week 2 Flashcards
1. Name and describe parts of the neuron and explain their basic function a. Types of neurons b. External structures c. Internal structures 2. Name and describe the supporting cells of the CNS 3. Discuss the role of the Blood-Brain Barrier
What is the CNS?
central nervous system comprises the brain and the spinal cord.
What is the PNS?
peripheral nervous system is everything outside of the CNS
Do the CNS and PNS interact?
Yes, all the cells come together to create the skin, nails your hair.
What is the Cell?
basic units of the structure and function of living things
What is Cell Theory?
All organisms are made of one or more cells
All life functions occur within cells
All cells come from already existing cells
What is the neuron?
(Eukaryotic cell)A cell with a nucleus
cells of the nervous system that generate electrical signals (action potentials) which allow them to communicate with other neurons.
What is the difference between Eukaryotic and Prokaryotic cells?
prokaryotic cells, and these are cells of bacteria and these types of cells, the pro carrier itself. And have no nucleus
(Eukaryotic cell)A cell with a nucleus
What is a cerebral pyramidal neuron?
type of neurons that are found in areas of the brain such as the cerebral cortex, hippocampus and amygdala. Soma is in the center
What are medium spiny neurons?
play a key role in inhibitating and controlling movement of the body and the limbs of the body.
What are the 3 types of neurons?
Bipolar: 2 processes. Usually sensory neurons (e.g. retinal cells), also interneuron
Multipolar: Multiple processes: Most common neuron in the CNS
Unipolar or Pseudo-unipolar: One process. Sensory neurons
What are the 3 main types of neurons based on function.
Sensory neuron
Motor neuron
Interneuron
What is a sensory neuron?
Soma located in PNS
Detects changes in the external and internal environment and sends info to CNS
What is a motor neuron?
Soma(cell body) located within the CNS
controls muscle contraction and secretion of glands
What is an interneuron?
Located in CNS within neuronal structures
Connect somatic and motor information
Explain the process of Reflex.
We have neural connections that provide info about stimulation, such as heat, and sending that heat info to the CNS (afferent fibers) and then a response coming from the CNS into the PNS (efferent fibers) causing an automatic reflex.
What is afferent transmission?
info. coming from the PNS into the CNS
What is the efferent transmission?
exiting info. From the CNS to the PNS
What is the Sensory somatic nervous system?
movement of skeletal muscles.
What is the Autonomic nervous system?
the connection between the CNS and the PNS, within the body ; the heart, lungs, kidney, internal but still PNS
What is the node of ranvier?
small spaces not covered by myelin
What is mylien?
allows electrical signals to propagate down the axon from the cell body to the terminal button,
What is a dendrite?
Short branched extension of nerve cell along which impulses received from other cells at synapses are transmitted to the cell body
What is the cytoplasm?
jelly-like, fills up the soma and the organelles float in it
It is the place of chemical reactions
It is always in motion, moving material from one part of cell to other
What is the mitochondria?
powerhouse of the cell. It breaks down nutrients like glucose that gives it energy
What is the structure of the cell membrane?
Pliable lipid bilayer(2 layers), which separates the extracellular space of the cell from the intracellular space of the cell
The “head” of the bilayer are hydrophilic
The internal “tails” are hydrophobic
Selectively permeable so the interior is hydrophobic meaning only certain molecules can pass through – small, non-charged molecules (oxygen, carbon dioxide etc)
Proteins embedded (ion channels, ligand receptors, sodium-potassium pump)
What is the function of the cell membrane?
Protects inner cellular environment (Intracellular Fluid/ Extracellular Fluid)
Regulates molecules that enter and exit the cell (Gatekeeper)
Passive Transport (ion channels) vs. Active Transport (sodium-potassium pump)
Passive: requires little energy from cell
Active: require steady energy from the cell
What is the cytoplasm made up of?
cytosol and organelles
Cytosol = Thick, jelly-like substance ~ 80% water
What are organelles?
membrane-enclosed bodies within the cell
What is the Nucleus?
