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Flashcards in Cellular Nervous System Videos Deck (25)
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1
Q

Structure of Neurons

A

-Same basic components of all cells (organelles)
-Have processes for communicating with other nuerons and cells tpes
-Nissl Substance-Same organelle as endoplasmic reticulum
- Localizations of organelles may be different
-Neurons commicate with each other via electrical and chemical signals
-Neurons utliize a lot of oxygen and ATP
-

2
Q

Parts of Neuron

A

Dendrites - Receiver
Soma - Cell body where the nucleus is located and organelles
Axon Hillock - 1st part of the axon Electrical massage. Each neuron will only have one axon through which they send out information
Axon
Presynaptic terminal - electrical message will cause the release of neurotransmitter from their terminal to pass the message to other neurons
-think of electrical cable

3
Q

Communication between neurons: The Synapse

A

Synapsing Term used for connecting point,

with muscle, glands, organs or any type of tissue in the body.

4
Q

How do neurotransmitters and proteins get to the synaptic terminal?

A

Microtubules are train tracks so it will

5
Q

How do large neurotransmitters and proteins get to the synatic terminal

A
  • Large neurotransmitters and proteins are by Nissl Sustance (Rough ER) at the cell body and shipped to the terminal
  • Cargo made at the cell body is transported by microtubles. along using kinsesins (antergrade) away and dyneins (retrograde) back towards
6
Q

Morphology of Neurons

A

-Multiple polar neurons (multiple projections coming off the cell soma/cell body) found in brain

Bipolar - found in nose and retina 2 projections (dentrit and exon)

Unipolar - intervate our skin provide sensation for us (no dentrits on axon) on axon that goes to skin and one axon to our spine

7
Q

Glial Cells

A

Support cells in nervous system and communicate with neurons but not sending electrical signals as neurons do

Includes oligodroctyes and Schwann cells but also astrocytes, microglia (can regenerate) and go under mitosis

Out number neurons 10 to 1

8
Q

Astrocytes

A
  • Star shaped
  • Found throughout the Central Nervous System (brain and spinal cord)
  • Don’t fire action potentials or communicate electrically just not at synapses
  • Can release waves of calcium
  • Do not have synapses, but can release some neurotransmitters
  • Remove neurotransmitters from synapse (what purpose does this serve?) - shut off signal, quickly pass on the message and then stop
  • play a role and not directly involved in controlling our communication in different parts of our body
  • provides nutrition for neurons through connections with blood vessels
  • Important for providing nutrition to neurons through the Blood Brain Barrier
  • help form blood-brain barrier capillary and blood vessels in the brain are poorest -
  • Tight junctions between the cell that make up the capillaries within the brain and surrounding that are Astrocytes end feet. Any molecules that do get through they have to go through the astrocytes to get to the neurons. Non polar molecules can’t get through.

Critical for drug design and keeping foreign pathogens out and keeping neurons healthy.

-Neurons can’t divide or replicate

9
Q

Oligodendrocytes

A
  • Wraps axons in the CNS with myelin (fatty coating that wraps around the axons and helps ensures the electrical message stays within the axon and travels quickly
  • Found in brain and spinal cord
  • Can wrap multiple axons (insulation)
10
Q

What is Myelin

A
  • Fatty insulation around our nerves
  • Prevents electrical current from shorting out
  • Speeds conduction velocity of the electrical current
11
Q

Clinical Correlate: Multiple Sclerosis

A
  • Attack on Oligodendrocytes
  • Disease characterized by Demyelination in the CNS (although there are reports that MS can affect myelination in the PNS of some patients)
  • Autoimmune disease the body mistakenly attacks protein in the myelin and starts to degrade it
  • Onset age 20-40, more prominent in females living in the northern hemisphere
  • Abrupt onset attacks that are often relapsing-remitting

What kind of symptoms do you think these patients might have?

