Neuro exam 14 Nov Flashcards
What is the function of the autonomic nervous system?
It regulates involuntary bodily functions such as heart rate, breathing rate, digestion, and arousal responses (fight, flight, freeze).
What are the primary components regulated by the autonomic nervous system?
Heart rate, breathing rate, vasodilation, digestion, saliva production, eye function, facial expressions, body temperature, and neuro-endocrine responses.
What is sensory processing?
Sensory processing involves how the brain receives, interprets, and integrates sensory information from the environment.
What types of stimuli do sensory systems respond to?
Mechanical (touch, pressure), visual (light), thermal, chemical (odors, tastes), electrical, and magnetic stimuli.
What is Sensory Processing Disorder (SPD)?
A condition where the brain struggles to receive and respond appropriately to sensory information, affecting daily functioning and emotional regulation.
What are the types of Sensory Processing Disorders?
- Sensory Modulation Disorder (over/under-reactivity)
- Sensory Discrimination Disorder (difficulty distinguishing stimuli)
- Sensory-Based Motor Disorder (motor coordination issues).
What is range fractionation in sensory processing?
A process where different receptors detect varying segments of a stimulus range, allowing for sensitivity to different intensities.
How does adaptation occur in sensory receptors?
Adaptation is the decrease in responsiveness of a receptor to a constant stimulus over time, helping to prevent sensory overload.
What is the role of receptor fields in sensory perception?
Receptive fields are specific areas where sensory receptors detect stimuli, influencing the resolution and sensitivity of sensory perception.
What is the significance of topographic organisation in the brain?
It refers to the spatial arrangement of sensory inputs in the sensory cortex, allowing for precise localisation of sensory information.
What are the key structures of the human eye involved in vision?
Cornea, pupil, lens, vitreous humor, retina (rods and cones), bipolar cells, ganglion cells, and optic nerve.
How do photoreceptors transduce light into chemical reactions?
Photoreceptors (rods and cones) convert light into electrical signals through a series of chemical reactions, ultimately altering the release of neurotransmitters to bipolar cells.
How does the eye function under different light intensities?
Rods are specialized for low light (scotopic) vision, while cones are optimized for bright light (photopic) conditions, allowing the eye to adjust based on light levels.
How does the visual system create brightness?
Brightness perception is created by comparing the responses of cones sensitive to different wavelengths (short, medium, long) and through overall stimulation of photoreceptors.
What is the pathway of a neural signal from the retina to the brain?
Retina -> optic nerve -> optic tract -> thalamus (LGN) -> primary visual cortex -> dorsal (where) and ventral (what) streams.
How does the Royal Society for the Blind (RSB) support individuals with vision impairment?
The RSB provides services and support for people with vision impairment, employing occupational therapists to maximize function and engagement in daily activities.
Where are rods and cones located in the retina?
Rods are found in the peripheral retina, while cones are concentrated in the fovea (central part of the retina).
What is the impact of stroke on vision?
Approximately one-third of stroke survivors experience some form of vision loss, and occupational therapists assist in rehabilitation and adaptation to visual changes.
What is the difference in response time and acuity between rods and cones?
Rods have low acuity and slower response times, while cones have high acuity and faster response times.
Outline the transduction pathway of light in the eye.
Light → cornea → pupil → lens → vitreous humor → retina → rods/cones → bipolar cells → ganglion cells → optic nerve → optic tract → thalamus → occipital lobe → primary visual cortex.
What is sound?
Sound is a form of energy produced by vibrating objects, propagated through mediums like air or water, characterized by vibration, sound waves, frequency, amplitude, and wavelength.
What are the key properties of sound waves?
Frequency: Cycles per second (Hz), determines pitch (higher frequency = higher pitch).
Amplitude: Height of the wave, determines loudness (larger amplitude = louder sound).
Wavelength: Distance between consecutive compressions or rarefactions in a sound wave.
Describe the anatomy of the ear.
The ear consists of three parts:
Outer Ear: Pinna and ear canal, collects sound waves.
Middle Ear: Eardrum and ossicles (malleus, incus, stapes), transmits vibrations to the inner ear.
Inner Ear: Cochlea and hair cells, converts vibrations into electrical signals for the brain.
What is the process of auditory pathways to the brain?
- Sound waves enter the outer ear and vibrate the eardrum.
- Vibrations are transmitted through the ossicles to the oval window.
- Fluid movement in the cochlea stimulates hair cells, generating electrical signals.
- Signals travel via the auditory nerve to the brainstem.
- Signals are relayed to the primary auditory cortex in the temporal lobe for interpretation.
What are the types of hearing loss?
- Conductive Hearing Loss: Problems in outer/middle ear; e.g., ear infections, fluid.
- Sensorineural Hearing Loss: Damage to hair cells or auditory nerve; often irreversible (aging, noise).
