peripheral nervous system

Exploring Degenerative Diseases

Guillain Barre Syndrome

Guillain Barre Syndrome is a serious autoimmune condition affecting the peripheral nervous system. It occurs when the immune system attacks the nervous system, causing inflammation of the nerves. This results in numbness of the upper and lower limb and can also affect respiratory muscles.

Symptoms can affect both sides of the body and include:

  • Pain, tingling and numbness
  • Muscle weakness
  • Co-ordination problems / balance issues

As the condition progresses, muscle weakness can lead to:

  • Temporary paralysis of the legs, arms and face
  • Temporary paralysis of the respiratory muscles
  • Vision loss
  • Reduced ability to speak, swallow or chew
  • Reduced bladder and bowel control

Physiotherapy plays a vital role in Guillain Barre Syndrome in order to restore range of movement and function. Therapists focus on relieving pain and muscle stiffness through:

  • Movement and exercise
  • Manual therapy
  • Hydrotherapy / Aquatic therapy
  • Heat / cold therapy
Neurotransmitters

Central nervous system

  • Glutamate 
  • GABA 
  • Glycine 
  • Dopamine 
  • Serotonin 
  • Noradrenaline 
  • Histamine 
  • Orexin 
  • Endorphins 

Peripheral nervous system 

  • Noradrenaline 
  • Acetylcholine 

Neurotransmitter synthesis/packaging 

  • Some neurotransmitters are readily available amino acids eg Glutamate, glycine 
  • Some are synthesised by the cells that secrete them eg GABA, noradrenaline, dopamine 

Noradrenaline synthesis:

Packaging

  • In the presynapse, neurotransmitter is contained in vesicles 
  • The neurotransmitter must be packaged into the vesicle ready for release 
  • Uses transporters and proton gradients to package 

[packaging and release - above]

  • Neurotransmitter release is quantal – Each vesicle contains the same amount of neurotransmitter 
  • Therefore it is the number of vesicles fusing which determines the post synaptic potentials 
  • membranes must fuse for release - membrane fusion is energetically unfavourable so must be catalysed by something

SNARE Hypothesis 

  • Proteins on the presynaptic membrane ‘grab’ proteins on the vesicle membrane 
  • These SNARE proteins pull the two membranes close together 
  • SNARE proteins provide most of the energy for membrane fusion
  • v-SNARE (VAMP2) – on vesicle membrane 
  • t-SNAREs (syntaxin1A, SNAP-25) on target membrane 
  • Bind together to make SNARE complex 
  •  SNARE ‘zippering’ forces the membranes close together 
  • Spontaneous, highly energetically favourable 
  • Once assembled, they require ATP hydrolysis to separate them 
  •  Ca2+ binding to synaptotagmin provides extra energy to fuse the membranes

Neurotransmitter release

  • synaptic vesicle release sites are highly organised and regulated
  • exocytose into synaptic cleft

presynaptic active zone:


Neurotransmitter detection

  • Ionotropic (ion channel coupled) – Glutamate, GABA, Glycine 
  • Metabotropic (G-protein coupled) – monoamines, histamine etc. 
  • Some have both kinds, e.g. glutamate, GABA 
  • Ionotropic responses are faster 
  • Metabotropic responses can have more diverse effects 

Glutamate receptors

  • Glutamate is the main excitatory neurotransmitter in the brain 
  • Three classes of ionotropic receptor – AMPA – NMDA – Kainate 
  •  Named after pharmacological agonists 
  • All let in positive ions when they bind glutamate 
  • Glutamate also has a family of metabotropic receptors – mGluRs – These modulate neurotransmission 

AMPA Receptors 

  •  Main fast excitatory receptor 
  • Strength of a synapse is largely determined by its complement of AMPARs
  •  More AMPAR in the post-synaptic membrane = stronger synaptic transmission 

NMDA Receptors 

  • Minor role in postsynaptic firing 
  • Major role is in synaptic plasticity 
  • NMDA receptors are calcium permeable 
  • require strong neurotransmitter release to open 
I’ll Always Support You // Conor Maynard

— Heyy! Can you don an imagine where y/n isn’t famous (or a youtuber) and she’s dating conor? Thanks! —

I turned off my computer after I finished watching a video of my uni lecturer talking nonstop about the peripheral nervous system. I had enough time to do my makeup and get dressed before leaving to go to the boy’s flat which was just a couple minute walk from mine. Today, Conor is performing at Wembley stadium for the Rays of Sunshine concert.

