Neuroscience Chapter Overview

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Questions and Answers

What two main cell types compose nervous tissue?

Neurons and Astrocytes

Neurons and Ependymal cells

Neurons and Oligodendrocytes

Neurons and Glial cells (correct)

Which scientist proposed the Neuron Theory suggesting that neurons are singular elements?

Paul Broca

Camillo Golgi

Sigmund Freud

Santiago Ramon y Cajal (correct)

What position did Camillo Golgi hold regarding the structure of neurons?

He believed neurons were independent cells.

He saw them as a continuous network. (correct)

He argued they had no role in the CNS.

He claimed neurons were non-functional cells.

What innovative instrument did Santiago Ramon y Cajal develop to assist in his studies?

Camera lucida Signup and view all the answers

Which type of glial cell is specifically mentioned as surrounding neurons in a dorsal root ganglion?

Satellite Glial cells Signup and view all the answers

Which of the following best describes the outcome of the scientific debate between Cajal and Golgi?

Cajal's Neuron Theory was ultimately supported. Signup and view all the answers

What aspect of Santiago Ramon y Cajal's work was notable besides his scientific contributions?

His interest in figurative arts and drawings. Signup and view all the answers

What is the significance of Cajal's drawings in neuroanatomy?

They helped in visualizing and hypothesizing neuron morphology. Signup and view all the answers

What is the primary reason for calling the white matter 'white'?

It contains myelinated axons. Signup and view all the answers

Which structure is responsible for connecting the two hemispheres of the brain?

Corpus callosum Signup and view all the answers

What is the composition of the grey matter located in the spinal cord?

Primarily consists of cell bodies. Signup and view all the answers

What is the thickness range of the cortex mentioned?

2 – 4 mm Signup and view all the answers

Which portion of the spinal cord consists of 8 neuromeres?

Cervical Signup and view all the answers

What describes the shape of grey matter in the spinal cord?

Butterfly-shaped Signup and view all the answers

Which of the following describes the white matter in the spinal cord?

Surrounds the grey matter. Signup and view all the answers

What type of pathways carry sensory information to the brain?

Ascending pathways Signup and view all the answers

What are the names of the two fascicles of axons that convey somatosensory information?

Fasciculus Gracilis and Cuneatus Signup and view all the answers

Which cranial nerve is responsible for innervating the extrinsic muscles of the eye?

Cranial Nerve VI Signup and view all the answers

What does the sulcus of the basilar artery provide?

Posterior circulation of the brain Signup and view all the answers

Which cranial nerve emerges from the posterior part of the brain stem?

Cranial Nerve IV Signup and view all the answers

What forms the floor of the IV ventricle?

Triangles formed by the pons and medulla Signup and view all the answers

What is the appearance of the midbrain surface due to the small holes that serve as entrance points for vessels?

Substantia perforata Signup and view all the answers

Which cranial nerve emerges laterally to the basis of the pons?

Cranial Nerve V Signup and view all the answers

What is the function of the vestibular acoustic nerve?

Balance and hearing Signup and view all the answers

What is the primary function of a nucleus in the nervous system?

A collection of neurons with a common function delimited by anatomical boundaries Signup and view all the answers

Which of the following structures are part of the peripheral nervous system (PNS)?

Cranial nerves Signup and view all the answers

What distinguishes a tract in the central nervous system (CNS)?

It is a group of CNS axons with the same origin, destination, and function Signup and view all the answers

What are fascicles in the context of the nervous system?

A smaller group of axons in the spinal cord’s white matter Signup and view all the answers

What is the role of the autonomic nervous system (ANS)?

To regulate visceral activities without conscious control Signup and view all the answers

Which part of the nervous system is specifically responsible for the contraction of the gut?

Enteric nervous system Signup and view all the answers

What defines a ganglion in the context of the nervous system?

An enlargement along a nerve containing the cell bodies of PNS neurons Signup and view all the answers

What is the main function of the central nervous system (CNS)?

To receive and process sensory information and produce outputs Signup and view all the answers

What occurs during hyperpolarization in a neuron?

The voltage decreases, becoming more distant from the threshold Signup and view all the answers

Which of the following best describes the role of neuromodulators?

They regulate neurotransmission positively or negatively Signup and view all the answers

Which neurotransmitter is considered the most diffused excitatory neurotransmitter in the CNS?

Glutamate Signup and view all the answers

What type of junction involves the release of neurotransmitters to regulate gland activity?

Neuro-glandular junction Signup and view all the answers

Which neurotransmitter is primarily associated with the autonomic system?

Acetylcholine Signup and view all the answers

What is the most common inhibitory neurotransmitter found in the CNS?

GABA Signup and view all the answers

What type of post-synaptic elements can neurons interact with, besides other neurons?

Endocrine cells and exocrine cells Signup and view all the answers

Which of the following is true about the distribution of Acetylcholine in the CNS?

It has a restricted distribution in specific regions Signup and view all the answers

What are internodes in the context of axons?

Myelinated portions of axons. Signup and view all the answers

What is the purpose of the nodes of Ranvier?

To regenerate action potential by clustering sodium and potassium channels. Signup and view all the answers

What evolutionary advantage does saltatory conduction provide to vertebrates?

