rapid succession

The Limbic System

• Thalamus

• Hypothalamus

• Hippocampus

• Amgydala

• Cingulate Cortex

Limbic System

• “marginal”, structures found in the inner margin of the upper brain

• involved in emotions, motivation, memory, and learning

Thalamus

• acts as kind of relay station for incoming sensory information, processing before sending

• damage may result in loss or partial loss of any sensations

Hypothalamus

• regulates body temperature, thirst, hunger, sleeping and waking, sexual activity and emotions

• controls the pituitary, ultimate regulation of hormones

Hippocampus

• “seahorse”

• instrumental in forming long-term (permanent) declarative memories that are then stored elsewhere in the brain

Amgydala

• “almond”

• involved in fear responses and memory of fear

Cingulate Cortex

• found in the cortex

• found right above the corpus callosum in the frontal parietal lobes

• plays an important role in both emotional and cognitive processing

The Cortex

Cerebral Hemispheres

• Occipital Lobes

• Parietal Lobes

• Temporal Lobes

• Frontal Lobes

Cortex

• outermost part of the brain, which is the part of the brain most people picture when they think of what the brain looks like

• made up of tightly packed neurons and actually is only about one tenth of an inch thich on average

• very recognizable surface anatomy because it is full of wrinkles

Cerebral Hemispheres

connected by a thick, tough band of neural fibers (axons) called the corpus callosum

Corpus callosum

allows the left and right hemispheres to communicate with each other

Occipital Lobes

• processes visual information from the eyes in the primary visual cortex

• visual association cortex

Parietal Lobes

• contains somatosensory cortex

• processes information from the skin and internal body receptors for touch, temperature, and body postion

Temporal Lobes

• primary auditory cortex and the auditory association area

• area that in most people is particularly involves with language

Frontal Lobes

• front of the brain

• higher mental functions of the brain—planning, personality, memory storage, complex decision making, areas devoted to language

• helps controlling emotions

• contain motor cortex - control movement of the body’s voluntary muscles

The Association Areas of Cortex

• Broca’s Area

• Wernicke’s Area

• Split-Brain Research

Broca’s area

• Paul ___

• left frontal lobe devoted to the production of speech, allows a person to speak smoothly and fluently

Aphasia

refers to the inability to use or understand either written or spoken language

Wernicke’s area

• Carl ___

• involved in understanding the meaning of words

Split-brain research

• Roger Sperry

• left and right brain hemispheres of the brain

• left hemisphere - specializes in language, speech, handwriting, calculation (math), sense of time and rhythm, any thought requiring analysis

• right hemisphere - global processing involving perception, visualization, spatial perception, recognition of patterns, faces, emotions, melodies, and expression of emotions. Also comprehends simple language but does not produce speech