Nervous System and Pain - Week 1

The nervous system is composed of two main parts: the central nervous system (CNS) which includes the brain and spinal cord, and the peripheral nervous system (PNS), which encompasses the nerves extending from the CNS to the rest of the body.

The nervous system relies heavily on energy, primarily utilizing glucose and oxygen. Disruptions in its supply of these vital nutrients can lead to severe damage or even death of nerve cells.

Ascending pathways are responsible for transmitting sensory information from the periphery (your body) to the central nervous system (brain).

Descending pathways carry information from the central nervous system (brain) to the periphery (your body).

The brainstem is a critical part of the brain located at the base of the skull, essential for controlling essential functions such as breathing, heart rate, and consciousness. It consists of three components: the midbrain, pons, and medulla.

The cerebellum, located at the back of the brain, plays a vital role in coordinating movement, balance, and posture, ensuring smooth and precise bodily actions.

The thalamus serves as a relay station for sensory input from the body, processing and directing information to the appropriate areas of the brain for interpretation.

The basal ganglia is a group of interconnected brain structures that work together to regulate movement, making it smooth and coordinated.

A type of sensory receptor that detects vibration. They are located deep within the skin and are rapidly adapting, meaning they quickly stop responding to a constant stimulus.

A type of sensory receptor that is good at detecting static touch and pressure. They are located near the skin surface and are slowly adapting, meaning they continue to respond to a constant stimulus.

A type of sensory receptor that detects stretching of the skin. They are located in the middle layers of the skin and are slowly adapting.

The pathway that carries sensory information about touch, pressure, and vibration from the body to the brain. It decussates (crosses over) in the medulla.

The pathway that carries sensory information about pain and temperature from the body to the brain. It decussates in the spinal cord.

A type of sensory receptor that detects pain, which is triggered by nociceptors. They are free nerve endings in the skin.

Free nerve endings in the skin that detect changes in temperature. They use Transient Receptor Potential (TRP) channels to transduce temperature changes into electrical signals.

A receptor protein that is involved in the detection of temperature changes. It is found on thermal receptors.

A receptor that detects noxious heat above 125°F. It's activated by very hot temperatures and contributes to the sensation of burning pain.

A receptor that detects both heat and capsaicin (the compound in chili peppers) above 109°F. It contributes to the sensation of burning pain and is activated by both heat and spicy foods.

A receptor that detects noxious cold below 64°F. It's activated by very cold temperatures and contributes to the sensation of freezing pain.

A type of pain caused by the nervous system responding to noxious stimuli. It's a normal protective response to injury or damage.

A type of pain that results from damage to the peripheral or central nervous system. The body perceives pain even in the absence of a real injury.

A neural pathway that carries information about pain, temperature, and crude touch from the body to the brain. It originates in the spinal cord and ascends to the thalamus, then projects to the somatosensory cortex.

A network of brain regions involved in processing and experiencing pain.

The movement of a substance from an area of high concentration to an area of low concentration.

The movement of water across a semi-permeable membrane from a region of higher water concentration to a region of lower water concentration.

The pressure that must be applied to a solution to prevent the inward flow of water across a semi-permeable membrane.

The concentration of dissolved particles in a solution.

The effect of a solution's osmolarity on a cell.

A protein channel that allows water to move across cell membranes.

The difference in osmotic pressure between two solutions separated by a semi-permeable membrane.

A measure of how easily a solute can pass through a semi-permeable membrane.

A part of the brain responsible for coordinating movement, balance, and motor learning. It receives input from the brain and spinal cord, and sends output to the brain to fine-tune movements.

The cerebellum has three lobes: anterior, posterior, and flocculonodular.

Damage to the cerebellum can result in ataxia, a condition characterized by loss of coordination.

The cerebellum helps to refine and correct motor commands, ensuring movements are accurate and coordinated.

The spinocerebellum deals with error correction during movement and coordinates movements of the body.

The vestibulocerebellum is involved in maintaining balance and coordinating eye movements.

The cerebrocerebellum is responsible for motor learning and adapting motor programs to improve future movements.

The cerebellum receives sensory information from the body and the brain, and sends output to the brain to help regulate movement.

The Globus Pallidus (GPi) is a brain structure that is responsible for inhibiting the thalamus, which is involved in controlling movements. In the resting state, the GPi prevents unwanted movements by keeping the thalamus in check.

The direct pathway of the basal ganglia is responsible for initiating movements by stimulating the thalamus, which then activates the motor cortex. This pathway is stimulated by dopamine released from the substantia nigra.

The indirect pathway of the basal ganglia suppresses unwanted or excessive movements by increasing inhibition of the thalamus. When this pathway is correctly functioning, it controls and smooths our movements.

Parkinson's disease occurs due to a loss of dopamine-producing cells in the Substantia nigra. This results in a disruption of the direct pathway and an imbalance with the indirect pathway, leading to difficulties initiating and controlling movements.

Huntington's disease is caused by degeneration of neurons in the striatum, a key component of the basal ganglia. This causes an imbalance in the indirect pathway, leading to uncontrolled movements, like involuntary writhing or jerking motions.

The substantia nigra is a brain region that produces dopamine, a neurotransmitter crucial for the function of the basal ganglia. It plays a key role in both the direct and indirect pathways influencing movement control.

D1 dopamine receptors are involved in the direct pathway of the basal ganglia. When dopamine binds to these receptors, it activates the pathway, enhancing movement initiation.

The subthalamic nucleus (STN) is a brain structure that receives input from the globus pallidus external segment (GPe) and projects to the globus pallidus internal segment (GPi). It plays a crucial part in the indirect pathway, modulating movement control.