Synapse Structure and Function
87 Questions
3 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following BEST describes the cauda equina?

  • A bundle of nerve roots extending from the spinal cord below the end of the spinal cord. (correct)
  • A group of motor neurons in the lateral gray horn of the spinal cord that control smooth muscle, heart muscle, and glands.
  • A collection of myelinated axons in the white matter of the spinal cord.
  • A large collection of sensory neurons in the posterior gray horn of the spinal cord.

    • Damage to the posterior gray horns of the spinal cord would MOST LIKELY affect which of the following?

  • Sensory perception. (correct)
  • Motor control of skeletal muscles.
  • Communication between the left and right sides of the spinal cord.
  • Control of visceral organs.

    • Which of the following statements accurately describes the relationship between the spinal cord and the vertebrae?

  • The spinal cord extends only to the level of the first lumbar vertebrae, and the vertebrae protect the spinal cord only up to that level. (correct)
  • The spinal cord extends to the level of the first or second lumbar vertebrae, and the vertebrae protect the spinal cord up to the level of the sacrum.
  • The spinal cord extends to the level of the first or second lumbar vertebrae, and the vertebrae protect the spinal cord throughout its length.
  • The spinal cord extends to the tip of the spinal column, and the vertebrae protect the spinal cord throughout its length.

    • Which of the following BEST describes the function of the gray commissure in the spinal cord?

    <p>To connect the gray matter on one side of the spinal cord to the gray matter on the other side.</p> Signup and view all the answers

    Which of the following structures contains the cell bodies of the neurons that control skeletal muscle movement?

    <p>Anterior gray horn</p> Signup and view all the answers

    Which of the following is a CORRECT statement about the white matter of the spinal cord?

    <p>It contains both myelinated and unmyelinated axons.</p> Signup and view all the answers

    What is the function of the ascending tracts in the spinal cord?

    <p>To carry sensory information from the spinal cord to the brain.</p> Signup and view all the answers

    Which of the following statements accurately describes the function of the anterior white columns in the spinal cord?

    <p>To connect the anterior gray horns to the anterior median fissure.</p> Signup and view all the answers

    What is the most common symptom of encephalitis?

    <p>Headache</p> Signup and view all the answers

    Which of the following is NOT a common causative virus in AIDS patients with encephalitis?

    <p>St. Louis encephalitis virus</p> Signup and view all the answers

    What causes the characteristic spongiform appearance of the brain in prion diseases?

    <p>Formation of large vacuoles in the cortex and cerebellum</p> Signup and view all the answers

    What is the primary mode of transmission for bovine spongiform encephalopathy (BSE)?

    <p>Cattle feed containing infected animal byproducts</p> Signup and view all the answers

    Which of the following is NOT a symptom of Creutzfeldt-Jakob disease (CJD)?

    <p>High fever</p> Signup and view all the answers

    What is the characteristic symptom of fatal familial insomnia (FFI)?

    <p>Untreatable insomnia</p> Signup and view all the answers

    What caused the decline in the incidence of kuru in the Fore highlands of New Guinea?

    <p>Government efforts to curtail cannibalism</p> Signup and view all the answers

    What is the primary function of the cervical enlargement of the spinal cord?

    <p>Supply nerves to the shoulder girdles and upper limbs</p> Signup and view all the answers

    What is the function of the dorsal root ganglia?

    <p>Contain the cell bodies of sensory neurons</p> Signup and view all the answers

    What type of nerves are spinal nerves classified as?

    <p>Mixed nerves</p> Signup and view all the answers

    At what age does the spinal cord stop growing?

    <p>4 years old</p> Signup and view all the answers

    What is the function of the slender strand of fibrous tissue that extends from the inferior tip of the spinal cord to the coccyx?

    <p>To anchor the spinal cord and prevent upward movement</p> Signup and view all the answers

    Which of the following is NOT a part of the spinal cord anatomy?

    <p>Lateral Ventricle</p> Signup and view all the answers

    How many spinal nerves are there in the human body?

    <p>31</p> Signup and view all the answers

    What happens to the dorsal and ventral roots as the vertebral column elongates after age 4?

    <p>They grow longer</p> Signup and view all the answers

    What is the maximum width of the adult spinal cord?

    <p>14 mm</p> Signup and view all the answers

    What is the primary function of neurotransmitters within a synapse?

    <p>To transmit information between neurons or between a neuron and an effector cell.</p> Signup and view all the answers

    Which of the following accurately describes the direction of nerve impulse transmission across a synapse?

    <p>From the presynaptic neuron to the postsynaptic neuron.</p> Signup and view all the answers

    What is the synaptic cleft?

