Neuroglial Cells and Multiple Sclerosis Quiz

The nervous system is responsible for coordinating and regulating all body functions. It's a complex network that transmits information through electrical and chemical signals.

The central nervous system (CNS) is the control center of the body, consisting of the brain and spinal cord. It receives sensory information, processes it, and sends out commands.

The peripheral nervous system (PNS) connects the CNS to the rest of the body. It acts as a communication system, relaying information between the CNS and the organs, muscles, and skin.

The sensory division of the PNS carries information from the body to the CNS, like touch, temperature, and pain sensations.

The motor division of the PNS carries commands from the CNS to the body, controlling muscle movement and gland secretions.

The somatic nervous system controls voluntary movements of skeletal muscles. It's the part of the nervous system you consciously use to move your body.

The autonomic nervous system controls involuntary actions, like heart rate, digestion, and breathing, that happen without conscious effort.

The sympathetic and parasympathetic nervous systems are two branches of the autonomic nervous system that work in opposition to each other. The sympathetic system is responsible for the 'fight or flight' response, while the parasympathetic system promotes 'rest and digest' functions.

The process by which the effects of a neurotransmitter are terminated, allowing for the regulation of neural signaling.

The process by which a neurotransmitter is taken back up by the presynaptic neuron or astrocytes, reducing its concentration in the synaptic cleft.

The breakdown of a neurotransmitter by enzymes in the synaptic cleft, inactivating it.

The diffusion of a neurotransmitter away from the synaptic cleft, reducing its concentration and effect.

A type of synapse where electrical signals are transmitted directly between neurons through gap junctions.

Specialized channels that connect the cytoplasm of adjacent neurons, allowing for rapid electrical communication.

A type of postsynaptic potential that depolarizes the postsynaptic membrane, making it more likely to fire an action potential.

A type of postsynaptic potential that hyperpolarizes the postsynaptic membrane, making it less likely to fire an action potential.

A type of neuroglia in the CNS that acts as the brain's immune system. They function to engulf pathogens like bacteria and viruses to protect the brain.

Cells in the CNS that line the cavities filled with cerebrospinal fluid (CSF). They help circulate CSF and create a barrier between the CSF and the brain tissue.

Neuroglia in the CNS that produce myelin sheaths, which insulate nerve fibers and improve signal transmission. They serve as support cells for neurons.

A fatty substance that covers some nerve fibers and acts as an insulator, speeding up nerve impulse transmission.

The gaps between the segments of myelin sheath on a nerve fiber.

They are the primary functional cells of the nervous system, responsible for communication through electrical and chemical signals.

The fluid that surrounds the brain and spinal cord, providing cushioning and protection.

The central nervous system (CNS) is composed of the brain and spinal cord.

The change in electrical potential across a cell membrane during an action potential, moving from a negative resting potential to a positive peak potential before returning to resting potential.

The state of a neuron when it is not actively transmitting a signal, characterized by a negative electrical charge inside the cell relative to the outside.

The brief period following an action potential where the membrane potential is more negative than the resting potential. This makes it harder for another action potential to be triggered.

The point at which an action potential reaches its highest positive voltage during an electrical signal. This is the peak of the action potential.

The process by which an action potential travels along the axon of a neuron. This occurs through the sequential opening and closing of ion channels.

The electrical potential difference across a cell membrane, measured in millivolts (mV). This potential difference is created by the uneven distribution of ions inside and outside the cell.

The long, slender projection of a neuron that transmits electrical signals to other neurons or to effector cells.

An autoimmune disease primarily affecting young adults, where the immune system attacks the myelin sheath of neurons in the central nervous system (CNS).

Hardened lesions formed in the CNS due to the destruction of myelin by the immune system in MS.

The process of nerve impulse conduction being disrupted or slowed down due to damage to the myelin sheath.

The junction between two neurons or between a neuron and an effector cell (muscle or gland), where information is transmitted chemically or electrically.

The neuron that sends an impulse toward the synapse, transmitting information.

The neuron that receives an impulse from the synapse, processing incoming information.

A communication gap between neurons or a neuron and an effector cell, where neurotransmitters are released to transmit signals.

