ch 3

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of glial cells in the nervous system?

To process information from sensory stimuli

To provide scaffolding and insulation for neurons (correct)

To form a myelin sheath around muscle fibers

To release neurotransmitters during synaptic transmission

What recent finding about the ratio of glial cells to neurons has been reported?

Neurons actually exceed the number of glial cells significantly

The ratio may be nearly 1:1 between glial cells and neurons (correct)

Glial cells outnumber neurons by a factor of 3:1

There are about ten times more glial cells than neurons

Which part of the neuron is primarily responsible for receiving signals from other neurons?

Axon

Terminal buttons

Soma

Dendrites (correct)

What role do terminal buttons play in the neuron?

They contain synaptic vesicles that store neurotransmitters Signup and view all the answers

What does the myelin sheath do for axons?

Increases the speed of signal transmission Signup and view all the answers

Which of the following statements about the neuron structure is true?

The soma has branching extensions called dendrites. Signup and view all the answers

What misconception about glial cells has been clarified by recent research?

The ratio of glial cells to neurons may be close to one-to-one Signup and view all the answers

What is the primary function of neurons in the nervous system?

To function as interdependent information processors Signup and view all the answers

What do afferent fibers primarily carry?

Sensory information Signup and view all the answers

What is the primary function of the sympathetic nervous system?

Preparing the body for stressful situations Signup and view all the answers

Which of the following correctly describes homeostasis?

A balance of biological conditions Signup and view all the answers

During the fight or flight response, which of the following changes does NOT occur?

Blood pressure decreases Signup and view all the answers

Which part of the autonomic nervous system is involved in routine operations?

Parasympathetic division Signup and view all the answers

What type of situations does the sympathetic nervous system primarily respond to?

Stress-related activities Signup and view all the answers

What physiological changes are associated with sympathetic activation?

Increased heart rate and relaxation of the bladder Signup and view all the answers

Which division of the autonomic nervous system is typically outside of voluntary control?

Autonomic nervous system Signup and view all the answers

What is the primary effect of the sodium-potassium pump on the cell's charge?

It creates a net negative charge inside the cell. Signup and view all the answers

What occurs when a neuron reaches the threshold of excitation?

The action potential begins. Signup and view all the answers

Which ion is primarily responsible for the positive spike in membrane potential during action potential?

Sodium ions (Na+) Signup and view all the answers

How do electrical signals typically move along the axon?

In a leapfrog fashion between the Nodes of Ranvier. Signup and view all the answers

What happens after the peak action potential?

Potassium ions leave the cell causing repolarization. Signup and view all the answers

What role do negatively charged proteins play in the cell's resting potential?

They help create a net negative charge inside the cell. Signup and view all the answers

What initiates the opening of the ion channels in response to a signal?

Binding of neurotransmitters to receptors. Signup and view all the answers

What is the effect of potassium ions leaving the cell?

It contributes to repolarization of the membrane. Signup and view all the answers

What is meant by the 'all-or-none phenomenon' in relation to action potentials?

An action potential is triggered at a threshold and does not diminish as it travels. Signup and view all the answers

What occurs when the action potential reaches the terminal button?

Neurotransmitters are released into the synaptic cleft. Signup and view all the answers

How does reuptake help in neurotransmission?

It clears the synapse and regulates neurotransmitter production. Signup and view all the answers

What happens to excess neurotransmitters in the synaptic cleft?

They drift away, are broken down, or undergo reuptake. Signup and view all the answers

What analogy is used to describe the nature of an action potential?

An email that remains unsent until the 'send' button is pressed. Signup and view all the answers

What part of Phineas Gage's brain was severely damaged in the accident?

Prefrontal cortex Signup and view all the answers

How does the action potential ensure that pain signals are perceived equally regardless of the injury location?

The all-or-none property allows consistent signal transmission. Signup and view all the answers

Which area of the somatosensory cortex processes sensory information primarily from the body's senses?

Somatosensory cortex Signup and view all the answers

Which process occurs after neurotransmitters bind to receptors on the adjacent neuron?

A new action potential is triggered if the signal is strong enough. Signup and view all the answers

How does the surface area of body parts relate to their representation in the somatosensory cortex?

Larger body parts have greater representation Signup and view all the answers

What is the main area responsible for processing auditory information in the brain?

Auditory cortex Signup and view all the answers

What is the effect of sodium ions entering the cell during an action potential?

They help raise the charge past the threshold of excitation. Signup and view all the answers

Which function is primarily associated with the temporal lobe?

Hearing Signup and view all the answers

What does the somatosensory cortex primarily process?

Sensory information Signup and view all the answers

What illustrates the relationship between body parts and their representation in the somatosensory cortex?

The body map Signup and view all the answers

Where is Wernicke's area located and what is its primary function?

