• defined as 2 or more seizures caused 24 hours apart

• neurons in the brain sends the wrong nerve impulses

• 2 different types: focal epilepsy (partial epilepsy, seizure starts at one part of the brain) & generalised epilepsy (seizures start across the whole brain at the same time)

• can be caused by genetic factors, head injury, infections, brain tumours, developmental disorders etc.

• can also cause loss of awareness, uncontrolled movement, affect memory etc

• cannot be ‘cured’ but can be ‘controlled’ (most seizures can be treated w medicine)

disease: alzheimer’s disease

effect: neurons are injured and stop working properly in the brain, connections among networks of neurons may break down and many brain regions begin to shrink

q2:

painkillers are medications used to relieve pain and they act on the nervous system to reduce or block the perception of pain.

types of painkillers:

1. non-opioid analgesics that block enzymes involved in the production of chemicals that cause pain and inflammation. They mainly act peripherally

2. opioid analgesics (eg morphine) reduces the perception of pain by altering how the brain processes signals. They act centrally

3. adjuvant analgesics (eg, antidepressants) which modulate pain by affecting neurotransmitter levels or nerve excitability.

effects:

1. addiction: Opioid painkillers leads to feelings of euphoria. the brain may become dependent on the drug to experience pleasure

2. tolerance and dependence: people may develop a tolerance, requiring higher doses to achieve the same effect.

Disease: Motor neurone disease

Effect: Damages parts of the nervous system leading to weakening of the muscles. As the disegse becomes progressively worse..

1. Limbs become weaker

•muscles thin

-difficulty moving and stiff limbs

• muscle wasting → joint aches & pains

2. speaking and swallowing difficulties

   -choking

3. Excess saliva and drooling
   -difficult to clear saliva from chest/throat (muscles weakened, coughing becomes difficult)

4. Breathing difficulties
   nerves damaged: x transmit nerve impulses to muscles to stimulate breathing

› breathlessness

Q2

→ drugs are used to relieve pain, contains chemicals that primarily reduce inflammation and decrease pain signals sent to the brain

→ e.g. opioids change the perception of pain by reducing pain signal intensity that reach the brain, altering the emotional response to pain

→ highly addictive because they give feelings of euphoria and numb pain, causing the body to develop a tolerance and need higher doses which causes addiction.

→ this causes heavy dependence on painkillers, where the body needs it to function properly, if not having withdrawal symptoms. they can also cause organ damage or even death from overdose.

• Epilepsy > A chronic brain disorder in which groups of nerve cells or neurons send wrong nerve impulses (i.e. many neurons send nerve impulses at the same time), causing involuntary movements and behaviors (i.e. seizures)

• Can vary from person to person in both severity and frequency, with the most severe being repeated muscular contractions (also known as convulsions) and loss of consciousness. 

• Can develop as a result of anything that disturbs the normal functioning of nerve cells, such as sickness and brain tumors, or because of imbalance of nerve signalling in the brain (where neurons are unusually active/stop other neurons from sending signals)

2. What are pain killers and how do they act on the nervous system? Can they cause addiction and negative long term effects? Explain

• Drugs that reduce/eliminate the sensation of pain without affecting the cause. They send signals to the brain via the nerves to block pain signals which reduces the pain

• Can cause addiction such as opioid use disorder (OUD) by alternating the neurotransmitters in the brain and causing drug dependence, or overdose, which can suppress breathing and be fatal

• Long-term opioid treatment increases the risk of fractures, infections, cardiovascular complications, sleep-disordered breathing, bowel dysfunction, overdose, and mortality. Opioids may potentially affect cancer development

Brain tumor symptoms:

• Morning headache or headache that goes away after vomiting

• Seizures

• Vision, hearing, and speech problems

• Loss of appetite

• Frequent nausea and vomiting

• Changes in personality, mood, ability to focus, or behavior

• Weakness, loss of balance, and trouble walking

• Unusual sleepiness

Spinal cord tumor symptoms:

• Back pain or pain that spreads from the back towards the arms or legs

• A change in bowel habits or trouble urinating

• Weakness or numbness in the arms or legs

• Trouble walking

Qn2.

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Inhibit enzymes (COX-1 and COX-2) involved in the production of prostaglandins, which play a role in pain and inflammation.

NSAIDs inhibit the enzyme cyclooxygenase (COX), which is responsible for the production of prostaglandins. Prostaglandins in the CNS, particularly in areas like the spinal cord and brain, enhance pain signaling. By reducing prostaglandin synthesis in the brain, NSAIDs can reduce the perception of pain.

