Control Systems

Question 1

Which of the following is a component of the Central Nervous System (CNS)?
a) Cranial nerves
b) Spinal nerves
c) Brain
d) Sensory receptors

Answer 1

c) Brain

The Central Nervous System (CNS) consists of the brain and the spinal cord.

Question 2

The primary function of the Peripheral Nervous System (PNS) is to:
a) Integrate sensory information and make decisions. b) Control involuntary actions of smooth and cardiac muscle.
c) Connect the CNS to the limbs and organs.
d) Generate action potentials in response to stimuli.

Answer 2

c) Connect the CNS to the limbs and organs

The PNS acts as the body’s sensory and motor pathways.

Question 3

Voluntary control of skeletal muscles is a function of which division of the nervous system?
a) Autonomic Nervous System
b) Central Nervous System
c) Somatic Nervous System
d) Peripheral Nervous System

Answer 3

c) Somatic Nervous System

The Somatic Nervous System is responsible for the voluntary control of skeletal muscles.

Question 4

Involuntary control of cardiac muscle, smooth muscle, and glands is primarily the responsibility of the:
a) Somatic Nervous System
b) Peripheral Nervous System
c) Central Nervous System
d) Autonomic Nervous System

Answer 4

d) Autonomic Nervous System

The Autonomic Nervous System controls involuntary actions.

Question 5

Which of the following types of neuroglial cells is responsible for forming the myelin sheath in the Peripheral Nervous System?
a) Astrocytes
b) Oligodendrocytes
c) Schwann cells
d) Microglial cells

Answer 5

c) Schwann cells

Schwann cells are the myelinating cells of the PNS.

Question 6

The blood-brain barrier, which provides support and repair functions, is primarily associated with which type of neuroglial cell?
a) Schwann cells
b) Microglial cells
c) Astrocytes
d) Oligodendrocytes

Answer 6

c) Astrocytes

Astrocytes contribute to the blood-brain barrier and aid in repair.

Question 7

Which part of the neuron typically receives incoming information from other neurons?
a) Axon terminals
b) Axon
c) Cell body
d) Dendrites

Answer 7

d) Dendrites

Dendrites are the branched extensions that receive incoming information.

Question 8

The nerve impulse is transmitted away from the neuron cell body along the:
a) Dendrite
b) Axon terminal
c) Axon
d) Cell body

Answer 8

c) Axon

The axon transmits the nerve impulse away from the cell body.

Question 9

Neurotransmitters are released from which part of the neuron to transmit a signal to another cell?
a) Dendrite
b) Axon terminal
c) Axon
d) Cell body

Answer 9

d) Axon terminals / end bulbs

Axon terminals release neurotransmitters into the synaptic cleft.

Question 10

What is the typical value of the resting membrane potential (RMP) of a neuron?
a) +70 mV
b) 0 mV
c) -55 mV
d) -70 mV

Answer 10

d) -70 mV

The resting membrane potential is typically around -70 mV.

Question 11

The sodium-potassium pump maintains the resting membrane potential by actively transporting:
a) 3 sodium ions in and 2 potassium ions out.
b) 2 sodium ions in and 3 potassium ions out.
c) 3 sodium ions out and 2 potassium ions in.
d) 2 sodium ions out and 3 potassium ions in.

Answer 11

c) 3 sodium ions out and 2 potassium ions in

This active transport helps maintain concentration gradients.

Question 12

An action potential is initiated when the membrane potential at the axon hillock reaches the:
a) Resting membrane potential (-70 mV)
b) Hyperpolarization potential (less than -70 mV)
c) Threshold potential (-55 mV)
d) Repolarization potential (becoming more negative)

Answer 12

c) Threshold potential (-55 mV)

Voltage-gated sodium channels open at threshold potential.

Question 13

During the depolarization phase of an action potential, what is the primary event that occurs?
a) Potassium ions rush out of the cell.
b) Sodium ions rush into the cell.
c) The sodium-potassium pump actively transports ions.
d) Voltage-gated potassium channels open.

Answer 13

b) Sodium ions rush into the cell

Sodium ions rush in, causing depolarization.

