Botox! (and plastic surgery)
• Botox!
• Used to paralyze muscles in the face to prevent wrinkles from showing
• Unfortunately botox is short for botulinum toxin
• Produced by bacteria Clostridium botulinum
• The most deadly toxin known
• It would take about 0.000001 grams of this toxin to kill you if you breath it in
• Despite paralysis of muscles, botox actually directly affects the nervous system.
Nervous System.
The nervous system has several divisions Central Nervous System (CNS)
Consists of brain and spinal cord.
Peripheral Nervous System (PNS) Nerves and Ganglia outside the central
nervous system
The nervous system is made up of neurons and associated cells
Neurons
Many types of neurons but most have the same basic features
Cell body Contains nucleus and cell organelles
Dendrites Receive signals from other neurons
Axon Sends signals to other neurons or to muscles
Axon terminals
Axon Terminal Branch out from axon ending in synaptic
end bulbs
Synaptic end bulbs allow transfer of electrical or chemical impulses from nerve cells to other nerve cells or muscles
Signals can either excite muscles to contract, or inhibit to contract.
Botulism
Botulinum toxin works by blocking release of neurotransmitters at neuromuscular junctions (where nerve meets muscle cell)
This permanently prevents the muscle from contracting The toxin binds permanently to the synaptic end bulb
It can take months to years to recover from the toxin
Neurons firing
http://www.dailymail.co.uk/sciencetech/article-2581184/The-dynamic-mind-Stunning-3D-glass-brain-shows-neurons-firing-real-time.html
https://www.youtube.com/watch?v=C4Gt322-XxI
CNS (Central Nervous System)
The Brain is divided into several different areas The largest part of the brain is called the cerebrum Externally the cerebrum is divided into:
Frontal Lobe
Parietal Lobe
Occipital Lobe
Temporal Lobe
Cerebellum
Internally there are several other structures including: Thalamus
Problems with speech
Wernike’s and Broca’s areas
Wernike’s aphasia Fluent speech but not comprehensible Often people with Wernike’s aphasia don’t know they can’t be understood https://www.youtube.com/watch?v=B-LD5jzXpLE
Broca’s aphasia Broken speech but comprehensible https://www.youtube.com/watch?v=kOqtIrwyLbw
Parietal lobe
Sensations related to touch Pain Temperature Pressure
These sensations are received in the parietal lobe and interpreted.
Occipital lobe
Vision Interprets signals from the eyes Optic nerves cross over and images
on the left are interpreted by the right brain and vice versa
Cerebellum
Cerebellum Coordination of fine motor
movements
Balance and posture.
Looks kind of like cauliflower
https://www.youtube.com/watch?v=5eBwn22Bnio
Thalamus
Thalamus Responsible for sleep regulation Relay centre for motor and sensory
signals Signals are routed through the
thalamus to appropriate areas in the brain or the body
Cranial Nerves
12 cranial nerves Control of muscles in the face and
neck area Receive input from sensory organs
Vagus nerve Sensory and motor functions of many
vital body functions including:
Heartbeat, breathing, swallowing, digestion.
How does the brain work?
Good question!
