Chapter 2 Biological Perspective

Brain lateralization

Each hemisphere is specialized in specific skills and behavior

Medulla

Part of hindbrain where nerves cross from one side of the body to the opposite side of brain

Pons

Part of the hindbrain that relays messages between cerebellum and the cortex

Occipital lobes

Processes visual information from the eyes in the primary visual cortex VISION

Parietal lobes

Senses Processes information from the skin and internal body receptors for touch, temperature and body

parasympathetic system

Sometimes called the rest and digest system, conserves energy as it slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in the gastrointestinal tract

Terminal Buttons (also called: End Buttons, Axon Terminal, Terminal Branches of Axon, and Synaptic Knobs)

Terminal Buttons, a physiological term, refers to the small bulblike structures that are located at the branching ends of the axons (long, threadlike nerve cells) that hold vesicles (small sacs) that contain neurotransmitters (chemicals that stimulate brain cells). The neurotransmitters provide a chemical signal that links the nerve cells to one another.

Lobes

The brain is divided into four lobes Parietal, frontal, occipital, and temporal

Sensory cortex

Umbrella term for all our senses

Wernickes area

Understands the meaning of words Carl wernicke studied problems arising from damage in this area Wernickes aphasia- able to speak fluently but words would be the wrong ones

Receptor Sites

a physiological term for the part of a nerve that receives and reads chemical signals (neurotransmitters) from other nerves to transmit the electrical signals that transfer information through the brain and nervous system. This happens in an area of the nerve called the synapse which is essentially where one neuron ends and another begins. If you're not familiar with this, please do review the definition of synapse. This sounds complicated but it is a lot like a relay race where a stick or baton (neurotransmitter) is passed from one runner (synapse) to another (receptor) until it gets to the end of the race (the brain).

Inhibitory Neurotransmitters

balance mood and are easily depleted when the excitatory neurotransmitters are overactive.

Soma (Cell body)

cell body of a neuron and contains the nucleus of the cell. The soma doesn't play an active role in transmitting neural signals, but it keeps the cell functioning and holds the cell's DNA

Efferent Neurons (or Motor Neurons)

consists of all the nerve pathways carrying signals OUT of the brain and/or spinal cord.

Electroencephalogram (EEG)

is a noninvasive test that records electrical patterns in your brain. The test is used to help diagnose conditions such as seizures, epilepsy, head injuries, dizziness, headaches, brain tumors and sleeping problems. It can also be used to confirm brain death

Magnetic Resonance Imaging (MRI scan)

is a type of scan that uses strong magnetic fields and radio waves to produce detailed images of the inside of the body. Scanner is a large tube that contains powerful magnets. You lie inside the tube during the scan.

Afferent Neurons (or Sensory Neurons)

is all of the nerve pathways carrying signals TO the brain and/or spinal cord.

Position Emission Tomography (PET scan)

is an imaging test of the brain. It uses a radioactive substance called a tracer to look for disease or injury in the brain

Threshold

is the minimum amount of stimulation needed to start a neural impulse (you know, the electrical impulses that travel throughout your body carrying important information). There is a very scientific explanation to this that includes the actual mV (millivolts) of the inside and outside of the neural membrane, how the sodium pottasium channel works, and lots more, but for this definition let's just leave it as is. For more information on the sodium potassium pump and the neural impulse, consult your book or the biological psychology class notes on

Axon

long, spider-thin, tail-like structures found on neurons (nerve cells). Each neuron has a nerve body, dendrites, and axons, all of which are used to send information throughout your body. The axon carries signals (electric voltages) between the dendrites (the neuron's input sites) and the terminal buttons (the neuron's output sites that are at the very end of the axon). The signal always travels in the same direction - the signal comes into the neuron through the dendrites, through the cell body (soma), to the axon, and then out the terminal buttons to the dendrites of the next neuron. In this way information travels all around your body by going from neuron to neuron

Functional MRI (FMRI)

measures brain activity by detecting changes associated with blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled

Neuron

nerve cells and the basic building blocks of our entire nervous systems. The neurons act as sensors for all types of stimuli and communicate the stimuli throughout the body. For example, neurons communicate to the brain that you should not leave your hand on a hot stove; the neurons are composed of 3 main components, the axon (the tail), the soma (the body), and the dendrites (the branch-like arms that stem from the soma)

Excitatory Neurotransmitters

stimulate the brain.

Hindbrain

the lower part of the brainstem, comprising the cerebellum, pons, and medulla oblongata.

Broca's area

Allowe person to speak smoothly and fluently Paul broca- studied people with damage in this area that couldn't get words out Brocas aphasia- inability to use or understand written or spoken language

Corpus callosum

Allows left and right hemispheres to communicate Connects both sides

Central Nervous System

Brain and Spinal Cord

Brain plasticity

Brains ability to change throughout life And reorganize itself by forming new connections between Neurons

Peripheral Nervous System

Consists of: Autonomic Nervous System (involuntary), Sympathetic Nervous System & Parasympathetic Nervous System. connect the CNS to the limbs and organs, essentially serving as a relay between the brain and spinal cord and the rest of the body

Temporal lobes

Contain the primary auditory cortex Área involved with language Hearing or active listening Located behind the temples

Frontal lobe

Contains the motor cortex, logic/emotion, reasoning and working memory

Cerebral cortex

Controls complex thought processes Divided into left and right hemispheres

Left hemisphere

Controls right side of the body Involved with verbal processing and mathematics Includes the Broca's area and wernickes area

