It is through the transmission of nerve impulses that nerve cells (neurons) communicate with one another. Electrical signals travel down the dendrites of the neuron to form a nerve impulse or action potential, which is a type of nerve impulse. The action potential is the result of ions moving in and out of the cell as they conduct electrical current.
- The myelin sheath is composed of the following cells:
(a) Microglia
(b) Neuroglial cells
(c) Schwann cells
(d) Nerve cells.
The Answer is : (c)
Explanation: In the peripheral nervous system (PNS: nerves), Schwann cells produce myelin; in the central nervous system, oligodendrocytes produce myelin (CNS: brain and spinal cord). One Schwann cell forms a single myelin sheath in the PNS.
- Nissl’s granules are found in the following cells:
(a) Nerve cells
(b) White blood cells
(c) Red blood cells
(d) Platelets
The Answer is: (a)
Exp: The cyton of nerve cells contains Nissl’s granules. These are receptive to basic dyes.
- Which of the following is a myelin sheath disease?
a) Polio
b) leprosy
c) multiple sclerosis
d) Alzheimer’s disease
The Answer is: (c)
- This neurotransmitter is not a naturally occurring amine:
(a) Serotonin
(b) Dopamine
(c) Norepinephrine
(d) Neuropeptides
The Answer is (d)
- During saltatory conduction, a nerve impulse jumps from one _________ to another.
(a) Synapse
(b) Axon
(c) Node of Ranvier
(d) Myelin sheath
The Answer is: (c)
- _______ are neurons that transmit impulses away from the central nervous system
(a) Efferent nerves
(b) Afferent nerves
(c) Extensors
(d) Sensory nerves
The Answer is: (a)
Explanation: Efferent, or motor, nerve fibres conduct impulses away from the central nervous system, whereas afferent, or sensory, nerve fibres conduct impulses toward the central nervous system.
- Muscle cells and nerves contain the following potentials:
(a) membrane potential
(b) potassium equilibrium potential
(c) resting potential
(d) sodium equilibrium potential.
The Answer is (c)
Explanation: A neuron’s action potential generates the nerve impulse, while a muscle cell’s action potential generates the contraction required for movement.
- Which of the following possesses the greatest permeability in a resting nerve cell?
(a) Cl-
(b) Na+
(c) K+
(d) I-
The Answer is : (c)
- For the first time, this organism was used to study nerve cells:
(a) Grasshopper
(b) Drosophila melanogaster
(c) Octopus
(d) Giant squid
The Answer is : (d)
- Neurotransmitters have the ability to inhibit or stimulate neurons. For instance, ________ is inhibitory, whereas _________ is excitatory.
(a) GABA; glutamate
(b) Glutamate; glutamate
(c) Serotonin; dopamine
(d) None of the preceding
The Answer is : (a)
- The Myelin sheath originates from
a.) Microglia
b) Neuroglia
c.) Schwann cells
d) Neuronal cells
The Answer is: (c)
Explanation The myelin sheath is a greatly extended and modified plasma membrane that spirally wraps around the nerve axon. Myelin membranes are produced by and are found on Schwann cells in the peripheral nervous system (PNS) and oligodendroglial cells in the central nervous system (CNS) (CNS)
- The granules of Nissl are found in
(a) Neuronal cells
(b) The WBC
(c) Red blood cells
(d.) Platelets
The Answer is: (a)
Explanation: Nissl’s granules are found in the cytoplasm of neurons’ cell bodies, alongside other organelles such as the Golgi apparatus, endoplasmic reticulum, mitochondria, and nucleus. These granules give the cytoplasm of the cell body a slight tint. They aid in the synthesis of proteins in neurons.
- Which of the following is a myelin sheath disease?
a.) Poliomyelitis
b.) Leprosy
c.) Multiple sclerosis
d.) Alzheimer’s disease
The Answer is: (c)
Explanation: Multiple sclerosis has no known cause. It is classified as an autoimmune disease because the immune system of the body attacks its own tissues. In the case of multiple sclerosis, this immune system malfunction destroys the fatty substance that coats and protects brain and spinal cord nerve fibres (myelin)
- This neurotransmitter is not a metabolite of a naturally occurring amine.
(a) Serotonin Serotonin is a neurotransmitter.
(b) Dopamine Dopamine is a neurotransmitter.
(c) Norepinephrine Norepinephrine is a neurotransmitter.
(d) Peptides neuropeptides
The Answer is: (d)
Explanation: Neuropeptides are derived from large inactive precursor proteins referred to as pre propeptides. Pre Propeptides encode a family of distinct peptides and frequently contain multiple copies of the same peptide, depending on the organism.
- During saltatory conduction, a nerve impulse jumps from one _________ to another.
(a) Synaptic junction
b) An axon
(c) Ranvier’s node
(d) Sheath of myelin
The Answer is: (c)
Explanation: The Ranvier nodes are microscopic gaps within myelinated axons. Their purpose is to accelerate action potential propagation along the axon via saltatory conduction. The Nodes of Ranvier are the spaces between Schwann cells’ myelin sheaths that surround the neuron’s axon.
- The neurons that conduct impulses away from the central nervous system are referred to as .
(a) Nerves efferents
b) Nerves afferents
c.) Extensors
(d) Nerves of the senses
The Answer is: (a)
Explanation: Efferent nerves are those that transmit nerve impulses away from the central nervous system. They are responsible for transmitting impulses to muscles and organs. Efferent nerves are motor nerves, which are composed of a chain of motor neurons. They originate in the spinal cord and are responsible for the innervation of muscles.
- Muscle cells and nerves contain which of the following?
(a) Potential of the membrane
(b) Equilibrium potassium potential
c) potential at rest
(d) Potential of sodium equilibrium
The Answer is: (c)
Explanation: A cell’s resting potential is defined as the difference in electrical potential across the plasma membrane when the cell is unstimulated or in a state of relaxation.
- Neurotransmitters have the ability to inhibit or stimulate neurons. For instance, ________ is inhibitory, whereas _________ is excitatory.
a) Glutamate; GABA
b) Glutamate; glycine; glycine-aminobutyric acid
(c) Dopamine; serotonin
(d) None of the preceding
The Answer is: (a)