The difference in electrical charge between the inside and outside of a cell membrane when it is at rest.

The plasma membrane of a cell is more permeable to potassium ions (K+) than sodium ions (Na+).

Potassium ions (K+) diffuse out of the cell down their concentration gradient, while sodium ions (Na+) diffuse into the cell, resulting in a net negative charge inside the cell.

An active transport mechanism that pumps 3 sodium ions (Na+) out of the cell for every 2 potassium ions (K+) pumped in, maintaining the concentration gradient.

Temporary changes in the membrane potential, which can either be depolarization (more positive) or hyperpolarization (more negative).

A rapid, brief change in membrane potential that travels down the axon of a neuron.

Changes in the concentration of ions across the membrane or changes in the membrane permeability to ions can alter the resting membrane potential.

Graded potentials are short-distance signals that die out over time and distance, while action potentials are long-distance signals that can travel without diminishing.

The most posterior part of the occipital lobe, responsible for receiving visual information directly from the retinas.

The area surrounding the primary visual cortex, interpreting visual stimuli based on past experiences. It helps us recognize faces and understand what we're seeing.

Located at the superior margin of the temporal lobe, responsible for interpreting sound information like pitch and location.

Posterior to the primary auditory cortex, it stores memories of sounds and allows us to understand complex sounds and patterns.

A region in the insula and parietal cortex that gives us conscious awareness of our balance and head position.

Located in the medial aspect of the temporal lobes, this area allows us to consciously perceive smells.

Located in the insula, this area allows us to perceive taste sensations.

Located behind the gustatory cortex, this area allows us to feel internal sensations like a full bladder or an upset stomach.

The primary motor cortex is located in the precentral gyrus of the frontal lobe and is responsible for conscious control of voluntary muscle movements. It contains large pyramidal cells that send axons down the spinal cord to control specific muscles.

The premotor cortex assists in planning and coordinating movements, especially complex or learned motor skills. It also helps in coordinating multiple muscle groups for sequential or simultaneous actions.

Broca's area, located usually in the left hemisphere, controls the muscles involved in speech production. It is vital for planning and executing speech and voluntary motor activities associated with language.

The frontal eye field, located superior to Broca's area, is responsible for controlling voluntary eye movements. It helps direct our gaze and focus attention.

Somatotopy refers to the mapping of the body's muscles onto specific areas of the primary motor cortex. It's organized in a way that adjacent body parts are represented by adjacent areas of the cortex.

Motor homunculi are upside-down representations of the contralateral motor innervation of body regions. They depict the relative amount of cortex devoted to controlling different body parts, highlighting the areas with finer motor control.

The pyramidal tract, also known as the corticospinal tract, is formed by axons of pyramidal cells in the primary motor cortex that descend down the spinal cord. It carries signals to control voluntary movements of skeletal muscles.

The somatosensory cortex, located in the postcentral gyrus of the parietal lobe, receives sensory information from the body. It's responsible for processing touch, temperature, pain, and pressure sensations.

The most dorsal part of the diencephalon, forming the roof of the third ventricle. It houses the pineal gland, which secretes melatonin to regulate the sleep-wake cycle.

The part of the brain that connects the cerebrum to the spinal cord. It contains three regions: the midbrain, pons, and medulla oblongata.

This structure is responsible for coordinating movements, maintaining balance, and learning new motor skills, receiving input from both the cortex and sensory receptors.

The pineal gland is located in the epithalamus and secretes melatonin, a hormone that regulates the sleep-wake cycle.

The process where the cerebellum receives information from the cerebral cortex about intended movement and from sensory receptors about current body position, then calculates the best way to execute the movement smoothly.

This region of the brain plays a role in thinking, language, and emotion, similar to how it fine-tunes motor activities.

This region of the brain contains nuclei associated with 10 cranial nerves, making it vital for controlling automatic behaviors.

This region of the brain is similar in structure to the spinal cord, especially the white matter, but it also contains embedded nuclei.

Specialized cells that respond to changes in the environment, also known as stimuli. These changes trigger graded potentials which can lead to nerve impulses.

