Week 2 Flashcards
What are the CNS, PNS, and Nerves
Central Nervous System- contains the brain and spinal cord
Peripheral Nervous System- contains the nerves and most sensory organs
Nerves- Bundles of individual neurons contained within a protective membrane
what are the three types of neurons
sensory neurons; a neuron that detect changes in the external or internal environment and sends information about these changes to the CNS.
Motor neurons; a neuron that controls the contraction of a muscle or the secretion of a gland.
Interneurons; a neuron located entirely within the CNS and have a communicative role
List the 4 key parts of a Neuron
1, Soma
2, Dendrites
3, Axon
4, Terminal Buttons
Explain the Soma
The Soma is the brain of the cell. It contains membrane cytoplasm nucleus and mitochondria
explain membrane cytoplasm nucleus and mitochondria
membrane is a double layer of lipid molecules within protein molecules in bedded that is substance detectors, security guards and transport is.
Cytoplasm fills the space surrounded by the membrane and contains organelles
nucleus contains the chromosomes – jeans – protein production – important for structure and function
Mitochondria is the energy extraction and ATP
explain dendrites and the synapse
Dendrites help individual neurons talk with one another
Synapse is neural messages that are transmitted from neuron to neuron across the small gap
Explain the Axon and the myelin sheath
an axon is a long tube that carries information from the Soma of a neuron to its terminal buttons called the action potential. The myelin sheath is a fatty substance that works as an insulator of the action potential
Describe axoplasmic transport, anterograde transport, retrograde transport, and microtubules
Axoplasmic transport: Active processes by which substances are propelled along the inside of the length of an axon.
anterograde transport: movement from cell body to terminal buttons
Retrograde transport: movement from the terminal buttons to the cell body
Microtubules: bundles of protein filaments arranged in a hollow core the act as a train tracks to propel substances along the axon. Also provide structural support to a neuron
What are terminal buttons
Located at the end of an axon
They secrete a chemical into the synapse = neurotransmitter
List the 4 types of Glial Cells + brief explanation
Astrocytes (CNS): provide nutrients to neurons
Oligodendrocytes (CNS): provide support to axons and produce the myelin sheath
Microglia (CNS): a very small glial cells involved in phagocytosis
Schwann Cells (PNS): similar to oligedendrocytes, produce a myelin sheath covering pns
Explain the Blood Brain Barrier
The blood brain barrier is a barrier that exists between the blood and the fluid that surrounds the cells of the brain that is selectively permeable. BBB is thinner in some areas (area postrema - vomiting)
what are inhibitory synapses and inhibitory into neurons responsible for
they are the reason why you do not drop a coffee cup when it is too hot for your hand. You are able to stop the motor neuron action and reflex of dropping the cup
What is an action potential
The communication of information within a neuron
what is an membrane potential
The electrical charge across the cell membrane is called the membrane potential. It is the difference in electrical potential inside versus outside of the neuron
What is a resting potential
axons at rest have a negative electrical charge called the resting potential (inside of the axon is more negatively charged compare to the outside)
Explain hyper polarisation and depolarisation
hyper polarisation is when the electrical charge of an axon goes from resting potential – more negative
depolarisation is when the electrical charge of an axon goes from resting potential – more positive
when is In action potential more likely to be sent
when the neuron is D polarised it is more likely to send an action potential. Hyper polarisation is less likely to send an action potential
how is membrane potential established
The electrical charge within the neuron is the result of to opposing forces, diffusion and electrostatic pressure
Explain diffusion and Electro static pressure
diffusion is the movement of molecules from regions of high concentration to regions of low concentration.
Electrostatic pressure is the attractive force between atomic particles charged with opposite signs, or repulsive force between atomic particles charge with the same sign
what are ions, cations, anions
ions are charged particles
cations are positive
anions are negative
what are the ions related to membrane potential
organic ions which are negatively charged and remain inside the cell
chloride ions which are negatively charged and are mostly outside the cell
potassium ions which are positively charged inside the cell
sodium ions which are positively charged outside the cell
what is the sodium potassium pump
The sodium potassium pump contributes to the negative membrane potential by constantly pushing sodium ions outside of the cell and pushing potassium ions in.
Specifically three sodium ions are pumped out and 2 potassium ions are pumped in.
what are ion channels
Ion channels are protein molecules in the neuron membrane to open and close to allow ions to rush in and out of a neuron
what is action potential propagation
the all or none law and the rate law (rate law means the principle that variations in the intensity of a stimulus or other info being transmitted in an axon are represented by variations in the rate at which an axon fires; how often an action potential is triggered)
