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Flashcards in Final- NS fundamentals Deck (30):
1

Sensory (afferent)

-Transmits impulses from sensory receptors toward CNS
-Somatic-impulses from skin, skeletal muscles (conscious)
-Visceral-impulses from visceral organs toward CNS (unconscious)

2

Motor (efferent)

-transmits impulses away from CNS to effector organs
-somatic-impulses from CNS to skeletal muscles (conscious)
-autonomic-impulses from CNS to smooth muscle, cardiac muscle and glands (unconscious)

3

Difference between nuclei and ganglia

Nuclei-cluster of cell bodies in the CNS
Ganglia-cluster of cell bodies in the PNS

4

Anterograde transport

-moves substances away from cell body
-ex: neurotransmitters

5

Retrograde transport

-moves substances towards cell bodies
-ex: vesicles, NT recycling

6

What is MS made of and what is its purpose

-made of lipids from Schwann cells (PNS) and oligodendrocytes (CNS)
-purpose is the insulate axons and make AP faster

7

Depolarization

Makes the cell membrane more positive

8

Hyper polarization

Making the cell slightly more positive back to the RMP which is -55

9

Repolarization

Makes the cell negative down to -70

10

How do action potentials self propagate

Positive Na+ ions at origin activate neighboring VG Na+ channels

11

Saltatory conduction

Only generated at Nodes of Ranvier
Diffusion of Na+ ions under myelinated nerve segments cause a fast propagation of the AP stimulus in those regions

12

How can AP be blocked

-Novacain
-cold and pressure

13

Chemical synapse characteristics

-release and receptor of chemical NT
-slower than electrical

14

Electrical synapse

-least common
-neurons joined by gap junctions
-fast communication
-allow synchronization of interconnected neurons

15

Steps of chemical synapse transmission

1. AP arrives at axon terminal
2. VC Ca channels open, Ca rushes in
3. Ca entry causes synaptic vesicles to release NT by exocytosis
4. NT binds receptor on post synaptic neuron
5. NT fate
-stays in synapse
-taken up by transport proteins
-enzymatically degraded
-diffused away from synapse

16

EPSP

Brings the membrane close to the AP potential

17

IPSP

Brings the neuron away from the AP threshold
Opens K+ or Cl- channels

18

Temporal summation

One stimulus pushing the AP to its threshold

19

Spatial summation

Multiple stimuli pushing the AP to its threshold

20

ACh

-stimulates muscle to contract
-important in CNS for learning and memory
-develop Alzheimer's if you have low levels

21

Serotonin

-inhibitory in CNS
-Calms anxiety, relieves depression, helps us sleep
-low levels means you'll have anxiety and depression

22

Histamine

Involved in learning and memory
Stimulates wakefulness
Antihistamines-makes you sleepy

23

Dopamine

-stimulates pleasure centers
-stimulates attention, focus, motivation and drive
-elevated dopamine levels means you could have schizophrenia
-low levels of dopamine means you could have Parkinson's

24

Norepinephrine

-ANS
-acts on cardiac, smooth muscle and glands
-increases heart rate, blood pressure and dilated pupils
-increases arousal and attention

25

GABA

-inhibitory NT
-reduces anxiety and stress

26

Endorphins

-block transmission of pain
-increases pleasure sensations

27

Enkaphalins

-released in pregnant women during labor

28

Astrocytes

-most abundant
-attach neurons to capillaries
-guide formation of synapses
-control chemical environment around neurons

29

Micro glial cells

-monitor health of neurons
-phagocytose invading microorganisms or dead/dying cells

30

Difference between CNS and PNS

CNS-Brain and spinal cord
PNS-All the neural structures outside the brain and spinal cord