Nervous System CNS and PNS Practice Questions
20 free Nervous System CNS and PNS practice questions for the NCERT Biology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
The human neural system is divided into two main parts. Identify them:
- A Brain and Spinal Cord only
- B Somatic and Autonomic systems
- C Central Neural System and Peripheral Neural System
- D Sympathetic and Parasympathetic systems of the ANS
Correct answer: Central Neural System and Peripheral Neural System
The human neural system is broadly classified into the Central Neural System (CNS) and the Peripheral Neural System (PNS). The CNS includes the brain and spinal cord, while the PNS comprises all nerves associated with the CNS.
Which component of the neural system serves as the site of information processing and control?
- A Visceral Neural System
- B Somatic Neural System
- C Peripheral Neural System
- D Central Neural System
Correct answer: Central Neural System
The Central Neural System (CNS), consisting of the brain and the spinal cord, is the primary site where sensory information is processed and where motor commands are generated to control the body.
In the Peripheral Neural System, nerve fibers that transmit impulses from tissues/organs to the CNS are called:
- A Efferent fibers
- B Afferent fibers
- C Motor fibers
- D Somatic fibers
Correct answer: Afferent fibers
Afferent nerve fibers (sensory) carry impulses from peripheral tissues or sense organs toward the CNS. Conversely, efferent fibers carry regulatory impulses away from the CNS to the periphery.
The Somatic Neural System (SNS) is responsible for relaying impulses from the CNS to which of the following?
- A Involuntary organs
- B Smooth muscles
- C Skeletal muscles
- D Secretory glands
Correct answer: Skeletal muscles
The PNS is divided into the somatic and autonomic systems. The somatic neural system specifically relays impulses from the CNS to skeletal muscles, which are typically under voluntary control.
The Autonomic Neural System (ANS) transmits impulses from the CNS to:
- A Skeletal muscles under voluntary control
- B Involuntary organs and smooth muscles
- C Sense organs and receptor cells
- D Cerebral cortex and higher centres
Correct answer: Involuntary organs and smooth muscles
The ANS is a part of the PNS that regulates the functions of involuntary organs, smooth muscles, and glands. It operates mostly below the level of conscious awareness.
Which division of the Peripheral Neural System is further classified into Sympathetic and Parasympathetic systems?
- A Somatic Neural System
- B Visceral Neural System of the periphery
- C Autonomic Neural System
- D Central Neural System
Correct answer: Autonomic Neural System
The Autonomic Neural System is subdivided into the Sympathetic neural system (often associated with 'fight or flight') and the Parasympathetic neural system (associated with 'rest and digest').
The 'Visceral Neural System' is considered a part of the:
- A Central Neural System
- B Peripheral Neural System
- C Somatic Neural System of voluntary control
- D Brain stem
Correct answer: Peripheral Neural System
The visceral neural system is that part of the PNS which comprises the whole complex of nerves, fibers, ganglia, and plexuses by which impulses travel from the central nervous system to the viscera and from the viscera to the central nervous system.
Inside the skull, the brain is covered by cranial meninges. The outermost layer is called:
- A Pia mater
- B Arachnoid
- C Dura mater
- D Corpus callosum
Correct answer: Dura mater
The cranial meninges consist of three layers: the outer Dura mater (thick and tough), the middle thin Arachnoid, and the inner Pia mater which is in contact with the brain tissue.
Which structure connects the two cerebral hemispheres of the forebrain?
- A Cerebral aqueduct
- B Corpus callosum
- C Thalamus
- D Hypothalamus
Correct answer: Corpus callosum
The two cerebral hemispheres are connected by a massive tract of nerve fibers called the corpus callosum. This structure allows for communication and coordination between the left and right sides of the brain.
The layer of cells covering the cerebral hemisphere, which is thrown into prominent folds, is known as the:
- A Cerebral cortex
- B Medulla oblongata
- C Cerebellum
- D Hypothalamus
Correct answer: Cerebral cortex
The cerebral cortex is the outer gray matter layer of the cerebrum. Its highly folded nature (gyri and sulci) significantly increases the surface area for containing a large number of neurons.
