Three principle functions: - SENSORY INPUT (nervous system senses the spider on your leg) - INTEGRATION (your nervous system processes the input, and decides what should be done about it) - MOTOR INPUT (your hand shakes off the spider, it's a response that occurs when your nervous system activates certain parts of your body) NERVOUS SYSTEM DIVISION --- CENTRAL nervous system - CNS - brain - spine cord --- PERIPHERAL nervous system - PNS - around your body - SENSORY DIVISION (afferent) - picks up a sensory stimuli - MOTOR DIVISION (efferent) - sends directions from your brain to muscles and glands - SOMATIC nervous system - voluntary (skeletal movement) - AUTONOMIC nervous system - involuntary (heart, stomach, lungs) - SYMPATHETIC - sends the body into action - PARASYMPATHETIC - relaxes the body - Neurons (small part of your nervous tissue) - Glial cells (50% of mass of your brain) - provide support, nutrition, insulation, and help with signal transmission in the nervous system - GLIAL CELL TYPES - CNS - ASTROCYSTES - support, regulate ions, exchange materials between neurons and capillary - MICROGLIAL CELLS - defense against invading microorganisms - EPENDYMAL CELLS - create, secrete and circulate cerebrospinal fluid - OLIGODENDROCYTES - wrap and insulate, form myelin sheath - PNS - SATELLITE CELLS - surround neuron cell bodies - SCHWANN CELLS - insulate, help form myelin sheath 1. Neurons are some of the longest-lived cells in your body. 2. Neurons are irreplaceable. Most are AMITOCIT - when they get assigned a role, they can't divide anymore. 3. Neurons have huge appetites. They need a lot of oxygen and glucose. About 25% of daily calories are consumed by your brain NEURON STRUCTURE: - Soma - cell body - Dendrites- listeners - Axons- talkers NEURON TYPES: MULTIPOLAR neurons - three or more processes - one axon, bunch of dendrites BIPOLAR neurons - one axon, one dendrite (found in special places - retina of your eye) UNIPOLAR neurons - have only one process (found in your sensory receptors) NEURON FUNCTIONS: SENSORY neurons - afferent neurons -> transmit inpulses from sensory receptors toward the CNS -> mostly unipolar MOTOR neurons - efferent neurons -> impulse moves from the CNS to the rest of the body -> mostly multipolar INTERNEURONS - association neurons -> impulse moves between sensory and motor neurons -> mostly multipolar
my teacher makes us take notes of this videos every new unit and makes comments on where she wants us to write down some extra or where to leave out. so ya, crash course is pretty damn amazing.
Hank, in these past few years you have matured into one of the greatest communicator's and educator's on You-tube. I watch out of interest and thirst for knowledge not for help with an education program as many do, so I can only image how highly valued these video's are with those who are. Though this great resource was not available for my children's generation , I find it comforting to know that you will be here for my Grandchildren Damon and Jasmine when they need you. Thank you and every one involved.
Just to let you know, I'm watching this nervous system series to brush up on my basics as I'm writing a lit review for publication about chemotherapy-induced peripheral neuropathy XD Just wanted to let you know while these videos are awesome for those in AP bio/high school/college, us professionals also very very much appreciate the fun animation and clear-cut explanations as a way to brush up on our basics before having to talk in depth about glial cells and astrocytes and such. Thank you, Hank and team!
First the nail through the foot, now a damn spider on my bare skin. Seriously Hank, it's like you're trying your hardest to make these examples as potent as possible.
Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App! Download it here for Apple Devices: apple.co/3d4eyZo Download it here for Android Devices: bit.ly/2SrDulJ
I don't know if you read these comments, but I cannot thank you enough for making these videos! I have an amazing AP professor, but I'm such a visual person that your videos help me to make sense of what she is teaching. ALSO, as a hard of hearing person, THANK YOU for providing accurate subtitles that follow your rate of speech (which I'm sure is not an easy thing to do).
Motor Output: The response that occurs when your Nervous System activates certain parts of your body. Key: (MC)”word”: if its behind the word then it means it branches from it “word”(MC):means is it’s the nervous system or (NS) that it may have branches. Central Nervous System(CNS): Brain and spinal cord. Main control center. Peripheral Nervous System(PNS): All the nerves that branch off from the brain and spine that allow your CNS to communicate with the rest of your body. Works in both directions (PNS) Sensory Division(SD): Picks up sensory stimuli. Motor Division(MD): Sends directions from your Brain to Muscles and Glands. (MD)Sematic Nervous System(SNS): voluntary rules skeletal muscle movement. (MD)Autonomic Nervous System(ANS): involuntary keeps your heart beating. (ANS)Sympathetic Nervous System: Mobilizes the body into action (ANS)parasympathetic: Relaxes the body Astrocytes (Nervous System): Exchanges materials between neurons and capillaries. Microglial Cells(MC): Immune defense against invading microorganisms. (MC)Satellite Cells: Surround and support Neuron cell bodies. (MC)Schwan Cells: Produce an insulating barrier called by Myelin Sheath. Crazy facts about neurons: 1.They are the longest-lived cells in the human body. 2.They are irreplaceable. 3.They have huge appetites HERE ARE SOME NOTES IF YOU NEED THEM THE KEY MAY HELP YOU
These videos are a perfect example of how learning things does not have to be boring. It's all in the way they are presented. I remember going over stuff like this in HS/college and it was all just facts. You make it all come to life ❤️
does crashcourse offer any worksheets perhaps? these videos are extremely hopeful, but i'd love for them to have an accompanying test just to check if we retained all the information we were watching. that'd be rad.
