A 23 year old male patient demonstrating severe face and arm muscle spasms was brought to the emergency department by his brother. You note that the patient has many tattoos, including a fresh one on his shoulder. The brother tells you that the patient just got that tattoo yesterday, and that the tattoo parlor was “sketchy.” You order blood tests, and when you get the results, it confirms your suspicion: this patient is infected with Clostridium tetani, a common bacterium found in soil that can be transmitted by using dirty needles. The patient was never vaccinated against this bacterium. Clostridium tetani produces a toxin that affects neurons and their ability to release neurotransmitters. The worried brother asks you to explain this patient’s condition.
Upstream Causes
Direct causes
Severe face and arm muscle spasms
Can't speak
Fresh tattoo from possibly a dirty needle
HIV
Tetanus
Hepatitis B or C
Hep C
Fever
yellowish skin tone (Jaundice)
Swollen lymph nodes
Fever lasting more than 10 days
Being tired all the time
Hep B
Jaundice
Fever
Fatigue
Apetite loss
dangerous nerve ailment caused by the toxin of a common bacterium, Clostridium tetani.
Sudden, involuntary muscle tightening (muscle spasms) – often in the stomach
Painful muscle stiffness all over the body
Trouble swallowing
Jerking or staring (seizures)
Headache
Fever and sweating
Changes in blood pressure and fast heart rat
Indirect cause
Was never vaccinated for tetanus
DTaP vaccine protects young children from diphtheria, tetanus, and whooping cough
DT vaccine protects young children from diphtheria and tetanus
Tdap vaccine protects preteens, teens, and adults from tetanus, diphtheria, and whooping cough
Most all patients that present with tetanus is because they were not vaccinated
It is not a transferable disease
You can not get it from contact with someone
Jaw Cramping
Bacteria is most commonly found in soil
But can also be found in animal excrement, house dust, and the human colon
These spores enter the skin in this case via the infected tattoo needle
Produce a neurotoxin, tetanospasmin that enters your bloodstream
Your bloodstream carries the toxin to your nerves
Toxin/poison begins to block the relaxation muscle signals
Causing sustained muscle contractions shown above in both pictures
Eventually it will make it difficult to breath
Anatomy
Down stream causes
Physiology
Nervous tissue
Excitation Contraction
Organ systems
Nervous system: Detects & responds to stimuli
Muscular system: Assists with movement & heat production
Peripheral nervous system (PNS)
Central Nervous system (CNS)
Brain
Nerves and ganglia outside the brain and spinal cord
Autonomic nervous system
Somatic nervous system
Involuntary
Voluntary
Sympathetic nervous sysmtem
Parasympathetic nervous systems
Neurons
Axons
3 types of neurons
Axon hillock
Axon terminals
Myelin sheath
Nissl Body
Cell body
Node of ranvier
Dendrites
Schwann cell
Bi bolar
Multi polar
Uni polar
Cone shaped area where the axon leaves the cell body
Ends of the axon that contain synaptic vesicles
portion of the neuron that carries the impulse away for the cell body
Region of the neuron that receives incoming signals and conveys then towards the cell body
Fatty layers that surround and electrically-insulate the axon
Granules of touch endoplasmic reticulum in the cytoplasm
Gaps between the Schwann cells on a neurons axon
Cells that form myelin sheaths around axons of neurons in the central nervous system
Portion of the neuron that carries the impulse away form the cell body
Neurons with one extension off of their cell body
Neurons with two extensions from the cell body
Neurons with multiple extensions from the cell body
Most abundant
Found in special sensory organs: retina of the eye
commonly found in the dorsal root ganglia of the spinal cord
Synapse is a location where two neurons meet and exchange messages
Presynaptic neuron
Synaptic cleft
Neurotransmitter
Postsynaptic neuron
Chemical messengers released from the presynaptic neuron bind to the postsynaptic neuron
Neuron located before the synapse
Area of indirect contact between the presynaptic and postsynaptic neurons
Neuron location after synapse
Clostridium tetani
Excitatory VS Inhibitory
Summation
Process of converting an electrical stimulus to a mechanical response
Skeletal muscle fibers
Skeletal muscle cells
sarcolemma
T-tubules
sarcoplasmic reticulum
Plasma membrane of muscle fibers
extensions of the cell membrane that penetrate into the centre of skeletal and cardiac muscle cells
Stores calcium
Occurs when a neuron uses more than one message to determine if it should depolarize
Excitatory Neurotransmitters
Inhibitory Neurotransmitters
Hyper polarize the membrane
Make it more negative
Depolarize the membrane
Make it more positive
Excitatory postsynaptic potentials (EPSP)
Inhibitory postsynaptic potentials (IPSP)
Temporal summation
Spatial Summation
No summation
A message being transmitted every so often
A message being told by one person over and over
A message being told by multiple people at the same time
common soil bacterium
Rod shaped
Gram postive bacterium
Withstand extreme temperature conditions
Clostridium Tetani
Excitatory VS Inhibitory
Neurons
Process of summation
Organ system
Excitation-Contraction Coupling
Nervous system
Muscular system function
PNS
CNS
connect the CNS to the limbs and organs
The somatic nervous system
The autonomic nervous system
responsible for carrying sensory and motor information to and from the central nervous system
Voluntary movement
Sensory Neurons
Motor neurons
Sensory Neurons
Motor neurons
Carry info from nerves to CNS
Carry info from the brain and spinal cord to muscle fibers through out the body