- Neural Hearing Loss: Damage to auditory nerve/brain pathways.
- Central Hearing Loss: Issues in brain’s auditory processing, affecting sound interpretation.
What role do hair cells play in hearing?
Hair cells in the cochlea convert mechanical vibrations from sound into electrical signals. They are critical for detecting sound and are sensitive to damage, leading to sensorineural hearing loss.
Describe the vestibular system’s role in balance.
The vestibular system consists of semicircular canals and otolith organs, which detect head movements and orientation. It sends signals to the brain to help maintain balance and coordinate movements.
How do sound intensity and decibels (dB) relate?
Sound intensity is expressed in decibels (dB), a logarithmic scale measuring sound pressure. The human ear can detect sounds from 0 dB (threshold) to 120-130 dB, with sounds above 90 dB potentially causing inner ear damage.
What is the significance of the external ear?
The external ear collects sound waves and channels them to the tympanic membrane (eardrum), which vibrates in response to sound, marking the first step in sound transduction.
Explain the concept of sound waves and their cycles.
Sound waves are pressure waves that consist of compressions and rarefactions. A single alternation of compression and rarefaction is one cycle, characterized by properties like amplitude and frequency, impacting perceived sound.
What is the process of sound wave transduction in the ear?
Sound waves enter the ear through the pinna, travel down the ear canal to the cochlea, stimulating hair cells in the fluid. These hair cells create electrical impulses that travel along the auditory nerve to the brain, where they are interpreted as sound.
What are the different types of sensory receptor organs?
- Photoreceptors: Rods (night vision, low light) and Cones (color vision).
- Mechanoreceptors: Meissner’s (light touch), Pacinian (deep pressure), Merkel (sustained pressure), Ruffini (skin stretch).
- Thermoreceptors: Cold and warm receptors.
- Nociceptors: A-delta fibers (sharp pain) and C fibers (dull pain).
- Chemoreceptors: Olfactory (smell), gustatory (taste), internal chemoreceptors (blood chemistry).
What is the concept of labelled lines?
Each sensory modality has a dedicated neural pathway. When a receptor is activated, it sends signals through specific neurons to designated brain areas (e.g., visual pathway via optic nerve, pain pathway via spinothalamic tract).
Name the tactile receptors in the skin and their properties.
Meissner’s Corpuscles: Light touch, fast-adapting.
Pacinian Corpuscles: Deep pressure, fast-adapting.
Merkel Discs: Light touch, slow-adapting.
Ruffini Endings: Skin stretch, slow-adapting.
Outline the pain pathways to the brain.
Activation: Nociceptors detect stimuli.
Transmission: Signals travel via A-delta and C fibers to the spinal cord.
Processing: Signals are relayed to the thalamus and then to the cortex (somatosensory and emotional areas).
How can pain be modulated?
- Pharmacological: NSAIDs, opioids, antidepressants.
- Physical: Physical therapy, heat/cold therapy.
- Psychological: Cognitive-behavioral therapy, relaxation techniques.
- Neuromodulation: Spinal cord stimulation, TMS.
- Gate Control Theory: Non-painful stimuli inhibit pain signal transmission.
Briefly outline the pain cycle.
Initial Injury: Tissue damage activates nociceptors.
Pain Perception: Signals transmitted and processed by the brain.
Behavioral Response: Protect the injured area.
Chronic Pain Development: Persistent pain alters nervous system sensitivity and processing.
What is nociception?
Nociception is the neural feedback mechanism that responds to noxious stimuli, such as heat, cold, mechanical force, and chemical stimulation, resulting in pain perception.
What are the two pathways for pain transmission?
- Spinothalamic Pathway: Nociceptors near the skin surface transmit sharp, well-localized pain to the thalamus.
- Reticulothalamic Pathway: Nociceptors in deeper tissues transmit dull, poorly localized pain via the reticular formation to the thalamus.
Describe the difference between acute pain and neuropathic pain.
Acute Pain: Short-term response to tissue damage.
Neuropathic Pain: Results from nerve damage, often causing shooting or burning sensations, numbness, and tingling.
Describe the components of the reflex arc.
The reflex arc includes:
Sensory receptor
Sensory neuron
Integrating center (spinal cord)
Motor neuron
Effector (muscle or gland)
How do muscle spindles function?
Muscle spindles consist of afferent fibers that send signals to the spinal cord when a muscle is stretched. The brain interprets this information to coordinate muscle responses.
What are some benefits of touch?
Touch can improve bonding, decrease stress, lower heart rate/blood pressure, reduce muscle tension, lessen depression and anxiety, relieve pain, and enhance immune function.
What are the two types of proprioceptive receptors?
- Muscle Spindles: Monitor muscle length and speed of stretch.
- Golgi Tendon Organs: Monitor muscle tension and prevent overload.