I know! If only they were that adorable in real life. Actually, wait, no...that would mean each cell has a face, which means each cell is infinitely more complex than a single cell ought to be, which means AGH THE COMPLEXITY.
Humans make me happy :) especially when they just wanna help each other being awesome. *clears throat* Yo Crashcorse the allmighty knowledge bringer!! Can you tell me what the artist's name is that has created what it is that music's at the end of your shows? I Really really really really like Really want to know, its such a light, productive, happy sound and yeap :p
I wish my professor explained the topic in this manner. Very effective breakdown. Thanks for the effort always. Hands down the best channel for bio lessons!
Watching these as I finish up my prerequisites for med school! The history and literature videos helped me so much in high school, and these are helping me in the "real world" too!
Svakalegt Or toes, apparently once having a toe some how leave your body it is Really hard to get used to it with all sorts of balance issues or so I've heard.
That was actually a really good artistic representation of a jumping spider. They're harmless (not significantly venomous) and only bite if you make them. Better yet, a few species are super-curious and will actively explore you. Really fascinating stuff.
I’m watching this to get to know my body better. I have fibromyalgia (overactive nerves). It helps to know how the system is supposed to work. Thank you for explaining in a way i can understand! Keep up the good work! 😊
This is a beautifully made video (graphics, script, and oral presentation) and covers an enormous amount of information in only 10 minutes. Excellent work!
Just again, wow. You guys at crash course are awesome. Using this in my science class for an overview of the human organ systems and it's much appreciated.
This is the best youtube channel ever Whenever I want to learn extra about something I go to Crash Course Please keep making videos for other subjects too!!!!!!!!!!!!
seriously......what have been trying to understand for the past few days.......u explained it in a way i think i can never forget in my whole life.....THANK YOU.......
This was by far the most helpful and amazing sort course! I study psychology and this channel has helped a lot through exams and tests. Thank you so much and keep up the awesome work!
hey ,if anyone else wants to uncover anatomy and physiology study tools try Pycanta Quick Anatomy Protocol (do a search on google ) ? Ive heard some pretty good things about it and my co-worker got amazing results with it.
thanks for making funny science videos it rlly helps me study and take notes.its better watching this than it is reading some boring thing my teacher gave me... so again this was very helpful thanks :)
I'm studying to be a masseuse and learning all about the anatomy. The module information I have is lots of written work and a little overwhelming! Your videos are a huge help to me. You break down the key facts into more bite size info! Thank you! :D :D I can now actually process this!
I did 4 pages of notes from this one 10 minute video, i learned more from this one video than i would in a 3 days of regular science class. Thanks Hank Green this helped me with notes I had to take for a science project
I'm a Japanese studying to become a pharmaceutical translator. This video helps a whole lot! It's really amazing every time seeing this man speak so fast so perfectly.
Who else is watching this because their teacher just gives out handouts instead of answering questions, lecturing, and creating good PowerPoints in order to help us properly learn the course material? I have a sneaking suspicion it's more than just me.
Adult neurogenesis is definitely a thing. I can understand why you might think it's still an unanswered question, since conclusive evidence has only been discovered in the past decade and your resident expert probably graduated long before then. But even from basics, odour receptors (technically neurons) turn over about once a month. Here's an article so you're not just listening to a stranger on the internet, you can listen to a peer reviewed stranger! www.ncbi.nlm.nih.gov/pmc/articles/PMC3106107/
I'm sure that Hank and the person who wrote the script for this video are aware of the existence of some limited neurogenesis, but for the most part, your neurons can't be replaced, and there is a limited amount of detail that can be covered in 10 minutes. I'm sure their expert, who probable graduated before you were born, didn't stop studying new advances in the field he's interested in when he graduated from college. Graduating from college is just the foundation for learning in a science field, not the end of learning. This video was just a basic overview of the nervous system.
This was done very well, except that you made the mistake many people do: saying the sympathetic 'excites' the body and the parasympathetic 'calms' the body. They do act as opposing forces, BUT the sympathetic stimulates SOME things (heart, lungs, skeletal muscles, etc), and inhibits others (digestive, reproductive, excretory, etc), and the parasympathetic stimulate what the sympathetic inhibits and inhibits what the sympathetic stimulates.
Compliments to the sound designing, ***** (right?), for the squeaky wheel sound on the human joint! That was great. Also, I didn't know that the brain used up so many calories everyday. No wonder I can't think thoughts when my sugar drops!
This is really helpful! I was stressing earlier because I didn't understand anything my university teacher was saying. But having it explained in a fun, engaging and easy way really helped! :D
At 7:37 the graphical representation for unipolar is kind of incorrect because the one you are showing is called a "pseudo unipolar neuron" commonly found in dorsal root ganglion which has a axon and a dendron appearing extension
Is there anybody else like me just scrolling down the comments after watchin the vid with a thought: "So,,,,,, what do my palls think bout this briliance???"
