Week 31 / Nervous System - 1 Flashcards
Question: What are the two main components of the central nervous system (CNS)?
Answer: The brain and the spinal cord.
Question: What are the three main surface anatomical divisions of the brain?
Answer: The cerebral hemispheres, cerebellum, and brainstem.
Question: What are the key cellular components of the brain?
Answer: Nerve cells, glial cells, blood vessels, and cerebrospinal fluid.
Question: What percentage of the body’s neural tissue is contained within the brain?
Question: What is the average weight of the brain at birth and in adulthood?
Answer: The brain contains almost 98% of the body’s neural tissue.
Answer:
Newborn brain weight: 350-400 g
Adult brain weight: 1300-1400 g.
Question: What are neurons and what is their role in the nervous system?
Answer: Neurons are the primary constituents of the nervous system. They receive messages through their dendrites, and axons carry outgoing messages.
Question: What is the primary function of the central nervous system (CNS)?
Answer: The CNS underlies all the activity of the nervous system, forms a communication network, coordinates all body systems, and integrates information from all parts of the body.
Question: What is the role of dendrites in a neuron?
Answer: Dendrites receive messages from other neurons and carry them to the neuron’s cell body.
Question: What function does the axon serve in a neuron?
Answer: The axon carries outgoing messages from the neuron.
Question: What is a nerve in the peripheral nervous system (PNS)?
Answer: A nerve is a group of axons bundled together in the PNS. Examples include cranial nerves and spinal nerves.
Question: What is a nerve fascicle (or fasciculus)?
Answer: A nerve fascicle (or fasciculus) is a bundle of funiculi, and a funiculus is a bundle of axons.
Question: What is a nucleus in the context of the nervous system?
Answer: A nucleus (or nuclei in plural) is a collection of neuron cell bodies in the CNS.
Question: What is a tract in the central nervous system (CNS)?
Answer: A tract is a group of axons bundled together in the CNS.
Question: What is Multiple Sclerosis (MS)?
Question: What is Guillain-Barré Syndrome (GBS)?
Answer: Multiple sclerosis (MS) is a CNS demyelinating disease where myelin damage causes symptoms such as muscle weakness, stiffness, spasms, vision changes (optic neuritis, diplopia), and nystagmus.
Answer: Guillain-Barré Syndrome (GBS) is a PNS demyelinating disease that often starts with tingling and weakness in the feet and legs and spreads to the upper body and arms. It is typically triggered by an infection with a virus or bacteria.
Question: What is a ganglion?
Answer: A ganglion (or ganglia in plural) is a collection of neuron cell bodies found in the somatic and autonomic branches of the peripheral nervous system (PNS).
Question: What is the function of the myelin sheath?
Answer: The myelin sheath, made up of glial cells, covers some neurons to increase neuron efficiency and provide insulation.
Question: What are the two main types of tissue in the brain and spinal cord?
Answer: The two main types of tissue are:
White matter, which consists of bundles of axons coated with a myelin sheath.
Gray matter, which consists of masses of cell bodies and dendrites, each covered with synapses.
Question: What is the function of association fibers in the CNS?
Answer: Association fibers connect cortical areas within the same hemisphere of the brain.
Question: What do commissural fibers do in the CNS?
Answer: Commissural fibers connect corresponding cortical areas in the two hemispheres and cross from one cerebral hemisphere to the other through commissures.
Question: What is the role of projection fibers in the CNS?
Answer: Projection fibers connect the cerebral cortex with the corpus striatum, diencephalon, brainstem, and the spinal cord.
Question: What is a commissure in the context of the CNS?
Answer: A commissure is a bridge of nerve fibers that allows commissural fibers to cross from one cerebral hemisphere to the other.
Question: What type of nerve carries signals from sensory neurons to the CNS?
Answer: Afferent nerves carry signals from sensory neurons to the CNS.
Question: What type of nerve transmits signals from the CNS to muscles and glands?
Answer: Efferent nerves transmit signals from the CNS along motor neurons to muscles and glands.
Question: What is a characteristic of mixed nerves?
Answer: Mixed nerves contain both afferent and efferent axons, conducting both incoming sensory information and outgoing muscle commands in the same bundle.
Question: What does the descending (efferent) pathway involve?
Answer: The descending (efferent) pathway involves the transmission of signals from the brain toward the periphery.
Question: Which type of nerve is exemplified by spinal nerves?
Answer: Spinal nerves are an example of mixed nerves as they contain both afferent and efferent axons.
Question: What is the ascending (afferent) pathway responsible for?
Answer: The ascending (afferent) pathway is responsible for transmitting signals from the periphery toward the brain.
Question: What do the dorsal root ganglia contain?
Answer: The dorsal root ganglia contain the cell bodies of sensory neurons.
Question: Where are the dorsal root ganglia located?
Answer: The dorsal root ganglia are located outside the spinal cord.
Question: Where is the first point of synapse for sensory neurons?
Answer: The first point of synapse for sensory neurons is the dorsal horn.
Question: Where is the dorsal horn located?
Answer: The dorsal horn is located inside the spinal cord.
