Central Nervous System and the Brain

Central nervous system (CNS)

Contains the brain and the spinal cord.

Peripheral nervous system (PNS)

All of the nerves outside of the brain and spinal cord. It carries messages to and from the CNS

Cerebral cortex

The top part of the brain. It controls consciousness, memory and the senses

Cerebellum

At the back of the brain, controls the body’s balance and muscle coordination.

Hypothalamus

In the middle of the brain, controls body temperature and sends signals to the pituitary gland.

Medulla

At the bottom of the brain, part of the brain stem, control unconscious actives like breathing and heartbeat.

CT scans

Use X-rays showing what areas of the brain are damaged

PET scans

Use radioactive chemicals to measure activity in different parts of the brain.

MRI scans

Use magnetic fields to produce detailed brain structure images

Neurones

Nerve cells that carry electrical impulses from one part of the body to another.

Synapse

A gap in between 2 neurons, passes chemicals between them

Sensory neurones

Carry messages from the receptors like the skin to the CNS

Motor neurons

Carry instructions from the CNS to effectors like muscles or glands

Effectors

Respond by predicting a response like muscles contracting or glands releasing hormones

Reflex arc

How the body acts quickly without thinking. An automatic response to a stimulus to keep you safe.

sympathetic nervous system

prepares the body for exciting and stressful situations. for example eyes dilating, sweating to cool down

parasympathetic nervous system

slows the activity of the heart and respiratory system to restore itself when not in stressful situations.

adrenaline and noradrenaline

involved in the control of sleep, mood and concentration.

acetylcholine

involved in memory and cognition

dopamine

involved in motor control (how we move)

serotonin

involved in the control of sleep and mood, provides the feeling of being happy

GABA

helps the brain to calm down by reducing the signals between neurones.

blood brain barrier

semi permeable membrane that protects the brain from harmful substances in the bloodstream.

parkinson’s disease

a progressive neurological disorder affecting movement. caused by destruction of the dopamine neurons

symptoms of parkinson’s

slowness of movements

muscle tremor

poor balance

stiffness

levodopa

passes through the blood brain barrier where is it broken into dopamine

how does levodopa work

reduces dopamine in the brain. stimulating he dopamine receptors to make more dopamine.

what are the side effects of levodopa

involuntary movements

impulsive and compulsive behaviours.

nausea, loss of appetite, anxiety

advice for patients taking levodopa

warn about the risk of impulsive behaviours.

levodopa can cause sleepiness, driving is dangerous.

don’t stop taking suddenly

how do dopamine agonists work

stimulate the dopamine receptors, mimicking the action of dopamine.

Multiple Sclerosis (MS)

neurological condition cause by damage to the nervous system in the spine and brain.

Myalgic encephalomyelitis (chronic fatigue syndrome)

extreme fatigue ranging from excessive tiredness to joint pain and headaches

huntingtons disease

inherited disease which happens due to the deterioration of brain tissue. it has no cure and is a progressive disease

symptoms of huntingtons disease

difficultly concentrating, memory lapses and change in persona

motor neurone disease

affects the motor neurones in the brain and spinal cords which are responsible for the body’s voluntary movement

dementia

a progressive syndrome where the brain function deteriorates overtime

acetylcholine

a neuro transmitter that helps neurones to communicate

acetycholinesterase

an enzyme that breaks acetylcholine into acetic acid and choline

acetylcholine inhibitors

stimulate the receptors to produce more acetylcholine

glutamate

a neurotransmitter that is involved in learning and memory

what does memantine do

blocks the glutamate receptor lowering glutamate levels to avoid them becoming too toxic

panic disorder

feelings of anxiety and stress regularly and at any time. Often no apparent reason.

phobias

an overwhelming fear of an object, place, situation, feeling or animal.

PTSD

caused by stressful frightening events that’s can develop straight after or years after it happening.

social anxiety disorder.

when people worry about social situations such as meeting strangers, group activities or going shopping.

generalised anxiety disorder

long term condition that causes people to feel anxious about a wide range of situations and issues.

physical symptoms of anxiety.

shaking, palpitations, stomach pains, headaches, poor sleep, tiredness

psychological symptoms of anxiety

become withdrawn, feeling on edge, feeling worried, irritated

what are some non drug treatments of anxiety

relaxing activities, exercise, avoiding smoking and alchohol, therapies

how do SSRI’s work

inhibit the serotonin reuptake helping to improve mood. they can take upto weeks to work.

how do SNRI’s work

inhibit serotonin and noradrenaline reuptake to improve mood.

how does pregabalin treat anxiety

it is used when other drugs have failed to treat anxiety. it works like the neurotransmitter GABA to calm down the brain.

depression

a chemical imbalance in the brain where there is an insufficient amount of serotonin, dopamine and noradrenaline

what are the risk factors of developing depression

genetics, giving birth (post natal), loneliness, long term illness, alcohol and drugs, stressful life events

psychological symptoms of depression

low mood and sadness, feeling tearful, low self esteem, being irritable, no motivation, feeling anxious, having thoughts of harming yourself

physical symptoms of depression

moving and speaking slowly, changes in weight and appetite, constipation, lack of energy, changes to menstrual cycle and disturbed sleep

non drug treatments for depression

exercise, talking with people, CBT

SSRIs (selective serotonin reuptake inhibitors)

they inhibit serotonin reuptake at nerve junctions increase the concentration of it in the brain. examples could be sertraline, citalopram

SNRIs (selective noradrenaline reuptake inhibitors)

inhibit both serotonin and noradrenaline reuptake at nerve junctions increasing the concentration in the brain. examples are venlafaxine

tricyclic antidepressant (TCAs)

block the uptake of serotonin and noradrenaline, increasing the amount of them in the brain. examples could be amytriptyline and trazadone

Mirtazepine

increases the release of noradrenaline and serotonin

insomnia

when someone has problems sleeping.

causes of insomnia

stress and anxiety, depression, noise or light, being uncomfortable, alcohol or caffeine.

when should drugs be used to treat insomnia

once sleep hygiene measures have been tried to reduce the risk of addiction and tolerance build up

when should SSRIs be taken

in the morning because it may cause issues with sleeping

drugs used for drowsiness

sedating antihistamines (promethazine),Zdrugs (zopiclone) melatonin,diazepam, lorazepam