The conscious awareness of a stimulus.

The interpretation and understanding of the meaning of a stimulus.

Respond to stimuli that cause pain, such as extreme temperatures, pressure, or inflammatory chemicals. These signals often activate other types of receptors like thermoreceptors, mechanoreceptors, and chemoreceptors.

Respond to stimuli arising outside the body, like touch, pressure, temperature, and light. They are found in the skin and most special sense organs.

Respond to stimuli arising within internal organs and blood vessels, like changes in chemical composition, tissue stretch, and temperature. They often don't cause conscious awareness.

Respond to stretch in muscles, tendons, joints, ligaments, and connective tissues. They inform the brain about body position and movement.

A class of sensory receptors that respond to mechanical stimuli, such as touch, pressure, vibration, and stretch.

Reflexes that occur without direct involvement of higher brain centers. The brain is still notified and may influence the reflex.

Modified skeletal muscle fibers within muscle spindles that are enclosed in a connective tissue capsule. They can contract, but their central region lacks myofilaments and is noncontractile.

Regular effector fibers of a muscle that can contract and generate force. They are responsible for muscle movement.

Sensory endings within muscle spindles that wrap around the spindle. They are stimulated by the rate and degree of stretch.

Sensory endings within muscle spindles that are located at the ends of the spindle. They are stimulated by the degree of stretch only, not its rate.

A reflex that occurs when a muscle is stretched, causing it to contract. Information travels from the muscle spindle to the spinal cord and back to the muscle.

A receptor located in tendons that detects changes in muscle tension. It sends information to the spinal cord about the force of muscle contraction.

A reflex that involves the contraction of flexor muscles in response to a painful stimulus, causing the limb to withdraw from the stimulus.

A protein in the nerve membrane that acts as an ion channel. It is activated by heat, low pH, and chemicals like capsaicin.

Located in the deeper layers of the epidermis, these receptors detect light touch.

Free nerve endings wrapped around hair follicles that detect bending of hairs, allowing us to feel light touch.

Encapsulated nerve endings that detect mechanical stimuli, often encased in connective tissue.

Small receptors located in the epidermis that detect discriminative touch, particularly in sensitive areas like fingertips.

Large receptors located in the deep dermis that respond to deep pressure and vibrations, but only when first applied.

Receptors in the dermis that detect itch, often triggered by chemicals like histamine.

These structures protect the eye and help it function properly. They include the eyebrows, eyelids, conjunctiva, lacrimal apparatus and extrinsic eye muscles.

This structure is responsible for lubricating the eye and acts like a transparent mucous membrane.

This membrane lines the underside of the eyelids.

This membrane covers the white of the eye but not the cornea.

This space between the palpebral and bulbar conjunctiva is where contact lenses reside.

The sense of touch, which is mediated by general receptors found throughout the body, is considered a general sense. In contrast, the senses of vision, taste, smell, hearing and equilibrium are known as special senses.

These receptors are distinct receptor cells localized in the head region, specifically focusing on a particular sense such as vision, taste, smell, hearing or equilibrium.

It is a small sphere with only one-sixth of its surface visible. It is protected by a fat cushion and bony orbit, and consists of accessory structures and the eyeball itself.

The clear, protective outer layer of the eye that bends light as it enters.

The colored part of the eye that controls the amount of light entering the pupil.

The opening in the center of the iris that allows light to pass through to the lens.

The transparent, flexible structure behind the pupil that focuses light onto the retina.

The light-sensitive inner lining of the eye that contains photoreceptor cells.

The central area of the retina responsible for sharp central vision.

The small depression in the macula that provides the highest visual acuity.

The point where the optic nerve connects to the retina, creating a blind spot because it lacks photoreceptor cells.

The ciliary body is a thickened ring of tissue surrounding the lens that plays a crucial role in lens accommodation. It contains smooth muscle bundles, known as ciliary muscles, which control the shape of the lens.

The iris is the colored portion of the eye located between the cornea and lens, continuous with the ciliary body. Its central opening, the pupil, regulates the amount of light entering the eye.

The neural layer of the retina is the inner layer of the retina, containing millions of photoreceptor cells, neurons, and glial cells. It's responsible for light energy transduction and visual processing.

