Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

SBI4U: Chapter 8 > 8.2: Structures and Processes of the Nervous System > Flashcards

8.2: Structures and Processes of the Nervous System Flashcards

1
Q

What are the 2 systems of the PNS and how are they different?

A
  1. Somatic System: Voluntary actions
  2. Autonomic System: Involuntary actions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does the somatic system consist of and do?

A
  • Sensory receptors in the head and extremities
  • Nerves that carry sensory information to the CNS
  • Nerves that carry information from the CNS to skeletal muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does the autonomic system do?

A
  • Controls glandular secretions
  • Functions cardiac muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 2 main types of cells in the nervous system?

A
  1. Neurons
  2. Glial Cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What do neurons do?

A
  • Conducts electrochemical signals
  • Respond to physical and chemical stimuli
  • Releases chemicals that regulate body processes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What do glial cells do?

A
  • Nourish neurons
  • Remove their wastes
  • Protect against infections
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the four common features of a neuron?

A
  1. Dendrites
  2. Cell Body
  3. Axon
  4. Branching Ends
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do dendrites do?

A
  • Receive nerve impulses from other neurons or sensory receptors
  • Relay impulses to the cell body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does the cell body do?

A
  • Contains a nucleus
  • Receives input from the dendrites
  • If the input is large enough, it is transmitted to the axon, where an impulse is initiated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does the axon do?

A
  • Receives and processes input from the cell body
  • Conducts input away from the cell body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where is the myelin sheath located and what does it do?

A
  • Encloses some axons of neurons
  • Protects the neurons
  • Speeds the rate of nerve impulse transmission
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the role of the nervous system?

A
  • Equipped to sense and responds to continuous changes in the internal and external environment
  • Performs the function of regulating body structures and process to maintain homeostasis despite various fluctuations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does the afferent system do?

A

Receives and transmits input to the CNS by afferent neurons. Carries impulses impulses from sensory receptors to the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the efferent system do?

A

Transports input from the CNS to muscles and glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Is the afferent system motor or sensory?

A

Sensory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which system is subdivided into the parasympathetic and sympathetic systems?

A

The autonomic system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which system is subdivided into the autonomic and somatic systems?

A

The efferent system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What do Schwann cells create?

A

Creates myelin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What do myelin sheath cells do?

A

Protect the neuron and speed up nerve impulse transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where are the nodes of Ranvier?

A

In between the Schwann cells, on the axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What do the nodes of Ranvier do?

A

Speed up the rate of electrical impulse transmission

22
Q

What are the 4 factors of nerve signalling?

A
  1. Reception
  2. Transmission
  3. Integration
  4. Response
23
Q

Explain reception in neural signalling

A

Detection of stimulus, performed by neurons and specialized sensory receptors

24
Q

Explain transmission in neural signalling

A

Movement of a message along the neuron to and effector (muscles or glands)

25
Q

Explain integration in neural signalling

A

Sorting and interpretation of multiple neural messages and determination of an appropriate response

26
Q

Explain response in neural signalling

A

Output or action

27
Q

What is a reflex arc?

A

A connection of neurons which responds to a stimulus

28
Q

What is the charge on the inside of the cell in a resting neuron?

A

Contains anions, so the charge is negative

29
Q

What are the 3 factors that maintains resting membrane potential?

A
  1. Large negatively charged neurons in intracellular fluid
  2. Plasma membrane has ion-specific channels that allow the passive movement of ions across the membrane
  3. Na/K Transport Pump
30
Q

What is the charge on the outside of a cell in a resting neuron?

A

Contains cations, so the charge is positive

31
Q

Explain the first factor of the resting membrane potential

A

Neurons are too large to move through the membrane

32
Q

Explain the second factor of the resting membrane potential

A
  • K channels are usually open during resting potential (-70mV)
  • Na is unable to move as easily
  • This causes the charge inside the cell to become more negative, relative to the outside, which is positive
33
Q

Explain the third factor of the resting membrane potential

A
  • Na/K pump releases 3 molecules of Na, while 2 molecules of K comes in
  • Uses ATP in hydrolysis
  • Higher Na concentration outside the cell, higher K concentration inside the cell
34
Q

What is the resting potential of an unstimulated neuron?

A

70mV

35
Q

Explain the 1st step of an action potential

A

Triggered when threshold potential is reached

36
Q

Explain the 2nd step of an action potential

A

When membrane potential reaches threshold potential, voltage-gated sodium channels open, making it permeable to sodium ions. The Na ions outside the cell move down their concentration gradient to an axon. In a millisecond or less, enough positively charged Na ions cross the membrane to a small area in the axon, making the potential difference 40mV

37
Q

Explain the 3rd step of an action potential

A

The change in potential difference causes the Na channels to close, opening the K channels. The K ions move down their concentration gradient to the outside of the axon and carries a positive charge out. The membrane potential depolarizes, making the potential difference -90mV, causing the K channels to close

38
Q

Explain the 4th step of an action potential

A

The NaK channel and the small amount of naturally occurring diffusion repolarizes the membrane to its original membrane potential of -70mV

39
Q

Explain the 5th step of an action potential

A

A few milliseconds after the action potential occurs, the membrane cannot be stimulated and Na channels are temporarily inactive. This is called the refractory period.

40
Q

Explain the myelinated neuron

A

The action potentials generate only at the nodes of Ranvier

41
Q

What is the main difference between myelinated and unmyelinated neurons? How does it work?

A

Myelinated- Impulse performs a saltatory condition, where the impulse jumps or leaps
Unmyelinated- Impulse is continuous and does not perform saltatory condition, making the impulse transmission slower

42
Q

How does the Na/K pump work?

A
  • NaK pump uses ATP from hydrolysis to pump 3 Na ions out and 2 K ions in
43
Q

What does acetylcholine do?

A
  • Aids in muscle contraction, memory formation, and learning
44
Q

What is the difference between excitatory and inhibitory neurotransmitters?

A

Excitatory: Speeds up nerve transmission by depolarizing the postsynaptic membrane
Inhibitory: Slows down nerve transmission by hyperpolarizing the postsynaptic membrane

45
Q

Explain the pre-synaptic neuron

A
  • When an action potential reaches the end of a presynaptic neuron, the impulse causes intracellular sacs that contain neurotransmitters to fuse with the membrane of the axon
  • Synaptic vessels release their contents into the synaptic cleft by exocytosis
  • Neurotransmitters diffuse across the synapse in a few milliseconds to reach the dendrites of the post-synaptic neuron/cell membrane of the effector
46
Q

Explain the post-synaptic neuron

A
  • Triggers nerve impulse in the next nerve cell
  • Chemical signals open ion-gated channels
47
Q

What is a neurotransmitter?

A
  • Chemicals released from vesicles through exocytosis into the synaptic cleft
  • Binds to receptors by on neurons, or effectors
48
Q

What is the role of epinephrine?

A
  • Fight or flight response
49
Q

What is the role of serotonin?

A
  • Aids in sleep, mood, attention, and learning
  • Inadequate amounts of serotonin is linked to depression
50
Q

What is the role of dopamine?

A
  • Affects sleep, mood, attention, and learning
  • Inadequate amounts is linked to Parkinson’s
  • Excessive amounts is related to schizophrenia
51
Q

What is the role of endorphins?

A
  • Creates a sense of euphoria
52
Q

What are examples of weak points in our nervous system?

A
  • Stimulants: Caffeine, nicotine
  • Gases: Carbon monoxide
  • Hallucinogens: LSD
  • Depressants: Meth
  • SSRIs: Prozac
  • Poisons

SBI4U: Chapter 8 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions