Biological Bases of Behavior (incomplete)

Most human traits result from the combined effects of __ and _

Nature and nurture

Genetic Predisposition

The increased chance of developing a specific trait or condition due to our genetic code

Every human cell has __ chromosomes in _ pairs

46 chromosomes in 23 pairs

Genes can be dominant or ___

recessive

IQ is both influenced by ___ and __

Environment and genetics

Sex is determined by __ pair of chromosomes

23rd (Male: X and Y Female: X and X

Turner’s Syndrome

Only a single X chromosome in the 23rd spot

Klinefelter’s Syndrome

Extra X chromosome

Down Syndrome

Extra chromosome on the 21st pair

Neuroanatomy

The study of the parts and functions of neurons

Neurons

Individual nerve cells

Dendrites

Rootlike things that make synaptic connections with other neurons

Soma

AKA Cell body

Contains nucleus and other parts needed to sustain life

Axon

Wirelike structure ending in terminal buttons

Myelin Sheath

Fatty covering around the axon that speeds neural impulses

Multiple Sclerosis

Occurs when the myelin sheath deteriorates around neurons, interfering with neural transmission

Terminal Buttons

AKA end buttons, terminal branches of axons, synaptic knobs

Branched end of axon that contain neurotransmitters

Neurotransmitters

Chemicals that enable neurons to communicate

Fit into receptor sites on dendrites of neurons

Synapse

The space between the terminal buttons of one neuron and the dendrites of the next

Neural Transmission

When a neuron transmits a message

Resting Potential charge

In its resting state a neuron has an overall slightly negative charge (because mostly negative ions are within the cell and mostly positive ions are surrounding it)

The cell membrane is selectively ___ to __

permeable, maintain difference in charge in and around a neuron

Reaction process from a neuron A to B

1) Terminal buttons of A are stimulated and release neurotransmitters into synapse

2) Neurotransmitters fit into receptor site on dendrites of neuron B

3)Threshold is reached and cell membrane of B becomes permeable for positive ions

4) Charge reaches terminal buttons of neuron B which release neurotransmitters into the synapse

5) Process repeats is enough neurotransmitters are received to pass the threshold

Threshold

Level of neurotransmitters that allows the membrane to become permeable, firing the neuron

Action Potential

The electric message firing down the length of the neuron

All-or-none Principle

A neuron either completely fires or doesn’t fire at all with the same impulse every time

Depolarization

Process of neural firing (the cell becomes depolarized when + ions rush into the cell changing overall charge from negative to positive)

Electricity vs Chemicals in a Neuron

Electricity travels within the cell and Chemicals travel the gap of the synapse

Excitatory Neurotransmitters

They excite the next cell into firing

Inhibitory Neurotransmitters

They inhibit the next cell from firing

(Each synaptic gap at any time may contain many kinds of inhibitory and excitatory neurotransmitters)

Dopamine Function

Motor movement and alertness

Problems associated with Dopamine

Lack: Parkinson’s disease

Overabundance: Schizophrenia

Serotonin Function

Mood control

Problems associated with Serotonin

Lack: Clinical depression

Norepinephrine Function

Alertness, arousal

Problems associated with Norepinephrine

Lack: Depression

Glutamate Function

Excitatory neurotransmitter, involved in memory

Problems associated with Glutamate

Triggers migraines, seizures

GABA Function

Important inhibitory neurotransmitter

Problems associated with GABA

Internalizes when having seizures and can cause sleep problems

Endorphins Function

Pain control

Problems associated with Endorphins

Involved in addictions

Substance P Function

Pain perception

Problems associated with Substance P

Lack: Lack of pain perception

Acetylcholine Function

Motor movement

Problems associated with Acetylcholine

Lack: Alzheimer’s disease

Involved in Myasthenia gravis

Myasthenia Gravis

Condition that causes muscle weakness and is influenced by Acetylcholine