Nervous System Physiology

• The hypothalamus is a small region of the brain. It's located at the base of the brain, near the pituitary gland. 
  
• The hypothalamus is the link between the endocrine and nervous systems. The hypothalamus produces releasing and inhibiting hormones, which stop and start the production of other hormones throughout the body.
• Hence Hypothalamus integrates Nervous and endocrine system.
• So, the correct answer is 'Hypothalamus'.

The central nervous system includes brain and spinal cord. It integrates and stores the sensory information from external and internal sense organs and commands different organs to respond accordingly. This makes option A incorrect. Peripheral nervous system lies outside the central nervous system. It serves to carry the sensory information from external sensory receptors to CNS and motor signals from CNS to skeletal muscles via its somatic division (the voluntary actions). The autonomous division of peripheral nervous system controls the cardiac and smooth muscles and glands, thereby the functioning of internal organs, without our conscious control (the involuntary actions). This makes option B incorrect and option C correct. The 12 pairs of cranial nerves are part of peripheral nervous system and are mostly concerned with head, neck and facial region of the body (vagus nerve X being the part of autonomous division serves as an exception). Option D is incorrect.  Correct answer is C. 

The parasympathetic nervous system is responsible for the rest and digest response, which includes slowing down the heart rate.

This question is ambiguous. Alcohol affects MULTIPLE brain regions - cerebral cortex (judgment, disinhibition), cerebellum (coordination, balance), and medulla (respiration at high doses). The claimed answer B (cerebellum) explains ataxia but not alcohol's primary effects. If the question means 'coordination', B is correct. If it means intoxication generally, cortex (C) is more accurate. Given the options, cerebellum is likely the intended answer for motor effects.

The frontal lobe is responsible for higher-level cognitive functions, including decision-making, planning, problem-solving, and intellectual ability.

The sympathetic nervous system prepares the body for stress by increasing heart rate. It typically inhibits digestive secretions like saliva.

The temporal lobe, particularly the hippocampus located within it, plays a critical role in the formation and storage of memories.

The sympathetic nervous system mediates the fight or flight response, which causes physiological changes like increased heart rate and dry mouth during stressful situations like watching a horror movie.

The pneumotaxic center is located in the pons and helps regulate the respiratory rhythm by limiting inspiration.

Corpus callosum is a broad band of nervous tissue that connects two cerebral hemispheres. It consists of $300$ million fibres and is present only in mammals.

The autonomous nervous system control the heart beat rate via cardio regulatory centre in medulla oblongata. The emergency conditions activate the sympathetic motor nerve and make the adrenal medulla to release epinephrine and nor-epinephrine which in turn increase the heart beat rate.  Thus, the correct answer is C. The central nervous system (Central NS) includes brain and spinal cord. It integrates and stores the sensory information from external and internal sense organs and commands different organs to respond accordingly. Peripheral nervous system (PNS) lies outside the central nervous system and is further divided into somatic and autonomic nervous system. It serves to carry the sensory information from external sensory receptors to CNS and motor signals from CNS to skeletal muscles via its somatic division (the voluntary actions). The autonomic division of peripheral nervous system controls the cardiac and smooth muscles and glands, thereby the functioning of internal organs, without our conscious control (the involuntary actions). On the other hand, vagus nerve conducts the parasympathetic motor impulses which in turn slow down the hearth beat rate by effect of acetylcholine; a neurotransmitter released by parasympathetic nervous system. 

The acetylcholine is the neurotransmitter that is released by the presynaptic nerve fibres into the synaptic cleft which is received by the receptors on the post-synaptic nerves. It allows the transfer of the information from the presynaptic neuron to the post-synaptic neurons. The preganglionic and the post-ganglionic parasympathetic nerves are cholinergic because they secrete the acetylcholine. The preganglionic nerve fibres of the sympathetic nervous system are also cholinergic.

The premotor area occurs in the frontal lobe of the cerebrum. It is made up of the neurons that form the part of the autonomous nervous system and movements of the involuntary muscles like movements of pharynx and larynx. The prefrontal cortex of the frontal lobe is concerned with thinking and reasoning.

• Ionotropic glutamate receptors are ligand-gated ion channels that are activated by the neurotransmitter glutamate.
• Umami describes foods with an inherent savoriness(delicious, tasty). It has been described as brothy or meaty. You can taste umami in foods like Parmesan cheese, seaweed, miso, and mushrooms, which contain a high level of the amino acid, glutamate.
  
• As the umami food contains a high level of amino acid glutamate its mediated by ionotropic glutamate receptor. The receptor detects glutamate in the food and sends signals to the brain.
• So, the correct answer is 'Umami'.

Cyclostomates are primitive vertebrates that lack a myelin sheath around their nerve fibers.