The pigmented layer of the retina is a single-cell-thick layer located next to the choroid. Its primary function is to absorb light and prevent scattering, enhancing visual clarity.

Close vision and bright light cause the sphincter pupillae to contract, constricting the pupil. This is controlled by the parasympathetic nervous system.

Distant vision and dim light cause the dilator pupillae to contract, widening the pupil. This is controlled by the sympathetic nervous system.

The suspensory ligament, also known as the ciliary zonule, is a delicate structure extending from the ciliary processes to the lens. Its role is to hold the lens in place within the eye.

Pupil constriction and dilation are controlled by smooth muscle fibers within the iris. The sphincter pupillae constricts the pupil in response to bright light and close vision, while the dilator pupillae dilates the pupil in response to dim light and distant vision.

Cones are photoreceptor cells in the retina that are responsible for color vision and sharp detail. They require bright light for activation and are concentrated mainly in the fovea centralis.

Rods are photoreceptor cells in the retina that are highly sensitive to dim light. They are responsible for peripheral vision and night vision.

The most common type of color blindness is red-green color blindness, where either the red or green cones are absent, making it difficult to distinguish these colors.

Retinal is a light-absorbing molecule within photoreceptor cells that changes shape when light is absorbed, triggering a signal cascade.

Opsins are proteins that combine with retinal to form visual pigments, which are specific for different wavelengths of light.

The isomerization of retinal refers to the change in its shape from a bent form (11-cis-retinal) to a straight form (all-trans-retinal) upon light absorption. This shape change is essential for initiating the visual signal transduction pathway.

Color blindness is a genetic condition where one or more types of cone pigments are absent, leading to the inability to perceive certain colors.

The visual pigments are responsible for capturing light and converting it into electrical signals that travel to the brain. They contain retinal and opsins, specific for different wavelengths of light.

The fluid-filled space in the cochlea that is continuous with the oval window and contains perilymph (Na+ rich fluid).

The fluid-filled space in the cochlea that contains endolymph (K+ rich fluid) and is surrounded by the scala vestibuli and scala tympani.

The third chamber of the cochlea that extends to the round window and contains perilymph (Na+ rich fluid).

The membrane separating the scala vestibule from the scala media, acting as the "roof" of the cochlear duct.

The external wall of the cochlear duct that secretes endolymph, the K+ rich fluid.

A structure on the "floor" of the cochlear duct that acts as the supporting base for the spiral organ which contains hair cells.

A group of cells found within the cochlear duct that are responsible for converting sound vibrations into electrical signals that the brain can interpret.

Specialized cells within the spiral organ that convert sound vibrations into electrical signals.

Amino acids glutamate and aspartate are the chemical compounds that stimulate this taste sensation. Examples of umami-rich foods are beef and cheese.

A possible sixth taste, it is detected by the taste buds and is likely responsible for the pleasant sensation associated with fatty foods.

The taste buds on the tongue contain special cells called gustatory epithelial cells, which are activated by the presence of food molecules.

Different taste receptors have different sensitivities to taste stimuli. For example, the receptors for bitter taste are the most sensitive.

When food chemicals bind to taste receptors, they trigger a series of events that lead to the release of neurotransmitters. These neurotransmitters then transmit the taste information to the brain.

Taste adaptation occurs when the intensity of a taste sensation decreases over time. It typically takes 3-5 seconds to partially adapt and 1-5 minutes for complete adaptation.

The perception of taste is influenced by factors such as smell, temperature, and texture.

Taste plays a crucial role in guiding our food choices, ensuring we consume essential nutrients and avoid potentially harmful substances.

The endocrine system uses hormones transported in the blood to regulate various bodily functions, including metabolism, growth, and reproduction.

Endocrine glands lack ducts and release hormones directly into the bloodstream, while exocrine glands have ducts and release secretions onto a surface.

Hormones are chemical messengers that act on target cells to regulate their activities. They bind to specific receptors on these cells, triggering a cascade of events.

The hypothalamus is a neuroendocrine organ located in the brain that links the nervous and endocrine systems. It controls the release of hormones from the pituitary gland.