Question 14

Repolarization of the neuron during an action potential is primarily due to:
a) The continued influx of sodium ions.
b) The efflux of potassium ions.
c) The closure of potassium channels.
d) The action of the sodium-potassium pump.

Answer 14

b) The efflux of potassium ions

Potassium ions rush out, making the inside of the cell more negative.

Question 15

Hyperpolarization of the neuronal membrane occurs due to:
a) The rapid influx of sodium ions.
b) The closure of voltage-gated sodium channels.
c) An excessive efflux of potassium ions.
d) The action of the sodium-potassium pump restoring RMP.

Answer 15

c) An excessive efflux of potassium ions

More potassium leaves the cell than needed for resting potential.

Question 16

The ‘all-or-nothing’ principle of action potentials means that:
a) Larger stimuli produce larger action potentials.
b) Action potentials can vary in size depending on the strength of the stimulus.
c) An action potential either occurs at full strength or not at all.
d) Only very strong stimuli can trigger an action potential.

Answer 16

c) An action potential either occurs at full strength or not at all

If the threshold is reached, a full action potential is fired.

Question 17

The speed of nerve impulse conduction is increased by:
a) Smaller axon diameter and the absence of myelin. b) Larger axon diameter and the presence of myelin. c) Smaller axon diameter and the presence of myelin. d) Larger axon diameter and the absence of myelin.

Answer 17

b) Larger axon diameter and the presence of myelin

Larger diameters and myelin increase conduction speed.

Question 18

Saltatory conduction refers to:
a) The continuous propagation of an action potential along an unmyelinated axon.
b) The “leaping” of the action potential from one neuron to another across a synapse.
c) The rapid movement of sodium ions during depolarization.
d) The propagation of an action potential along a myelinated axon where it jumps between the Nodes of Ranvier.

Answer 18

d) The propagation of an action potential along a myelinated axon where it jumps between the Nodes of Ranvier

Action potentials jump between nodes, increasing speed.

Question 19

At a synapse, the signal is transmitted from the presynaptic neuron to the postsynaptic neuron via:
a) Electrical currents flowing directly between the neurons.
b) The physical connection of the axon of one neuron to the dendrite of another.
c) The release of neurotransmitters into the synaptic cleft.
d) The movement of ions through gap junctions.

Answer 19

c) The release of neurotransmitters into the synaptic cleft

Neurotransmitters diffuse across the cleft to bind to receptors.

Question 20

What is the role of neurotransmitter receptors on the postsynaptic membrane?
a) To synthesize neurotransmitters.
b) To store neurotransmitters in vesicles.
c) To bind to neurotransmitters and cause a change in the postsynaptic cell.
d) To break down neurotransmitters in the synaptic cleft.

Answer 20

c) To bind to neurotransmitters and cause a change in the postsynaptic cell

Receptors bind neurotransmitters, leading to changes in the postsynaptic cell.

Question 21

A reflex is best described as a:
a) Conscious and voluntary response to a stimulus.
b) Complex and highly variable response to a stimulus.
c) Predictable and involuntary response to a stimulus. d) Learned and adaptive response to a stimulus.

Answer 21

c) Predictable and involuntary response to a stimulus

A reflex is a rapid, involuntary response.

Question 22

In a monosynaptic reflex arc, which of the following components is absent?
a) Sensory receptor
b) Sensory neuron
c) Motor neuron
d) Interneuron

Answer 22

d) Interneuron

Monosynaptic reflex arcs do not involve interneurons.

Question 23

What are sensory receptors responsible for?
a) Transmitting motor commands to effector organs. b) Processing and integrating sensory information.
c) Detecting changes in the internal or external environment.
d) Releasing neurotransmitters to stimulate sensory neurons.

Answer 23

c) Detecting changes in the internal or external environment

They convert stimuli into nerve impulses transmitted by sensory neurons.

Question 24

What type of stimulus do mechanoreceptors primarily detect?
a) Light
b) Chemicals
c) Pressure
d) Temperature

Answer 24

Pressure

Mechanoreceptors are sensitive to physical distortion such as touch and vibration.