We’ve been dating for a couple months now, but we pretty much have kept out relationship out of the spotlight. My social media accounts were private, so no one outside my friends and family really knew anything about my life. At the beginning, I wasn’t comfortable exposing my life to his fanbase because I liked my privacy. But obviously, since him and his friends are constantly in front of a camera, recording all aspects of their lives, it’s only natural that his fans found out about me. Conor and I met at a small party, my friend who’s dating one of his mates had invited me. We spoke all night at that party, he asked for my phone number before I left, and we’ve been inseparable ever since.

I left my house, makeup and hair done, dressed in an off the shoulder short dress and ankle boots and walked a small distance to the apartment he shared with his friend and brother. I buzzed their intercom to let me through the gates and made my way to their door. I knocked on their front door and was embraced in a hug from Anna, his little sister. She had come down from Brighton to see Conor perform. I had recently met his entire family, to which they welcomed me with open arms.

“Y/N, I love the way you did your makeup!” Anna complimented. We got very close, we treated each other as if we were each others sisters.

“I was just going to say the same about yours”, I laughed.

“Yo, Y/N!”, Jack walked into the room and high fived me then hugged me. “What you been up to?”

“Just been forcing myself to study all morning, the usual”, I sighed. “You vlogging today?”

“Oh yeah!” Just as I mentioned that, he pulled out his camera. “Good morning guys, hope you’re all doing well. I’ve got special guests with me today, Y/N, Anna, be nice and say hello”.

I waved to his camera and poked my tongue out. Just a couple days ago, I gave him permission for me to be in this vlog. I walked off as he continued to talk about the concert to go find Conor. I found him in his room blow drying his hair. “Hey babe”, I hugged him from behind as I watched him from the mirror in front of us.

He smiled widely and turned off the blow dryer. “Hey beautiful. You look amazing today”, he then pulled me into a hug and kissed my lips, letting his lips linger on mine.

“So the superstar is in here, getting – ooh bad timing” I heard Jack from the doorway with the camera in his hands, recording us but catching us at a bad time. He then left, causing us to laugh.

“How’ve you been my love”, Conor asked.

“Not too bad, are you nervous for today?” I let go of Conor to let him finish getting ready so I sat on his bed.

“Nah, I think I’ll be fine”, he responded.

“Yeah, I know you will. You’re very good at what you do”, I smiled at him. As he was finishing getting ready, I was scrolling on my phone for about half an hour. “Babe, its ten past twelve, what time do we need to be there?” I asked.

“Shoot. We should be leaving soon, so I have time to rehearse and do those interviews”, he said checking his watch.

“Conor, the uber is here!” I heard Anna yell from the living room. We all then left and arrived at Wembley stadium.

“Y/N, how you feeling? You look worried” Jack laughed, sticking the camera in my face as we walked to Conor’s dressing room.

I laughed. “I don’t know why I’m nervous. I know he’ll do amazingly well tonight, as he always does”, I looked at Conor and kissed his cheek as he put his arms around me.

“Ew”, Jack joked around, He then turned the camera off.

“Will you guys be okay by yourselves?” Conor asked.

“We’re big kids, we’ll be fine”, Jack said.

“Don’t worry, we’ll keep an eye on Jack”, I said to Conor, Anna laughed and Jack then rolled his eyes. “Good luck baby. Love you”.

“Love you too”, Conor kissed me before leaving to do interviews then rehearse on stage.

We kept ourselves busy for the next couple of hours by eating and giving ourselves a little tour. I checked the time and it was a quarter past five, the show would be starting soon. Jack, Anna and myself were then escorted by two security guards to a closed of section in the arena, giving us a perfect view of the stage. Anna and I were really excited, seeing all these artists live for the first time. We danced to each performance, singing all the popular hits along with them. We were given breaks after each performance. The stadium lights then went off, and Conor popped up on stage, causing the crowd to go wild. Conor then performed some covers and his original songs, Anna and I were dancing our butts off while Jack was vlogging for his channel. We all got into the shot of his camera, mouthing the lyrics to the song Conor was singing. As Jack was filming Anna and I dancing, I looked up to see Conor right at the edge of the stage, looking directly at me. Whilst he was singing as I mouthed ‘I love you’ to my boyfriend.

“I love you too baby”, Conor said into the microphone right in the middle of his song, then the whole crowd went more wild, if that was even possible.

After Conor finished, the security guards then took us backstage, Jack still vlogging everything. All the lucky winners who won backstage passes then started screaming as we were passing them. A lot of the winners were then yelling for Jack, and some even asking me and Anna to take photos with them, to which we did.