In the temporal lobe, important for speech comprehension Signup and view all the answers

What happens to individuals with two copies of the sickle-cell gene?

They can develop full-blown sickle-cell anemia. Signup and view all the answers

In regions where malaria is prevalent, what advantage do carriers of the sickle-cell mutation have?

They are protected from malaria. Signup and view all the answers

What is a consequence of the sickle-cell gene's prevalence in the United States?

It results in minor health problems for carriers. Signup and view all the answers

How does Luwi’s situation exemplify Charles Darwin's theory of evolution by natural selection?

She survives due to her adaptive mutation in a malaria-endemic area. Signup and view all the answers

What is a likely outcome for Luwi regarding her future children?

They may inherit the sickle-cell mutation. Signup and view all the answers

What health issue may Sena face after being bitten by mosquitoes carrying malaria?

Progression to severe malaria and potential death. Signup and view all the answers

What is true about malaria's occurrence in the United States?

It is rare and does not significantly affect health outcomes. Signup and view all the answers

Why might the sickle-cell mutation be considered a burden in non-malarial regions?

It can lead to health complications for carriers. Signup and view all the answers

Study Notes

Psychological Research and Genetics

Psychological researchers study genetics to understand biological factors influencing behaviour.
Humans share biological mechanisms but are unique in their behaviours, thoughts, and reactions.
Genetic factors can influence how individuals respond to diseases.
Genetic components may play a role in psychological disorders (e.g., depression, schizophrenia) and health conditions (e.g., childhood obesity).

Sickle Cell Anemia

Sickle cell anemia is a genetic disorder affecting red blood cells.
Normally, red blood cells are round; in sickle cell anemia, they become crescent-shaped.
This change affects cell function, leading to blockages in blood vessels.
Symptoms include high fever, severe pain, swelling, and tissue damage.
Many individuals with sickle cell anemia die young.

Sickle Cell Anemia and Malaria

Sickle cell carriers (one copy of the sickle cell gene) are resistant to malaria.
In regions with high malaria rates, the sickle cell trait is more common among African descents because it confers an advantage against malaria.

Genetic Variation

Genetic variation is the genetic difference between individuals.
Variation is crucial for adaptation in a species.
Variation in humans starts with the egg and sperm.
Each contains 23 chromosomes with DNA (deoxyribonucleic acid) made up of base pairs.
Genes determine traits (e.g., hair colour).
An allele is a specific version of a gene.

Gene-Environment Interactions

Genes do not exist in a vacuum; our environment significantly affects how our genes express.
The "range of reaction" concept explains how genes set limits, but environment determines how much potential is realized.
Genes influence the environment and vice-versa; for example, a child of an athlete might be more likely to be involved with the sport, which might help them develop better.
Another viewpoint is 'genetic environmental correlation'. Our genes influence the environment, and the environment influences the expression of our genes.
Epigenetics examines how experiences can change how genes are expressed without altering the genetic code.

Genetic and Environmental Correlation

Genes and environmental factors can interact to influence a person's likelihood of developing a disorder, like schizophrenia.
Adoptees with a high genetic risk of schizophrenia developing the disorder if raised in a disturbed environment.
The study highlights that both genetics and environment are necessary for developing schizophrenia; genes alone are not the sole factor.

The Nervous System

The nervous system is composed of neurons and glial cells.
Glial cells support neurons physically and metabolically
Neurons communicate via electrical and chemical signals (electrochemical)
Neurons consist of a soma (cell body), dendrites, and an axon ending in terminal buttons.

Neuron Structure and Function

Neurons are building blocks of the nervous system.
The soma (cell body) receives input from other neurons.
Dendrites are branching extensions receiving signals.
The axon transmits electrical signals.
Axons may be myelinated (insulated) by glial cells for faster transmission.
Terminal buttons release neurotransmitters, which carry messages.
Neurons communicate using electrochemical signals.
The electrical signal is called an action potential.

Neurotransmitters and Drugs

Neurotransmitters are chemical messengers.
Some neurotransmitters are involved in psychological disorders (e.g., dopamine, serotonin)
Psychoactive drugs like agonists or antagonists can help balance neurotransmitters.
Agonists mimic neurotransmitter effects; antagonists block them.
Reuptake inhibitors prevent neurotransmitters from being reabsorbed.

The Central, Peripheral, and Endocrine Systems

The central nervous system (CNS) includes the brain and spinal cord.
The peripheral nervous system (PNS) connects the CNS to the rest of the body.
The PNS includes the somatic nervous system (voluntary actions and sensory input) and the autonomic nervous system (involuntary actions).
The endocrine system comprises glands producing hormones that regulate various bodily functions.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on the functions of glial cells and neurons in the nervous system. This quiz covers recent findings, neuron structure, the role of the sympathetic nervous system, and homeostasis. Brush up on key concepts and see how well you understand these crucial elements of neurobiology!