Thursday, August 29, 2013

Neuroglia

Neuroglia are support cells for the neurons in the nervous system.  They have a very wide variety of functions, and I'm sure it hasn't all been discovered.

Now, here's the interesting thing.  Studies done on (supposedly) Einstein's brain, show that he didn't really have any greater number of neurons, but actually had more neuroglia, particularly astrocytes, which were concentrated in the area of the brain involved in imagery and complex thinking (NPR news article on the subject, June 2010).


Picture source

My thought is that we don't know which came first - the astrocytes or his genius.  Perhaps using your brain well leads to making more astrocytes in order to support how much you're using certain areas of the brain, rather than the astrocytes coming first and giving natural intellectual ability.

So, on that note, we'll take a look at these cells. :)  Here is a good way to categorize them, from interactive-biology.com.  I'll expound on these more.

Source (interactive-biology.com)


 And for the visual folks out there, here are a couple of diagrams.
Source
Source

Neuroglia in the Central Nervous System 
Source
Oligodendrocytes (a type of macroglia)
  • Support neurons in the CNS by myelinating.  Have multiple "arms" with which they myelinate several axons.
  • Myelination insulates axons of neurons which allows their conduction to go much more quickly.  (For some info on how this works, go to this post on action potentials and scroll to the bottom for "saltatory conduction".)
  • Similar function in PNS is performed by Schwann cells

Astrocytes (a type of macroglia)
  • Named for their star appearance (astro = star, cyte=cell)
  • Maintain neuronal environment
  • Part of the blood-brain barrier
  • Control what substances are transported from blood to neural tissue (Source article)
  • Have their own signalling system and can regulate messages of neurons
  • Topic of much research - some are calling these "the other brain" (Source article)
    Source

My note on Astrocytes: wow, these look like such an exciting topic right now!  These are the cells that Einstein's brain had more of, and it looks like we are just discovering how integral they really are to the function of neurons!

Microglia
  • Immune cells of the CNS - these bad boys take care of infection by foreign pathogens, and keep any abnormal neurons in check, gobbling up anything that shouldn't be there.  In short, they are the macrophages of the brain and spinal cord.
  • Named for being small (micro), which allows them to get around to whatever small spaces necessary for fighting infection.
Source

Ependymal glia

Source on brainyinfo.com

Neuroglia of the Peripheral Nervous System
Schwann Cells/ Neurolemmocytes
Source

  • Schwann cells have the same function in the PNS that Oligodendrocytes have in the CNS, namely myelination.
  • The cell wraps itself around the axon of a neuron, insulating it, as seen below.  Pretty cool, eh?


Source on brainyinfo.com



Satellite Cells
  • Cushion neurons
  • Help control the environment of neurons and maintain synaptic integrity by insulating areas where there shouldn't be additional synapses on the neuron.



Tuesday, August 27, 2013

Plant Embryos

This post will be a running work in progress as I go through my Plant Biology class.  Here's what I've learned so far.


Source: stolaf.edu
The above picture (yes it's an actual photo of something under a microscope) is a good simple representation of the cotyledons of a dicot plant.  "Di" means "two", and "cot" refers to the cotyledons, so all embryonic dicots have two cotyledons.  Monocots then, naturally, have one cotyledon ("mono" means "one").
Simply put, cotyledons are embryonic leaves of the plant.

Here's a better detailed diagram:


Source on Britannica

Notice again that the dicot has 2 cotyledons.  Epicotyl will give rise to the shoot system and is above the cotyledons, while the hypocotyl is below the cotyledons and also contributes to the shoot.  This is easy to remember because "epi" means above or upon, while "hypo" means below.

The radicle gives rise to the root system.

Here's a fun picture showing a peanut.  The yummy part we eat is actually the cotyledons (leaves!).  I never knew that little nub in the middle that I sometimes discard was the actual plant in the making. :)





Key Terms in my own words (clicking on the term will take you to the wikipedia page for more info)  *PLEASE do not copy/ paste this to plagiarize homework assignments.  Read about it, rephrase in YOUR own words.  Don't let me be a source of academic dishonesty, even though I know a simplified list like this lends itself to that.  Please, please... be a smart cookie.
Cotyledon: embryonic leaf
Dicot: a category of plants which has 2 cotyledons in its embryonic stage
Monocot: a category of plants which has 1 cotyledon in its embryonic stage
Radicle: embryonic root.  First thing to emerge from seed.
Epicotyl: gives rise to shoot system, is above the cotyledons.
Hypocotyl: is below the cotyledons, contributes to the shoot system, adds height to the plant

Saturday, August 24, 2013

Long time no see. My excuse: boyfriend and Facebook

I'm very embarrassed to admit I have 6 posts in draft form.  Since I haven't posted since, what, March?... It's time I get my blogging juices flowing again by just putting SOMETHING live on the internet and then recommitting to posting more frequently (and to finishing those 6 posts!).

The interesting thing is I don't have readers that follow everything I post, it's more like a bunch of random people who come to learn about one particular thing I have blogged about and pops up on their search engine.  Which is great, I'm glad to be an educational source in any capacity.  But it does kind of lend itself to me being lazy.  People can still access my very popular posts anytime, so I don't feel like I'm letting anyone down or anything.  In fact, the posts I do like this one that doesn't have a specific scientific topic, usually don't even get read.

This blog has been my life, my love, my passion for almost 2 years, but the honest truth is - I got a boyfriend in March and since then my "free time" has no longer been used on blogging!  I have, however been doing lots of awesome real-life stuff.  Here, I'll put some pics to prove it! (Posted at the bottom.)

But I miss my blog and I feel I've been neglecting a huge part of "me", and I need to get back to it.

School starts Monday so this is a good chance to focus more on science and learning- my blog helps me do that by focusing my own studies and expanding on them.  Luckily I am taking NEUROSCIENCE this semester, and I'm so excited you don't even know!  So I bet you'll be seeing lots of posts related to that topic.

I think another reason for my recent blog laziness is that I got more involved on Facebook.  I found lots of really awesome science pages that post way cool stuff, so I've been getting my science fix that way.  Some of my favorites are: Science Is AwesomeGive a S*** About Nature, All Science All The Time, Nerds Do It BetterScience: The Magic of Reality, Science Alert, and lots more.  I get posts from probably 20 different places, it's awesome.  What I need to actually do is find out the info there, and then post it here!  I will try to start doing that and getting the info out to more people in Google search land.

So, here we go, another semester of awesome learning, coming right up!

Spelunking 3/14/2013

Holding a real human brain at The Leonardo 3/16/2013
Post on this


Hiking by Rock Canyon 3/29/2013

Hiking in the rain up Dry Canyon - found a deer carcass
Post on this

Visit to the Zoo - a friend of my boyfriend gave us a personal animal show :)

Zoo 4/29/2013

Backpacking up Dry Canyon 5/11/2013

I built a fort on Mother's Day 5/12/2013


Collared Lizard on a waterfall hike 5/20/2013

First time River Rafting!  Woohoo!  5/20/2013

Hiking a little peak in Roosevelt

Touching a snake from the Bean Museum


A sunset hike up dry canyon with the boys

Climbing trees at the duck pond
Found this weird animal up the tree

While camping, found this great part of the river to play in, in Spanish Fork 6/2/2013 





Dinosaur National Monument! 6/30/2013
I love bones!

Rain in Denver, Colorado 7/1/2013

Backpacking in the Rocky Mountains in Denver 7/3/2013


I got to be a camp counselor at Nature High Summer Camp! 7/8 - 7/13/2013
Post in the works



My boyfriend made a Portal cake for my birthday! :D 7/13/2013

We finished the summer off with a visit to the hospital (appendectomy).  At least a visit from the Kid History guys brightened things up.


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