Bio-psychology Flashcards
Genetic Variation
- The variation in alleles and genes, both within and among the population
- Begins with egg, and about 100 million sperms whereby fertilization occurs
Egg and Sperm
- The egg travels via the Fallopian tube, from the ovary to the uterus to be fertilized by the sperm
- Contains 23 chromosomes each
Chromosomes
- Long string of genetic material called Deoxyribonucleic acid (DNA)
- Each chromosomes is a sequence of DNA that make up genes
Genes
•Genes determine the specific human characteristics, also known as traits (e.g., height, eye color)
Allele
•A specific version of a gene (same gene, but different variation)
Zygote
•Created when 23 chromosomes from the egg and the sperm pairs up
Phenotype
- Refers to the expression of the trait (e.g, how it looks/function)
- Inherited physical characteristics
Genotype
- Refers to a pair of alleles for a trait
* A genetic make up of that individual
Polygenic
•A trait that is controlled by multiple genes
Homozygous
•2 copies of the same alleles
Heterozygous
•Combination of allele for a given gene
Gene Mutation
- A sudden permanent change in a gene
* It is harmful and lethal; rarely beneficial
Range of Reaction
- Asserts that our genes set the boundaries within which we can operate
- Our environment interacts with the genes to determine where in that range we will fall
Epigenetics
•Looks beyond the genotype itself and studies how the same genotype can lead to very different phenotypes
Identical Twins
- Single fertilized egg that splits
* Genetic material is exactly the same
Fraternal Twins
- Two different eggs fertilized by different sperms
* Genetic material varies
Nervous System
•Composed of 2 basic cell types – glial cells and neurons
Glial Cells
- Supportive to the neurons physically and metabolically
- Provide scaffolding on which nervous system is built
- Allow neuronal communication
- Insulation to neurons
- Transport nutrients and waste products
- Mediate immune responses
Neurons
- Interconnected processors; essential for all of the tasks of the nervous system
- Central building blocks of the nervous system
- 100 billion strong at birth
- Outer surface is made up of semipermeable membrane
- Surrounded by extracellular fluid, and contains intracellular fluid
Semipermeable Membrane
•Allows smaller molecules/molecules without an electrical charge to pass through
Nucleus
•Located in the soma/cell body
Soma
- Keeps the cell functioning and holds the cell’s DNA
* Branching extensions known as dendrites
Dendrites
- Inputs sites where signals are received from other neurons
- Transmitted electrically across the soma and down a major extension known as axon
- Ends at multiple terminal buttons
Terminal Buttons
•Contains synaptic vesicles that house neurotransmitters
Axons
- Carries signals between the dendrites and the terminal buttons
- Range in length from a fraction of an inch to several feet
Myelin Sheath
- Coats the axon and acts as an insulator; increasing the speed at which the signals travels
- Crucial for normal operation of neurons within the nervous system
- Loss of insulation can be detrimental to normal function
Synaptic Vesicles
- Release neurotransmitters into the synapse where communication between neurons occurs
- Synapse – Small space between two neurons
Neuronal Membrane
- Separates extracellular and intracellular fluid
- Critical role; electrical signal that passes through the neurons depends intra- and extracellular fluids being electrically different (membrane potential)
Resting Potential
- Neuron’s membrane potential is held in a state of readiness
- Ions line up on either side of the cell membrane, ready to rush across the membrane when neuron gets active and when the membrane opens its gates
Threshold of Excitation
•Refers to the level of neural depolarization that is necessary to generate an action potential
Peak Action Potential
•Happens when the neuron opens protein channels in its membrane
Depolarization
- Difference between the electric charge on the inside and the outside of the cell membrane
- When the cell becomes positively charged (or less negative)
Repolarization
•Change in membrane potential that returns it to a negative value just after the depolarization phase of an action potential which has changed the membrane potential to a positive value
Hyperpolarization
