Central Nervous System and Neuroglia Overview

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Questions and Answers

What is the primary function of receptors located on the dendrites of neurons?

Receive signals from other neurons (correct)

Terminate neurotransmitter activity

Produce neurotransmitters

Conduct electrical impulses away from the neuron

Which neurotransmitter is involved in muscle action and memory?

Dopamine

Serotonin

Acetylcholine (correct)

Norepinephrine

What is the primary role of inactivators in the nervous system?

To terminate neurotransmitter activity (correct)

To convert neurotransmitters into hormones

To strengthen synaptic connections

To enhance neurotransmitter activity

Which structure divides the right and left hemispheres of the brain and facilitates communication between them?

Corpus callosum Signup and view all the answers

Which lobe of the brain is primarily responsible for processing visual information?

Occipital lobe Signup and view all the answers

What function is primarily associated with the hypothalamus?

Regulates body temperature and metabolism Signup and view all the answers

What term describes the convoluted elevations in the cerebrum?

Gyri Signup and view all the answers

What condition is associated with a deficiency of dopamine in the basal nuclei?

Parkinson's disease Signup and view all the answers

What does the Central Nervous System (CNS) primarily consist of?

Brain and spinal cord Signup and view all the answers

Which function of the nervous system is responsible for interpreting sensory information?

Integrative function Signup and view all the answers

Which cells are the most abundant in the CNS and perform supportive roles?

Astrocytes Signup and view all the answers

How do sensory nerves function within the nervous system?

Gather and relay information to CNS Signup and view all the answers

What role do ependymal cells play in the nervous system?

Assist in cerebrospinal fluid formation Signup and view all the answers

What is the primary function of motor nerves?

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

Identify the part of the neuron that receives signals from other neurons.

Dendrites Signup and view all the answers

What is the main role of interneurons in the nervous system?

Integrate sensory information and trigger motor response Signup and view all the answers

What is the role of myelination in the nervous system?

It acts as a protective barrier for axons. Signup and view all the answers

What type of cell forms the myelin sheath in the PNS?

Schwann cells Signup and view all the answers

During which phase of the action potential does Na+ rush into the neuron?

Depolarization Signup and view all the answers

How does saltatory conduction affect nerve impulse transmission?

It facilitates the impulse to jump between Nodes of Ranvier. Signup and view all the answers

What distinguishes white matter from gray matter in the nervous system?

Gray matter consists of unmyelinated axons and synapses. Signup and view all the answers

What is the function of the synaptic cleft?

It is a space that allows chemical signals to pass between neurons. Signup and view all the answers

What is the effect of K+ diffusion during repolarization?

It causes the inside of the neuron to become negative again. Signup and view all the answers

What are small clusters of cell bodies in the PNS called?

Ganglia Signup and view all the answers

What is the primary function of the medulla oblongata?

Control of heart rate, blood pressure, and respiration Signup and view all the answers

Which layer of the meninges is the thickest?

Dura mater Signup and view all the answers

What is the function of the reticular formation?

Regulating muscle tone and alerting the cerebral cortex Signup and view all the answers

What characteristic is associated with the limbic system?

Involvement in emotional responses Signup and view all the answers

Which component of the brain is primarily responsible for regulating breathing rate?

Pons Signup and view all the answers

Which statement about cerebrospinal fluid (CSF) is not correct?

CSF flows through the subdural space. Signup and view all the answers

What is the primary role of the blood-brain barrier?

Protect the brain from harmful substances Signup and view all the answers

Which brain structure is involved in processing reflex centers for vision and hearing?

Midbrain Signup and view all the answers

Study Notes

Central Nervous System (CNS) and Peripheral Nervous System (PNS)

CNS includes the brain (cranial cavity) and spinal cord (spinal cavity).
PNS consists of nerves connecting the CNS to the rest of the body.
CNS functions: sensory (gathering information), integrative (interpreting information), and motor (carrying information to muscles and glands).

Neuroglia (Glial Cells)

Most abundant CNS cells; support, nourish, protect, and insulate neurons.
Do not conduct nerve impulses.
Astrocytes: most abundant and diverse, provide structural support and contribute to the blood-brain barrier.
Ependymal cells: line brain cavities and assist in cerebrospinal fluid (CSF) formation.

Neurons

Specialized for electrical transmission.
Types: sensory (afferent; PNS to CNS), motor (efferent; CNS to PNS), and interneurons (integrate information within CNS).
Neuron parts: dendrites (receive signals), cell body (contains nucleus, integrates signals), axon (transmits signals).
Axon structure: myelin sheath (insulates axon; formed by oligodendrocytes in CNS, Schwann cells in PNS; neurilemma in PNS allows regeneration), Nodes of Ranvier (facilitate saltatory conduction).
White matter (myelinated axons) vs. gray matter (unmyelinated axons, cell bodies, interneurons, synapses).
Nuclei (CNS) and ganglia (PNS) are clusters of cell bodies.

Nerve Impulse (Action Potential)

Electrical signal conveying information along a neuron.
Stages: resting membrane potential (K+ outward leak; inside negative, outside positive), depolarization (Na+ influx; inside positive, outside negative), repolarization (K+ outward diffusion; inside negative, outside positive).
Myelin sheath and saltatory conduction (impulse jumps between Nodes of Ranvier) increase speed.

Synapse

Junction between neurons for chemical information transfer.
Components: synaptic cleft (space between neurons), receptors (on dendrites, receive neurotransmitters), neurotransmitters (chemicals; e.g., acetylcholine and norepinephrine), inactivators (terminate neurotransmitter activity).

Brain: Structure and Function

Cerebrum: largest part; right and left hemispheres connected by corpus callosum; four lobes (frontal – executive functions, primary motor cortex, Broca's area; parietal – primary somatosensory area; temporal – primary auditory cortex, olfactory area, Wernicke's area; occipital – visual cortex); cerebral cortex (gray matter, higher mental functions); white matter (connects brain parts); gyri (elevations); sulci (grooves); basal nuclei (regulate movement, facial expression; dopamine deficiency causes Parkinson's disease).
Diencephalon: thalamus (sensory relay station); hypothalamus (regulates temperature, water balance, metabolism, ANS).
Brainstem: midbrain (sensory/motor relay, reflexes), pons (breathing regulation), medulla oblongata (vital center – heart rate, blood pressure, respiration; vomiting center; opioid sensitive).
Cerebellum: coordinates voluntary muscle activity, posture, and balance.
Limbic system: emotional brain.
Reticular formation: alerts cerebral cortex, regulates muscle tone; reticular activating system (sleep-wake cycle; NREM and REM sleep).

Brain Protection

Bone (cranium, vertebral column).
Meninges: dura mater (outermost, dural sinuses), arachnoid mater (middle, subarachnoid space with CSF), pia mater (innermost, blood vessels).
Cerebrospinal fluid (CSF): formed in ventricles by choroid plexus; protects, nourishes, removes waste.
Blood-brain barrier.

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Description

Test your knowledge of the Central Nervous System (CNS) and Peripheral Nervous System (PNS). This quiz covers the functions of neurons and the role of glial cells. Understand how these components work together to support bodily functions.