“Oh my god, Y/N you’re so pretty!”, one of the girls yelled, I thanked her. I took a bunch of selfies with different people, even though I wasn’t famous at all, I guess being the girlfriend of a famous person does put me into the public’s eye, whether I like it or not. As soon as Conor walked into the room, the attention then diverted to him and everyone started screaming. I watched him have his mini meet and greet, his face genuinely lighting up as he met everyone, it melted my heart. I took a couple of sneaky pictures as I watched him chat with his fans. As soon as the night was done, I was so exhausted that I fell asleep on Conor’s shoulders during the ride home.

“Y/N, baby, wake up”, he whispered into my ears, I groaned but got up anyway.

We all walked into their flat, Anna and Jack going straight to bed. I made my way to Conor’s bathroom to brush my teeth with a toothbrush I keep here. I took off my makeup and went to Conor’s drawer to steal a tshirt to wear to bed. I sat on Conor’s bed going through the videos and photos I took of tonight, smiling to myself. Conor jumped into bed behind me and pulled me down with him by my waist. I showed him the photos I took of today and he asked me to send them to him.

“Thank you so much for coming and supporting me tonight”, Conor said as he kissed my hands.

“Are you crazy? I will always support you, till the end. You make me so proud”, I kissed his cheeks then his lips.

“I know things can sometimes get a little crazy being with me, but still thank you”, he smiled

“A little crazy?”, I joked around.

“You know what I mean. But I guess our relationship is a little more out into the open now”, he said.

“I don’t mind it anymore, I don’t want to try and hide our love. It’s too stressful. From now on things will be different, especially since I’m going to be in Jack’s new vlog. Not just in the background anymore”, I said, my hands slightly rubbing his cheeks.

“Good, now I can flaunt my sexy girlfriend to the whole world, and make everyone jealous”, he laughed and kissed me on my lips. We then fell asleep in each other’s arms. For Conor, I would sacrifice anything for him, even if that means giving up some parts of my private life. I don’t care anymore, I would do anything for this boy. And I wouldn’t have it any other way.

So this is my first published little short fic! thank you to the person who requested this. I really hope you all enjoyed it. Sorry if im not too good haha, let me know what needs improving or let me know if you enjoyed it. please feel free to message me any requests!

Cranial Nerves

Nerves supplying the body can be divided in to cranial and spinal. Cranial nerves emerge from the brain or brain stem and spinal from the spinal chord. There are 12 pairs of cranial nerves. They are components of the peripheral nervous system, with the exception of the optic nerve, as their axons extend beyond the brain to supply other parts of the body. They are named numerically from region of the nose (rostral) to back of the head (caudal). Here’s a brief overview of all twelve nerves and their basic functions.

I – The Olfactory Nerve. The cells of this nerve arise from the olfactory membrane of the nasal mucosa. The dendrites of the nerve cells project in to the olfactory mucosa. The axons of these cells combine to form the olfactory nerve. They join the brain at the olfactory bulb, located at the end nearest the nose. The fibres are short and lie deep and protected from casual injury. It is often found that loss or interference of sense of smell is due to blockage of the air passage leading to the olfactory mucosa, not due to nerve damage.

II – The Optic Nerve. This nerve connects the retina to the diencephalon of the brain. It is the only cranial nerve considered to be part of the central nervous system. This means the fibres are incapable of regeneration, hence why damage to the optic nerve produces irreversible blindness. Interestingly the eye's blind spot is a result of the absence of photoreceptor cells in the area of the retina where the optic nerve leaves the eye. I find the optic nerves easy to spot when looking at the brain from below as they form the optic chiasm. This is the point at which they cross and forms a clear ‘x’.

III- The Oculomotor Nerve. This nerve controls most of the eye’s movements including the constriction of the pupil and levitation of the eyelid. Damage to the nerve can cause double vision and inability to open the eye. A symptom of damage to this nerve is tilting of the head.

IV – The Trochlear Nerve. This nerve is a small somatic motor nerve and innervates the dorsal oblique muscle of the eye, responsible for allowing the eye to look down and up as well as internal rotations. Damage to the nerve can cause one eye to drift upwards in relation to the undamaged eye, meaning patients tilt their heads down to compensate.

V – The Trigeminal Nerve. This is the largest cranial nerve and is so called as it has three major divisions. It is sensory to the skin and deeper tissue of the face and motor to certain facial muscles, playing a large role in mastication.

VI – The Abducent Nerve. This nerve controls the movement of the lateral rectus muscle of the eye. It also plays a role in eye retraction for protection. Injury produces the inability to deviate the eyeball away from the midline of the body.

