Chapter 48 Learning Objectives

How do neurons communicate? How do the signals travel through the nervous system?

How do neurons communicate? How do the signals travel through the nervous system?

receives information, transmits it along an axon and transmits the information to other cells via synapses. Travel through from the brain to spinal cord, nerves

What structures of the nervous system process information?

central nervous system

What are the parts of a neuron, and is a function/feature of each?

Dendrite: where a neuron receives input from other cells

Axon: to carry electrical impulses

Cell Body/Soma: contains the nucleus and cytoplasm, ensures the synthesis of many of the components required for the structure and function of a neuron

What are the three stages of information processing in the nervous system? What type of neurons are involved at each stage?

1. Sensory Input: sensory neurons transmit information from external stimuli and internal conditions.

2. Integration: interpret the sensory input and CNS then decides how to respond.

3. Motor Output: leaves the CNS via motor neurons to effector cells which then move or release hormones for examples

What are the differences between the central nervous system and the peripheral
nervous system?

The CNS is responsible for integrating, processing, and coordinating sensory input and motor output. The PNS provides sensory information to the CNS and carries motor commands from the CNS to peripheral tissues and system.

What is a membrane potential? What ions are involved? How do changes in membrane potential occur?

every cell has a voltage (difference in electrical charge across its plasma membrane

Ions: potassium, sodium and chloride

does not change unless there is a net charge movement across the membrane

What is a resting potential and how is it maintained?

is the membrane potential of a neuron that is not sending signals.

Sodium-potassium pumps move two potassium ions inside the cell as three sodium ions are pumped out to maintain the negatively-charged membrane inside the cell

What is an action potential? How is an action potential generated? How is an action potential propagated?

changes in membrane potential

gets generated when the negative inside potential reaches the threshold (less negative).

is propagated along the axon of a neuron through a process called saltatory conduction, which involves depolarization and repolarization

What is a myelin sheath and what function does it serve?

is a fatty substance that surrounds nerve cell axons and insulates them, allowing electrical impulses to travel quickly and efficiently.

What is a chemical synapse and what occurs there?

connections between two neurons or between a neuron and a non-neuronal cell

Describe how neurotransmitters are used to communicate between neurons. How are they released? What happens to them after they are released? What effect(s) can they cause in the target (postsynaptic) cell?

The presynaptic neuron releases a chemical (i.e., a neurotransmitter) that is received by the postsynaptic neuron's specialized proteins called neurotransmitter receptors. The neurotransmitter molecules bind to the receptor proteins and alter postsynaptic neuronal function. Activation of postsynaptic receptors leads to the opening or closing of ion channels in the cell membrane

What are agonistic and antagonistic neurotransmitter mimics?

Agonistic: bind to neurotransmitter receptors or transporters and mimic the effects of the regular neurotransmitter

Antagonistic: block neurotransmitter receptors and prevent normal operation

How can habituation alter nerve activity?

Prolonged exposure to a stimulus may cause cells to lose the ability to respond to it

Neurons

send and receive signals from your brain

Ganglia

groups of nerves or brain cells that are closely related. Play a role in connecting the parts of the peripheral and central nervous system

Brain

function of coordinating center of sensation and intellectual activity

Dendrites

structure of neurons which conduct electrical impulses toward the cell body of the nerve cell

Axon

carry electrical impulses

Synapse

connect neurons and help transmit information from one neuron to the next

Neurotransmitters

chemical messengers that carry signals from one nerve cell to another target cell

Membrane Potential

every cell has a voltage (difference in electrical charge across its plasma membrane

Resting Potential

is the membrane potential of a neuron that is not sending signals.

Action Potential

changes in membrane potential

Gated Ion Channels

changes in membrane potential occurs because neurons contain channels that open or close in response to stimuli

Voltage Gated Ion Channels

open or close in response to a change in voltage across the plasma of the neuron

Depolarization

reduction in the magnitude of the membrane potential

Myelin Sheath

is an insulating layer, or sheath that forms around nerves

allows electrical impulses to transmit quickly and efficiently along the nerve cells

Ligand Gated Ion Channel

integral membrane proteins that contain a pore which allows the regulated flow of selected ions across the plasma membrane

Acetylcholine

is a neurotransmitter, a chemical that carries messages from your brain to your body through nerve cells.

chief neurotransmitter of the parasympathetic nervous system, the part of the autonomic nervous system

Neuropeptides

modulate the activity of co-released neurotransmitters to either increase or decrease the strength of synaptic signaling.

Endorphins

a type of neurotransmitter, or messenger in your body. Are neurotransmitters released by the pituitary gland and hypothalamus in the brain. As natural hormones, they can alleviate pain, lower stress, improve mood, and enhance your sense of well-being