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Flashcards in Lecture notes Nervous system Deck (73):
1

What is the order of muscle conduction?

1) Motor neuron action potential
2) Synaptic knob & neuromuscular junction
3) Sarcolemma action potential
4) T-tubule action potential
5) Release of Ca++from terminal cisternae

2

What are the next events after the 5 first muscle conduction events?

1 )Ca++ bonds to troponin causing shift in
tropomyosin
2) Bonding site is exposed on actin
3) Myosin head bonds to actin
4) Stored energy is released as “power stroke”
5) Actin moves relative to myosin
6 )ATP used to detach head and bend myosin back to resting position (energy loaded)
7 )Cycle repeated

3

What is the structural and functional unit of the nervous system?

Neuron

4

Neuroglia

• Assist the neuron
• Do not conduct an impulse
• 4 types in CNS
• 2 types in PNS

5

Ependymal (CNS)

* Produce CSF (Cerebral spinal fluid)
* Concentrated in choroid plexus

6

Astrocyte (CNS)

* Most common
* Structural, Blood Brain Barrier, Regulate AP

7

Microglia (CNS)

For CNS Defense- think of WBC’s

8

Oligodendrocyte (CNS)

Produce myelin sheath

9

Neurolemmocyte (PNS)

Produce myelin sheath

10

Satellite (PNS)

Separate cell bodies of ganglia and homeostasis of ganglion environment

11

What are the two structural divisions of the
nervous system?

CNS and PNS

12

What are the two functional divisions?

Sensory and Motor

13

What is the involuntary system called?

Autonomic

14

Which part of a neuron can have more than one branch coming off the cell body?

Dendrites

15

What are the 3 structural neurons?

Unipolar, bipolar, multipolar

16

What are the parts of a polysynaptic reflex?

RSIME

17

What is the voltage for the resting potential of a neuron?

-70mv inside v outside

18

What is the impulse?

Reversal of charge transferred to adjacent areas (+30mv)

19

If stimulated anywhere along a neuron the impulse will travel in the dendrite to axon direction. True or False?

False! It will travel in BOTH directions

20

What maintains the resting potential?

Ion pumps and diffusion

21

What kind of molecules are the ion pumps?

Proteins

22

Where are they located?

In the cell membrane of neurons and muscles

23

A “strong enough” stimulus has to be above the _____ to cause an action potential?

Threshold

24

What are the “helper” cells of the nervous
system called?

Neuroglia (glia)

25

Which produces CSF?

Ependymal

26

Which fights disease?

Microglia

27

Which produces myelin sheath?

Oligodendrocytes and Neurolemmocytes

28

Which isolates cell bodies in the spinal ganglia?

Satellite

29

Myelin is

A waxy membranous wrapping that Insulates the axon

30

the myelinating cell of the PNS

Neurolemmocyte (Schwann Cell)

31

Neurilemma is the

The outermost part

32

Neurofibril node (Nodes of Ranvier) are

Small gaps between each myelinating cell. The axon is exposed

33

The myelinating cell of the CNS myelinate several axons

Oligodendrocytes

34

Speeds up impulses

Saltatory conduction

35

Two factors effect speed of conduction

1. Size of the axon
2. Insulation with myelin sheath, Large, insulated axons are faster

36

Nerve is

A bundle of neuron fibers

37

* Fibers bundled as tracts
* Cell bodies in nucleus
* Myelin by oligodendrocytes

Central nervous system

38

* Fibers bundled as nerves
* Cell bodies in ganglion
* Myelin by neurolemmocytes

Peripheral Nervous System

39

Describe chemical synapse

*The axon ending (of the pre-synaptic neuron) has many synaptic vesicles filled with
neurotransmitter (acetylcholine, serotonin, norepinephrine, dopamine, GABA)
* When the action potential reaches the synaptic knob, the synaptic vesicles release their contents into the synaptic cleft
* The neurotransmitters cross this synaptic cleft and bind to receptor sites on the post-synaptic neuron (2nd neuron) or effector (muscle or gland)

40

Why have a synapse?

Keeps impulse unidirectional

41

Synapse and memory

* They also play a role in memory
* As signals cross a synapse the association is strengthened
* This is how memories are “built"

42

Neurons can synapse with?

* Other neurons
* Muscles
* Glands

43

Sympathetic deals with

Fight-or-flight responses

44

Parasympathetic deals with

Rest-and-digest responses

45

Sympathetic nerves: Summary, origin, specific responses, neurotransmitter

Summary: Fight or flight
Origin: Thoracolumbar
Specific responses: Gland secretions decrease (saliva gets thick), GI tract inhibited, sphincters contract, pupils dilate, increased pulse rate
Neurotransmitter: norepinephrine

46

Parasympathetic nerves: Summary, origin, specific responses, neurotransmitter

Summary: Rest-and-digest
Origin: Cranial-sacral
Specific responses: Gland secretions increase (saliva gets watery), GI tract stimulated, sphincters relax, pupils constrict, decreased pulse rate Neurotransmitter: acetylcholine

47

Autonomic includes

Subconscious pathways

48

* Glands are closer to CNS
* Short preganglionic neurons
* Long post ganglionic neurons

Sympathetic

49

Sympathetic trunk is

Ganglion and synapse

50

*Preganglion neurons arise from cranial or pelvic nerves
* Ganglion are closer to organs
* Long preganglion neurons and short postganglionic neurons

Parasympathetic

51

Primitive brain comes from

Neural tube

52

What germ layer does the brain from the neural tube derive from?

Ectoderm

53

What if it doesn’t close at the caudal end?

Spina bifida

54

The cephalons short version

Prosencephalon
• Telencephalon
• Diencephalon
Mesencephalon
Rhombencephalon
• Metencephalon
• Myelencephalon

55

The cephalons long version

Telencephalon
• Cerebrum
Diencephalon
• Thalamus and hypothalmus
Mesencephalon
• Peduncles and Colliculi
Metencephalon
• Pons and Cerebellum
Myelencephalon
• Medulla oblongata

56

For the brain, Gray is located on

Outside

57

Gray is

Cell bodies & unmyelinated axons

58

White is

Myelinated axons..

59

Funiculus is the spinal cord is

White matter

60

What is the communication between left and right hemispheres in the brain?

Corpus callosum

61

How much energy does the brain use?

The human brain takes up 2% of human body weight but uses 20% of its energy

62

Olfactory is

* Odor detection
* Sensory

63

Optic

Sight-Sensory

64

Oculomotor, Trochlear & abducens

To the eye. eye muscles

65

Trigeminal

* Three branches
* Face-sensory
* Chewing-motor

66

Facial

* Motor to face
* Sensory from tongue

67

Vestibulocochlear

* Hearing and balance
* Sensory

68

Glossophparyngeal

* Tongue sensory
* Throat-motor

69

Vagus

* Visceral- sensory
* Throat- motor

70

Accessory

* Neck and upper back
* Motor

71

Hypoglossal

Tongue-Motor

72

What happens when a neuro damaged?

• Depends on the damage
• If cell body is damaged the neuron is lost and is not replaced
• If axon is in PNS it may repair
• If axon is in CNS usually no repair
• Depends upon the neurolemma

73

Why is there no repair to the CNS neurons?

Repair within the CNS is limited due to several factors.
*Oligodendrocytes do not release a nerve growth factor
* The large number of axons crowded within the CNS tend to complicate regrowth activities
* Astrocytes & connective tissue coverings may form some scar tissue that obstructs axon regrowth