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High School Anatomy > Nervous System Study Guide > Flashcards

Flashcards in Nervous System Study Guide Deck (53)
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1
Q

What are the two primary divisions of the nervous system?

A

The Central Nervous System (CNS) and the Peripheral Nervous System (PNS)

2
Q

What primary areas do the two main divisions of the nervous system cover?

A

The CNS is the brain and spinal cord, the PNS is all other neural tissue

3
Q

What are the further divisions of the PNS?

A

The PNS is divided into the Afferent and Efferent groups. The Efferent group is divided into the Somatic and Autonomic systems. The Autonomic system is divided into the Sympathetic and Parasympathetic systems.

4
Q

What two categories is the PNS divided into?

A

The Afferent (sensory) and Efferent (effector) groups

5
Q

What is the efferent division of the PNS divided into?

A

The somatic (voluntary) and autonomic (involuntary) divisions

6
Q

What is the autonomic division of the PNS divided into?

A

It’s divided into the sympathetic (stimulating) and parasympathetic (calming) systems

7
Q

What are the basic functions of the CNS?

A

To processes and coordinate

8
Q

What are the functions of the CNS in-depth?

A

To process and coordinate: sensory data from inside and outside the body, motor commands that control activities of peripheral organs, and higher functions of the brain (like intelligence, memory, learning, and emotion)

9
Q

What are the functions of the PNS?

A

To deliver sensory info to the CNS, and carry motor commands to the peripheral tissue systems

10
Q

What does the afferent division of the PNS do?

A

It carries sensory info from the PNS sensory receptors to the CNS receptors

11
Q

What does the efferent division of the PNS do?

A

It carries motor commands from the CNS, to the PNS, and then to the effectors (muscles and glands)

12
Q

What is the function of the somatic nervous system (SNS)?

A

It controls skeletal muscle/ voluntary muscle contractions

13
Q

What is the function of the automatic nervous system (ANS)?

A

It controls subconscious contractions/ contractions of smooth and cardiac muscle

14
Q

What does the sympathetic division of the ANS do?

A

It has a stimulating effect

15
Q

What does the parasympathetic division of the ANS do?

A

It has a relaxing effect

16
Q

What are the two different cell types in the nervous system and their general functions?

A

Neurons and neuroglia. Neurons send and receive signals, and neuroglia support and protect the neurons.

17
Q

What are the major organelles of a neuron cell (or lack thereof)

A

They have a nucleus, nucleolus, cytoplasm, mitochondria, RER, ribosomes (nissl bodies), cytoskeleton. No centrioles.

18
Q

What is the size of the axon? What is its function?

A

It’s long and carries electrical signals (action potentials) to the target

19
Q

Describe the axon hillock

A

It’s a thick section of the cell body and it attaches to the initial segment

20
Q

What are the collaterals?

A

The branches of a single axon

21
Q

What are the axon terminals?

A

Also called the synaptic terminals, they’re the tips of the axon

22
Q

Describe bipolar neurons

A

They’re small, they have one dendrite and one axon, and they lead to the special sensory organs (sight, smell, etc)

23
Q

Describe unipolar neurons

A

They’re very long axons, they’re fused to dendrites and an axon, the cell body is on one side, and they’re found in sensory neurons in the PNS

24
Q

Describe multipolar neurons

A

They have very long axons, they have multiple dendrites and one axon, they’re common in the CNS, and they include all skeletal muscle motor neurons

25
Q

Define synapse

A

The area where a neuron communicates with another cell

26
Q

Define presynaptic cell

A

The neuron that sends the signal

27
Q

Define postsynaptic cell

A

The cell that receives the signal

28
Q

How does a synapse work?

A

Neurotransmitters are released at the presynaptic membrane into the synaptic cleft, and they affect receptors of the postsynaptic membrane

29
Q

What are the types of neuroglial cells in the CNS?

A

Ependymal cells, astrocytes, microglia, and oligodendrocytes

30
Q

What are the types of neuroglial cells in the PNS?

A

Satellite cells and Schwann cells

31
Q

Where are ependymal cells located?

A

They form the epithelium called ependyma, and they line the central canal of the spinal cord and the ventricles of the brain

32
Q

What do the ependymal cells do?

A

They secrete CSF (cerebrospinal fluid), they have cilia or microvilli that circulate the CSF, they monitor the CSF, and they contain stem cells for repair

33
Q

What do astrocytes and satellite cells do?

A

They maintain the blood-brain barrier, they repair damaged neural tissue, and they guide neuron development.

34
Q

What do microglia do?

A

They migrate through neural tissue and clean up cellular waste/debris/pathogens

35
Q

What do oligodendrocytes do?

A

Their processes contract other neurons and they wrap around the axons to form the CNS myelin sheath (which speeds up action potentials and makes nerves appear white)

36
Q

What do Schwann cells do?

A

They form the myelin sheath around peripheral axons

37
Q

Define the electrochemical gradient

A

It’s the sum of chemical and electrical forces acting on the ion across a cell membrane

38
Q

Define passive ion channels

A

Passive channels are leaky and always open, and their permeability changes with conditions.

39
Q

Define active ion channels

A

Active channels are gated and open and close in response to stimuli.

40
Q

What are the three types of gated channels?

A

Chemical, voltage, and mechanical

41
Q

Describe chemically gated channels

A

They open when bound to chemicals, and are found on the neuron cell body + dendrites

42
Q

Describe voltage gated channels

A

They open with electricity and are found on axons, the sarcolemma, and the heart

43
Q

Describe mechanically gated channels

A

They respond to membrane distortion and are found in sensory receptors

44
Q

What does the sodium potassium pump do?

A

It resets the membrane balance of ions and reestablishes the concentration gradient for each ion

45
Q

How does the binding of neurotransmitters with receptors affect the movement of either sodium or potassium? What effect does this have on the membrane?

A

During hyperpolarization, potassium channels open and positive ions move out, causing the membrane to be more negative. The sodium potassium pump maintains and restores the resting potential and makes it more positive.

46
Q

Define hyperpolarization

A

The negativity of the resting potential increases as a result of opening a potassium channel. Positive ions move out.

47
Q

What are the two types of refractory periods?

A

Absolute and relative

48
Q

What’s the relationship between axon diameter and the speed of transmission?

A

The bigger the axon’s diameter, the faster the speed

49
Q

Describe continuous propagation

A

It happens in unmylinated axons, all parts of the membrane are depolarized, and the action potential travels in one direction

50
Q

Describe salutatory propagation

A

It’s fast and doesn’t use much energy, it happens in myelinated axons, and the local current jumps from node to node

51
Q

Define refractory period

A

The time in which the membrane won’t respond normally to additional stimuli

52
Q

Describe an absolute refractory period

A

When sodium channels are open or inactivated and no action potential is possible

53
Q

Describe a relative refractory period

A

The membrane potential is almost normal and a very large stimulus can initiate action potential