“Control center” of the cell
Contains chromosomes/DNA/genes
It directs many of the cell’s activities
What does an underactive mitochondria lead to?
underactive mitochondria can lead to specific behavioral disorders like depression, hearing loss and motor slowing.
What does a hyperactive mitochondria lead to?
associate with autism spectrum disorder.
What is the Endomembrane System
Endoplasmic reticulum
Golgi Apparatus
Lysosomes
What is the Endoplasmic reticulum?
Location for synthesis of proteins (rough endoplasmic reticulum - RER) and lipids (smooth endoplasmic reticulum - SER)
What are Ribosomes?
organelles in the cytoplasm and within the RER which transports proteins for the cell
What is the Golgi Apparatus?
organelle that packages the products synthesized by the ER
What are Lysosomes?
organelle that breaks down damaged cellular components or foreign material. Also facilitates apoptosis
What are the RER and SER important for?
Ensures the wellness of the cell functioning of the cell and therefore the organism
What is the Cytoskeleton?
part of cytoplasm which is important for cell shape and movement
What are Microtubules?
A long strand of bundles of protein filaments (tubulin)
Involved in transporting substances from place to place within the cell and along the axon.
It is one if these 3:
Axoplasmic transport (aka axonal transport)
Anterograde -> soma to periphery
Retrograde -> periphery towards soma
What are TAU proteins?
They stabilize microtubules
When there is distribution of TAU protein they can disrupt the Microtubule network
Distribution found in TAU pathologies can be found in… ?
This pathology can be found in alzheimer’s disease
What is the supporting cell of the CNS?
Glia cell, or Neuroglia:
The “glue” of the nervous system
What are the roles of the glia cells?
Various roles: support neurons, modulate neuron communication, and maintains homeostasis of the nervous system
What are the 4 types if Neuroglia cells in the CNS?
Ependymal cells
Astrocytes
Microglia
Oligodendrocytes
What are the 2 types of Neuroglia in the PNS?
Schwann Cells
Satellite Cells
Describe the Ependymal cell.
Lines each of the 4 ventricles and spinal cord
Filters blood to make CSF (cerebral spinal fluid)
Desribe the Astrocytes.
Physical support to cell Repair damage to tissue Controls chemical environment Fosters neural communication (tripartite synapse) Nourishes cells
Desribe the Microglia.
Smallest of glia
Macrophage of the CNS
Immune defense
How is the Microglia an immune defense in the CNS?
the immune response in the central nervous system, by acting as macrophages clearing cellular debris and dead neurons from the nervous tissue through the process of phagocytosis,which is essentially where the microglia are eating the cells
What are Oligodendrocytes?
Myelin sheath of the CNS
a single oligodendrocytes not only provides multiple seven segments on a single axon, but among multiple axons
Implicated in MS (multiple sclerosis)
MS refers to scars
What are the Schwann Cells?
Provide myelin sheath to axons in the PNS
Each myelin “segment” is made up of a single Schwann cell
An entire schwann cell will wrap around the axon
What are the Satellite Cells?
Surround neurons in sensory, sympathetic and parasympathetic ganglia
Regulate extracellular space in the PNS
Activate in response to tissue damage – aid in repair of damaged tissue
Implicated in chronic pain and muscular dystrophy
Explain the Ehrlich & Goldman BBB experiement.
Ehrlich injected colored dye into the bloodstream into the rodent and he noticed that the tissue was stained, the brain remained unstained. The PNS absorbs the blue dye
He then injected the dye straight into the CNS , the cerebral spinal fluids and it stained the brain but none of the tissue of the PNS
What is the BBB (blood brain barrier)?
BBB is a semi-permeable barrier
Passive diffusion of oxygen, carbon dioxide, small uncharged molecules, lipid soluble molecules
Active transport for glucose, amino acid, choline, iron, hormones
What is the function of the BBB?
Protection from forgein substances
Homeostasis, regulates sodium and potassium, ensures balance
Nutrition, transports glucose to provide energy
What can the BBB be compromised by?
Hypertension
Radiation
Infection, trauma/inflammation
What are Circumventricular Organs?
Allows the brain to monitor the physiological status of the body
Type of Circumventricular Organs; Area postrema– vomiting center