    <p>The space between the presynaptic and postsynaptic membranes.</p> Signup and view all the answers

    At a neuroglandular junction, what role does the neuron play?

    <p>It controls or regulates the activity of a secretory cell.</p> Signup and view all the answers

    Which event directly triggers the release of neurotransmitters from the axon terminal into the synaptic cleft?

    <p>The arrival of an action potential at the axon terminal.</p> Signup and view all the answers

    What is the function of synaptic vesicles?

    <p>To store and release neurotransmitters into the synaptic cleft.</p> Signup and view all the answers

    What is a key characteristic of cholinergic synapses related to neurotransmitters?

    <p>They release acetylcholine (ACh) as their primary neurotransmitter.</p> Signup and view all the answers

    How does a neurotransmitter such as acetylcholine (ACh) transmit a signal to the postsynaptic neuron?

    <p>By binding to receptors on the postsynaptic membrane.</p> Signup and view all the answers

    What triggers the exocytosis of synaptic vesicles and release of acetylcholine (ACh) at a cholinergic synapse?

    <p>Entry of calcium ions into the axon terminal.</p> Signup and view all the answers

    How does acetylcholinesterase (AChE) remove ACh from the synaptic cleft?

    <p>By breaking down ACh into acetate and choline.</p> Signup and view all the answers

    What is the primary mechanism by which organophosphates exert their toxic effects?

    <p>Deactivating acetylcholinesterase.</p> Signup and view all the answers

    Which of the following is used as an antidote to restore cholinesterase activity in organophosphate poisoning?

    <p>Pralidoxime (2-PAM).</p> Signup and view all the answers

    What is the immediate effect of ACh binding to receptors on the postsynaptic membrane?

    <p>Depolarization of the postsynaptic membrane.</p> Signup and view all the answers

    Which of the following neurotransmitters primarily has inhibitory effects on postsynaptic neurons?

    <p>Dopamine.</p> Signup and view all the answers

    What is the fate of norepinephrine (NE) after it has been released into the synapse?

    <p>It is broken down by monoamine oxidase.</p> Signup and view all the answers

    Which of the following is a symptom associated with muscarinic receptor stimulation in acute organophosphate poisoning?

    <p>Increased salivation.</p> Signup and view all the answers

    What is the name given to synapses that release norepinephrine (NE)?

    <p>Adrenergic.</p> Signup and view all the answers

    Which of the following events occurs first at a cholinergic synapse after the arrival of an action potential?

    <p>Depolarization of the axon terminal.</p> Signup and view all the answers

    Which of the following symptoms is associated with nicotinic receptor stimulation at the neuromuscular junction in acute organophosphate poisoning?

    <p>Muscle fasciculations.</p> Signup and view all the answers

    What is the effect of drugs that stimulate receptors that otherwise only respond to neurotransmitters?

    <p>They can have complex effects on perception, motor control and emotional states.</p> Signup and view all the answers

    Which of the following neurotransmitters is also known as noradrenaline?

    <p>Norepinephrine (NE).</p> Signup and view all the answers

    Which of the following is a route of entry for organophosphates into the body?

    <p>Through the skin or respiratory tract.</p> Signup and view all the answers

    What is the primary effect of norepinephrine (NE) on postsynaptic neurons?

    <p>An excitatory, depolarizing effect.</p> Signup and view all the answers

    What type of synapse uses norepinephrine as its neurotransmitter?

    <p>Adrenergic synapse</p> Signup and view all the answers

    Which neurotransmitter is utilized in the preganglionic nerves of the sympathetic nervous system?

    <p>Acetylcholine</p> Signup and view all the answers

    What happens when 10 excitatory synapses and 10 inhibitory synapses are active simultaneously?

    <p>The effects cancel each other out</p> Signup and view all the answers

    How do neuronal pools interact with each other?

    <p>By direct control or stimulation/depression of activity</p> Signup and view all the answers

    What is the primary function of the meninges?

    <p>To provide support and protect the CNS</p> Signup and view all the answers

    Which meningeal layer is the outermost covering of the CNS?

    <p>Dura mater</p> Signup and view all the answers

    What type of neural circuit is characterized by multiple inputs converging on a single neuron?

    <p>Convergence</p> Signup and view all the answers

    What is characterized by the spreading of stimulation from one neuron to multiple neurons?

    <p>Divergence</p> Signup and view all the answers

    What is one effect of blocking calcium channels at cholinergic synapses?

    <p>Inhibition of action potential generation</p> Signup and view all the answers

    What is the role of interneurons within a neuronal pool?

    <p>To provide processing and integration of sensory and motor signals</p> Signup and view all the answers

    What is the estimated number of interneurons in the human body?

    <p>20 billion</p> Signup and view all the answers

    What type of neural circuits allows both voluntary and involuntary control of a motor function?

