Lecture 1 Flashcards
What are the 3 steps when it comes to a information transmission in the nervous system?
1) sensory input
2) integration to proper motor unit
3) motor output
What are the two main divisions of the nervous system and what are they made of?
CNS- brain/spinal
PNS- all nerves that extend from the brain and spinal
Name the two main divisions of the PNS, what kind of information is it?
What sub divisions do these have? What are their functions?
1) sensory(afferent): somatic sensory fibers (aware of it, input comes from skin, muscles, joints to the brain) & visceral sensory fibers (unaware of it, from the GI, heart, etc.
2) motor: efferent, transmits impulses from CNS to the effector organs. Broken up into 2 divisions: somatic (in control of) and autonomic (no control)—> fight or flight, etc
Autonomic NS breaks into two divisions, what are they and what is their function?
sympathetic–> fight or flight, during activity
parasympathetic–> rest/digest, conserve energy
work opposite to each other
Name the 6 types of Neuroglia
astrocyte, microglial cell, ependymal cell, oligodendrocytes, satellite cells, schwann cells
Astrocytes:
What does it look like, general characteristics and main functions.
Look like stars
most abundant, highly branched, cling to neurons, synaptic ends and capillaries in the brain.
Support neurons, plays a role in exchange of molecules past the BBB (made of capillaries and astrocytes)
What determines if a molecule will be able to pass the BBB easily or not?
size, lipid soluble
Microglial cells:
What it looks like, main function
Small, ovoid cells with thorny like branches, migrate to injured neurons and transform into phagocytes to kill pathogens or debris
Ependymal Cells:
Distinctive shape and feature, function
columnar or squamous.have cilia, line the cavity and aid in the flow of the cerebral spinal fluid
Oligodendrocytes vs Schwann cells:
Where are they each found
oligo: CNS
Shwann: PNS
both wrap neurons with myelin to form the myelin sheath in white matter
Neurons:
1) What is Amitotic?
2) What is the cell body, Rough ER called?
3) What is meant when referring to a Nuclei or Ganglia?
1) never divides
2) Soma or perikaryon, Nissle Body
3) Nuclei is a cluster of neural cell bodies in the CNS and Ganglia lie along nerves in the PNS
Dendrites:
Describe what they look like and what their main function is.
Short, numerous branches, RECEIVE sensory input and send message to Soma, some have spines
The Axon:
Structure- Where does it arise from? Length? Branched? What is the ending called?
arise from the axon hillock, can be short or a meter long (nerve fibers), occasionally branched (axon collaterals), ending is called the axon terminal.
Axon:
Functional Parts- main job? where are signals transmitted from–to? What happens to the signal at the end of the axon? What does it lack? What is anterograde and retrograde?
conduct motor output to effector cells.
trasmitted along the axolemma to the axon terminal where the electrical signal is passed chemically via NT at the synapses.
It lacks rough ER and Golgi, gets protein from Stoma.
Anterograde is movement away from the cell, enzymes, Mitochondria, membrane compounds, etc
Retrograde is movement towards the stoma: dead organelle, signal molecules, viruses and bacterial toxins etc.
Multiple Sclerosis:
Describe it, what are some KEY symptoms , what causes it? How can it be spotted under xray? What are treatments?
Chronic, relapsing/remitting disorder, causes demyelination of the brain and optic nerve, can be genetic or multifactorial. Causes vision loss, paralysis of eye, vertigo and psychiatric problems. Caused by mutated CD4 (t helper) cells releasing cytokines and attracting phagocytes because it doesn’t recognize myelin as self cells. Can be spotted by finding plaques that are unsymmetrical on each side of the brain. Treated by high dosage of steroid use or interferon.