The pituitary gland is a small gland located at the base of the brain. It releases hormones that regulate growth, metabolism, and reproduction.

The thyroid gland is located in the neck, and it produces hormones that regulate metabolism, heart rate, and body temperature.

The parathyroid glands are small glands located near the thyroid gland. They produce hormones that regulate calcium levels in the blood.

The adrenal glands are located on top of the kidneys. They produce hormones that help regulate stress response, blood sugar levels, and blood pressure.

Autocrines are local chemical messengers that act on the very cells that secrete them. In essence, they signal themselves.

Paracrines are local chemical messengers that act on cells nearby, but not the ones that released them.

Steroid hormones are a class of hormones synthesized from cholesterol. Examples include the gonadal (sex) hormones and adrenocortical hormones.

Target cells are tissues with receptors for a specific hormone. They are the only cells that can be affected by that particular hormone.

Hormones that bind to receptors on the cell membrane and trigger a cascade of events through second messengers within the cell.

Hormones that can pass through the cell membrane and bind to receptors inside the cell, directly influencing gene expression.

A signaling pathway that uses cAMP as a second messenger, amplifying the signal initiated by a water-soluble hormone.

An enzyme that converts ATP into cAMP, a crucial step in the cAMP signaling pathway.

Enzymes that add phosphate groups to other proteins, changing their activity and amplifying the signal in the cAMP pathway.

An enzyme that degrades cAMP, effectively stopping the cAMP signaling cascade.

Signaling pathways that utilize PIP2 and calcium as second messengers, also triggered by water-soluble hormones.

A molecule that binds to a receptor, initiating a signaling cascade within the cell.

A hormone produced by the anterior pituitary that stimulates growth, cell division, and protein synthesis.

The main target cells for Growth Hormone (GH) are bone and skeletal muscle.

GH release is triggered by low blood GH or glucose, or high amino acid levels. Its release is inhibited by increases in GH and IGF levels.

A hormone produced by the liver, skeletal muscle, and bone in response to GH that stimulates cell growth.

A condition caused by excessive GH production, resulting in abnormal growth of hands, feet, and face. It typically occurs in adults.

A condition caused by a lack of GH, leading to stunted growth. It occurs in children.

A condition caused by excessive GH production, resulting in abnormally tall stature. It typically occurs in children.

A hormone produced by the stomach that stimulates GH release.

Hormones activate G protein, which activates phospholipase C. This enzyme splits PIP2 into two second messengers: diacylglycerol (DAG) and inositol trisphosphate (IP3).

Calcium ions act as a second messenger by altering enzyme activity, binding to regulatory protein calmodulin, and activating enzymes that amplify the signal. This creates a strong cellular response.

Cyclic guanosine monophosphate (cGMP) is a second messenger for selected hormones, acting as a signaling molecule in various processes.

Not all hormones utilize second messenger systems. Some hormones have a direct effect on target cells.

Insulin receptor, an example of a tyrosine kinase enzyme, autophosphorylates upon insulin binding, activating the receptor and triggering cell responses.

Steroid and thyroid hormones enter target cells due to their lipid solubility, and bind to intracellular receptors.

The receptor-hormone complex enters the nucleus, binds to a specific DNA region, and initiates DNA transcription to produce mRNA.

The mRNA is translated into specific proteins, which can have various functions like metabolic activities, structural purposes, or cell export.

Prolactin (PRL) is a hormone produced by the anterior pituitary gland. It's primarily responsible for stimulating milk production in women after childbirth. Its role in men is not fully understood.

Dopamine acts as a prolactin-inhibiting hormone (PIH). It typically prevents prolactin release until needed, with decreased levels leading to lactation.

Increased estrogen levels stimulate prolactin release, which explains why women experience breast swelling and tenderness during their menstrual cycle.

Prolactin levels rise naturally towards the end of pregnancy, preparing the body for lactation. Suckling further stimulates prolactin release, ensuring sustained milk production.

Tropic hormones are hormones that regulate the secretion of other hormones. They work like middlemen, signaling other endocrine glands to release their own hormones.