•The membrane potential becomes more negative at a particular spot on the neuron’s membrane
Electrical Charge
•Caused when charged molecules (ions) dissolve in the fluid
Ions Movement
- Ions in high concentration areas move to low concentration areas
- Positive ions move to areas with negative charge
Psychotropic Medications
•Drugs that treat psychiatric symptoms by restoring neurotransmitter balance
Acetylcholine
- Involves in muscle action and memory
* Increase arousal, enhance cognition
Dopamine
- Involves in mood, sleep, learning
* Increase pleasure, suppress appetite
Norepinephrine
- Involves in heart, intestines and alertness
* Increase arousal, suppress appetite
Beta-endorphin
- Involves in pain and pleasure
* Decrease anxiety and tension
Gamma-aminobutyric Acid (GABA)
- Involves in brain function and sleep
* Decrease anxiety and tension
Glutamate
- Involves in memory and learning
* Increase learning and enhance memory
Serotonin
- Involves in mood and sleep
* Modulate mood and suppress appetite
Agonists
•Mimic a neurotransmitter of the receptor site; strengthen its effect
Antagonists
•Blocks/impede the normal activity of a neurotransmitter at the receptor
Central Nervous System (CNS)
•Comprised of brain and spinal cord
Peripheral Nervous System (PNS)
- Connects the CNS to the rest of the body
* Made up of thick bundles of axons, known as nerves
Somatic Nervous System
- Associated with activities traditionally thought of as conscious or voluntary
- Involved in the relay of sensory and motor information to and from the CNS
Motor Neurons
- Carry instructions from the CNS to the muscles
* Efferent (moving away from) fibers
Sensory Neurons
- Carry sensory information to the CNS
* Afferent (moving towards) fibers
Automatic Nervous System
- Controls our internal organs and glands
- Generally considered to be outside the realm of voluntary control
- Subdivided to sympathetic and parasympathetic divisions
Sympathetic Nervous System
- Involved in preparing the body for stress-related activities
- Adaptive and increase chances of survival (stressful or high-arousal situations)
Parasympathetic Nervous System
•Associated to returning the body to routine, day-to-day operations
Homeostasis
•A state of equilibrium, in which biological conditions (such as body temperature) are maintained in optimal levels
Spinal Cord
- Connects the brain to the outside world; routes messages to and from the brain
- Has it own system of automatic reflexes, called reflexes
- Functionally organized in 30 segments, corresponding to the vertebrae
Medulla Oblongata
- Lowest part of the brain stem; found below the pons and above the spinal cord
- Controls basic processors of life (breathing and digestion)
- Regulates cardiovascular and respiratory functions
Baroreceptor
•Fastest mechanism to regulate acute blood pressure changes via controlling heart rate, contractility, and peripheral resistance.
Vertebrae
•Protects the spinal cord
Cerebrospinal Fluid
•Cushions the spinal cord
Spinal Reflex
•Allow the body to react extraordinary fast
Cerebral Cortex
- Located at the surface of the brain
* Very uneven, characterized by a distinctive patterns of folds/bumps, known as gyri; and grooves known as sulci
Gyri and Sulci
•Allow us to separate the brain into functional centers
Longitudinal Fissure
- Most prominent sulcus
* Deep groove that separates the brain into two halves
Left and Right Hemispheres
•Connected by thick bond of neural fibers known as corpus callosum
Corpus Callosum
- 200 million axons
- Allows the two hemispheres to communicate
- Process information on one side to the other
Brain Lateralization
•A phenomenon in which a skill or function is preferably controlled by one side of the brain over the other, causing the hemispheres to have specialized functions
Forebrain
- Largest part of the brain (divided into 4 lobes)
* Contains cerebral cortex and a number of other structures that lie beneath the cortex
Subcortical Structures
- A group of diverse neural formations deep within the brain
* Include thalamus, hypothalamus, pituitary gland, and the limbic system
Frontal Lobe
- Located in the forward part of the brain, extending back to the fissure known as central sulcus
- Involves in reasoning, motor control, emotion and language
- Contains motor cortex – planning and coordinating movement
Parietal Lobe
- Process information from the body’s senses
* Contains somatosensory cortex – process sensory information (e.g., touch)