NSAIDs can also reduce fever by acting on the hypothalamus (a part of the brain that regulates temperature). This is because fever is partly caused by prostaglandins acting on the hypothalamus, and NSAIDs reduce their production.

while they aren’t addictive, prolonged use of NSAIDs can lead to other issues such as stomach ulcers, kidney problems, or cardiovascular risks, especially if taken in high doses or for extended periods.

example: parkinson’s disease

• the neurons in the brain (substantia nigra)gradually become damaged->leading to a shortage of dopamine (a neurotransmitter that’s essential for smooth, coordinated muscle movements.)

• Decreased dopamine leads to irregular brain activity

• Might lose a chemical messenger called norepinephrine that controls many body functions (e.g. blood pressure)

factors that may cause parkinson’s disease: 

• Genes: rare unless many family members have had Parkinson's disease.

• Environmental factors: Exposure to certain toxins or other environmental factors may increase the risk of later Parkinson's disease. One example is MPTP.

• Alpha-synuclein found within Lewy bodies.: Alpha-synuclein is a protein found in all Lewy bodies and occurs in a clumped form that cells can't break down-> found in the spinal fluid of people who later have Parkinson's disease.

• Altered mitochondria: Changes to mitochondria can cause cell damage. These changes have been found in the brains of people with Parkinson's disease.

symptoms: 

• Tremor

• Slowed movement

• Rigid muscles

• Poor posture and balance.

• Loss of automatic movements

• Speech changes

• Writing changes

Q2. What are pain killers and how do they act on the nervous system? Can they cause addiction and negative long term effects? Explain.

Example: Opioids

Usually, Endorphins temper pain signals by binding to receptors, however opioid drugs bind more strongly and for a longer period of time, which make them able to manage more severe pain than these endorphins. However, since thes bind is so strong, the effects are more widespread. Opioid receptors also influence everything from mood to normal bodily functions. 

The binding to opioid receptors trigger the release of dopamine, which is closely linked to signs of an opioid high (sense of euphoria). A high dosage greatly suppresses the release of noradrenaline (influences basic bodily functions), which can decrease heart and breathing rates to dangerous levels, which can cause fainting and even death.

Why is it addictive? The body slowly grows tolerant to the drug, where the opioid receptors become less responsive and the body decreases the amount of these receptors. To experience the ”opioid high” as previously mentioned, people have to take larger and larger doses of the drug, leading to physical dependence and dopamine.

Negative effect: accidental overdose. If someone stops taking these opioids for a long time, their opioid tolerance goes back down. At that point, what would have even a normal dose before they quit could be lethal if they were to take it again. To this day, the cases of accidental overdoses due to opioids are still increasing exponentially.

Alzheimer’s disease is a brain disorder that slowly destroys memory and thinking skills, and eventually, the ability to carry out the simplest tasks. It causes loss of cognitive functioning and behavioural abilities to such an extent that it interferes with a person’s daily life and activities.

How does Alzheimer's disease affect the brain?

Changes in the brain may begin a decade or more before symptoms appear. During the very early stage of Alzheimer’s, toxic changes take place in the brain, including abnormal buildups of proteins that form amyloid plaques and tau tangles.

• Previously healthy neurones stop functioning, lose connections with other neurones, and die. Many other complex brain changes are thought to play a role in Alzheimer’s as well.

• The damage initially appears to take place in the hippocampus and the entorhinal cortex, which are parts of the brain that are essential in forming memories. As more neurones die, additional parts of the brain are affected and begin to shrink. By the final stage of Alzheimer’s, damage is widespread and brain tissue has shrunk significantly.

Question 2:

Painkillers relieve pain by interrupting pain signals in the nervous system.

Types of painkillers:

• Non-opioids (e.g., ibuprofen, acetaminophen) reduce inflammation or block pain-causing chemicals and are less addictive.

• Opioids (e.g., morphine, oxycodone) target receptors in the brain to block pain but can lead to addiction due to their euphoric effects.

Long-term risks: addiction, tolerance, withdrawal, and damage to organs like the liver or kidneys. Non-opioids can also cause issues like stomach ulcers with prolonged use.

q1: Huntington’s disease is an inherited condition that causes brain cells to slowly lose function and die. It affects the cells in parts of your brain that regulate voluntary movement and memory.

There are two types of Huntington’s disease:

• Adult onset: most common form. Symptoms usually begin after age 30.

