Peter Gray's Psychology: Chapter 5 Flashcards

Questions and Answers

Who was Hippocrates?

A mathematician

A Greek physician (correct)

A Roman general

A Greek philosopher

What are neurons?

A nerve cell; the basic building block of the nervous system.

How many nerve cells are contained in the brain?

100 billion

What are synapses?

Points of communication between neurons. Signup and view all the answers

How many synapses are contained in the brain?

100 trillion Signup and view all the answers

What is the central nervous system (CNS)?

Made up of the brain and the spinal cord. Signup and view all the answers

What does the peripheral nervous system (PNS) consist of?

Nerves extending from the central nervous system. Signup and view all the answers

What are nerves?

A bundle consisting of axons of many neurons within the peripheral nervous system. Signup and view all the answers

What are the three types of neurons?

Motor, sensory, interneurons Signup and view all the answers

What do sensory neurons do?

Carry information from sensory organs into the central nervous system. Signup and view all the answers

What do motor neurons do?

Carry information from the CNS to operate muscles and glands. Signup and view all the answers

What are interneurons?

Neurons that carry messages from one set of neurons to another within the CNS. Signup and view all the answers

What is the cell body of a neuron?

The widest part of the neuron; contains the cell nucleus and other basic machinery. Signup and view all the answers

What are dendrites?

Thin, tubelike extensions that receive input to the neuron. Signup and view all the answers

What are axons?

Thin, tubelike extensions from the cell body that carry messages to other neurons. Signup and view all the answers

How long can the longest axon in the human body be?

5 feet Signup and view all the answers

What is the axon terminal?

The endpoint of a neuron where neurotransmitters are stored. Signup and view all the answers

What is the myelin sheath?

A layer of fatty tissue that encases the fibers of many neurons. Signup and view all the answers

What is action potential?

A neural impulse; a brief electrical charge that travels down an axon. Signup and view all the answers

What is the cell membrane?

A cell structure that controls which substances can enter or leave the cell. Signup and view all the answers

What is intracellular fluid?

The watery solution found within cells; also called cytoplasm. Signup and view all the answers

What is extracellular fluid?

Fluid surrounding and bathing a cell. Signup and view all the answers

What are soluble protein molecules?

Molecules that have negative charges and exist only in the intracellular fluid. Signup and view all the answers

What are potassium ions?

Ions that are more concentrated in the intracellular fluid than in the extracellular fluid. Signup and view all the answers

What are sodium ions and chloride ions?

Ions that are more concentrated in the extracellular fluid than in the intracellular fluid. Signup and view all the answers

What is resting potential?

The slightly negative charge across the membrane of an inactive neuron. Signup and view all the answers

What is the depolarization phase?

A shift in which sodium moves inward to reverse the electrical charge across the cell membrane. Signup and view all the answers

What is the repolarization phase?

A shift in which positively charged potassium ions move out of the cell to reestablish resting potential. Signup and view all the answers

Study Notes

Hippocrates and the Brain

Hippocrates was a Greek physician known for observing the link between head injuries and changes in thoughts and actions, prompting a focus on the brain in medicine.

Neurons and Nervous System

Neurons are the fundamental units of the nervous system, acting as nerve cells that transmit signals.
The human brain contains approximately 100 billion neurons.
The brain features around 100 trillion synapses, which are essential communication points between neurons.

Nervous System Structure

The central nervous system (CNS) comprises the brain and spinal cord, coordinating most activities of the body.
The peripheral nervous system (PNS) consists of nerves branching from the CNS to connect with sensory organs, muscles, and glands.

Types of Neurons

There are three main classes of neurons: sensory neurons, motor neurons, and interneurons.
Sensory neurons transmit information from sensory organs (e.g., eyes, ears) into the CNS.
Motor neurons convey information from the CNS to muscles and glands for action.
Interneurons, found only within the CNS, facilitate communication between neurons and play critical roles in reflexes and complex behaviors.

Neuron Structure

The cell body is the neuron’s main part, housing the nucleus and vital cellular machinery.
Dendrites are branch-like structures that receive signals from other neurons, with motor and interneuron dendrites closely connected to the cell body.
Axons are long, slender projections that send messages away from the cell body to other neurons or muscle cells.
The longest human axon spans about 5 feet, stretching from the toe to the brain.

Neuronal Communication

The axon terminal is where neurotransmitters are released to convey messages between neurons.
The myelin sheath covers many neuron fibers, enhancing the speed of neural impulse transmission through node hopping.

Action Potential

Action potential refers to the electrical signals traveling along an axon, capable of firing at rates up to 1,000 times per second.
This signal initiates movement across the cell membrane, aided by the cell’s membrane, which selectively allows substances to enter and exit.

Cellular Composition

Intracellular fluid, or cytoplasm, is the liquid inside the cell, while extracellular fluid surrounds it.
Soluble protein molecules carry negative charges, primarily found in the intracellular environment, influencing ionic balance.
Potassium ions (K+) are mainly located inside the cell, while sodium ions (Na+) and chloride ions (Cl-) are more concentrated outside.

Neuronal States

Resting potential describes a neuron's baseline state, marked by a slight negative charge when inactive.
During the depolarization phase, sodium ions rush into the neuron, temporarily inverting the electrical charge across the membrane.
The repolarization phase occurs as potassium ions exit the cell, restoring the resting potential.

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Description

Test your knowledge with these flashcards from Chapter 5 of Peter Gray's Psychology. This chapter focuses on the biological bases of behavior, discussing key concepts such as neurons, synapses, and the impact of head injuries. Perfect for students looking to reinforce their understanding of neuroscience in psychology.