Allows faster message transfer without increasing axon diameter. Signup and view all the answers

What is the primary distinction between the conduction strategies of vertebrates and some invertebrates?

Vertebrates rely on myelination, while invertebrates rely on increased axon diameter. Signup and view all the answers

Which type of neurons comprise 95% of the neurons in the nervous system?

Multipolar neurons. Signup and view all the answers

What defines multipolar neurons?

They possess many dendrites and a single axon. Signup and view all the answers

What characteristic of squid axons allows them to convey action potentials at high speeds despite being unmyelinated?

Their large diameter enables the transfer of greater ion currents. Signup and view all the answers

Which type of neuron is characterized by having one axon and one dendrite?

Bipolar neurons. Signup and view all the answers

Study Notes

Neuroanatomy Summary

Terminology:
- Center: neurons grouped in a common function
- Nucleus/nuclei: refers to a group of neurons with a shared function, enclosed by anatomical boundaries.
- Tract: a group of CNS axons sharing the same origin, destination, and function
- Fascicles/columns: smaller/larger group of axons; located in specific areas of the spinal cord's white matter.
- Nerve: a group of PNS axons
- Ganglion/ganglia: a structure along a nerve containing cell bodies of PNS neurons.
The Nervous System - Macroscopic Organization:
- Central Nervous System (CNS): comprises the brain and spinal cord, enclosed by the skull and vertebral canal.
- Peripheral Nervous System (PNS): consisting of cranial nerves and spinal nerves which connect the CNS to the rest of the body and its associated ganglia.
- Autonomic Nervous System (ANS): the part of the CNS and PNS responsible for regulating visceral functions (e.g. heart rate, digestion) independent of our conscious control. This includes the enteric nervous system.
Organizational Principles of the CNS:
- The organization of the nervous system follows rules regarding layering (cortex) vs. grouping in nuclei; also, the relationship between sensory and motor pathways (afferent or efferent, respectively). Most functional systems control the opposite side of the body.
Microscopic Anatomy of the Nervous System:
- Neurons: Specialized cells for receiving, processing, and transmitting signals (including sensory, motor, and interneurons). Three major types include multipolar, bipolar, and pseudounipolar.
- Synapses: Connection points between neurons, where neurotransmitters are released to propagate signals.
- Glial cells: support cells in the CNS that act as support, insulation, and metabolic support for neurons (astrocytes, microglia, oligodendrocytes, and ependymal cells). Satellite glial cells support neurons in ganglia.
Protective Layers:
- Dura mater: the tough outermost layer of protective membranes around the brain and spinal cord and its coverings (attached to the skull).
- Arachnoid: a soft, web-like layer beneath the dura mater.
- Pia mater: innermost layer, closely adhering to the brain tissue. In the spinal cord, pia mater is connected to the dura mater by the denticulate ligaments.
Vascularization of the Brain:
- Arterial circulation: the brain receives blood from the internal carotids and vertebral arteries, which form a circle of Willis, enabling blood to reach different parts of the brain, ensuring a back-up circulation path.
- Venous circulation: blood drains from the brain through various venous sinuses within the dura mater.
Spinal Cord:
- Macroscopic Anatomy: The spinal cord is an extension of the brain stem and is divided into segments (cervical, thoracic, lumbar, and sacral) with corresponding enlargements for limbs. It is enclosed within the vertebral column, and continues as the medulla oblongata (brain stem).
- Microscopic Anatomy: The spinal cord has a central gray matter area and an outer white matter area, where nerve tracts are located.
Cranial Nerves:
- Nuclei Organization: The brain stem houses the nuclei of most cranial nerves. Cranial nerves have important sensory and/or motor functions. cranial nerves are numbered I through XII.
Basal Ganglia:
- Structures: The basal ganglia are a group of nuclei in the brain that control motor function via specific pathways. Putamen, Globus pallidus (internal and external), Nucleus accumbens.
- Function: involved in motor control, procedural learning, and more.
Limbic System:
- Organization: The limbic system is a complex set of structures involved in emotional processing, motivation, learning, and memory; it's arranged in a circuit of structures that interact. Amygdala, hippocampus, cingulate gyrus.
Autonomic Nervous System (ANS):
- Function: the ANS regulates involuntary bodily functions including blood pressure, heart rate, digestion, and more.
- Parts: sympathetic (fight-or-flight) and parasympathetic (rest-and-digest).
Eyes, Hearing, Smell:
- Anatomy: Includes the structures of the eye (cornea, iris, lens, retina, etc.) and ear including the ossicles (malleus, incus, stapes), inner ear receptors (cochlea, semicircular canals), and the structures for smell, olfactory epithelium, etc.
- Functional pathways: outlines mechanisms for vision and hearing including the optic and auditory pathways, tonotopic organization.
Telencephalic White Matter:
- Corpus Callosum, Anterior Commissure, Hippocampal Commissure (fornix).

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Test your knowledge of key concepts in neuroscience, including the types of cells that make up nervous tissue and the contributions of influential scientists like Cajal and Golgi. This quiz covers foundational topics in neuroanatomy and cellular functions essential for understanding the nervous system.