The cerebral cortex is referred to as 'Gray Matter' because of the:
- A Presence of myelin sheaths on axon fibers
- B Concentration of neuron cell bodies
- C High blood supply to cortical neurons
- D Presence of cerebrospinal fluid in sulci
Correct answer: Concentration of neuron cell bodies
The cerebral cortex appears gray because it is densely packed with neuron cell bodies, which lack the white fatty myelin found on axons. Myelinated fibers constitute the inner 'white matter'.
In the cerebral cortex, 'Association Areas' are responsible for:
- A Regulating body temperature, thirst, and hunger
- B Processing simple sensory input signals
- C Executing direct voluntary motor commands
- D Intersensory links, memory, and communication
Correct answer: Intersensory links, memory, and communication
Association areas are regions of the cerebral cortex that are neither clearly sensory nor motor in function. They handle complex integrative tasks like memory, logic, and connecting different types of sensory data.
The Thalamus serves as a major coordinating center for:
- A Thermoregulation and temperature homeostasis
- B Sensory and motor signaling
- C Hunger, thirst, and feeding behavior
- D Respiratory rhythms and breathing rate
Correct answer: Sensory and motor signaling
The cerebrum wraps around the thalamus, which acts as a relay station. It filters and directs almost all sensory and motor information traveling to and from the cerebral cortex.
Which part of the forebrain contains centers that control body temperature, urge for eating, and drinking?
- A Thalamus
- B Cerebrum
- C Hypothalamus
- D Pons of brainstem
Correct answer: Hypothalamus
The hypothalamus, located at the base of the thalamus, is the master regulator of homeostasis. It contains centers for thermoregulation and controls appetite and water balance.
The 'Limbic System' is formed by the association of the inner parts of cerebral hemispheres and which other structures?
- A Pons and Medulla
- B Amygdala and Hippocampus
- C Cerebellum and Midbrain
- D Thalamus and Corpus callosum
Correct answer: Amygdala and Hippocampus
The limbic system includes the amygdala, hippocampus, and parts of the hypothalamus. It is involved in emotional behavior (excitement, fear) and motivation.
The canal passing through the midbrain is called the:
- A Corpus callosum
- B Cerebral aqueduct
- C Foramen magnum
- D Third ventricle of forebrain
Correct answer: Cerebral aqueduct
The cerebral aqueduct (or Aqueduct of Sylvius) is a narrow channel that passes through the midbrain. It connects the third ventricle in the forebrain to the fourth ventricle in the hindbrain.
Which of the following is NOT a component of the hindbrain?
- A Pons of the hindbrain
- B Cerebellum
- C Medulla oblongata
- D Corpora quadrigemina
Correct answer: Corpora quadrigemina
The hindbrain consists of the pons, cerebellum, and medulla oblongata. The corpora quadrigemina (four lobes on the dorsal portion) is a part of the midbrain.
The part of the brain that has a very convoluted surface to provide additional space for many more neurons is the:
- A Pons of the brainstem
- B Cerebellum
- C Medulla oblongata
- D Midbrain tegmentum
Correct answer: Cerebellum
The cerebellum, often called the 'little brain', has a highly convoluted surface. This structural adaptation allows it to pack in more neurons to coordinate complex body movements and balance.
The 'Brain Stem' is formed by which of the following?
- A Forebrain, Midbrain, and Hindbrain together
- B Midbrain, Pons, and Medulla oblongata
- C Cerebrum and Cerebellum
- D Thalamus and Hypothalamus
Correct answer: Midbrain, Pons, and Medulla oblongata
The brain stem consists of the midbrain, pons, and medulla oblongata. It forms the connection between the brain and the spinal cord and controls many basic life functions.
The Medulla oblongata contains centers that control which of the following vital functions?
- A Memory, learning, and higher intelligence
- B Respiration, cardiovascular reflexes, and gastric secretions
- C Vision, hearing, and auditory reflexes
- D Voluntary movement of limbs and posture
Correct answer: Respiration, cardiovascular reflexes, and gastric secretions
The medulla is the lowest part of the brain stem. It houses vital autonomic centers that regulate heart rate (cardiovascular reflexes), breathing (respiration), and digestion (gastric secretions).