Question 25

What sensation are nociceptors responsible for? a) Touch b) Temperature c) Pain d) Pressure

Answer 25

Pain ## Footnote Nociceptors are triggered by various stimuli, including chemicals released by damaged cells.

Question 26

Which type of sensory receptor allows for the sensation of body position? a) Thermoreceptors b) Chemoreceptors c) Proprioceptors d) Photoreceptors

Answer 26

Proprioceptors ## Footnote Proprioceptors provide information about body position and movement.

Question 27

Which division of the autonomic nervous system is associated with the 'fight or flight' response? a) Parasympathetic b) Somatic c) Central d) Sympathetic

Answer 27

Sympathetic ## Footnote The Sympathetic division prepares the body for action in stressful situations.

Question 28

The "rest and digest" functions are primarily governed by the: a) Sympathetic nervous system b) Somatic nervous system c) Parasympathetic nervous system d) Central nervous system

Answer 28

Parasympathetic ## Footnote The Parasympathetic division promotes functions like slowing heart rate and increasing digestive activity.

Question 29

Which glial cells in the CNS are responsible for myelination? a) Astrocytes b) Microglia c) Ependymal cells d) Oligodendrocytes

Answer 29

Oligodendrocytes ## Footnote Oligodendrocytes produce myelin, insulating axons and speeding up nerve impulse transmission.

Question 30

Damage to oligodendrocytes in the CNS is characteristic of which disease? a) Alzheimer's disease b) Parkinson's disease c) Multiple sclerosis (MS) d) Amyotrophic lateral sclerosis (ALS)

Answer 30

Multiple sclerosis (MS) ## Footnote MS is an autoimmune disease where the immune system attacks the myelin sheath in the CNS.

Question 31

What are the gaps between myelinating cells along an axon called? a) Synaptic clefts b) Nodes of Ranvier c) Axon terminals d) Dendritic spines

Answer 31

Nodes of Ranvier ## Footnote These gaps are crucial for saltatory conduction in nerve impulses.

Question 32

What type of molecule is acetylcholine? a) Neuroglial cell b) Sensory receptor c) Neurotransmitter d) Ion channel

Answer 32

Neurotransmitter ## Footnote Acetylcholine is an excitatory chemical used at synapses.

Question 33

What role do calcium ions play during transmission across a synapse? a) Binding to receptors on the postsynaptic membrane. b) Initiating the action potential in the postsynaptic neuron. c) Triggering the release of neurotransmitters from the presynaptic terminal. d) Actively transporting neurotransmitters across the synaptic cleft.

Answer 33

Triggering the release of neurotransmitters from the presynaptic terminal ## Footnote Calcium ions facilitate the fusion of synaptic vesicles with the presynaptic membrane.

Question 34

Where is the regeneration of damaged axons more likely to occur? a) Binding to receptors on the postsynaptic membrane. b) Initiating the action potential in the postsynaptic neuron. c) Triggering the release of neurotransmitters from the presynaptic terminal. d) Actively transporting neurotransmitters across the synaptic cleft.

Answer 34

Peripheral Nervous System due to the intact neurilemma formed by Schwann cells ## Footnote The neurilemma allows for regeneration, which does not typically occur in the CNS.

Question 35

What effect does an inhibitory neurotransmitter have on the postsynaptic membrane? a) Depolarization of the postsynaptic membrane. b) Increased permeability of the postsynaptic membrane to sodium ions. c) Hyperpolarization of the postsynaptic membrane, making it harder to reach threshold. d) The generation of an action potential in the presynaptic neuron.

Answer 35

Hyperpolarization of the postsynaptic membrane, making it harder to reach threshold ## Footnote Inhibitory neurotransmitters stabilize the postsynaptic membrane potential.

Question 36

Fast pain travels via which type of fibers? a) Unmyelinated C fibres. b) Small, myelinated B fibres. c) Large, myelinated A fibres. d) Non-myelinated Remak bundles.

Answer 36

Large, myelinated A fibres ## Footnote Fast pain is characterized as sharp and superficial, transmitted through A fibers.

Question 37

Which label (A to D) corresponds to the movement of Potassium ions out of the neurone?

Answer 37

B