Question: How can nerves be categorized based on where they connect to the CNS?
Answer: Nerves can be categorized into spinal nerves and cranial nerves.
Question: What do cranial nerves innervate, and where do they connect?
Answer: Cranial nerves innervate parts of the head and connect directly to the brain, especially to the brainstem.
Question: How are cranial nerves typically assigned?
Answer: Cranial nerves are typically assigned Roman numerals from I to XII and descriptive names.
Question: How many pairs of spinal nerves are there in humans?
Answer: There are 31 pairs of spinal nerves in humans.
Question: What do spinal nerves connect to?
Answer: Spinal nerves connect through the vertebral column to the spinal cord and then to the CNS, innervating much of the body.
Question: How are spinal nerves categorized based on their connection to the spinal column?
Answer: Spinal nerves are designated with letter-number designations based on the vertebra through which they connect to the spinal column.
Question: What are the two roots of each spinal nerve, and what do they relay?
Answer: Each spinal nerve branches into two roots:
Posterior or dorsal root: relays sensory information.
Anterior or ventral root: relays motor information.
Question: What is the cell body (soma) of a neuron responsible for?
Answer: The cell body (soma) produces all the proteins for the dendrites, axons, and synaptic terminals, and contains organelles like mitochondria, Golgi apparatus, and ribosomes.
Question: What is the role of dendrites in a neuron?
Answer: Dendrites receive incoming signals from other neurons and make up most of the receptive zone of the neuron. They also have membrane receptors.
Question: What is the function of the axon in a neuron?
Answer: The axon conducts action potentials away from the neuron cell body and has knob-like swellings at the very end called synaptic knobs or end buttons, where neurotransmitters are released.
Question: What are the synaptic knobs (end buttons) at the end of an axon responsible for?
Answer: Synaptic knobs (end buttons) release neurotransmitters.
Question: What is the function of the terminal buttons in a neuron?
Answer: The terminal buttons are located at the end of the neuron and are responsible for sending the signal to other neurons. They contain vesicles holding neurotransmitters and convert electrical impulses into chemical signals.
Question: What is a synapse?
Answer: A synapse is the site of transmission of electric nerve impulses between two nerve cells or between a neuron and a gland or muscle cell.
Question: What role do neurotransmitters play in the synapse?
Answer: Neurotransmitters carry the signal across the synapse, are released into the synaptic gap, and bind to and activate receptors on the other nerve cells.
Question: What is the role of kinesin in axonal transport?
Answer: Kinesin transports substances from the cell body to the axon terminal, toward the plus end of the microtubule, in a process known as anterograde transport.
Question: What is the direction of transport for dynein in axonal transport?
Answer: Dynein transports substances from the axon terminal to the cell body, toward the minus end of the microtubule, in a process known as retrograde transport.
Question: What does anterograde transport refer to in axonal transport?
Answer: Anterograde transport refers to the movement of substances from the cell body to the axon terminal, primarily facilitated by kinesin.
Question: What role do microtubules play in axonal transport?
Answer: Microtubules act like train tracks for the transport of nutrients, proteins, and other important substances from the neuron cell body to other parts of the nerve cell.
Question: What are the three main components of a synapse?
Answer: The three main components of a synapse are:
Presynaptic ending
Postsynaptic neuron
Synaptic cleft (or space)
Question: In Alzheimer’s Disease, what happens to the tau protein?
Answer: In Alzheimer’s Disease, the tau protein becomes abnormal and causes the collapse of the microtubule structures, leading to impaired axonal transport.
Question: What is the primary protein involved in neurofibrillary tangles in Alzheimer’s Disease?
Answer: The primary protein involved in neurofibrillary tangles in Alzheimer’s Disease is tau.
Question: What are neurofibrillary tangles (NFTs) and what do they consist of?
Answer: Neurofibrillary tangles (NFTs) are insoluble twisted fibers that form inside neurons. They consist of abnormally processed tau protein and disrupt the function of microtubules.
Question: What are neurotransmitter receptors?
Answer: Neurotransmitter receptors are integral membrane glycoproteins that bind neurotransmitters and trigger a response in the postsynaptic neuron.
Question: How do drugs affect neurotransmitter receptors?
Answer: Drugs can bind to neurotransmitter receptors and either:
Reproduce the action of the neurotransmitter (agonists), or
Block the action of the neurotransmitter (antagonists).
Question: Are there different subtypes of neurotransmitter receptors?
Answer: Yes, receptor subtypes have been identified for most neurotransmitters, allowing for a variety of responses depending on the specific receptor involved.
Question: What is the function of sensory neurons?
Answer: Sensory neurons carry signals from the outer parts of the body (periphery) into the central nervous system (CNS).
Question: What do motor neurons do?
Answer: Motor neurons carry signals from the CNS to the outer parts of the body, such as muscles, skin, and glands.
Question: What is the role of interneurons?
Answer: Interneurons connect various neurons within the brain and spinal cord, facilitating communication between different parts of the CNS.
Question: Which nerve fibers are responsible for transmitting information about touch and pain?