VII – The Facial Nerve. This nerve innervates the muscles of facial expression. It also functions in the conveyance of taste sensations from the front two thirds of the tongue. As well as this it can increase saliva flow through certain salivary glands.

VIII – The Vestibulocochlear Nerve. This nerve is named after the vestibular and cochlear components of the inner ear. It transmits information on sound and balance. Damage can lead to deafness, impaired balance and dizziness.

IX – The Glossopharyngeal Nerve. This nerve has any roles including the innervation of certain muscles of the palate of the mouth, certain salivary glands and the sensory mucosa of the root of the tongue, palate and pharynx. Damage can lead to difficulty swallowing as well as the loss of ability to taste bitter and sour things in humans.

X – The Vagus Nerve. This is a very important nerve and one frequently discussed when considering many important systems within the body. It is the longest of all cranial nerves and extends to supply the pancreas, spleen, kidneys, adrenals, and intestine. It has parasympathetic control of the heart and digestive tract as well as certain glands and involuntary muscles.

XI – The Accessory Nerve. This plays a role in neck turning and elevation of the scapula (shoulder). Muscle atrophy of the shoulder region indicates damage to this nerve.

XII – The Hypoglossal Nerve. This nerve’s name relates to the fact that is runs under the tongue, innervating the tongue’s internal and external musculature. It has important roles in speech, food manipulation and swallowing.

Stretchy Prosthetic Skin Feels Pressure, Temperature

by Txchnologist staff

Researchers in South Korea and the U.S. have developed what they call a “smart” prosthetic skin embedded with heat, humidity and pressure sensors that can relay sensations to the wearer. 

They say their stretchy silicone-based material can recreate the feelings of temperature and mechanical strain and pressure through electrodes that stimulate the wearer’s nerves. They argue their integrated device represents the next generation of prosthetic skin research by making previously rigid or semi-flexible sensors soft.

“Recent advances in the design of prosthetic limbs integrated with rigid and/or semi-flexible tactile sensors provide sensory reception to enable feedback in response to variable environments,” the team write in the paper reporting their work published today in the journal Nature Communications. "However, there still exists a mechanical mismatch between conventional electronics in wearable prosthetics and soft biological tissues, which impede the utility and performance of prosthetics in amputee populations.“

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2

Galen

Aelius Galenus or Claudius Galenus (Greek: Κλαύδιος Γαληνός; AD 129 – c. 200/c. 216), better known as Galen of Pergamon was a prominent Greek physician, surgeon and philosopher in the Roman empire. Arguably the most accomplished of all medical researchers of antiquity, Galen influenced the development of various scientific disciplines, including anatomy, physiology, pathology, pharmacology, and neurology, as well as philosophy and logic. The son of Aelius Nicon, a wealthy architect with scholarly interests, Galen received a comprehensive education that prepared him for a successful career as a physician and philosopher. He traveled extensively, exposing himself to a wide variety of medical theories and discoveries before settling in Rome, where he served prominent members of Roman society and eventually was given the position of personal physician to several emperors. Galen’s understanding of anatomy and medicine was principally influenced by the then-current theory of humorism, as advanced by ancient Greek physicians such as Hippocrates. His theories dominated and influenced Western medical science for more than 1,300 years. His anatomical reports, based mainly on dissection of monkeys, especially the Barbary Macaque, and pigs, remained uncontested until 1543, when printed descriptions and illustrations of human dissections were published in the seminal work De humani corporis fabrica by Andreas Vesalius where Galen’s physiological theory was accommodated to these new observations. Galen’s theory of the physiology of the circulatory system endured until 1628, when William Harvey published his treatise entitled De motu cordis, in which he established that blood circulates, with the heart acting as a pump. Medical students continued to study Galen’s writings until well into the 19th century. Galen conducted many nerve ligation experiments that supported the theory, which is still accepted today, that the brain controls all the motions of the muscles by means of the cranial and peripheral nervous systems.

“Τῆς ἰατρικῆς ἐστιν εἴδη πέντε· ἡ μὲν φαρμακευτική͵ ἡ δὲ χειρουργική͵ ἡ δέ διαιτητική͵ ἡ δέ νοσογνωμονική͵ ἡ δὲ βοηθητική· ἡ μἐν φαρμακευτική διά φαρμάκων ἰᾶται τὰς ἀρρωστίας, ἡ δὲ χειρουργικὴ διά τοῦ τέμνειν καὶ καίειν ὑγιάζει͵ ἡ δὲ διαιτητικὴ διά τοῦ διαιτᾶν ἀπαλλάττει τῆς ἀρρωστίας͵ ἡ δὲ νοσογνωμονική διὰ τοῦ γνῶναι τὸ ἀρρώστημα͵ ἡ δὲ βοηθητική διά τοῦ βοηθῆσαι εἰς τὸ παραχρῆμα ἀπαλλάττει τῆς ἀλγηδόνος.”

