Nervous Systems

2/27/2021

Nervous Systems

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How do nervous systems affect creatures?

In this class we will learn about the nerve systems of various species, the nervous systems of humans, how nerve systems help us survive, and how certain chemicals affect nerve cells.

Parts of a nerve cell

http://hyperphysics.phy-astr.gsu.edu/hbase/Biology/nervecell.html

https://www.researchgate.net/figure/a-Structure-of-neuron-with-axon-dendrites-and-synapses-b-Structure-of-a-synaptic_fig3_278827467

https://lifesciences.umaryland.edu/neuroscience/Research-Focus-Groups/Synapses--Circuits/

https://courses.lumenlearning.com/wm-biology2/chapter/nervous-system/

https://amyloidosis.net.au/patients-and-carers/organ-involvement/nerves/

Nerve SYstem Vocabulary

The brain and the spinal cord make up the central nervous system (CNS)

The CNS interlinks with the peripheral nervous system, which through a network of nerve fibers sends messages around the body (hands and Feet etc.)

The peripheral nervous system has three main divisions: Autonomic, Sensory and Motor. Below are types of nerves in the PNS:

sensory nerves, which connect to the skin.
motor nerves, which connect to the muscles.
autonomic nerves, which connect to the internal organs.

The sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response.

The parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.

Afferent neurons: sensory, carry information to brain

Efferent neurons: action, motor, carry information away from brain

Somatic Nervous System: controls all the stuff you think about doing

Autonomic Nervous System: all the things we do without thinking, breathing, digestion, heartbeat

Sympathetic Nervous System: fight or flight

Parasympathetic Nervous System: bodily functions: digestion, heart, constricts lungs, makes nose runny

How Neurons Connect to other Neurons

Sodium Potassium Pump: uses ATP to let 3 sodium ions out in exchange for 2 potassium ions getting in.

Ion Channel: do not need ATP to function, ions such as Sodium, each cell can have around 300 different types of ion channels, each for a specific type of ion.

Action Potential: the change in electrical potential associated with the passage of an impulse along the membrane of a muscle cell or nerve cell.

https://www.britannica.com/science/action-potential

Depolarization and Repolarization

https://www.cliffsnotes.com/study-guides/anatomy-and-physiology/nervous-tissue/transmission-of-nerve-impulses

Sodium Potassium Pump

NERVOUS System Review

Nervous SYstems in various animals

A sea sponge is considered an animal, it is however one of the most ancient animal type that we know of, they do not have a nervous system like other animals do, each cell reacts to stimuli independently, a sea sponge is a collection of cells that are living together like lego pieces.