Chapter 2

Chapter 2 - Psychology 101

Neurons

The primary, specialized cells within nervous system

Nerves

A bundle of neurons working together

Nervous System

Network of neurons and nerves that carry messages to and from all parts of the body and brain

Central Nervous System (CNS)

The brain, spinal cord, and brain stem

Peripheral Nervous System (PNS)

Transmits information to and from the central nervous system

Brain

The body’s master control center

Brain Stem

• Connects brain to the spinal cord

• Main route of communication to and from the body

• controls survival processes (heart rate, digestion, etc.)

Spinal Cord

• Main pathway for nerve impulses to and from the brain

• Responsible for reflexes

Reflex

An involuntary, instinctual, and nearly instantaneous response to stimulus

Reflex Arc

A pathway that acts on impulses before it reaches the brain

Autonomic NS

Regulates involuntary processes

Somatic NS

Conscious control of skeletal muscle movement

Sympathetic NS

• Prepares body for action

• “Fight or Flight”

Parasympathetic NS

• Restores the body to normal arousal

• Maintains Homeostasis

• “Rest and Digest”

Primary Structures of a Neuron

Soma, Dendrite, and Axon

Soma

• Cell Body

• Houses the Nucleus

• Directs impulses from dendrites to axon

Dendrite

• Treelike structures that extend from soma

• Receive information from a sending neuron through receptor sites

Axon

Pathway for impulses from the soma to the axon terminals

Axon Terminals

Rounded areas at the end of axon that store and release neurotransmitters for communication between neurons

Myelin Sheath

insulates and protects axon

Myelination

The process of forming a protective sheath around neuron axons

Glial Cells

delivers nutrients to neurons

Schwann Cells

helps optimize brain function

Neuroplasticity

• Compensate for injury and disease

• Adapt to new experiences or changes in the environment

Resting Potential (negatively charged)

A neuron at rest (not active)

Action Potential (positively charged)

A neuron at work (firing)

All-or-Nothing Principal

Neurons fire completely or not at all

Absolute Threshold

the least amount of a stimulus necessary to begin an action potential

________ _________ travel from dendrites toward the axon and axon terminals

Neural impulses

Synapse (Synaptic Cleft or Gap)

• Fluid filled space between the axon terminal and dendrite receptors

• Allows communication between neurons

Vesicle

Sack-like structures inside the axon terminal that contain neurotransmitters

Neurotransmitters

Chemical found in vesicles - when released, affect the receiving cell

Reuptake

The process where neurotransmitters are reabsorbed into the vesicles by neurons after transmitting

Enzymes

molecules that clean the synapse by breaking down neurotransmitters

Acetylcholine (ACH)

Skeletal Muscle stimulation/control

Norepinephrine (noradrenaline)

• Arousal, adrenaline, energy

• Prepares the body for action (role in Fight or Flight)

Endorphins

Slows or halts transmission of pain signals

GABA (Gamma-amino-butyric acid)

Decreases neural activity (reduces arousal/calming)

Glutamate

Increases neural activity (arouses NS)

Serotonin

Affects mood and reduces anxiety (released in the Brain and Brain Stem)

Dopamine

Affects brain’s reward and motivation centers (Released in the brain)

Glands

Organs that produce and release hormones into the bloodstream

Hormones

Chemicals released into the blood stream that affect body functions

Pituitary Gland (The Master Gland)

• Found in Brain

• Controls all other glands

• Secretes Oxytocin, growth hormone

• Vasopressin “ADH” (Controls water within the body)

Pineal Gland

• Base of the brain

• Wake and Sleep Cycles

• Secretes Melatonin

Pancreas

• Controls levels of sugar in blood

• Secretes insulin

  (Too little insulin = Diabetic, Too Much = Hungry often/gain weight)

Gonads (Sex Glands)

• Responsible for production of male and female gametes

• Produce sex hormones (Testosterone and Estrogen)

• Facilitate sexual development, sex drive, and sexual function

Longitudinal Fissure

A large cleft which separates the brain’s left and right hemispheres

Brain Lateralization

how some neural functions tend to be more dominant in one hemisphere than the other

Cerebellum (Cortex or the Forebrain)

• Largest division of the brain

• plays a major role in movement

Frontal Lobe (front of the brain)

• Expressive language

• working memory

• motor skills

• emotions

Occipital Lobe

It is associated with interpreting visual stimuli and information

Which Parts of the Cortex are responsible for higher forms of though, such as language?

Frontal and Temporal Lobes

Broca’s Area

• Production of articulate speech production

• Moves muscles for speaking

• fluent speech

Wernicke’s Area

• Near Auditory Complex

• Interpretation and comprehension of speech

• producing speech that has meaning

Limbic system

A system in the brain strongly associated with emotions

Limbic System

emotional regulation, memory processing, and behavior

Thalamus

Sensory relay station - senses evoke emotions

Hypothalamus

• Regulates Autonomic NS

• Includes the pituitary gland

Amygdala

Recognizes danger/threat

Hippocampus

Plays a key role converting short-term to long-term memory