• Early onset (juvenile Huntington’s disease): affects children and teenagers, very rare.

Physical symptoms:

• Uncontrolled movements like jerking or twitching (chorea).

• Loss of coordination (ataxia).

• Trouble walking.

• Difficulty swallowing (dysphagia).

• Slurred speech.

What causes it?

• genetic change (mutation) of the HTT gene causes Huntington’s disease. The HTT gene makes a protein called huntingtin. This protein helps neurons function.

• It helps in the transport of materials within neurone especially along microtubules (the cell’s transport system). Helping to move essential molecules, proteins, and organelles to the parts of the neurone where they are needed, particularly in long neurone like those in the brain. it also contributes to synaptic transmission, process of communication between neurons at the synapse. it helps to release and recycle neurotransmitters, huntingtin protein ensures that neurons can communicate effectively with each other.

• Huntington’s disease > mutations in the HTT gene, DNA doesn’t have all the information needed to properly make the huntingtin protein

• resulting in the proteins growing in an abnormal shape and destroy (instead of help) your neurons, becomes toxic to neurons, neurons die because of this genetic mutation.

• the destruction of nerve cells happens in the basal ganglia or the region of your brain that regulates body’s movements. It also affects the brain cortex that regulates your thinking, decision-making and memory.

q 2

• effect of painkillers—>depresses central nervous system, making it more difficult for pain signals to reach the brain.

  theybind to proteins called opioid receptors on nerve cells in the brain, spinal cord, intestines and other organs in the body—>opioids block the pain pathways sent from the body through the spinal cord to the brain

• Opioids are a class of drugs that include the illegal drug heroin, synthetic opioids such as fentanyl, and pain relievers available legally by prescription, such as oxycodone (OxyContin®), hydrocodone (Vicodin®), codeine, morphine, and many others.

• opioids can cause addiction, even when prescribed by doctors—>they trigger the release of endorphins to make you ‘ feel good’, such as reducing the amount of pain you feel

• hydrocodone is an opioid used to treat severe chronic pain that cannot be effectively treated by nonopioid alternatives—>commonly prescribed for moderate-to-severe pain management in postoperative settings, trauma patients, and individuals with cancer—>usually taken orally

• considered a strong painkiller

• attaches to proteins in your brain called mu-opioid receptors to change how you react to pain. This helps lower how much pain you feel.

• has high addiction liability—>means that it may be easier for people to get addicted to it if they do take it

  
  

Myelitis is the inflammation of spinal cord.

Due to inflammation, the covering around the nerve cells in your spinal cord is damaged. This interrupts the signals between spinal nerves and the rest of your body, causing issues such as loss of sensation, movement and bladder control.

Question 2

Painkillers are types of drugs called analgesics, which are used to treat pain.

The greatest difference is that painkillers target the levels of pain one feels, by interrupting pain signals before they get to the brain.

However, for long term pain or inflammation, they are unlikely to improve the underlying problem that’s causing it.

Painkillers contain paracetamol while compound painkillers could contain co-codamol, paracetamol and ibuprofen, ibuprofen and codeine.

Paracetamol is used to reduce fever and can help manage mild to moderate aches and pain.

Though paracetamol is safe for most people, your doctor may advise against using it if you have another health issue.

If you have problems such as lower back pain, or osteoarthritis, taking paracetamol alone may not be the most effective treatment.

However, be careful if you’re taking medicines for migraines, coughs, colds and flu, or compound painkillers, because these drugs often already contain paracetamol.

Taking too much paracetamol can cause liver failure.

If paracetamol isn’t helping, a healthcare professional may recommend other treatments, such as a programme of exercise, physiotherapy, or a stronger type of pain relief.

Healthcare professionals are unlikely to prescribe compound painkillers containing the opioids codeine and dihydrocodeine for longer than a few days, because there’s little evidence that they help long-term pain.

To avoid accidentally taking too much of any drugs, make sure that the compound painkiller contains and avoid these ingredients while taking it.

Because each of the ingredients can cause different side effects, compound painkillers may increase one’s risk of an unpleasant reaction.

Compound painkillers can reduce your pain, but they may cause more side effects.

Compound painkillers containing aspirin, paracetamol, or ibuprofen, carry the same risk of side effects as taking these drugs separately.

People who take painkillers containing opioids can become dependent on them if they take them for a long period of time.

