How do we control ourselves? Flashcards

1
Q

What are the functions of the Nervous System?

A
  1. Maintaining homeostasis
  2. Receives sensory input
    o Internal
    o External
  3. Integrating information
  4. Motor output
  5. Establish and maintain mental activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the structural divisions of the nervous system?

A

-Central nervous system (CNS)
o Brain and spinal cord
-Peripheral nervous system (PNS)
o Spinal nerves and cranial nerves

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

What is a Neuron, Axon, Nerve & Sensory Receptors?

A
  • Neuron (nerve cell): basic structural unit of the nervous system
  • Axon: nerve fibre
  • Nerve: bundle of axons (or nerve fibres) and their sheaths (outer covering)
  • Sensory receptors: separate specialised cells which detect temperature, pain, touch, pressure, light, sound, odour and other stimuli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a Action Potential, Effector organ/cell, Ganglion, Plexus and Synapse?

A
  • Action potential: electrical signal
  • Effector organ or effector cell: the organ, tissue or cell in which an effect or an action takes place
  • Ganglion: collection of cell bodies located outside the CNS
  • Plexus: extensive network of axons or cell bodies
  • Synapse: junction of a neuron with another cell e.g. end of a neuron with a muscle cell or another neuron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the Autonomic nervous system.

A
  • Involuntary and under subconscious control
  • Action potentials in the motor neurons travel from the CNS to smooth or cardiac muscle, or glands
  • Two-neuron system
  • Cell bodies of the neurons are located in the CNS and autonomic ganglion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the Somatic nervous system

A
  • Voluntary and under conscious control
  • Action potentials in the motor neurons travel from the CNS to skeletal muscles
  • Single neuron system
  • Cell bodies are located in the CNS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the cells of the NS (CNS & PNS)

A

-Neuron
-Neuroglia
CNS
-Astrocytes
-Ependymal cells
-Microglia
-Oligodendrocytes
PNS
-Schwann cells
-Satellite cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the structure of a Neuron

A

-Structural unit of the nervous system
-Dendrites
o Dendritic spines
-Cell body (soma)
-Axon
o Axon hillock
o Initial segment
o Trigger zone
o Axon collaterals
o Axon terminal or presynaptic terminal
o Terminal boutons or synaptic knobs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the types of neurons in terms of function?

A
  • Sensory (afferent) neuron – information to the CNS
  • Motor (efferent) neuron – information away from the CNS
  • Inter-neuron – information from one neuron to another neuron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the types of neurons in terms of structure?

A
  • Multipolar
  • Bipolar
  • Unipolar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are Astroycyte Cells?

A
  • Forming a supporting framework for blood vessels and neurons
  • Assists in the formation of tight junctions between endothelial cells of the capillaries
  • Respond to tissue damage in the CNS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are Ependymal Cells?

A

-Line the central cavities of the brain and spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are Microglial Cells?

A
  • Monitor the health of surrounding neurons

- Phagocytose microorganisms, infection, trauma or inflammation

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

What are Oligodendrocytes?

A

-Cover axons which forms an insulating sheath around them → myelin sheath

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

What are Schwann Cells?

A
  • Also called neurolemmocytes
  • Form a myelin sheath around axons
  • Insulating
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are Satellite Cells?

A
  • Provide support and nutrition to cell bodies in ganglia

- Protect cell bodies from harmful substances

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

What is in the Grey Matter in the CNS & PNS?

A

CNS: Brain= Outer cortex of brain & nuclei
Spinal Cord= Inner ‘grey’ part
PNS:Ganglion

18
Q

What is in the White Matter in the CNS & PNS?

A

CNS: Brain=Deeper nerve tracts
Spinal Cord=Outer part
PNS:Nerves

19
Q

What is a membrane potential?

A

-Membrane potential= the difference in charge across the cell membrane

20
Q

What characteristics of a cell membrane allow a membrane potential to occur?

A
  1. Differences in ionic concentration (particularly for Na+ and K+ ) across the cell membrane
  2. Permeability of the cell membrane to ions
21
Q

What are non-gated ion channels?

A
  • Also known as ‘leak’ ion channels
  • Ion specific
  • Cell membrane has more K+ leak ion channels compared to Na+ leak ion channels
22
Q

What are gated ion channels?