Sensory info
Physical action in response to stimuli
responsible for regulating involuntary body functions
Like breathing and your heart beat
system allows these functions to take place without needing to consciously think about them happening
The parasympathetic system
The sympathetic system
maintain normal body functions and conserve physical resources
Once the treat has passed this system helps body go back to "normal"
slow the heart rate, slow breathing, reduce blood flow to muscles, and constrict the pupils
regulates the flight-or-fight response
prepares the body to expend energy and deal with potential threats
triggers a response by speeding up heart rate, increasing breathing, increasing blood flow to muscles, activating sweat secretion, and dilating the pupils
Allows the body to respond quickly to the situation
responsible for integrating sensory information and responding accordingly
Brain
Spinal cord
central control module of the body and coordinates activity
physical motion, secretion of hormones, the creation of memories, and the sensation of emotion
Spinal cord
carries information between the brain and body, but also carries out other tasks
connects with the nerves of the peripheral nervous system
Motor commands from the brain travel from the spine to the muscles
Sensory information travels from the sensory tissues toward the spinal cord and finally up to the brain
Contains circuits that control certain reflexive responses, such as involuntary movement your arm might make if you burn your finger
Spinal nerves can coordinate all of the muscles necessary to walk
Movement of our bodies which is voluntarily controlled by skeletal muscles
Involuntary movement happens with your smooth muscles and cardiac muscles
Food digestion (smooth muscles)
Walking, running, or swimming to name a few
Heart beat and blood flow (cardiac muscles)
electrically excitable cells in the nervous system that function to process and transmit information
Neurons send signals using action potentials
a shift in the neuron’s electric potential caused by the flow of ions in and out of the neural membrane
interneurons
motor neurons
Sensory neuron
Smell, hear, taste,feel and see
Most common type
Pass signals from sensory neurons and other interneurons to motor neurons
Movement
Involuntary
Voluntary
allow the brain and spinal cord to communicate with muscles, organs, and glands all over the body
The sequence of events converting action potentials in a muscle fiber to contraction
Motor neurons synapse with muscle cells at the neuromuscular junction
They release acetylcholine (ACh)
ACh attaches to chemically gated sodium ion channels on sarcolemma
Causing Sodium to rush in and depolarizes
Voltage-gated calcium channels open
calcium binds to troponin
Tropomyosin unblocks the myosin-binding sites on actin
myosin attaches to and slides past actin
Two types of summation
Excitatory increase the likelihood that the neuron will fire an action potential
Inhibitory decrease the likelihood that the neuron will fire an action potential
Depolarize
Hyperpolarize
Neurotransmitter binding opens chemically gated ion channels allowing sodium and potassium to pass simultaneously
The electrochemical gradient for sodium is bigger than potassium so more sodium enters then potassium leaves and results in depolarization
Neurotransmitter binding opens chemically gated ion channels allowing either potassium of Chloride to pass
Resulting hyperpolorization
Spatial summation
Temporal summation
Receiving one message over and over again
Receiving the same message from multiple neurons over and over again
Neurons constantly bring (presynaptic) messages and receive (postsynaptic)messages
They add the messages together
The electrical sum of the messages predicts whether or not the neuron depolarizes
The number must reach -55mV (threshold) in order to have action potential
Will not have an action potential if -55mV is not met
Once it reaches threshold the action potential depolarizes up to +30
Voltage potassium gates opens to repolarize
Hyper polarization occurs, becomes to negative
With the help of leaky channels resting membrane potential is reached at -70 mV
Enters the body through a cut or break in the skin
Produces and releases a neurotropic exotoxin called tetanospasmin.
Transported with blood and lymph, and taken up via endocytosis by nerve cells at the neuromuscular junctions
Once inside the neurons, tetanus toxin cannot be neutralised by antitoxin
Tetanus toxin acts on four areas of the nervous system
Brain
Spinal cord
Sympathetic system
Motor end plates in the skeletal system
Toxin blocks the release of the inhibitory neurotransmitters glycine and gamma-amino-butyric acid in the central nervous system
Leaves excitatory nerve impulses unopposed resulting in muscle spasms
Nervous System
Painful muscle contractions
Particularly your jaw and neck
Also referred to as "lock Jaw"
Interferes with breathing and swallowing
No cure
Treatment focuses on managing complications until the effects of the tetanus toxin resolve
Complete recovery from a tetanus infection requires new nerve endings to grow, which can take up to several months.
Once tetanus toxin has bonded to your nerve endings it is impossible to remove
Skeletal system
Severity of spasms may cause the spine and other bones to break
Respiratory system
Pulmonary embolism
Blood clot that travels from one part of body blocks main artery of lung or one of its branches
Respiratory failure
Most common cause of death
Muscle spasms interfere or stop your breathing
Cardiovascular system
Lack of oxygen may induce cardiac arrest
Pneumonia
Blocks motor neurons