CBSE Questions for Class 11 Medical Biology Neural Control And Coordination Quiz 7 - MCQExams.com

• Autonomic ganglia are clusters of neuronal cell bodies and their dendrites.
• They are essentially a junction between autonomic nerves originating from the central nervous system and autonomic nerves(motor and sensory nerves) innervating their target organs in the periphery. Hence, the motor neurons of the autonomic nervous system exist at Autonomic ganglia.
So, the correct answer is 'Autonomic ganglia'.

• 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, Internal organs are regulated by the autonomic nervous system.

• The medulla oblongata (or medulla) is a long stem-like structure located in the brainstem
• . It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involuntary) functions ranging from vomiting to sneezing. 
• The medulla contains the cardiac, respiratory, vomiting and vasomotor centres and therefore deals with the autonomic functions of breathing, heart rate and blood pressure. Hence, a pair of brain structure and function is incorrect is Medulla: basic emotional drives.
So, the correct answer is 'Medulla: basic emotional drives'.

• The nervous system is divided into two types CNS and peripheral nervous system.
• The peripheral nervous system is in turn divided into the somatic nervous system and autonomic nervous system.
• The autonomic nervous system regulates the internal and involuntary movement.For example,respiration,cardiovascular,digestive etc.
• The autonomic(visceral) nervous system is again divided into the sympathetic and parasympathetic nervous system.
• The enteric nervous system receives inputs from the parasympathetic and sympathetic parts of the nervous system,
  
• Sympathetic decreases the rate of digestion whereas parasympathetic increases the rate of digestion via the enteric nervous system.
• A nerve leading to the small intestine causes the rate of digestion to increase, this nerve belongs to Peripheral, Peripheral and Enteric.
  

Rods and cones are photoreceptors in the human retina. Rods are responsible for vision at low light levels (scotopic vision). They do not mediate colour vision and have a low spatial acuity. Cones are active at higher light levels (photopic vision), are capable of colour vision and are responsible for high spatial acuity. So, the correct answer is 'Rods are responsible for scotopic vision and Cones are responsible for photopic vision'.

• Neuron or nerve cells are the functional units of the nervous system. Each neuron has a cell body that encloses the nucleus and cytoplasm. 
• A number of processes arise from the cell body. These processes are called dendrites. In the given diagram P represents the dendrites. Dendrites play an important role in receiving nerve impulses from other neurons. 
• The cell body is the spherical part of the neuron that contains the nucleus and connects to the dendrites, which bring information into the neuron, and the axon, which sends information to other neurons.
  
• Myelin sheaths are sleeves of fatty tissue that protect the nerve cells. 
  
• The myelin sheath is regularly interrupted along the length of the axon by specialized regions called the nodes of Ranvier, which are necessary for the propagation of an action potential along the axon. The nodes of Ranvier are essential in the speed and timing of the delivery of impulses from one neuron to another.
  

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• The different cells in the body can regenerate in order to replace the damaged or the worn-out cells. 
• The neurons are one of the brain cells. The cells divide during the embryonal stage. After the birth of a child, the cells lose their capacity to divide. 
• These cells have the least capacity of regeneration. 
• Thus, the correct answer is option C. 

• The blind spot is the region in the posterior part of the eye. There are no photoreceptor cells, rods and cone cells are absent in this region.
• The rods and the cones are the cells that can detect light and help in the formation of the image. 
• As the light cannot be detected, there is no image formation at this spot.

• The membrane which covers the brain and the spinal cord is called as the meninges. 
• There are three layers of the meninges. The outermost is the Dura mater, middle one is the arachnoid mater and the innermost is the pia mater. 
• Dura mater is the tough membrane which is present in the outermost region. The three meninges provide protection to the brain from shock and injury. 
• Thus, the correct answer is option B. 

Schwann cells are cells in the peripheral nervous system that wraps around the axons of motor and sensory neurons to form the myelin sheath.

It makes the conduction of impulses through the neuron more efficient.

• Compared with mammals, birds have relatively large eyes. In simple terms, a bigger eye means better vision, and excellent vision is essential for avoiding collisions in flight or for capturing fast-moving or camouflaged prey.
• All birds which are predators have a strong sense of vision to locate their pay from larger distances. For example, kite, eagle. vulture, etc.
  
• So, the correct answer is 'All the above'.

• Neurofilaments are the main structural elements in neurons of the brain. These are fibrous proteins and have a diameter of 10nm. 
• They are majorly composed of intermediate filaments which are located abundantly in axons. 
• These intermediate filaments are also present in cyton and dendrites. Their function is the transmission of neural impulses. 
  Thus the correct answer is option B.

• Neuroglia, are non-neuronal cells in the central nervous system (brain and spinal cord) and the peripheral nervous system. 
• They maintain homeostasis, form myelin, and provide support and protection for neurons.
•  Neuroglia is also called as glial cells. There are six types of neuroglia—four in the central nervous system and two in the PNS.  
• Neuroglia in the CNS include astrocytes, microglial cells, ependymal cells and oligodendrocytes. Hence, neuroglia cells are Astrocytes, oligodendrocytes microglia.

• Cows can see colour through there eyes, but the distribution of rod and cone cells in the cow's retina is different from the distribution in humans.
  
• The eyes of the cow can differentiate between colours like red and green, blue and yellow, black and white, but in a less advanced way than humans do.
• Hence eyes help the cow to differentiates the different colours.
• So, the correct answer is 'Eyes'.

• The word ''Opthalmology'' comes from the Greek roots ''Ophthalmol'' means ''Eye'' and ''Logos'' means ''Study''. Hence Ophthalmology literally means the ''The science of eyes''. 
• An Ophthalmologist is a specialist in medical and surgical eye problems.
• Hence Ophthalmology is the study of Caring, diagnosis and cure of eye diseases.
• So, the correct answer is 'Ophthalmology'.

• Neurons are nerve cells that transmit nerve signals to and from the brain.
•  The neuron consists of a cell body (or soma) with branching dendrites (signal receivers) and a projection called an axon, which conduct the nerve signal.
• The cell body of neurons is also called as neurocyton or perikaryon, containing the nucleus. Hence, Cell body of the neuron is called perikaryon.

• Non-myelinated nerve are the nerve cell in autonomic nervous system in which there is no myelin sheath surrounding its axon. 
• Myelin is a lipid-rich (fatty) substance formed in the central nervous system (CNS) by glial cells called oligodendrocytes, and in the peripheral nervous system (PNS) by Schwann cells. 
• Myelin insulates nerve cell axons to increase the speed at which information (encoded as an electrical signal) travels from one nerve cell body to another (as in the CNS) . Hence, Non-myelinated nerve fibres occur in autonomic nerves.