AP PSYCHOLOGY NEURAL SYSTEMS

Central Nervous System

1) Brain 

2) Spinal Cord

Peripheral Nervous System

1) Somatic- (skeletal) nervous system

• Voluntary behaviors

2) Autonomic- Self regulation of internal organs and glands

• 1-Sympathetic NS: Arousing:

  • pupils dilate, HR, BP, respiration increase, and digestion processes slow down and |Flight or Fight response|

• 2- Parasympathetic NS: Calming opposite of Sympathetic nervous system response

Sympathetic NS

1. rousing

   1. Pupils dilate, HR, BP, respiration increase, and digestive processes slow down.

   2. Fight or flight response.

Parasympathetic NS

1. calming-opposite of sympathetic nervous system response.

Sensory Neuron (Afferent Nerves)

neurons of the peripheral NS take incoming sensory information to the spinal cord and brain.

Motor Neurons

neurons take information from the spinal cord out to muscles and glands.

Interneuron

They communicate with each other and connect the sensory and motor neurons

A simple Reflex

• A simple reflex involves afferent (sensory) neurons carrying sensory information to the spinal cord. 

• Interneurons connect the afferent neurons to the efferent (motor) neurons. 

• A reflex does not involve the brain.

Cell Body

• Contains nucleus and support systems

• directs metabolism 

• Controls protein manufacturing

Dendrites

• Tree-like branches that receive information from other neurons

• new dendrites can grow

• provides new connections for basis for learning

Axon

• Long fiber that passes info to other neurons

• Tube+branches at the end

• Action Potential occurs here

Myelin Sheath

• Fatty substance on some axons--speeds up neural transmissions

• “allows action potential to jump at each Node of Ranvier”

Terminal Branches of Axon

•  Form junctions with other cells and contain synaptic vesicles

• The electrical impulse trigger synaptic transmission to the dendrites of the receiving neurons

Synaptic vesicles

•  sac-like structures that contain neurotransmitters

Synapse

• The tiny gap between the sending and receiving neurons

Neural Networks

 Clusters of neurons that work together and become strengthened with use.

Glial Cell

• a white fatty tissue that are spread among neurons in the brain to give supply nutrients. 

• Makes up the Myelin Sheaths

Neural Communication

• Neurons communicate via an electrochemical process

Resting Potential

 Neuron is at rest and is said to be Polarized (-70 millivolts).  The inside of the cell is more negative than the surrounding fluid.

Action Potential

 When stimulated at or above threshold, the cell becomes depolarized (+50 millivolts) as positively charged sodium ions rush into the cell. The neuron has now "fired".  It is an all-or-nothing response. The cell then returns to its polarized state.

Refractory Period

For 1/1000 of a second after firing, the cell cannot fire again.  This is somewhat like a camera flash recharging itself.

Reuptake

Neurotransmitters are reabsorbed by the sending neuron and recycled for future use

Agonists

Drugs that are so similar to a neurotransmitter that they can mimic its effects-or-they may block reuptake of a neurotransmitter.

Antagonists

 Drugs that inhibit a neurotransmitter’s release-or-they may occupy the receptor site on the receiving neuron, thus blocking the neurotransmitter from binding.

Acetylcholine (Ach)

• Muscle movement,

• learning, 

• memory.

• An undersupply is involved in Alzheimer's disease.

Dopamine

 Involved in

• learning,

• attention,

• emotion

• Excess dopamine is involved in schizophrenia.

Serotonin

Affects

• mood,

• hunger,

• sleep,

• arousal. 

• An undersupply is linked to depression.

Norepinephrine

Helps Control: 

• alertness

• arousal

• An undersupply can lead to depression

• An oversupply can lead to manic symptoms

GABA

•  Major inhibitory neurotransmitter.

• An undersupply can lead to

• tremors

• seizures

•  insomnia.

Glutamate

•  Major excitatory neurotransmitter;

• Involved in memory

• Oversupply can lead to ..

• overstimulate the brain leading to migraines (this is why some people avoid MSG in food).

Endorphins

• natural opiate-like neurotransmitter

• linked to pain control and pleasure.

Substance P

 involved in

• pain perception

• immune response

Psychoactive Drug

A chemical substance that alters perceptions and mood.

Tolerance

The diminishing effect with regular use of the same dose of a drug; requiring the user to take larger and larger doses in order to obtain the same effect.

Withdrawal

The discomfort and distress that follow discontinuing the use of an addictive drug.

Physical Dependence

A physiological need for a drug, marked by unpleasant withdrawal symptoms when the drug is discontinued.

Psychological Dependence

A psychological need to use a drug, such as to relieve negative emotions.

Depressants

•  Drugs (such as alcohol, barbiturates, and tranquilizers) that reduce neural activity and slow body functions.

  • Ex. Barbiturates: depress the activity of the CNS (reduces anxiety, but impairs judgment and memory) 

Stimulants

• Drugs (such as caffeine, nicotine, and the more powerful amphetamines and cocaine) that excite neural activity and speed up body functions. 

  • Ex. Amphetamines: Stimulates Neural activity (associated with mood changes and associated energy) 

  • Ex. Ecstasy: Stimulate that causes mild hallucinogen (Short time euphoria, and harms emotion and cognition)

Hallucinogens

• Psychedelic ("mind-altering") drugs, such as LSD and marijuana, that distort perceptions and may evoke sensory images in the absence of sensory input (i.e., hallucinations).

  • Ex. THC: Major ingredient in marijuana

Opiates

 Opium and its derivatives (such as morphine and heroin); they depress neural activity, temporarily lessening pain and anxiety.