Galen saw himself as both a physician and a philosopher, as he wrote in his treatise entitled That the Best Physician is also a Philosopher. Galen was very interested in the debate between the rationalist and empiricist medical sects and his use of direct observation, dissection and vivisection represents a complex middle ground between the extremes of those two viewpoints. Many of his works have been preserved and/or translated from the original Greek, although many were destroyed and some credited to him are believed to be spurious. Although there is some debate over the date of his death, he was no younger than seventy when he died.

The MS might be flaring again… so far it’s the same symptoms I got years ago before I was diagnosed – the rush of tingles down my back when I bend my neck just so. And a lot of fatigue and brain fog, which as always is hard to pin on any one thing, especially after a long week at work. Spent the morning feeling two minutes behind everything. I feel better now, though still run down. I feel like the Advil I took this afternoon helped a bit, though. Since it’s inflammatory, maybe it pushes it back a bit. Who knows.

It’s disconcerting to say that least but for the moment it’s still peripheral nervous system. In the freaky internal negotiations of this kind of thing, it’s the least of my fears. But it’s… well, it is. It’s the slow, shitty, unfair slide. The fatigue is rotten.

Suzuya’s loss of pain theory

*SPOILERS FOR THOSE WHO HAVEN’T READ THE MANGA*

but seriously why havent you read the manga yet!

So the first time this thought came to mind was during juuzou’s battle with the twin sisters. During that time he got his stomach slit.

even after that he kept on fighting. All those sick moves, defeated the sisters and his split stomach did not hinder him. On a physical level, yes they did because his insides were probably dangling out, but not on the pain scale. After the battle he just casually stitch himself like no big deal

i didn’t know much then so i placed the thought aside but something like this again happened during the owl battle when suzuya got his right leg cut off

Firstly he didn’t even know his leg got cut off and then he told shinohara that it didn’t hurt. But then we have shinohara getting his right leg cut off. Screams and pain.

Well it could’ve been due to his torturous past that he didn’t feel pain or had a high endurance level. But he is still human and pain is pain. Getting your leg chopped off is probably much painful than needles etc. And im pretty sure Shinohara had had physical injuries before but look at the blood probably coming out of his mouth. On the other hand..jouuzou not even a flinch

Then i did a bit research 

“Congenital insensitivity to pain
Congenital insensitivity to pain is considered a form of peripheral neuropathy because it affects the peripheral nervous system, which connects the brain and spinal cord to muscles and to cells that detect sensations such as touch, smell, and pain.”

Dissociated sensory loss

“They found that opiates(endorphins) interact with specialized receptors in cells that are primarily massed in the brain and spinal cord. When opiates enter these receptors, they hinder or block the cell’s transmission of pain signals.”

IN COMMON WORDS

  1. Stress and pain (recurrently) are the two most common factors leading to the release of endorphins. Excessive release of endorphins can cause Loss of pain.
  2. spinal cord infection and fracture can also be a cause to loss of pain

we’re all familiar with jouuzou’s past 

and of course this one

if you’re thinking that kanaki was tortured too then note that kaneki was tortured for aprox 10 days while suzuya was for like 3-5 years (i don’t know exactly)

i’m no neurologist but my theory is that Suzuya Jouuzou has lost his ability to feel physical pain after being tortured for what like 3-5 years. Though he still has sense of touch.

what do you guys think?

More (Detailed) Neuroscience and Behavior Notes

Other Neuroscience and Behavior Notes (with pics!)
What’s not included in that^ post is here and vice versa. Also some things might repeat.