Motor cortex

Controls the muscles on the opposite side of the body

Accident

The damage to Gage's frontal cortex caused by the iron rod seems to have resulted in a loss of social inhibitions

Endocrine system

The endocrine glands secrete chemicals called hormones directly into the bloodstream Pituitary- controls all the others glands Pineal gland- secretes melatonin helps track day length and seasons Thyroid gland- regulates growth and metabolism Gonads - sex glands contains ovaries and testes Adrenal glands- release cortisol when the body is under stress

Hemispheres

Two halves of the living brain connected by the corpus callosum

Myelin Sheath

a fatty substance that covers neurons. Around your neurons is a myelin sheath (a layer of myelin) that helps increase the speed at which information can travel on the neurons. If you could look at a neuron you would see the sheath covering the axon of the neuron in a way that looks like a row of sausage links

Midbrain

a small central part of the brainstem, developing from the middle of the primitive or embryonic brain.

Endorphins

are the body's very own natural analgesics, or painkillers. They are released during times of stress and pain

Dopamine

deficiency results in Parkinson's Disease, and people with low dopamine activity may be more prone to addiction. helps regulate movement and emotional responses

Thalamus

part of the forebrain that relays information from sensory organs to cerebral cortex

Cerebellum

part of the hindbrain that controls balance and maintains muscle coordination

Neural Firing

potential is part of the process that occurs during the firing of a neuron. During the action potential, part of the neural membrane opens to allow positively charged ions inside the cell and negatively charged ions outside All or nothing

Sympathetic Nervous System

prepares the body for intense physical activity and is often referred to as the fight-or-flight response.

Lesions

refers to any type of abnormal tissue in or on brain tissue. Major types are traumatic, infectious, malignant, benign, vascular, genetic, immune, plaques, brain cell death or malfunction, and ionizing radiation

All-or-None Principle

refers to the fact that a neuron either fires completely or not at all

Hypothalamus

regulates amount of fear and aggression we feel Regulates temperature, thirst, hunger, sleeping, waking, sexual activity Secretes hormones that regulate when we wake up and how fast we digest food

Autonomic Nervous System

regulates the functions of our internal organs (the viscera) such as the heart, stomach and intestines; is part of the peripheral nervous system and it also controls some of the muscles within the body.

Somatic Nervous System

responsible for movement of voluntary muscles and the process known as a reflex arc. This system carries nerve impulses back and forth between the central nervous system

Reticular Formation

system of nerves running from the hindbrain and through the midbrain to the cerebral cortex, controlling arousal and attention

Forebrain

the anterior part of the brain, including the cerebral hemispheres, the thalamus, and the hypothalamus

Dendrites

the branch-like structures of neurons that extend from the cell body (Soma). The dendrites receive neural impulses (electrical and chemical signals) from the axons of other neurons. The signal always travels in the same direction - the signal comes into the neuron through the dendrites, through the cell body (soma), to the axon, and then out the terminal buttons to the dendrites of the next neuron. In this way information travels all around your body by going from neuron to neuron

Spinal Cord

the cylindrical bundle of nerve fibers and associated tissue that is enclosed in the spine and connects nearly all parts of the body to the brain, with which it forms the central nervous system.

Synapse

the entire junction between neurons, including the pre-synaptic neuron's axon terminal, the synaptic cleft, and the dendrite of the post-synaptic neuron, across which communications flow, usually in the form of neurotransmitter molecules secreted by the pre-synaptic neuron (on its axon terminal) that travel a short distance across the synaptic cleft (this is the actual space between the neurons - the space between the axon terminal of one neuron and the dendrite of the other) to the post-synaptic neuron. Once at the post-synaptic neuron, some of the neurotransmitters will attach themselves (bind) to some receptors. It is important to know that the neurotransmitters and receptors work like a lock and key; that is, they both have certain shapes and only specific neurotransmitters can fit into certain receptors

Acetylcholine

the most widely spread neurotransmitter; stimulates muscle contractions and, thus, all behavior. required for proper memory and cognition, as well as motor control

Action Potential

the release of the neural impulse, consisting of a reversal of the electrical charge within the axon

Computerized Axial Tomography (CAT or CT scan)

uses computer processing to create cross-sectional images, or slices, of the bones, blood vessels and soft tissues inside your body. CT scan images provide more detailed information than plain X-rays do.

Limbic system

Includes the thalamus, hippocampus, amygdala, and Cingular cortex Involved in emotions, motivation, learning, and memory

Neurotransmitters

(information being sent from neuron to neuron) works at both the electrical and chemical levels. When the space between two neurons is small enough the electrical signal can simply jump the gap and continue on its way. However, when the gap is too large, the signal must be converted from electricity to chemicals. These chemicals are neurotransmitters, which can be defined as chemicals released by neurons which carry information from one neuron to another. These chemicals are then read or received by a neuron's synapses

Hippocampus

Instrumental in forming long term declarative memories Curved structure within the each temporal lobe responsible for formation of long term memories

Amygdala

Involved in fear responses and memory of fear Damage to this part will result in no fear

Right hemisphere

Involved with spatial perception, visual recognition and emotion

Serotonin

It is commonly regarded as a chemical that is responsible for maintaining mood balance; can affect mood and social behavior, appetite and digestion, sleep, memory and sexual desire and function

Association area

Made up of neurons in the cortex that are devoted to making connection between the sensory information coming into the brain