T4 Flashcards
Neural pathways
Neural pathways are networks of neurons in the brain and nervous system that communicate with each other to process and transmit information.
These pathways are critical for everything the brain does, from basic survival functions like breathing and heart rate control to complex tasks like thinking, learning, memory, and emotions.
Key Elements of Neural Pathways:
(5)
Neurons: The basic units of the nervous system. They send electrical and chemical signals to communicate.
Synapses: Junctions between neurons where chemical or electrical signals are transmitted.
Axons and Dendrites:
- Axons: carry signals away from the neuron cell body to other neurons, muscles, or glands.
- Dendrites: receive signals from other neurons.
Neurotransmitters: Chemical messengers released at synapses to transmit signals from one neuron to another.
Myelin: Fatty tissue that insulates axons and speeds up the transmission of electrical signals.
Formation and Plasticity
(neural pathways)
Neural Pathway Development: Pathways form and strengthen through experiences and learning. When certain patterns of neural activity occur repeatedly, the connections between neurons become more robust, making communication more efficient.
Neuroplasticity: This is the brain’s ability to reorganize itself by forming new neural pathways. This happens during learning, after injury, or throughout life as the brain adapts to new experiences.
example neural pathways
Sensory Pathways: Carry sensory information (e.g., touch, vision, sound) to the brain.
Motor Pathways: Carry signals from the brain to muscles, enabling movement.
Cognitive and Emotional Pathways: These involve regions of the brain like the prefrontal cortex, amygdala, and hippocampus, controlling higher-order functions like decision-making, memory, and emotional regulation.
Neural pathways are fundamental for how we perceive the world, move, and think. The brain’s adaptability (plasticity) allows …
these pathways to change and optimize based on experience, which is key to learning and rehabilitation.
Neural tracts are critical for communication within the CNS. They relay:
Sensory Information: Signals about sensations like touch, pain, and temperature from the body to the brain for processing.
Motor Commands: Instructions from the brain to muscles and glands for movement or physiological functions.
Cognitive and Emotional Processing: Tracts connect various brain regions that control memory, emotions, and higher-order cognitive functions.
neural tracts (def)
Are bundles of axons in the central nervous system that carry signals from one part of the brain or spinal cord to another.
They serve as “highways” that transmit information across the brain and nervous system.
Key Points about Neural Tracts:
Composition: Neural tracts are composed of axons.
Location: Neural tracts exist primarily within the central nervous system (CNS), which includes the brain and spinal cord.
Types of Tracts: Based on their function and direction, neural tracts are classified into different types:
- Ascending Tracts: Carry sensory information up from the body to the brain.
- Descending Tracts: Transmit motor signals down from the brain to the body.
Examples of Major Neural Tracts:
Corticospinal Tract: This is a descending motor tract that carries signals from the brain to the spinal cord and is crucial for voluntary movement control, especially in the limbs.
Spinothalamic Tract: An ascending sensory tract that transmits signals related to pain, temperature, and touch from the spinal cord to the thalamus in the brain.
Dorsal Column-Medial Lemniscus Tract: Another ascending sensory pathway that transmits fine touch, vibration, and proprioception (sense of body position) information to the brain.
Corticobulbar Tract: A descending tract that connects the cerebral cortex to the brainstem, controlling muscles in the face, head, and neck.
Optic Tract: Part of the visual system, this tract carries visual information from the eyes to the visual cortex in the brain for processing.
Neuroprosthetics
There are 2 types: Cortical neuroprosthetics and Peripheral Nervous System (PNS) neuroprosthetics.
Hand Prosthesis types
Prosthetic hands:
- Passive:
Cosmetic (most used (70%))
- Active:
Body powered (cheap, robust, simple)
Myoelectric
recording muscular activity
Accessible muscles:
sEMG (superficial)
iEMG (intramuscular, within muscle)
Non-Accessible muscles:
ENG (intraneural, inside nerve)
sEMG-TMR: sEMG-Targeted Muscle Reinnervation
Targeted Muscle Reinnervation
Targeted Muscle Reinnervation: Reconnect the residual nerves coming from the spinal cord (SC) to another muscle, the chest muscles.
- Simple surgical procedure.
- Chest muscles very close to upper extremity.
- Chest muscles are not used a lot in daily activities.
Brachial plexus anatomy
After five months it is verified that only the following nerves are properly reinnervated:
Musculocutaneous nerve (ventral)
Median nerve (ventral)
Ulnar nerve (ventral)
Radial nerve (dorsal)