 

Neurons: The Basic Elements of Behavior
The Structure of the Neuron

  • Neurons: Nerve cells, the basic elements of the nervous system
  • Perhaps as many as trillion neurons throughout the body are involved in the control of behavior.
  • The nucleus incorporates heredity material that determines how a cell will function.
  • Neurons are physically held in place by glial cells. Glial cells provide nourishment to neutrons, insulate them, help repair damage, and generally support neural functioning.
  • Terminal Buttons AKA Terminal Branches
  • Myelin Sheath: made up of fat and protein
  • Neural impulses generally move across neurons in one direction only

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shinycat69 reblogged your photo:

Wait, is guillan-barre just another name for MS?…

They aren’t. They are two different diseases. GB mostly impacts the peripheral nervous system while MS impacts the central nervous system (in its actual nerve damage). They often present the same and autoimmune diseases as a whole have so many similarities. People with GB generally make a full recovery while people with MS don’t. Triggers are slightly different as well. Mostly I shared because  I think talking about them all and promoting research for all of them is helpful for all of us. 

youtube
  • central nervous system 中枢神経系 ちゅうすうしんけいけい
  • peripheral nervous system 末梢神経系 まっしょうしんけいけい
  • stroke 発作 ほっさ
  • Broca’s area ブローカ野 ぶろーかや
  • Broca’s aphasia ブローカ失語症 ぶろーかしつごしょう
  • brain のう
  • spinal cord 脊髄 せきずい
  • meninges 髄膜 ずいまく
  • cerebrospinal fluid 脳脊髄液 のうせきずいえき
  • neural tube 神経管 しんけいかん
  • prosencephalon or forebrain 前脳  ぜんのう
  • mesencephalon or midbrain 中脳 ちゅうのう
  • rhombencephalon or hindbrain 菱脳 りょうのう
  • telencephalon 終脳 しゅうのう
  • diencephalon or interbrain 間脳 かんのう
  • metencephalon 後脳 こうのう
  • myelencephalon 髄脳 ずいのう
  • brain stem 脳幹 のうかん
  • cerebellum 小脳 しょうのう
  • cerebral hemispheres 大脳半球 だいのうはんきゅう
  • cerebrum 大脳 だいのう
  • pons 脳橋 のうきょう or  きょう
  • medulla oblongata 延髄 えんずい
  • thalamus 視床 ししょう
  • epithalamus 視床上部 ししょうじょうぶ
  • hypothalamus 視床下部 ししょうかぶ
  • mammillary body 乳頭体  にゅうとうたい
  • limbic system 大脳辺縁系 だいのうへんえんけい or 辺縁系 へんえんけい
  • reptilian brain 爬虫類脳 はちゅうるいのう
  • cerebral cortex 大脳皮質 だいのうひしつ
  • gyrus  かい
  • sulcus 脳溝 のうこう or  みぞ
  • corpus callosum 脳梁 のうりょう
  • lobe よう
  • frontal lobe 前頭葉 ぜんとうよう
  • occipital lobe 後頭葉 こうとうよう
  • parietal lobe 頭頂葉 とうちょうよう
  • temporal lobe 側頭葉 そくとうよう
  • Wernicke’s area ウェルニッケ野 うぇるにっけや
  • hippocampus 海馬 かいば
  • amygdala 扁桃体 へんとうたい

Human Central Nervous System and Peripheral Nervous System Connections

The central nervous system (CNS) of the human consists of the brain, spinal cord, and cranial nerve II (the optic nerve which connects to the eyeball).

When compared to the peripheral nervous system (PNS), the CNS differs in several key ways. It’s largely autonomic (requires no input for it to work) instead of voluntary, is much more protected (by bone and the blood-brain barrier), and interprets input, rather than integrating it.

As the PNS is much less protected, it’s vulnerable to damage by toxins, disease, mechanical injury, and autoimmune disorders. The degenerative conditions of the CNS are almost always hereditary.

Dictionnaire Universel d'Histoire Naturelle. Charles d'Orbigny, 1849.

Peripheral nerves of a mouse embryo

Unlike the brain and spinal cord that are housed in protective bone, peripheral nerves connect regions of the body to the central nervous system like telephone cables. Peripheral nerves relay movement information from the brain to the muscles, for example, or sensory information from the skin to the brain. Remarkably, and also different from the brain and spinal cord, peripheral nerves have a tremendous capacity to regenerate when injured. Severed peripheral nerves grow about 1 mm per day (about an inch per month) until the two severed ends reconnect and innervate a once paralyzed muscle.

Image by Zhong Hua, Johns Hopkins University School of Medicine.

anonymous asked:

wait, so are you a neuroscience major? What do you do? I think it sounds really cool, but i'm bad at math, so.

Hi Anon,

I am in fact a neuroscience major twice.  I did my undergrad degree in Neuroscience, and now I’m doing my Ph.D. in neuroscience.  And I love it.  Its a fantastic subject.

I am actually not completely sure what you want to know about from your ask, so I’m just going to sort of attempt to cover everything I can think of, and if you want something clarified you can come back and ask again.