  • Depends on what part of the brain are attacked and see patches of sclerosis
  • Motor symptoms, poor balance, difficulty with sensation or lightening bolt sensation, pain, visual symptoms, hearing difficulty, cognitive difficulty

No cure

12
Q

Microglia

A
  • Functions as phagocytes (bulk active transport Endocytosis) in CNS type of endocytosis
  • Clean up damaged and debris
  • Abnormal activity linked to disease (Azhlmers, parkinson,stroke)

-Sometimes find macrophages that may get in but most of the time can’t get pass the Blood Brain Barrier

13
Q

Ependymal Cells

A

Single layer of cells that lines the fluid-filled spaces of the brain and the central canal of the spinal cord

-Help move fluid along

What are the projections coming off of their apical surfaces, and why do you think they are present?
-Cilia to produce movement with fluid

• What type of epithelial tissue are ependymal cells?
-Simple epithelium and different types of morphology

14
Q

Neural Stem Cells

A
  • We have small numbers of neural stem cells in the brain
  • Located around the ventricles (cavities of the brain)
  • Found in hippocampus (memory)
  • Damaged brain areas appear to attract stem cells

-Recovery might be poor

  • Do we make enough to make a difference?
  • Induce repair
  • Can we transplant neural stems cells into damaged brain regions to induce repair?
  • Will they know when to stop dividing
  • Can the new neuro cells actually form the right connect or form improper connection
15
Q

Tumors in the Nervous Systems

A

-Brain tumors are not due to neurons because they don’t divide
-Gliomas are tumors of glial cells (ie.astrocytoma)
Why are tumors even benign ones (not going to spread) problematic in the CNS? - We have fixed cavaties within the skull and spinal cord as the tumors grow there will compress brain or spinal cord tissue

Metastatic tumors (from elsewhere in the body are likely more common than all other CNS tumors combined)

16
Q

Schwann Cells

A
  • Wrap nerves in peripheral nervous system with myelin
  • Can wrap only one axon at a time
  • Acts as phagocytes in PNS
  • No microglia in PNS
17
Q

Clincial Coorelate: Gullian-Barre Syndrome

A

-Acute inflammation and demyelination of peripheral nerves
-Attack on Swchann cells
-Autoimmune in nature
-My start in the feet and spread on
-2-4 weeks occurs after a viral infections
-What do you think the symptoms are for this disease (contrast it with MS)?
-Motor deficit, sensory information
MS -Visual deficit, cognitive deficit

-this disease can affect muscles in the diaphragm

18
Q

Organization of the Nervous System

A

CNS (brain and spinal cord) - sending commands out to PNS, sending impulses to trigger muscles contractions

Peripheral NS (cranial and spinal nerves) - communicating back to CNS and sensory type of information

Sensory info (afferent) - coming into the PNS and heading to CNS

Motor (efferent) - Coming down from the CNS and out to PNS to get to our muscles

Most of the decisions are based on the sensory system and leads to a motor output.

We really need both of them to function normally.

19
Q

Meninges

A

Three laters that surround the brain
Function: support and protection
-Dura Mater (outlayer, thic leathery layer, Acacnoid Mater (looks like spiderwebs and empty space filled with fliuds), Pia Mater (against the brain tissue itself)

20
Q

Dura Meter

A
  • Tough outer covering (calvarium)
  • Attached to the interior of the skull above and the arachnoid mater below
  • Holds the brain in place
21
Q

Falx Cerebri and Tentorium Cerbelli

A

Falx Cerebri extension of the dura mater separates the two hemispheres of the brain

Tentorium Cerebelli separates the two hemispheres from the cerebellum. (think of it like a tent) runs more transverse plane

22
Q

Arachnoid Mater

A
  • Loose connective tissue
  • membrane below the dura
  • blood vessels will run between subarachnoid space
  • Thinner and more loosely attached
  • cerebral spinal fluid
23
Q

Pia Mater

A

Very thin, basically impossible to remove
Transparent – when you look at the brain, you are looking through the pia mater
- more squamous and flat

24
Q

Clinical Correlate: Meningitis

A

• Inflammation of the meninges surrounding the brain or spinal cord
• Caused by bacterial (more servere) or viral infection – biggest problem is body’s
immune response
• S&S: headache, fever, confusion, vomiting, neck stiffness, photophobia
• Symptoms worse in upright position bc blood from heart has to put up against gravity and contribute to more pressure in the head.
-lead to death

25
Q

A stroke

A

When neurons die as a result of a lack of blood flow. It is the neural equivalent to a heart attack