Nervous System Part 1 Flashcards
Complete the following:
The nervous system is a —— of fibres which span the body co-ordinating a diverse range and voluntary and —— actions. It transmits ——between parts of the body. It responds rapidly to changes within the internal and external ——. It works alongside the —— system to maintain ——.
The nervous system is a NETWORK of fibres which span the body co-ordinating a diverse range and voluntary and INVOLUNTARY actions. It transmits SIGNALS between parts of the body. It responds rapidly to changes within the internal and external ENVIRONMENT. It works alongside the ENDOCRINE system to maintain HOMEOSTASIS.
Describe the difference between the central nervous system and the peripheral nervous system.
- CNS refers to the nervous tissue in brain and spinal chord
- PNS refers to any nervous tissue not in the CNS
Describe the role of the somatic nervous system.
The Somatic Nervous system is the voluntary system of the PNS.
- It transmits sensory information from the head/limbs etc to the CNS
- it transmits motor signals to skeletal muscles only
With regards to neuron function, complete the following table:
Function»_space;»> Neuron:
Processes sensory information, analyses, stores and makes decisions:
Detects internal and external environmental changes:
Produces a response to sensory information to effect change:
Function»_space;»> Neuron:
Processes sensory information, analyses, stores and makes decisions»_space;»> Integration
Detects internal and external environmental changes»_space;»> Sensory
Produces a response to sensory information to effect change»_space;»> Motor
State which nervous system controls:
a. Voluntary movements
b. Involuntary movements
a. Voluntary movements – Somatic Nervous System
b. Involuntary movements – Autonomic Nervous system
With regards to the effects of the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS), complete the following table:
Location »_space;»> Sympathetic effect »_space;»> Parasympathetic effect:
Pupil:
Liver:
Heart:
Lungs:
Gastrointestinal tract:
Adrenal Glands:
Sympathetic effect VS Parasympathetic effect:
Pupil:
Dilation VS Contraction
Liver:
Conversion of glycogen to glucose VS Glycogen synthesis
Heart:
Heart rate and blood pressure increased VS. Heart rate and blood pressure decreased
Lungs: Bronchodilation. VS Bronchoconstriction
Gastrointestinal tract:
Reduced motility and secretions VS Increased motility and secretions
Adrenal glands:
Release adrenaline Vs No involvement
Name the specific body location of the following:
a. Sympathetic nervous system
b. Parasympathetic nervous system
a. Sympathetic nervous system – Thoraco-lumbar
b. Parasympathetic nervous system – Cranio-sacral
Explain how the enteric nervous system is linked to the CNS.
The enteric nervous system is the nervous system of the gut. It is linked with the CNS via the sympathetic and parasympathetic nerve fibres
Describe the role of the following in the enteric nervous system:
a. Sensory neurons
b. Motor neurons
c. Interneurons
a. Sensory neurons – Monitor chemical changes (via chemo receptors) in the GI tracts and stretching (via stretch receptors) of its walls.
b. Motor neurons – govern motility and secretions of the GIT and associated glands
c. Interneurons – Connect the two plexus – myenteric and submucosal
Draw and label a neuron:
a. Axon
b. Dendrites
c. Cell body
d. Nodes of Ranvier
e. Myelin sheath
f. Terminal endings
Define the following terms:
a. Action potential
b. Nerve stimulus
c. Nuclei
d. Ganglia
e. Tracts vs Nerves
a. Action potential – The electrical current that runs along the axon
b. Nerve stimulus – anything able to generate an action potential
c. Nuclei – cell bodies that cluster together in the CNS
d. Ganglia - cell bodies that cluster together in the PNS
e. Tracts Vs Nerves
Axon bundles are called tracts in the CNS and nerves in the PNS
Describe the main role of dendrites.
Branches coming off the neuron. They are the receiving portion of the cell and they communicate with other neurons and dendrites.
Can axons regenerate? Explain.
