In man, PTH or parathyroid hormone is released when blood calcium level falls.

This option is correct.

 This option is correct because these are the four different types of waves are shown in the EEG of a normal human.

This is the correct option.

This option is correct because they all perform the major function of brain considered as brain stem.

This option is correct because humans have 12 pairs of cranial nerves. These are the nerves arising from Central Nervous System (CNS).

This option is correct.

This option is correct because vagus has the maximum number of branches and it is also known as wondering nerve.

This option is correct because the convolutions/folds increase the surface area of cortex for accomodating more nerve cells in it.

This option is correct because brain is situated in the cranial cavity of the skull and forms 98% of the weight of the whole CNS.

This option is correct because endorphins are produced during the time of physical/emotional stress for example: child birth, etc.

This option is correct because temporal lobe has three important areas which have important functions in the sense of smell, hearing  and understanding. Speech and rest are the parts of other lobes.

This option is correct because auditory nerve is formed by the union of vestibular nerve and the cochlear nerve.

This option is correct because multiple sclerosis occurs due to the destruction of  myelin sheath of neuron.

This option is correct because they are unconditioned and involuntary reflexes without any function of brain, these are inborn.

This option is correct because macula lutea contains a yellow pigment called xanthophyll. Hence, it is also known as yellow spot.

This option is correct because cornea is vascular and does not get blood supply. It absorbs oxygen directly from air.

This option is correct because it maintains the shape of the front part of the eye and provides nutrients to the lens.

This option is correct because it contains centres for homeostasis by regulating body temperature. It is present in the brain which is a part of the nervous tissue and the hormones released by posterior pituitary gland (endocrine gland) are synthesized in hypothalamus.

This option is correct because ruffini's corpuscles is an example of calo receptor which responds to heat and temperature.

This option is correct because vitreous humour is present behind the lens and the space inside the retina. It is a clear, semi-solid jelly like substance and is not secreted by the cilliary process. It cannot be replaced in any significant quantity.

This is the correct option.

 This option is correct because lymphatic vessels are not present in the nervous tissues.

This option is correct because hindbrain is also known as rhombencephalon.

Graves disease is due to hypersecretion of thyroxine.