Neuroscience is a really really broad field. It covers everything brain and nerve related.  So topic wise that’s everything related to the brain, the spinal cord, and the peripheral nervous system, as well as how the nervous system interacts with other systems like the immune system.  Neuroscientists work at every level of biology. That ranges from genetics, to how specific proteins work inside cells (molecular biology or biochemistry), to specific cells, or how cells interact (cellular neuroscience, electrophysiology), to larger networks (systems neuroscience), right up to how the brain produces thought and behaviour (cognitive neuroscience). Neuroscientists can also work on making computer models of cells or of brains (computational neuroscience).  That isn’t even all the major branches, it’s really very diverse.

I specifically, am working in Neuroimaging, and investigating personality using functional MRI.  Neuroimaging is one of the most multidisciplinary fields, it involves information from cognitive neuroscience, psychology,cellular neuroscience, and neurovascular physiology (the specific way the blood supply to the brain works is a field in and of itself) to design experiments and interpret data, but to actually do experiments I use techniques from computer science, statistics and signal processing. And actually using MRI involves physics, but I’m not involved in that directly, I just trust the physicists and MR techs and say thank you to them a lot. I love this and its one of the reasons I picked this field to work in. 

If you want to know what exactly what neuroscientists do all day, you’re really going to have to pick a field or two though, because if I try to sum them all up I’ll be here all night. But very briefly, it can range from what I do, to focusing more on behavioural tests, and working with patients with specific illnesses or lesions, or working with animals to see the effects of whatever you’re studying on their brain, to working with individual cells cultured in dishes, its hugely variable.

And neuroscientists come from a lot of backgrounds, a lot of us started in some part of biology, or psychology and increasingly, from actual neuroscience undergrads, because they’re getting more common, but there are also engineers and physicists, and computer scientists, and in some places you can do cognitive science degrees, which are a combination of computer science, psychology, neuroscience and philosophy, centred around cognition.

In terms of what a neuroscience UNDERGRAD does, if you’re more interested in getting a first degree, you’re probably going to do a little bit of everything neuroscience related.  Neuroscience programs vary a but, you’ll do intro sciences and math, then the biological sciences (genetics, cellular, biochem, organic chemistry, etc), and then a combination of specific neuroscience courses and psychology courses. The man who designed my program thought a liberal arts type background was important, so I also took some anthropology, and humanities, and a combined history/ethics course, but depending on where you are you might stay more science focused. And in terms of course type, it’ll be a combination lectures, lecture/lab combos and some discussion classes, where you read and analyze current research, in all likelihood.  I also had pure lab courses. You’ll essentially finish with a crash course in each of the neuroscience related fields.

Its a really great degree.  I went into it planning to go into a neuroscience Ph.D. which worked well, but it will also set you up well to go to medical school, or into clinical psychology, or physiotherapy/occupational therapy, if you’re interested in health care. Not to mention any number of research adjacent careers. If you want specifically, to know about the mechanics of a research career, come back and let me know, I’ll make a separate post, its kind of involved.

I want to specifically address you’re comment that you’re bad at math.  PLEASE DO NOT LET MATH SCARE YOU AWAY FROM NEUROSCIENCE!!!

Its a little hard to give specific advice about this because ‘bad at math’ can cover everything from intimidated, to having a disability like dyscalculia.  

At undergrad level, I took 2 math courses, calculus, and linear algebra.  And an introductory statistics course.  Outside of my math specific courses there was a few basic calculations in chemistry and genetics, and in my research based courses I used the stats I’d already learned in my stats course. But it isn’t a math heavy degree.  

If mostly you’re just intimidated, or have trouble keeping up with math and the undergrad math is what’s frightening you off, most universities have a LOT of tutorial resources for intro math, because a lot of people have trouble with them (and they mostly get through them and go on to do very well). If you’re concerned about statistics, don’t be, the actual math involved in statistics is incredibly straight-forward, it looks complicated, when you write it out, but its essentially all the y = mx + b equation you learned in 7th or 8th grade, with some fancy clothing on. Also, a lot of stats is done using statistics programming.  That doesn’t involve doing the math yourself, it involves understanding what to tell the computer.

That’s pretty much how I do math too.  I use really complicated math (I spent all today on independent components analysis), but I don’t actually have to be able to do it, just understand how it works, and how to interpret the results it gives me. 

If you do have dyscalculia or some other math-related learning disability I can’t really give a lot of specific advice, but there is plenty of neuroscience you can do that doesn’t involve math, and you can almost certainly work around it in courses if your instructors are cooperative (the majority of professors are nice and will help, they just don’t know what you need until you explain, unfortunately).