Axons can repair but only at the rate of 1-2 mm per day and it does depend on the health of the overall tissue and surrounding cells as to whether they can facilitate healing
Describe TWO roles of the myelin sheath.
Electrically insulates the axon
Increases speed of signal transmission
State which vitamin is required as a co-factor in myelin production?
B12
Describe ONE key difference between ‘grey matter’ and ‘white matter’.
In the CNS …
Grey:
* The appearance of tissue in certain areas of the CNS.
* It is composed of lots of cell bodies and also contains dendrites and unmyelinated axons.
White:
* It appears that way because of the myelin sheath.
* When we talk about white matter we are talking about myelinated axons.
Fill in the diagram
Describe THREE key differences between ‘neurons’ and ‘neuroglial cells’.
Neuron Vs Glial
Can relay an electrical signal Vs Cannot relay an electrical signal
Cannot divide. Set at birth. V Can divide and multiply
Bigger Vs Smaller
A lot less of them Vs 50 x more prevalent
List TWO key functions of neuroglial cells.
- The glue that surrounds neurons and keep them in place
- Supply nutrients and oxygen to neurons
- Destroy pathogens and remove dead neurons
- Fill in the gaps left by damaged neurons
To answer this question fully, think about the functions of all 6 glial cells
Match the nervous system CNS or PNS to the neuroglial cell:
a. Schwann cell
b. Astrocytes
c. Microglia
d. Ependymal cells
e. Satellite cells
f. Oligodendrocytes
a. Schwann cell - PNS
b. Astrocytes - CNS
c. Microglia - CNS
d. Ependymal cells -CNS
e. Satellite cells - PNS
f. Oligodendrocytes - CNS
What do each of these glial cells do and where are they located?
a. Astrocytes
b. Microglia
c. Satellite Cells
d. Oligodendrocytes
e. Epindymal cells
f. Schwann Cells
a. Astrocytes
Contributes to the blood brain barrier and physically support neurons by wrapping around them holding them to their blood supply
b. Microglia
Is phagocytic mopping up damage in the brain and is mobile in the brain -
c. Satellite Cells
Provides structural support in PNS ganglia and exchange substances in the nervous system
d. Oligodendrocytes
Myelinates axons in the CNS
e. Epindymal cells
Produces cerebrospinal fluid
f. Schwann Cells
Myelinates axons in the PNS
Name the neuroglial cell that:
a. Contributes to the blood brain barrier and physically support neurons by wrapping around them holding them to their blood supply -
b. Is phagocytic mopping up damage in the brain and is mobile in the brain
c. Provides structural support in PNS ganglia and exchange substances in the nervous system
d. Myelinates axons in the CNS
e. Produces cerebrospinal fluid
f. Myelinates axons in the PNS
a. Contributes to the blood brain barrier and physically support neurons by wrapping around them holding them to their blood supply - Astrocytes
b. Is phagocytic mopping up damage in the brain and is mobile in the brain - Microglia
c. Provides structural support in PNS ganglia and exchange substances in the nervous system – Satellite Cells
d. Myelinates axons in the CNS - Oligodendrocytes
e. Produces cerebrospinal fluid – Epindymal cells
f. Myelinates axons in the PNS – Schwann Cells
Describe the function of these neuroglial cells in the PNS:
Satellite Cells
Schwann Cells
Satellite Cells
* Provides structural support in PNS ganglia
* Exchange substances in the nervous system
Schwann Cells
* Myelinates axons in the PNS
Describe the function of these neuroglial cells in the CNS:
Astrocytes
Microglia
Oligodendrocytes
Ependymal cells
Astrocytes
* Contributes to the blood brain barrier
* physically support neurons by wrapping around them holding them to their blood supply -
Microglia
* Phagocytic mopping up damage in the brain
* Mobile in the brain
Oligodendrocytes
* Myelinates axons in the CNS
Ependymal cells
* Produces cerebrospinal fluid
What is a ‘graded potential’ and ‘action potential’.