Answer: Primary afferent axons transmit information about touch and pain to the spinal cord and brain.
Question: What is the correlation between the thickness of a nerve fiber and the speed of information transmission?
Answer: The thicker the nerve fiber, the faster information travels in it.
Question: Which nerve fibers are myelinated?
Question: Which nerve fibers are unmyelinated?
Answer: A-alpha, A-beta, and A-delta nerve fibers are myelinated.
Answer: C-nerve fibers are unmyelinated.
Question: What types of sensory receptors exist based on their location?
Answer: Sensory receptors may be external (cutaneous), internal (visceral/somatic), or both.
Question: What contributes to variations in sensitivity of sensory receptors?
Answer: The type and density of sensory receptors contribute to variations in sensitivity.
Question: How are sensory receptors categorized?
Answer: Sensory receptors are either specialized endings of afferent neurons or separate cells (e.g., hair cells in the inner ear or taste receptor cells).
Question: What are sensory receptors highly sensitive to?
Answer: Sensory receptors are highly sensitive to specific inputs or sensory modalities, such as movement, odor chemicals, or visible light photons.
Question: What do sensory receptors detect and respond to?
Answer: Sensory receptors detect and respond to physical and/or chemical stimuli.
Question: How do sensory receptors convert energy?
Answer: Sensory receptors convert one form of energy (e.g., heat, pressure, or chemicals) into another form, such as electrical energy or depolarization.
Question: What do photoreceptors detect?
Question: What do mechanoreceptors respond to?
Question: What do thermoreceptors detect?
Question: What do osmoreceptors respond to?
Question: What is the function of chemoreceptors?
Question: What do proprioceptors provide information about?
Question: What do polymodal receptors respond to?
Question: What do nociceptors detect?
Answer: Photoreceptors detect visible wavelengths of light.
Answer: Mechanoreceptors respond to mechanical changes in the environment, such as movement, tension, and pressure.
Answer: Thermoreceptors detect changes in temperature.
Answer: Osmoreceptors respond to changes in osmotic pressure, such as detecting changes in extracellular fluid (ECF) osmolality.
Answer: Chemoreceptors detect chemical composition, such as oxygen (O2), carbon dioxide (CO2), and chemicals linked to taste and smell.
Answer: Proprioceptors provide information about joint position sense.
Answer: Polymodal receptors respond to more than one type of stimulus.
Answer: Nociceptors detect damage or distortion of tissues, leading to pain sensation.
Question: Which type of receptor is characterized by a channel through which ions can move inside and outside the cells?
Answer: Ligand-gated ion channel (LGIC) receptors.
Question: What do G-protein-coupled receptors (GPCRs) act through?
Answer: G-protein-coupled receptors act through both ligand-gated ion channels (LGIC) and enzyme-linked pathways.
Question: Which type of receptor involves enzymatic activity on the intracellular side when the extracellular ligand binds?
Answer: Kinase-linked receptors
Question: Where are nuclear receptors located?
Answer: Nuclear receptors are located in the nucleus of cells.
Question: What are examples of ligands that activate nuclear receptors?
Answer: Examples include estradiol, progesterone, testosterone, cortisol, aldosterone, and thyroid hormone.
Question: Which receptor type is involved with muscarinic or adrenergic receptors?
Answer: G-protein-coupled (GPCR) receptors.
Question: What is the primary function of ligand-gated ion channels (LGICs) like nicotinic or NMDA receptors?
Answer: To allow ions to move in and out of the cell, contributing to electrical signaling.
Question: Which receptor type is associated with cytokine receptors, epidermal growth factor, and platelet-derived growth factor?
Answer: Kinase-linked receptors.
Question: Are most autoreceptors excitatory or inhibitory?
Answer: Most autoreceptors are inhibitory.
Question: What is an autoreceptor?
Answer: An autoreceptor is a receptor located on the neuron (terminals, soma, and/or dendrites) that binds a specific ligand released by that same neuron.
Question: What type of receptors are most autoreceptors?
Answer: Most autoreceptors are G-protein coupled receptors (GPCRs).
Question: Which autoreceptor is associated with dopamine signaling?
Answer: Dopamine D2 receptor.
Question: Which of the following is a common autoreceptor?
A) Dopamine D1 receptor
B) Alpha 2a adrenoreceptor
C) 5-HT2 serotonin receptor
D) Nicotinic acetylcholine receptor
Answer: B) Alpha 2a adrenoreceptor.
Question: Which of the following is NOT a common autoreceptor?
A) M2 muscarinic receptor
B) H3 receptor
C) Alpha 1 adrenoreceptor
D) 5-HT1A serotonin receptor
Answer: C) Alpha 1 adrenoreceptor.
Question: Which receptor type is common among autoreceptors in the parasympathetic nervous system?
Answer: M2 and M4 muscarinic receptors.
Question: Which of the following autoreceptors is associated with serotonin signaling?
Answer: 5-HT1A and 5-HT1B serotonin receptors.
OPEN PP FOR Neurotransmitters and hormone receptors
OPEN PP FOR Neurotransmitters and hormone receptors