    <p>Convergence</p> Signup and view all the answers

    Which layer of the meninges is directly adhered to the surface of the brain?

    <p>Pia mater</p> Signup and view all the answers

    What is contained within the epidural space of the spinal cord?

    <p>Areolar tissue, blood vessels, and adipose tissue</p> Signup and view all the answers

    What does an epidural block primarily affect?

    <p>Only spinal nerves in the immediate area of injection</p> Signup and view all the answers

    What is a common cause of epidural hematomas?

    <p>Laceration of an artery during blunt head trauma</p> Signup and view all the answers

    What separates the dura mater from the arachnoid layer?

    <p>Subdural space</p> Signup and view all the answers

    Which sign indicates meningeal inflammation in bacterial meningitis?

    <p>Kernig's sign</p> Signup and view all the answers

    Why is the pia mater important for the brain?

    <p>It is highly vascular and supplies blood to the neural tissue.</p> Signup and view all the answers

    What is the significance of cerebrospinal fluid (CSF) in the subarachnoid space?

    <p>It acts as a shock absorber and transports nutrients.</p> Signup and view all the answers

    Which symptoms are commonly associated with meningitis?

    <p>Altered mental status, fever, headache, and stiff neck</p> Signup and view all the answers

    What happens if blood accumulates in the epidural space?

    <p>It leads to an epidural hematoma.</p> Signup and view all the answers

    What layer firmly binds to the nervous tissue of the brain?

    <p>Pia mater</p> Signup and view all the answers

    How does blood pressure impact epidural versus subdural hemorrhages?

    <p>Higher arterial blood pressure can cause more rapid distortion of neural tissue.</p> Signup and view all the answers

    What condition occurs when blood enters the space between the dura mater and the skull?

    <p>Epidural hemorrhage</p> Signup and view all the answers

    What is the function of arachnoid layer's lymphatic fluid?

    <p>It reduces friction between the dura and arachnoid layers.</p> Signup and view all the answers

    What is the primary purpose of a lumbar puncture?

    <p>To measure cerebrospinal fluid (CSF) pressure</p> Signup and view all the answers

    Which of the following is a common organism causing bacterial meningitis in adults?

    <p>Neisseria meningitidis</p> Signup and view all the answers

    Which symptom is typically associated with viral meningitis but not bacterial meningitis?

    <p>Presence of white blood cells</p> Signup and view all the answers

    What is a notable difference between viral and bacterial meningitis regarding treatment?

    <p>Bacterial meningitis requires the use of antibiotics</p> Signup and view all the answers

    Which organism is known to cause opportunistic infections leading to meningitis in immunocompromised patients?

    <p>Candida species</p> Signup and view all the answers

    What finding in cerebrospinal fluid indicates bacterial meningitis?

    <p>Cloudy fluid with high protein concentration</p> Signup and view all the answers

    Which type of meningitis is commonly referred to as aseptic meningitis?

    <p>Viral meningitis</p> Signup and view all the answers

    What is a potential cause of tubercular meningitis?

    <p>Tuberculosis infection in the lungs</p> Signup and view all the answers

    What is the typical initial symptom of encephalitis?

    <p>Severe headache</p> Signup and view all the answers

    Which method is often required for the diagnosis of cysticercosis?

    <p>Computed tomographic scan</p> Signup and view all the answers

    What is a common treatment for brain abscesses?

    <p>Surgical drainage</p> Signup and view all the answers

    Which organism is primarily responsible for causing meningiococcemia?

    <p>Neisseria meningitidis</p> Signup and view all the answers

    What complication can arise from Naegleria fowleri infection?

    <p>Acute meningoencephalitis</p> Signup and view all the answers

    What is a key characteristic of fungal meningitis?

    <p>Tendency to be chronic and hard to treat</p> Signup and view all the answers

    Study Notes

    Synapse Structure and Function

    • A synapse is a site where a neuron communicates with another cell (neuron or effector)
    • Nerve impulses travel along axons as action potentials.
    • At the axon terminal, action potentials trigger neurotransmitter release to transfer information
    • Synapses can be on dendrites, cell bodies, or axons
    • Neuroeffector junctions are synapses between neurons and other cell types
    • Neuro-muscular junctions are neuron-to-muscle cell synapses, while neuro-glandular junctions are neuron-to-secretory cell junctions.
    • Communication is unidirectional across a synapse.