They are both types of electrical signal in a neuron
A graded potential is any electrical impulse that travels around the cell body and dendrites of a neuron.
An action potential is any electrical impulse that travels down the axon.
Name TWO characteristics that facilitate graded and action potentials.
Specific ion channels can open and close when stimulated.
Electrical differences across the cell membrane (resting potential),
Name TWO stimuli that trigger ion channels.
Ion channels are transmembrane proteins.
Na+ and K+ channels are the really important ones.
Stimuli that trigger ion channels:
- changes in voltage
- chemicals (hormones)
- mechanical pressure
Complete the following:
Neurons at rest possess an —– gradient across the cell membrane. This is created by the build-up of —– ions on the inside of the cell membrane relative to the extracellular fluid which contains more —– ions The separation of charges create —– energy. The resting potential is approximately -70mV. Cells exhibiting a membrane potential are said to be —– or charged.
Neurons at rest possess an ELECTROCHEMICAL gradient across the cell membrane. This is created by the build-up of NEGATIVE ions on the inside of the cell membrane relative to the extracellular fluid which contains more POSITIVE ions The separation of charges create POTENTIAL energy. The resting potential is approximately -70mV. Cells exhibiting a membrane potential are said to be POLARISED or charged.
Describe in detail the resting potential (think sodium, chloride, potassium, proteins and the sodium-potassium pump).
Inside the neuron in the intracellular fluid we will find an accumulation of
- potassium ions (K+) and also,
- large negatively charged protein molecules that cannot leave the cell.
Overall it carries a negative charge
Outside and around the neuron in the extracellular fluid we find an accumulation of sodium ions (Na +) and Chloride ions (Cl-). Overall it carries a positive charge.
Therefore we have more positivity outside than we do inside. The inside is negatively charged compared to the outside. This creates a very specific charge in our neurons. In an axon that is at rest and not carrying an electrical signal, the charge in that Neuron will be - 70mV. That is the separation of charge between the inside and the outside.
We call this disparity between the inside and the outside, this build up of negative ions on the inside of the cell membrane, relative to the extracellular fluid which contains more positive ions, the resting potential.
Why don’t things even up in the concentration gradient through passive transport? Normally it would but in this case as the NA+ as CL- try to move back to equalise the charge, the separation of charges is maintained by the sodium-potassium pump which pumps 3 Na+ out for every 2 K+ it pumps back in (using ATP).
What are the two phases of the action potential?
- Depolarisation
- Repolarisation
Describe in detail all steps in the following processes:
a. Depolarisation
b. Repolarisation
a. Depolarisation
Depolarisation is when a positive charge builds up inside the cell - the negative membrane potential (-70mV) becomes positive and reaches +30mV.
Step 1: Depolarisation is triggered by stimulation of a nerve ending.
Step 2: That stimulation must reach a threshold value -55mV in order to generate an action potential.
Step 3: Na+ channels open allowing Na+ to flood into the cell up to about +30mV
Step 4: A positive charge builds up inside the cell
b. Repolarisation
Repolarisation is where we get the restoration of the membrane potential to -70mV.
To do this potassium channels now open but much more slowly than Na+ channels. The result is that Na+ channels just start to close as K+ channels open.
K+ can flood out of the cell restoring the membrane potential to -70mV
- Explain what is meant by the:
a. Refractory period
b. Absolute refractory period
c. Relative refractory period
a. Refractory period
The time after depolarization and repolarization where we can’t generate another action potential.
The reason we can’t generate another action potential is because ions (Na+ and K+) are on the wrong side of the membrane and the charge is all over the place.
b. Absolute refractory period
Even a really strong stimulus would not be able to generate an action potential because the ions are in the wrong place.
c. Relative refractory period
The time when you could generate another action potential but the stimulus would have to be bigger than the original stimulus.