Occipital Lobe
- Contains primary visual cortex
* Interprets incoming visual information
Temporal Lobe
- Associated with hearing, memory, emotion and some aspects of language
- Contains auditory cortex – process auditory information
Prefrontal Cortex
•Responsible for higher-level cognitive functions
Broca’s Area
- Located at prefrontal cortex
- Essential for language production
- Damage – difficulty producing language in any form
Wernick’s Area
- Located in temporal lobe
- Responsible for speech comprehension
- Damage – able to produce sensible language, however, individuals will be unable to understand it
Thalamus
- Involve in the sensory relay of the brain
* All senses (except smell) are routed through the thalamus before being directed to the other areas for processing
Limbic System
•Involved in motivation, emotion, learning, and memory
Midbrain
•Comprised of structures located deep within the brain between the forebrain and hindbrain
Reticular Formation
- Extends up into the forebrain and down into the hindbrain
* Regulates sleep and wake cycle, arousal, alertness and motor activity
Substantia Nigra and Ventral Tegmented Area (VTA)
- Located in the midbrain
- Contains cell bodies that produce the neurotransmitter dopamine
- Critical for movement
- Involved in mood, reward, and addiction
Hindbrain
- Located at the lower back part of the brain
* Contains medulla, pons and cerebellum (together known as brain stem)
Medulla
•Controls the automatic nervous system (e.g, breathing, blood pressure, and heart rate)
Pons
- Connect the brain and spinal cord
* Regulates brain activity during sleep
Cerebellum
- Receives messages from muscles, tendons, joints and structures in our ears
- Control balance, coordination, movement and motor skills
- Process procedural memory or memory involved in learning and remembering how to perform tasks
Computerized Tomography (CT) scan
- Taking a number of x-rays of a particular section of an individual’s body or brain
- Pass through different densities at different rate
- Often used to determine if someone has a tumor or significant brain atrophy
Position Emission Tomography (PET) scan
- Create pictures of the active brain and shows brain’s activity
- Provide little details
- Requires the brain to be exposed to radiation
Magnetic Resonance Imaging (MRI)
- Individual is being placed inside a machine that generates strong magnetic field
- Tissues of different densities give off different signals
- Magnetic field – causes the hydrogen atoms in the body’s cell to move
- Magnetic field turned off – hydrogen atoms emit electromagnetic signals as they return to their original position
Functional Magnetic Resonance Imaging (fMRI)
•Shows changes in brain activity over time by tracking blood flow and energy levels
Electroencephalography (EEG)
- Measures brain’s electrical activity
- An array of electrodes is being placed around an individual’s head
- Result in a printout of the electrical activity and brainwaves – shows both amplitude and frequency (m/s)
Endocrine System
•Consists a series of glands that produce hormones
Hormones
- Secreted into the bloodstream and travels throughout the body
- Slower to take effects and longer lasting
- Affects any cells that contain receptors for them – send signals
- Regulates all sorts of bodily functions – controlled through the interactions between the hypothalamus and the pituitary gland
Pituitary Gland
- Descends from the hypothalamus at the base of the brain
- Its messenger hormones controls all the other glands in the endocrine system
- Mostly carries out instructions from the hypothalamus
- Secretes growth hormones, endorphins for pain relief and number of key hormones that regulate fluid in the body
Thyroid Gland
- Releases hormones that regulate growth, metabolism and appetite
- Disease: Hyperthyroidism – thyroid secretes too much thyroxine – cause agitation, bulging eyes, and weight loss
Adrenal Gland
- Sit atop our kidneys
* Secretes hormones involved in the stress response (e.g., epinephrine and nor-epinephrine)
Pancreas
- An internal organ
* Secretes hormones that regulate blood sugar levels (insulin and glucagon)
Gonads
- Secrete sexual hormones – important in reproduction
- Mediate both sexual motivation and behavior
- Female: Ovaries – estrogens and progesterone
- Male: Testes – androgen (e.g., testosterone)