- pain that starts in the back and goes down the leg. It can be caused by anything that presses on the surface nerve or the nerve roots in the spine

- causes people to suffer from nerve pain -> usually a burning, stabbing or shooting feeling (gets worse when one walks, coughs etc.)

qn2: aspirin

• in a group of painkillers called salicylates

• can treat flu-like symptoms and bodily aches (headache, toothache, etc.)

• high doses lower inflammation

• recommended for people with irregular blood pressure, smokers, people with diabetes, etc.

• irreversibly inhibits both cyclooxyrgenase enzymes used to convert arachidonic acid to prostaglandins

• blocks pain receptors as a result

• high chance of addiction as there is a release of beta-endorphins and the feeling of the chemical may be addictive

• long term effects: addiction as the user becomes overly dependent on it, depression, liver and heart problems

Painkillers are medications that reduce or eliminate pain. They work in various ways, depending on their type, by interacting with the nervous system to block or dull pain signals.

Painkiller types:

1. Nonsteroidal anti-inflammatory drug

- Ibuprofen, Aspirin

• treat mild to moderate pain, inflammation or arthritis

- Acetaminophen (Paracetamol)

• Used for mild to moderate pain and inflammation.

2. Opioid Painkillers:

- Morphine, Oxycodone, Codeine

• Used for moderate to severe pain. Very effective but carry a high risk of addiction and serious side effects.

3. Adjuvant Analgesics:

• Examples: Certain Antidepressants, Anticonvulsants

• Used for chronic or nerve-related pain. Often combined with other painkillers. Can have side effects like drowsiness.

Effects on the Nervous System:

Painkillers interact with the central nervous system (CNS) by modifying the transmission of pain signals either at the site of pain, in the spinal cord, or in the brain itself. Opioids, in particular, are effective because they inhibit the release of neurotransmitters involved in the perception of pain and increase the body’s threshold for pain.

Addiction and negative long-term effects:

1. Addiction (primarily with opioids):

• opioid painkillers can lead to addiction due to their ability to cause euphoria by releasing dopamine. Overtime, the brain may become reliant on the drug to experience pleasure, leading to physical dependence and addiction.

2. Negative long-term effects:

• Opioids: long term use can lead to hyperalgesia, a condition where the body become more sensitive to pain.

• NSAIDs: can result in gastrointestinal issues (ulcers, bleeding), kidney damage and cardiovascular risks

• Acetaminophen can lead to liver damage or failure.

Epilepsy: chronic brain disorder where neurons sometimes send the wrong signals and cause seizures

seizures: many neurons send signals at the same time, taster than usual, surge of electrical energy causes involuntary movements

other effects:

-loss of consciousness 

- convulsions

-lapse of awareness

conditions that lead to epilepsy :

-brain tumors

-head trauma

-alcoholism 

-strokes, heart attacks

q2

• Painkillers are a type of drug called analgesics, used to treat pain.

• painkillers target the levels of pain you’re feeling, by interrupting pain signals before they get to the brain.

• Paracetamol modulates neurotransmission with behavioral alterations, showing improvement in memory

• analgesic action of paracetamol is on the central nervous system.

• inhibits cyclooxygenase (COX)-1 and -2 in high concentrations but stimulates in low doses on central nervous system

does it cause addiction?

• does not cause addiction but dependence on the medicine can cause withdrawal symptoms like drowsiness after suddenly not eating the painkiller

long term effect of using it

• Long-term use of paracetamol can cause: tiredness. breathlessness. and fingers and lips to go blue.

• hyperactivity

• excitable behaviour

• hallucinations

• lack of coordination

• fear of water

• fear of fresh air

among humans. After a few days, people will succumb and die to this disease. It is uncommon to survive rabies.

Q2: Morphine is a commonly used opioid painkiller 

• used to treat severe or chronic pain

• binds to the mu-opioid receptors in the central and peripheral nervous system, interrupting nerve impulses.

• can be taken as 

  • liquid by mouth

  • quick or slow release tablets

  • capsules

•  side effects include

  • drowsiness

  • anxiety

  • nausea

• it poses a serious risk of addiction when used long term 

• easily abused 

• misuse may cause addiction, overdose, death

• Morphine is a commonly used opioid painkiller 

• used to treat severe or chronic pain

• binds to the mu-opioid receptors in the central and peripheral nervous system, interrupting nerve impulses.

• can be taken as 

  • liquid by mouth

  • quick or slow release tablets

  • capsules

•  side effects include

  • drowsiness

  • anxiety

  • nausea

• it poses a serious risk of addiction when used long term 

• easily abused 

• misuse may cause addiction, overdose, death
  

• misuse may cause addiction, overdose, death