Describe the difference between continuous conduction and saltatory conduction under the following headings:
Myelination
Depolarisation
Speed
Energy efficiency
ContinuousVS Saltatory
Myelination: Unmyelinated VS myelinated
Depolarisation: Step-by-step VS Leaps
Speed: Slower VS Faster
Energy efficiency: Less VS more
Describe the role of the Nodes of Ranvier.
At the nodes of Ranvier, there are high concentrations of Na+ gates. This causes the current to appear to jump from node to node (saltatory conduction).
Explain why ‘ice’ is applied to an injury.
Cold slows down action potentials. Ice pain signal’s are relayed more slowly.
Describe in detail how the ‘synapse’ transmits a signal.
Synapse receives the depolarising wave and we get sodium channels opening and sodium entering the axon again and again.
This causes calcium channels to open and we get the influx of calcium into the synaptic bulb.
Sodium in in droves…then calcium …
When calcium ions are in large quantities in that synaptic end bulb, they cause the synaptic vessels which store the neurotransmitter to break down and that process of break down is known as exocytosis.
Neurotransmitters are released into the synaptic cleft.
The released neurotransmitters diffuse across this gap (the synaptic cleft) and bind to receptors on the post synaptic neuron.
This causes something to happen in the next neuron depending on whether it is excitatory (continues) or inhibitory (stops) .
Which category do the following neurotransmitters belong to?
a. GABA
b. Dopamine
c. Acetylcholine
d. Serotonin
a. GABA – Amino Acid
b. Dopamine - Monoamine
c. Acetylcholine – Unique molecule
d. Serotonin - Monoamine
Explain TWO differences between ‘excitatory’ and ‘inhibitory’ transmitters.
Name TWO ways in which neurotransmitters are inactivated following a nerve impulse.
Between impulses the transmitter molecules are rapidly removed from the synaptic cleft to prevent continuous stimulation of postsynaptic neurons.
There are two types of removal:
Re-uptake – the neurotransmitter is reabsorbed back into the presynaptic neuron and restored inside a vesicle ready to be used again.
Enzyme degradation – neurotransmitter is broken down by an enzyme (such as MAO) into smaller inactive product which are then reabsorbed by the presynaptic neuron and resynthesised into active neurotransmitter.
Name the amino acid precursor of glutamate.
Glutamine
Indicate if GABA is a major inhibitory or excitatory neurotransmitter.
Inhibitory
GABA is an inhibitory neurotransmitter. It lessens a nerve cell’s ability to receive, create or send chemical messages to other nerve cells.
GABA is known for producing a calming effect.
Name ONE vitamin needed for conversion of glutamate to GABA.
B6
Name the amino acid precursor of:
a. Serotonin
b. Dopamine
a. Serotonin - Tryptophan
b. Dopamine - Tyrosine
Describe serotonin’s role in the gastrointestinal tract.
It is needed to encourage intestinal motility (peristalsis) and epithelial cell secretion.
Name TWO functions (not GI tract) of serotonin.
Sleep regulation
Pain
Attention
Learning and memory
Thermoregulation
GIT intestinal motility
State the location in the brain where most dopamine is stored.
It is particularly abundant in the substantia nigra.
List TWO functions of dopamine.
Movement - Patients with Parkinson have a lack of dopamine in the substantia nigra
Reward mechanisms – Dopamine released with sugar, alcohol, cocaine
Regulating muscle tone
Cognition and emotion
List ONE function of acetylcholine.
Muscle contractions
Cognition – Embedding and recalling memory. 90% of Alzheimer’s patients are deficient in ACH
Name TWO natural body analgesics
Endorphins are hormones that are released when your body feels pain or stress.
They are produced in your brain and act as messengers in your body.
Help to
* improve mood.
* relieve pain
* reduce stress
Endorphins can be boosted by exercising, eating, having sex, getting a massage and many other ways.
Endorphins
Dynorphins
Enkephalins
List ONE neuropeptide that enhances pain.
Substance P
List TWO neurotransmitters broken down by MAO.
