CBSE Questions for Class 11 Medical Biology Neural Control And Coordination Quiz 6 - MCQExams.com

• The axon terminals are the end of axon fiber and located close to the dendrites of another neuron, forming a connection known as a synapse and allowing them to send messages from neuron to neuron with the help of neurotransmitter. 
• So, a nerve cell transmits it's impulse to another through its axons. 

• Iris is the coloured part of the eye that controls the amount of light entering the eye by adjusting the size of the pupil, a hole shaped opening in the middle of the eye. 
• The cornea is the transparent window of the eye located within the otherwise opaque sclera. 
• It serves to refract the light rays. The lens capsule is a clear membrane-like structure that serves to refract and focus light rays on the retina. 

• The eardrum is also called the tympanic membrane. 
• It is present in the human ear. 
• It receives sound vibrations from the outer air and transmits them to the auditory ossicles in the middle ear cavity. 
• Hence its main function is to convert and amplify vibration in the air to vibration in the fluid. 

Bipolar neurons are sensory neurons, they are found in olfactory epithelium, the retina of the eye, and ganglia of the vestibulocochlear nerve. They have two processes, dendrite which conveys information from the periphery and axon, which carries information toward the brain. These cells have mainly sensory function. Hence option C is correct.

Sensory neurons are nerve cells that transmit sensory information (sight, sound, feeling, etc.). They are activated by sensory input and send projections to other elements of the nervous system, ultimately conveying sensory information to the brain or spinal cord.

Correct Option: D

Explanation:

The location of transmission of electrical nerve impulses between 2 nerve cells (neurons) or between a nerve cell and a muscle cell is called a synapse.

Hence, the structure labelled as A in the diagram of the neurons is called the synapse.

• The neuron is a single nerve cell. There are three basic types of neurons association, afferent, and efferent. 
• The association neurons comprise the central nervous system (CNS) i.e., the brain and spinal cord. 
• The afferent neurons are also known as the sensory neurons. They bring the stimuli from the sensors (e.g., skin, eyes, ears) to the CNS. 
• The efferent neurons are also known as motor neurons. They bring the responses from the brain to the muscles and the glands.

• The Peripheral Nervous System is divided into two systems: the autonomic nervous system, which regulates involuntary actions such as breathing and digestion, and the somatic nervous system, which governs voluntary action and body reflexes.
•  The autonomic nervous system is a control system that acts largely unconsciously and regulates bodily functions such as the heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal. Hence, Autonomic nervous system controls Involuntary activities.

The myelin sheath of neurons provides them with an insulating covering. It allows rapid transmission of signals from the nervous system to the body and vice-versa. Any damage to the myelin sheath will cause hindrance and slowing down of the transmission of signals to the axons.

So, the correct answer is 'Action potentials would be conducted too slowly along the neurons'.

• The sympathetic nervous system (SNS) is part of the autonomic nervous system (ANS), which also includes the parasympathetic nervous system (PNS).
• The sympathetic nervous system releases hormone called adrenaline most often termed as the fight or flight response.
•  Adrenaline, also known as epinephrine, is a hormone, neurotransmitter, and medication. Adrenaline is normally produced by both the adrenal glands and certain neurons. It plays an important role in the fight-or-flight response by increasing blood flow to muscles, the output of the heart, pupil dilation response, and blood sugar level. Hence, the Sympathetic nervous system is stimulated by the hormone Adrenaline. 

• The autonomic nervous system is a control system that acts largely unconsciously and regulates bodily functions such as the heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal. Hence, Heart rate, Digestion and Urination functions are influenced by the autonomic nervous system. 

• A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. 
• In the human body, there are 31 pairs of spinal nerves, one on each side of the vertebral column. 
• Sensory nerves/neurons gather information of the environment and send it to the brain, Hence, In spinal nerve  Sensory neuron is responsible to carry the message to the brain.