let's continue the playlist on physiology in the previous video we've talked about the cell membrane today let's talk about the nucleus the control center of yourself so let's get started we have talked about cell organelles before the mitochondria is the powerhouse the lysosome is the soldier the endosome is the delivery guy in the plasmic reticulum it depends rough endoplasmic reticulum is the translator and the uber smooth endoplasmic reticulum is the doughnut Golgi is the sorter peroxisomes is the gym trainer less than 500 years ago a guy named Antony van Leeuwenhoek discovered a lumen at the center of the cell he called it a nut or a carrion or a nucleus nucleus literally means kernel seed or a nut in Greek it's called carrion so how about Carrio lysis Carrio means nucleus lysis means like destruction or dissolution so carrier lysis destroy the nucleus the nucleus is the largest organelle and animal cells it's the control center it contains the genetic material form of DNA DNA is packed together in the form of chromosomes surrounded by a membrane called a nuclear membrane and has pores to allow passage of substances it maintains the integrity of genes because genes are parts of DNA they contain viscous liquid could old the nucleoplasm or a Macario lymph which is the substance of the nucleus the nuclear membrane is an envelope surrounding the nucleus it's a double membrane because any membrane in your body is a double membrane so it has an outer membrane inner membrane and an inter membrane space called the peri nuclear space it maintains the internal environment of the nucleus how by separating the nucleus from the cytoplasm cool has membrane pores again for selective exchange molecules and ions molecules are big they need carrier proteins ions are small they can just diffuse the outer membrane is continuous with the rough endoplasmic reticulum and it's studied with the ribosome same as with the rough endoplasmic reticulum here is your amazing encyclopedia of yourself called the DNA in form of a double helix okay so this is when you unpack it but when you pack it it's like surrounding histones which they wrap around them and then they form this chromatin and then they form the chromosomes how many chromosomes do we have in our somatic cells 46 DNA transcription means DNA into RNA especially mRNA the mRNA exits a nucleus through the the pores and then in the cytoplasm and gets translated into proteins that's why DNA helps or codes for protein synthesis how about the nucleolus nucleolus literally means a small nucleus it occupies around quarter of the nucleus it appears darker under the microscope but it doesn't have a membrane around it there is no such thing as a nucleoli membrane it doesn't exist the function of the nucleolus assembly of ribosomes and synthesis of RNA the nucleolus and Lars when the cell is synthesizing proteins it's active now it's the same thing as your skin getting darker while having sex same idea you're more active then the nuclear matrix or the substance of the nucleus itself provides support and it includes something called the nuclear lamina a subtype of intermediate filaments which I've talked about in a previous video the vast majority of cells in your body have one nucleus however there are exceptions red blood cells for example have zero not any red blood cells that match your red blood cell very nice osteo class or bone one of the bone cells they have multiple nuclei in white blood cells the nucleus may be segmented or elevated called the BI lobed tri lobed whatever this is a segmented neutrophil the main function of pores are passage of large molecules for small molecules or ion they can just diffuse in the next video we're going to talk about the nucleolus until then don't forget to subscribe and please consider supporting this channel on patreon thank you very much for watching until next time be safe stay happy and study hard