Serotonin.
Adrenaline.
Noradrenaline.
Dopamine.
List TWO neurotransmitters broken down by COMT.
Adrenaline.
Noradrenaline.
Dopamine.
Explain what is meant by a synapse
A junction between two neurons or a neuron and a muscle
Where is most serotonin found
In the GIT - 95% of it
Describe TWO signs / symptoms of an injured spinal nerve.
Tingling; Numbness; pain»_space;> in the associated distribution
Describe the main role of spinal nerves.
They carry impulses to and from the spinal cord
Why is the power of a neuron to regenerate based on its location
PNS fibres can regenerate but only if
1. the cell body is intact because that is where the nucleus would be. The nucleus is needed to code for the newly produced axon.
2. Schwann Cells are present
CNS nerve fibres do not retain the capacity to undergo division/regenerate
However….If a patient was to damage an area of tissue within the CNS we can sometimes get neuroplasticity. We adapt and create new pathways
Describe how the signs / symptoms develop in carpal tunnel syndrome (CTS).
The carpal tunnel is a narrow passageway in the anterior wrist that contains tendons and the median nerve.
This median nerve provides sensory information to the hand and controls movements in the hand and fingers
The median nerve becomes compressed in the wrist and hand carpal tunnel syndrome.
List TWO pathologies that can cause Carpal tunnel syndrome (CTS)
Pathologies - RA, Hypothyroidism, acromegaly
Also – fluid retention due to pregnancy, overuse, posture, using vibrating tools
State TWO signs / symptoms of carpal Tunnel Syndtome - CTS.
- Tingling, numbness or pain in the median nerve distribution.
- Symptoms are often worse at night
- Weakness of grip and weak thumb opposition
List ONE test used to diagnose CTS.
Two tests that will reproduce carpal tunnel syndromes if the median nerve is at play:
Tinel’s test (tapping on the median nerve) depolarises the median nerve. If there is damage, by tapping this it will create symptoms very quickly
Phalen’s test - also reproduces symptoms
Define Bell’s palsy.
The nerve that controls the facial muscles (facial nerve) becomes inflamed or compressed.
List ONE viral cause of Bell’s palsy.
Herpes simplex
Name TWO characteristic signs / symptoms of Bell’s palsy.
- Sudden unilateral weakness or paralysis of the facial muscles.
- Sometimes cannot close eye on affected side
- Loss of taste and intolerance to loud noise if severe
Name the pathological feature common to Guillain Barre Syndrome (GBS) and multiple sclerosis.
Both autoimmune and both interfere with laying down of myelin on axons
Using definitions compare Guillain barre syndrome and multiple sclerosis.
Guillain-Barre is a form of post-infectious de- myelinating disease with neuritis. It is associated with acute, ascending, progressive inflammation and demyelination of peripheral nerves.
MS is autoimmune inflammatory disease causing demyelination of axons in CNS neurons with damage. T-Lymphocytes attack myelin antigens. Multiple areas of sclerosis (scar tissue) along axons disrupt conduction.
MS and GBS are both auto immune and both inflammatory and both demyelinating. MS is in the CNS and GBS in the PNS.
List ONE viral cause of Guillain barre syndrome (GBS)
Epstein-Barr
in 75% of cases it is autoimmune after an infection like Epstein-Barr
Describe what is meant by ‘molecular mimicry’ in GBS.
In 75% of cases GBS is triggered by a recent infection (one–three weeks after respiratory / GIT infection or post-vaccination e.g., flu / EBV).
Molecular Mimicry is where antibodies formed against virus cross react with lipids in myelin.
Name TWO signs / symptoms of GBS.
Guillain–Barré syndrome ( GBS) is a rapid-onset muscle weakness caused by the immune system damaging the peripheral nervous system.
- Sudden, progressive, bilateral ascending paralysis.
- Paraesthesia (pins and needles)and sensory changes.
- Neuropathic pain into legs.
