Chapter 3

NotesAP Tips

Know the basic structure of a neuron

Dendrites receive information from adjacent neurons; process incoming chemicals and propel info to the nucleus

The axon is the neural fiber that transmits info from the soma to the other end of the neuron; encased by myelin, a fatty substance that protects info stored inside the axon

The axon terminal is the ending part of the neuron that releases information

Know the types of neurons

Sensory (afferent) neurons transmit info from the spinal cord to the brain; they help our brains register sensory information

Motor (efferent) neurons transmit info from the brain to muscles and glands

S.A.M.E.

Be familiar with the process of neural transmission—specifically, the all-or-none principle, and know which ions enter and exit during polarization and depolarization.

Order of events in the firing of a neuron

Polarization Resting potential Depolarization Action potential Threshold All-or-none principle Refractory period

Polarization

Negatively charged chloride ions exist within the axon, resulting in a negative charge.

Resting potential

Negatively charged ions wait for stimulation within the axon. The neuron is said to be inactive and is waiting for another action potential.

Depolarization

When stimulated, the channels along the axon allow positively charged sodium and potassium ions to enter. This causes sodium and potassium channels to open, thus propelling the electrochemical process down the axon.

Action potential

A change in the balance of the overall charge of the neuron causes the electrochemical signal to travel ( it is fired) along the axon.

Threshold

A point of excitation on the neuron that must be reached for an action potential to occur

All-or-none principle

Once the threshold is reached, the neuron will fire at full strength. If the threshold is not reached, the neuron will not fire.

Refractory period

The period after a neuron fires, at which time it is less susceptible to stimulation from other neurons. The neuron must recharge itself electrically until it reaches polarization. Once this occurs, the neuron is ready to fire again.

Know about specific neurotransmitters and the resulting effects of an excess or a deficiency.

Acetylcholine Dopamine Serotonin GABA Norepinephrine Glutamate

Know the organization of the nervous system

Central Nervous System Peripheral Nervous System Autonomic Nervous System

Central Nervous System (CNS)

Responsible for processing and distributing information throughout the body

Brain

Responsible for cognitive functioning

Spinal Cord

Responsible for transmitting information throughout the body.

Peripheral Nervous System (PNS)

Responsible for voluntary movement and regulation of vital processes.

Somatic Nervous System

Responsible for voluntary movement

Autonomic Nervous System

Regulation of vital human functioning (breathing, digestion, heartbeat, etc)

Sympathetic Nervous System

Spends reserved energy

Parasympathetic Nervous System

Restores and repairs spend energy

Know about the 4 brain lobes Frontal lobe: responsible for

controlling inhibitions, short-term memory, reasoning, and planning for the future

Parietal lobe: responsible for receiving and combining tactile (touch) stimuli from all over the body to allow the formation of a single concept.

Occipital lobe: responsible for processing visual stimuli, as well as maintaining balance

Temporal lobe: responsible for processing auditory stimuli

Be able to identify the functions of Broca’s and Wernicke’s areas.

Broca’s area: responsible for transferring thoughts into audible spoken words

Wernicke’s area: responsible for transforming spoken words into thoughts

Know the location and functions of brain structures

Complete table

Know the area of the brain responsible for hunger.

Hypothalamus

Know how psychologists look into the brain.

EEG: electrodes are placed on the scalp to measure the brain’s electrical activity

CT or CAT Scan: produces a 2-dim image based on x-rays taken around a single axis

MRI: uses a large magnetic field to reconstruct the image within the body/brain

fMRI: measures neural activity within the brain

PET scan: uses radioactive liquid to measure metabolic and glucose processing (3-dim view)

Know the major glands, their hormones, and their functions

Complete table