https://www.youtube.com/watch?v=BKVv6v-Hd0A
https://www.youtube.com/watch?v=cbqjxmTNivQ
Cerebrovascular accident (stroke)
50,000 strokes in Canada every year 3rd leading cause of death Occurs when blood-flow to the brain is interrupted
Two kinds of stroke: Ischemic stroke – due to blockage of an artery Hemorrhagic stroke – bleeding into the brain
Stroke signs and symptoms
Numbness in the face or extremities, typically on one side only Face may droop
Slurred speech Blurred vision Sudden headache Loss of coordination
Stroke Diagnosis
Physical exam looking for the symptoms of stroke
Listen to the carotid arteries with a stethoscope Checks to see if there is reduced blood-flow
CT scan will likely be ordered This allows the doctor to see bleeding or damage done to brain cells
CT scans can also look at large blood vessels of the brain to look for blockage
MRI May be used in conjunction with CT scan
Stroke Diagnosis
Blood tests Low blood glucose can give similar symptoms Blood clotting factors may be looked at
Electrocardiogram Looks at electrical activity of the heart Looks for heart problems that may have lead to stroke
Carotid angiograph Allows imaging of the carotid arteries
Treatment - Ischemic stroke
Works best within 3 hours of stroke Medication given to remove the clot
Typically through a vein in the arm Can be done directly to the brain through a catheter (tube) in the groin region
Aspirin is given to prevent blood clots from forming to prevent another stroke at the time of treatment
Mechanical removal of blood clot Catheter used to physically break up or remove the clot. May not actually be beneficial
Treatment – Ischemic stroke
Surgery to remove plaques from carotid arteries Angioplasty and stents
A balloon is inserted into the carotid arteries to expand the opening A stent is then put in place to support the opened artery
Treatment – Hemorrhagic stroke
Aim is to reduce bleeding and pressure in the brain Drugs which can lower blood pressure
Supportive medical care while the body absorbs the blood
Surgery may be required if the bleeding is excessive to relieve pressure
Recovery
Recovery depends on what part of the brain is affected but could include any of the following:
Speech therapy Physical therapy Recreational therapy Occupational therapy Psychiatric services
Prevention:
Eat a healthy diet Low in trans and saturated fats, and low cholesterol High fibre (helps lower cholesterol) Low sodium
Maintain a healthy weight Exercise Stop smoking (or just don’t start)
Smokers have increased risk of stroke
Limit drinking Drinking too much alcohol raises blood pressure
Alternative/complementary approaches
Acupuncture Ease pain and treat paralysis caused by stroke
Massage May help mood, lower blood pressure, relax body and mind
Yoga Low impact exercise Smooth physical movements and improved breathing
Aromatherapy Relieve pain and relax
Rosemary, lavender, and peppermint
Alternative/complementary approaches
Change in diet Naturopathic doctors may suggest many specific foods
High in potassium, magnesium, calcium, and omega 3-6 fatty acids
First Nations traditional healers may suggest a diet including foods which have been traditionally consumed by First Nations people in North America.
Alternative/complementary approaches
Herbal medicine and vitamin supplements May be used to improve blood circulation and brain function First Nations traditional healers may suggest willow bark
Has been used historically and lowers blood pressure
Naturopathic doctors may suggest vitamins to supplement those lacking in the diet
Herbal medicine may be suggested to help with proper circulation Ex. Ginko biloba – increase circulation in the brain by dilating cerebral blood
vessels
Spinal Cord
Bundles of ascending sensory nerves and descending motor nerves
Extends from the brain stem to the first and second lumbar vertebrae Spinal nerves enter and exit
between vertebrae
Peripheral Nervous System (PNS)
31 spinal nerves emerge from the spinal cord Spinal nerves belong to the Autonomic or Somatic nervous systems
Autonomic Nervous System (ANS) responsible for sensory information from internal organs and control of smooth muscle
Somatic Nervous System (SNS) responsible for sensory information, and control of skeletal muscle.
Sensory signals travel up the spinal cord to the brain Motor signals travel down the spinal cord, exit and travel to the desired
muscles Sensory neurons are located in dorsal root ganglions
Reflex arc
A reflex arc is an automatic movement in response to stimuli
Stretch reflex
Sensory signal does not ascend to the brain in this case
Signal transmission
Signal transmissions occur through action potentials Action potentials are electrochemical
signals that travel through axons ending at the synaptic end bulb resulting in signals sent to any cells in contact with the end bulb
1. Sensory receptors send signals to the dorsal root ganglion
2. sensory neurons relay the information into the spinal cord
3+4. sensory information is relayed to the brain.
Signal transmission
5. reflex arcs send the signal to a motor neuron
6. signals from the brain stimulate motor neurons in the anterior of the spinal column
7. motor neuron receives signal from 5 or 6 and relays the signal to the muscle.
8. autonomic nervous system sends motor signals to smooth muscle
Alzheimer's disease
Characterized by: Loss of memory
Begins with loss of short-term memory and expands
Change in personality Confusion Become suspicious easily
6th leading cause of death in North America
Alzheimer’s disease
No known cure Medications can reduce symptoms to
improve quality of life
Exact cause is unknown Plaques of protein deposits within the
brain Nervous tissue starts to disappear
Tangles of protein found within neurons preventing proper function.
Heat stroke
Not related to the types of strokes we have been discussing Due to exposure to high temperatures and possibly dehydration
Temperature higher than 105 F or 40.5 C
The body can not maintain homeostasis Complications with the nervous system
Can cause brain damage
Elderly (over 65) and very young (less than 4) are more susceptible