Describe the pathophysiology of multiple sclerosis.
It is an autoimmune, inflammatory and demyelinating disease in the CNS
T lymphocytes attack myelin antigens on the CNS,
* leading to multiple areas of sclerosis (hardening/scar tissue) along axons,
* leading to disruptions in conduction
* leading to multiple systems including vision issues, deafness and loss of balance, burning and pulling sensations, tingling and loss of sensation, cognitive changes and depression, weakness, bladder urgency and incontinence
Describe the main pattern of multiple sclerosis.
Relapsing – Remitting: Most MS follows a relapsing-remitting pattern (85%) where the disease goes from relapse to remission to relapse etc
Primary – Progressive: Serious from the start and progress from the start. Poor prognosis
Secondary – Progressive: When it starts as relapsing-remitting and as the disease progresses it becomes progressive
Explain how the following vitamins can contribute to multiple sclerosis
Vitamin D
Vitamin B12
Vitamin D
Low Vit D is one of the biggest risk factors for MS. Oligodendrocytes need it to produce myelin.
* Correlation between Vit D deficiency/proximity to the equator and MS
* Correlation with other countries that also are known to have Vit D deficiency, for example because they apply a lot of sunscreen or cover skin for religious reasons Eg: Australia and Saudi Arabia
Vitamin B12
B12 normally acts as a co-factor in myelin formation and also has immunomodulatory effects.
List ONE viral trigger of multiple sclerosis.
Epstein-Barr
Name the diagnostic tool which can be used to view optic nerve demyelination in multiple sclerosis.
MRI Opthalmoscopy
List FOUR signs / symptoms of multiple sclerosis.
Working down the body …
- Cognitive changes and depression.
- Visual symptoms are common: Blindness, loss of vision of one eye and occasional pain (neuritis). Double vision and nystagmus (jerking of eyeball).
- Deafness and loss of balance.
- Bladder urgency and incontinence.
More general symptoms
1. Paraesthesia
- Burning, pulling sensations.
- Tingling and loss of sensation.
- Weakness
Define motor neurone disease (MND).
The progressive degeneration of motor neurons in the spinal cord, motor cortex and brain stem.
MOTOR not sensory therefore no sensory symptoms like tingling/numbness but motor symptoms like paralysis and weakness.
Discuss ONE suggested pathophysiology for MND.
The current hypotheses focus on abnormal mitochondrial function causing oxidative stress in motor neurons.
Genetics is also implicated
List TWO characteristic signs / symptoms of MND.
- Typically presents as weakness in upper limbs - dropping objects or difficulty manipulating objects.
- Wasting of hand muscles and tremor of limbs at rest.
- Later stages can affect the legs (tripping), cause slurred speech, dyspnoea and dysphagia.
- Death by respiratory failure — typically within 3–5 yrs
Describe the difference between dementia due to:
a. Alzheimer’s disease (AZ)
b. Vascular dementia
a. Alzheimer’s disease (AZ)
50% of dementia diagnosis. Associated with
* Degeneration of the cerebral cortex
* Reduced acetylcholine production
* Deposition of Protein Plaques called beta amyloid plaques
b. Vascular dementia
25% of dementia diagnosis
* Associated with cardio vascular disease and poor oxygen delivery
* Often associated with stroke or multiple strokes cutting off circulation in aregion of the brain
* Parkinson’s disease.
Describe in detail the pathophysiology of Alzheimers
Alzheimer’s is a neurodegenerative disease of the cerebral cortex.
The hippocampus is among the areas first affected. It is where we store memories. As the hippocampus degenerates we lose the ability to recall these memories. Typically, more short term memories.
Later as the disease progresses it spreads to the amygdala which is the area of the brain that is active when we are dealing with emotions and longer term memories.
Whilst progressing, additional regions of brain become affected.
Associated with Beta Amyloid plaques, atrophy of neurons and less acetycholine.