    Synapse Structure (Presynaptic and Postsynaptic Neuron)

    • A synaptic cleft, a narrow space, separates the plasma membranes of opposing neurons.
    • The presynaptic neuron releases neurotransmitters from its axon terminal
    • The postsynaptic neuron receives neurotransmitters at its membrane

    Nerve Impulse Transmission at a Synapse

    • Arrival of an action potential depolarizes the axon terminal
    • Depolarization opens calcium channels, allowing calcium ions to enter.
    • This triggers synaptic vesicle exocytosis, releasing neurotransmitters into the synaptic cleft.
    • Neurotransmitters diffuse across the cleft and bind to receptors on the postsynaptic membrane.
    • Binding may cause depolarization (excitatory) or hyperpolarization (inhibitory) in the postsynaptic membrane.
    • Neurotransmitters are removed by enzymatic breakdown (e.g., AChE for acetylcholine) or reuptake.
    • Acetylcholine (ACh) is a common neurotransmitter at cholinergic synapses (widespread in & out of CNS).
    • Norepinephrine (NE), also called noradrenaline, functions at adrenergic synapses.
    • Neurotransmitter effects are temporary due to enzymatic breakdown or reuptake.

    Cholinergic Synapse (Specific Example)

    • Action potential arrives and depolarizes presynaptic axon terminal
    • ACh is released, triggered by calcium influx
    • ACh binds to receptors on postsynaptic membrane, causing depolarization
    • AChE breaks down ACh into acetate and choline, ending its effect.

    Neurotransmitter Effects and Drugs

    • Neurotransmitters can have excitatory or inhibitory effects.
    • Many drugs affect the nervous system by interacting with neurotransmitter receptors, altering perception, motor control, or emotional states.
    • The balance between excitatoryand inhibitory stimuli determines whether an action potential is generated in the postsynaptic neuron.

    Neuronal Pools

    • Neuronal pools are groups of interconnected interneurons with specific functions.
    • Each pool has a limited number of inputs and outputs, and can have excitatory and inhibitory neurons.
    • Pool outputs may stimulate or inhibit other pools or motor neurons.

    Divergence and Convergence (Neural Circuits)

    • Divergence: Information spreads from one neuron to many.
    • Convergence: Multiple neurons synapse on a single neuron, enabling both voluntary and involuntary control of body processes.

    Meninges (Protection for CNS)

    • Meninges are 3 specialized membrane layers surrounding the brain and spinal cord.
    • Provide physical stability, shock absorption, and transport needed oxygen/nutrients.
    • Layers: dura mater, arachnoid, pia mater.

    Dura Mater

    • Outermost layer; fused to the skull.
    • Two fibrous layers for the brain, separated by a gap.
    • Dural folds in brain help hold the brain in place.
    • Has epidural space in spinal cord (containing areolar tissue, blood vessels, and adipose tissue.)

    Arachnoid

    • Separated from dura by the subdural space.
    • Contains lymphatic fluid for reducing friction.
    • Squamous epithelial cells form the layer.
    • Deep to arachnoid is the subarachnoid space (filled with CSF), providing shock absorption and transporting substances.

    Pia Mater

    • Innermost layer; tightly bound to underlying neural tissue.
    • Blood vessels servicing the brain and spinal cord run along its surface within the subarachnoid space.
    • Highly vascular in the brain, supplying oxygen and nutrients.

    Spinal Cord Structure

    • Approximately 45 cm long, with cervical and lumbar enlargements for limb control.

    • Tapered to a conus medullaris, where a fibrous filum terminale anchors it to coccyx.

    • A central canal filled with cerebrospinal fluid (CSF).

    • Posterior median sulcus and anterior median fissure are surface features.

    • 31 segments give rise to pairs of spinal nerves. (Cervical, thoracic, lumbar, sacral, coccygeal)

    • Spinal nerves are mixed nerves (sensory and motor fibers)

    • Cauda equina (horse’s tail) refers to the long ventral and dorsal roots of spinal nerves inferior to the spinal cord tip.

    Spinal Cord Anatomy

    • Gray matter forms an "H" or butterfly shape around the central canal, with posterior and anterior horns.
    • White matter surrounds the gray matter—posterior, lateral, and anterior columns.
    • Contains ascending tracts (sensory information) and descending tracts (motor commands).

    Studying That Suits You

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

    Quiz Team

    Description

    Explore the intricate details of synapse structure and function in this quiz. Learn about how neurons communicate through synapses, including the mechanisms of neurotransmitter release and reception. Understand the differences between various types of synapses and their roles in nerve impulse transmission.

    More Like This

    Structure of Neuron and Synapse - OPTM4106
    38 questions

    Structure of Neuron and Synapse - OPTM4106

    FunnyDryad avatar
    FunnyDryad
    Synapse Structure and Function Quiz
    22 questions

    Synapse Structure and Function Quiz

    EnergySavingAgate5138 avatar
    EnergySavingAgate5138
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser