Howdy again! This may, sadly, be my last blog post of the year. So to end it strong, oh don't be nervous, we're not going to talk about anything gross like anatomy or physiology, but rather nerves! And I may or may not have just lied in my past statement: we are totally going to talk about anatomy and physiology!
Today our area of expertise is coming from the brain. After all, the brain is our transmitting tower that sends messages all over our body telling it how to react to everything, and I do mean everything, that happens around us.
To begin, the nervous system is divided into two parts: Central Nervous System (CNS) and Peripheral Nervous System (PNS). Now the CNS contains the brain and spinal cord whereas the Peripheral Nervous System contains basically everything else. It has the Autonomic nervous system which communicates with our internal organs and glands and is in charge of arousal (Sympathetic division) and calming (Parasympathetic). The PNS also contains the Somatic nervous system which communicates with our sensory organs and voluntary muscles and is in charge of our sensory nervous system and our motor nervous system.
Within our nervous systems, like with everything in our body, it contains specific functions:
The integrative function is slightly different in which it sorts through information and results in the creation of sensations, thoughts, memories, and decision making. This is associated with the association neuron and inter neuron.
Our motor function does exactly what is sounds like: helps us move. This is what tells our body to dodge something coming towards us or kick the ball during soccer, even when and where fingers need to be placed on a musical instrument. These signals are sent from the CNS to the effectors which are the muscles or glands. The goal of our motor function is usually to maintain homeostasis.
Today our area of expertise is coming from the brain. After all, the brain is our transmitting tower that sends messages all over our body telling it how to react to everything, and I do mean everything, that happens around us.
To begin, the nervous system is divided into two parts: Central Nervous System (CNS) and Peripheral Nervous System (PNS). Now the CNS contains the brain and spinal cord whereas the Peripheral Nervous System contains basically everything else. It has the Autonomic nervous system which communicates with our internal organs and glands and is in charge of arousal (Sympathetic division) and calming (Parasympathetic). The PNS also contains the Somatic nervous system which communicates with our sensory organs and voluntary muscles and is in charge of our sensory nervous system and our motor nervous system.
Within our nervous systems, like with everything in our body, it contains specific functions:
- Sensory
- Integrative
- motor
The integrative function is slightly different in which it sorts through information and results in the creation of sensations, thoughts, memories, and decision making. This is associated with the association neuron and inter neuron.
Our motor function does exactly what is sounds like: helps us move. This is what tells our body to dodge something coming towards us or kick the ball during soccer, even when and where fingers need to be placed on a musical instrument. These signals are sent from the CNS to the effectors which are the muscles or glands. The goal of our motor function is usually to maintain homeostasis.
Getting back to the Peripheral Nervous System, the PNS connects the CNS to organs and muscles, blood vessels, and glands and consists of 12 cranial nerves, 31 spinal nerves, and autonomic nerves which assist in the regulation of the heart muscle.
Earlier on I had mentioned that within the Peripheral Nervous System there was the Somatic and Autonomic Nervous Systems. To go further in depth, the somatic nervous system communicates primarily with our sense organs and is in charge of our skeletal muscles whereas the autonomic nervous system is in charge of the smooth muscles of our internal organs, glands, and heart muscles as well as responsible for regulating the body's unconscious actions. ANS can be broken into three groups:
Earlier on I had mentioned that within the Peripheral Nervous System there was the Somatic and Autonomic Nervous Systems. To go further in depth, the somatic nervous system communicates primarily with our sense organs and is in charge of our skeletal muscles whereas the autonomic nervous system is in charge of the smooth muscles of our internal organs, glands, and heart muscles as well as responsible for regulating the body's unconscious actions. ANS can be broken into three groups:
- parasympathetic-"rest and digest": lowers heart rate, lowers blood pressure, and increases digestion
- sympathetic-"fight or flight":increases heart rate, increases blood pressure, slows down digestion
- enteric: can work autonomously from the brain and spine and governs the GI (gastrointestinal) tract
Did you know that the brain contains over 100 billion neurons and that its communication system is an electrochemical process? It's pretty amazing. What's also amazing is the structure of a neuron.
To give a quick rundown on this amazing element in our bodies: so the dendrites are the recievers and basically bring info into the cell body which passes through the cell body which has a nucleus. This is all connected to the myelin sheath which is the insulating fatty layer that speeds up transmission. This bundle of awesomeness is connected by the nodes of ranvier (totally sounds like something from Monty Python and the Holy Grail) and the axons. The axons act as a conducting fiber. In the middle of the myelin sheath there is the Schwann's (like to food truck) cells which produce the myelin. And at the end of the strand there are the axon terminals which act as the transmitters. Mind blown, right?!? I'm not done! So there are the neurotransmitters, okay, and these pass between the small gap between neurons known as synapses. There are two types of neurotransmitters:
- Acetylcholine: stimulate muscle contraction
- Monoamines: cognitive processes, psychiatric disorders
Last but not least, to follow up with our blogging tradition: The Connection. I have to admit that every time I think of a connection I think of the song "Rainbow Connections" by Kermit the Frog. But anyway, how does the skeletal system and the nervous system connect? Alison Smith wrote a genius article about this very topic and she explains that the "posterior parietal cortex and premotor brain regions" are what initiate the movements that our bodies make. She goes on to explain that the cortex gathers sensory info and in precise calculations it tells the body where to move, the distance, the force needed to complete the movement, and what it will do once this task is performed. She makes the point, and we should all know this, that no movement would be possible without an infrastructure, a braced system, those things we call bones and the skeletal system. Besides allowing us movement, the skeletal system does so much more than that. Our brain is the source of everything and surrounding it, armor as it were, is a semi-thick casing of bone. The same goes for our spinal cord. The thousands of nerves and wires and bundles are all enclosed in a casing of bone for protection, and although this bone isn't as hard as titanium, it saves our lives day in and day out without us putting much thought into it. Have you ever stood up and forgot that the cabinet was opened or you just didn't realize that you were closer to the edge of the table than you thought and your head, back, leg, whatever hit it? Well if everything important in our bodies wasn't surrounded by bone, our mush of brain and sensitive nerves would be smashed to smithereens. It's simply a complicated thing to think about: the millions of things that happen without us knowing in our bodies just to allow us to take just one more deep breath, climb just one more step, swim that one more lap, play that piano. Think of doing that without bones: impossible!
Thank you.
Thank you.
- https://faculty.washington.edu/chudler/organ.html
- http://www.livestrong.com/article/170400-how-skeletal-system-works-with-nervous-system/
- https://www.youtube.com/watch?v=jSFLZ-MzIhM
- http://www.innerbody.com/image/nervov.html
- http://www.rsd.edu/schools/carmichael/masters/pdf/hwsystmswrky.pdf