Beta amyloid plaques are the key diagnostic feature of alzheimers.
Name the areas of the brain affected by:
a. Earlier stages of AZ
b. Later stages of AZ
a. Earlier stages of AZ
Hippocampus
b. Later stages of AZ
Amygdala
Explain how the following factors could contribute to AZ:
a. Homocysteine
b. Stress
c. Hormones defieicieny
d. Heavy metals
e. Chronic inflammation
a. Homocysteine
* The Amino acid homocysteine needs to be converted to methionine. This conversion needs B6/9/12 vitamins and thus we accumulate more homocysteine because it isn’t converted
* High increases risk.
* Facilitate a build-up of toxic β-amyloid and tau in the brain
b. Stress
* Higher cortisol levels linked to memory issues
c. Hormones defiicieny increases risk of cognitive impairment
- Oestrogen deficiency can make post menopausal women more prone to learning and memory problems.
- Testosterone deficiency in men as it has a neuroprotective effect.
- Thyroid hormone deficiency linked to an increased risk of cognitive impairment.
d. Heavy metals
Thought to degenerate the blood brain barrier and allow some of the other substances to enter through.
* Excessive levels of copper (sml qty is beneficial)
* Mercury.
* Aluminium toxicity (e.g. from vaccines, cans, foil, antiperspirants etc.).
e. Chronic inflammation
- Such as sugar (and insulin resistance), dairy, gluten.
- Leaky gut (promoting inflammation).Gluten is implicated here.
Identify which gene is associated with AZ.
ApoE4 gene
Name TWO nutritional deficiencies associated with AZ.
B1, B3, B6, B12, folate, omega-3 fatty acids.
Name ONE micro-organism that may contribute to AZ.
a. Oral bacteria such as P. gingivalis have been identified in tissue biopsies.
b. Herpes simplex virus.
List TWO signs / symptoms associated with:
a. Early stages of AZ
b. Later stages of AZ
a. Early stages of AZ
Hippocamous Stage
* Slight memory loss (especially short-term) i.e., forgetting recent conversations.
* Repeated questions and confusion.
* Decreased initiative (↓hobbies, ↓hygiene)
b. Later stages of AZ
Amygdala Stage
* Significant memory loss (incl. long-term memory).
* Subtle changes in higher order functions i.e. understand jokes.
* Mood disturbances: agitation and aggression.
* ‘Loss of sense of self’ — autobiography (left hippocampus).
* Difficulty with language, unsteady, depression.
Using pathophysiology, compare Parkinson’s disease with Alzheimer’s disease.
Parkinsons is a progressive neurological movement disorder affecting movement caused by degeneration of dopamine producing neurons in the area of the brain called the substantia nigra located in the mid brain. It leads to an accumulation of abnormal protein plaques (Lewy bodies) within neurons.
Alzheimers is also a neurodegenerative disease but it is of the cerebral cortex staring at the hippocampus and moving to the amygdla. It affects memory and emotion. It only affects movement in later stages but this is due to loss of memory. It leads to a build of beta amylin plaque.
List TWO causes of Parkinson’s disease.
- Mitochondrial dysfunction (oxidative stress).
*Genetics. - Constipation and diet low in polyunsaturated fats.
- Toxic environmental factors:
i.e.carbon monoxide, manganese poisoning, exposure to pesticides and herbicides.
List THREE characteristic signs / symptoms of Parkinson’s disease.
- Bradykinesia: Short, shuffling steps (difficulty stopping / starting)
- Resting tremor (‘pill rolling’).
- Stooped / flexed posture/ arms at side
- Lack of normal subconscious movements (swinging arms).
- Muscle rigidity, mask-like face
- Low/deep voice.
What is Huntington’s Disease?
- Genetic disease with a defect on chromosome 4
- An inherited neurodegenerative disorder affecting the basal ganglia
- Results in loss of muscle coordination (chorea), cognitive impairment and poor regulation of mood and emotions.