A
  • Gated ion channels – require signals to open them
  • Ligand-gated ion channel
  • Voltage-gated ion channel
  • Other-gated ion channel
23
Q

What is a resting membrane potential?

A

-Resting membrane potential – the difference in charge across the cell membrane in a resting cell

24
Q

What occurs at a resting membrane potential?

A
  • Intracellular side is more negative
  • RMP of neurons = - 70 mV where the negative sign indicates the charge on the intracellular side of the cell.
  • RMP caused by leak ion channels and the Na+/K+ pump
25
Q

What is Depolarisation, Hyperpolarisation and Repolarisation?

A

Depolarisation – when the membrane potential becomes more positive i.e. the inside of the cell becomes more positive. E.g. - 70 mV  - 30 mV
Hyperpolarisation – when the membrane potential becomes more negative i.e. the inside of the cell becomes more negative. E.g. - 70 mV  - 75 mV
Repolarisation – membrane potential returns to normal

26
Q

What is a graded potential?

A
  • Graded potentials can lead to action potentials
  • Graded potential – short-lived, localised changes in membrane potential
  • Often occur in dendrites or the cell body of a neuron
  • Ability to summate
  • Decremental
  • Not able to transfer information over long distances
27
Q

What is afterpotential?

A

Afterpotential – short period of hyperpolarisation of an action potential

28
Q

What is the first step of the operation of the gates?

A
  1. Resting membrane potential:
    - All gated Na+ and K+ channels are closed.
    - K + leak channels (not visible on this image) are open which allow movement of K+ to the outside of the cell. This creates a negative intracellular charge = RMP.
    - Na+ /K+ pump (not visible on this image) also creates the RMP.
29
Q

What is depolarisation in the operation of the gates?

A
  1. Depolarisation:
    - Na+ gated channels open and Na+ moves into the cell and inside of the cell becomes more positive.
    - K + gated channels are closed.
    - Membrane potential becomes more positive.
30
Q

What is repolarisation in the operation of the gates?

A
  1. Repolarisation:
    - Na+ gated channels close.
    - K + gated channels open and K+ moves out of the cell and the intracellular side becomes more negative.
    - Membrane potential becomes more negative.
31
Q

What happens at the end of repolarisation and the afterpotential in the operation of the gates?

A
  1. End of repolarisation, and the afterpotential:
    - Na+ gated channels close.
    - K + gated channels close as well but they close slowly so K+ continues to leave the cell and this produces the afterpotential.
    - Membrane potential becomes very negative.
32
Q

What happens at the resting membrane if the operation of the gates?

A
  1. Resting membrane potential:
    - Na+ gated channels are closed.
    - K + gated channels are closed.
    - Resting membrane potential is re-established by Na+/K+ pump (an active process as it is against their concentration gradients) which redistribute ions as all Na+ and K+ gated channels are closed.
33
Q

What dose the refractory period consist of?

A
  • Absolute refractory period

- Relative refractory period

34
Q

Where does the propagation of axon potentials occur and what does it follow?

A
  • This takes place in unmyelinated axons only
  • Following depolarisation, each segment of the axon membrane becomes repolarised
  • The propagation of the action potential occurs in one direction
35
Q

What is Saltatory Conductiomn?

A

Propagation of action potentials in myelinated axons

36
Q

What are the parts of a synapse and what are electrical & chemical synapses?

A
  • Junction of a neuron with another cell e.g. end of a neuron with a muscle cell or another neuron
  • Pre-synaptic
  • Synapse
  • Post-synaptic
  • Electrical synapses → current
  • Chemical synapses→ chemicals e.g. hormones, neurotransmitters
37
Q

How are neurotransmitters removed?

A
  • Breakdown by enzymes
  • Re-absorption back into the presynaptic terminal
  • Diffuse away from the synapse
38
Q

What are reflexes?

A
  • Automatic response to a stimulus
  • Are somatic or autonomic
  • Are homeostatic
39
Q

What are the components of reflexes?

A
  • Sensory receptor
  • Sensory neuron
  • Interneuron
  • Motor neuron
  • Effector organ
40
Q

What are the types of reflexes?

A
  • Stretch (monosynaptic)
  • Golgi tendon
  • Withdrawal