But please, please, whatever you do, don’t buy into the obnoxious idea that struggling with math in school permanently shuts you out of STEM!

I hope this at least moves in the direction of what you wanted to know, I will happily answer any other neuroscience or brain related questions you may have :). Neuroscience is wonderful and I totally recommend it.

Different types of medicine
  • Anesthesiologist - administers drugs and monitors patient condition during surgery; also provides pain management for acute and chronic conditions.
  • Cardiologist, Interventional Cardiologist, Cardiac Electrophysiologist - a cardiologist specializes in diseases of the heart and blood vessels; an interventional cardiologists uses guided imaging to diagnose and treat those diseases; a cardiac electrophysiologist specializes in treating irregular heart rhythms caused by electrical problems in the heart.
  • Cardiovascular Surgeon, Cardiothoracic Surgeon - a cardiovascular surgeon specializes in the surgical management of blood vessels and heart disorders; a cardiothoracic surgeon specializes in pathological conditions within the chest.
  • Emergency medicine - physicians who care for patients with acute illnesses or injuries which require immediate medical attention; they diagnose a variety of illnesses and undertake acute interventions to stabilize the patient.
  • Endocrinologist - diagnoses and treats diabetes, hormone imbalances, thyroid disease and other disorders of the endocrine system.
  • Family medicine - provides continuing, comprehensive health care for the individual and family. Encompasses all ages, both sexes, each organ system, and every disease entity; a family physician’s care is based on knowledge of the patient in the context of the family and the community, emphasizing disease prevention and health promotion.
  • Gastroenterologist - specializes in diseases of the digestive system.
  • Geriatrician (Geriatric Medicine) - general practice physician who specializes in caring for older adults.
  • Hematologist - a hematologist specializes in diseases of the blood and bone marrow.
  • Hepatologist - specializes in diseases of the liver.
  • Hospitalist - internal medicine physician whose practice is limited to hospital inpatients.
  • Intensivist - hospital-based critical care medicine specialist who treats patients in intensive care settings.
  • Internal medicine - provides diagnosis, management and nonsurgical treatment of unusual or serious diseases.
  • Medical Geneticist - provides testing, counseling and therapy for genetic diseases.
  • Medical Oncologist, Radiation Oncologist - a medical oncologist specializes in the diagnosis and treatment of all types of cancers and tumors; a radiation oncologist specializes in the application of radiation to manage disease.
  • Neonatologist - cares for premature and critically ill newborns.
  • Nephrologist - specializes in diseases of the kidneys.
  • Neurologist, Neurosurgeon - a neurologist specializes in the diagnosis and treatment of all types of disease and functions of the brain, spine, peripheral nerves, muscles and nervous systems; a neurosurgeon provides surgical management of those disorders.
  • Neurophysiologist - a neurologist who diagnoses disorders of the central, peripheral and autonomic nervous systems through clinical evaluations and electrophysiologic testing.
  • Obstetrician/Gynecologist, Urogynecologist - an obstetrician/gynecologist specializes in the medical and surgical care of the female reproductive system and its associated disorders; a urogynecologist specializes in female urological problems.
  • Opthalmologist, Optometrist - an ophthalmologist provides comprehensive eye and vision care, including to medically or surgically treat eye disorders; an optometrist specializes in diagnosing diseases of the eye and correcting vision.
  • Orthopedic Surgeon - also known as an orthopod, an orthopedist is a surgeon who treats diseases, disorders and injuries of the musculoskeletal system.
  • Otolaryngologist - the technical name for an ear, nose and throat physician.
  • Pathologist - usually works behind the scenes to diagnose diseases by studying tissues, body fluids and organs.
  • Pediatrician - a child’s physician who provides preventive health maintenance for healthy children and medical care for children who are acutely or chronically ill; pediatricians manage the physical, mental, and emotional well-being of their patients, in every stage of development - in good health or in illness.
  • Perinatologist - specializes in caring for high-risk pregnancies.
  • Physiatrist - specializes in physical medicine and rehabilitation.
  • Podiatrist - specialist that treats both medical and surgical deformities of the foot and ankle.
  • Pulmonologist - specializes in lung disease.
  • Radiologist, Interventional Radiologist - radiologists perform and interpret imaging tests; interventional radiologists also perform minimally invasive procedures, such as embolization, thrombolysis and biopsies, using imaging guidance.
  • Rheumatologist - specializes in arthritis and diseases of the joints, as well as autoimmune disorders, such as lupus.
  • Sleep doctors - diagnoses and treats sleep disorders, and also may have expertise in behavioral and cognitive methods to prevent them.