Note: The basal ganglia are located in the brain stem, thalamus, and cerebral cortex areas of the brain. This group of structures is important in regulating voluntary movements.
What is the nerve involved in carpal tunnel syndrome
Median Nerve
What is the nerve implicated in Bell’s palsy
Facial nerve
At what age are individuals typically affected by
A. Multiple Sclerosis
B. Motor neuron disease
A. Multiple sclerosis – 20 to 50
B. Motor neuron disease – 50 - 70
State three suspected causes/risk factors of Alzheimer’s
Heavy metals
Chronic inflammation – gluten, dairy, sugar
Bacteria like gingivitis
High homocysteine levels
High cortisol levels
lots of free radicals
lots of atherosclerosis/cardiovascular disease
Genetics
Name the part of the brain affected by Parkinson’s disease
Substantia Nigra
Name 8 neurotransmitters of the nervous system
Glutamate
GABA
Seratonin
Dopamine
Adrenaline and noradrenaline
Acetylcholine
Nitric Oxide
For the neurotransmitter glutamate… answer the following:
Primary mode of action
Location it works in
Derived from what amino acid
Role
Glutamate is the most abundant excitatory neurotransmitter released by nerve cells in your brain. It plays a major role in learning and memory. For your brain to function properly, glutamate needs to be present in the right concentration in the right places at the right time. Too much glutamate is associated with such diseases as Parkinson’s disease, Alzheimer’s disease and Huntington’s disease.
Primary mode of action: Excitatory
Location it works in - CNS
Derived from what amino acid - Glutamine
Role - Memory, learning
For the neurotransmitter GABA… answer the following:
Primary mode of action
Location it works in
Derived from what amino acid
Role
Primary mode of action - Inhibitory
Location it works in - Brain
Derived from what amino acid - Glutamate together is vitamin B6 dependent
Role - Prevents neural overactivity
For the neurotransmitter serotonin… answer the following:
Primary mode of action
Location it works in
Derived from what amino acid
Role
Primary mode of action - Inhibitory
Location it works in - 95% enteric nervous system and 5% CNS
Derived from what amino acid - Tryptophan
Role -
Sleep
Attention
Intestinal mobility and secretions
Pain regulation
For the neurotransmitter dopamine … answer the following:
Primary mode of action
Location it works in
Derived from what amino acid
Role
Primary mode of action: inhibitory
Location it works in: Brain - Substantia Nigra
Derived from what amino acid: Tyrosine
Role:
Reward
Cognition
Movement
Muscle tone
For the neurotransmitters Adrenaline and Noradrenaline… answer the following:
Primary mode of action
Location it works in
Derived from what amino acid
Role
Primary mode of action: Excitatory
Location it works in:
Sympathetic nervous system; Brain - motor Neurons
Derived from what amino acid: Tyrosine
Role: mobilise body and brain to take action when danger
For the neurotransmitter acetylcholine… answer the following:
Primary mode of action
Location it works in
Derived from what amino acid
Role
Primary mode of action: Excitatory
Location it works in:
Parasympathetic nervous system
CNS
motor neuron junction
Derived from what amino acid - N/A
Role:
Muscle contraction
cognition
For the neurotransmitter Nitric Oxide… answer the following:
Primary mode of action
Location it works in
Derived from what amino acid
Role
Primary mode of action:
Excitatory
Location it works in:
Smooth muscle
Derived from what amino acid:
Arginine
Role: vasodilation
What are the causes of Multiple Sclerosis
Autoimmune
Genetics
Vitamin D and vitamin B 12 deficiency
Name the key differences between a graded potential and an action potential
Graded potentials are changes in membrane potential that vary according to the size of the stimulus, as opposed to being all-or-none
Graded Potential:
* for short distance, communication
* occurs in dendrites and cell body
* No threshold
* Longer duration
Action potential:
* for long-distance communication
* Occurs along the axon
* All or nothing – has a threshold
* Shorter duration
