(d) When the set point of hypothalamus is disturbed by high temperature, it stimulates vasodilation and sweating while in low temperature there is vasoconstriction and shivering.
(a) Crista ampullaris is a sensory organ of rotation.
It maintains the dynamic balance of the body.
Macula (otolith organ) maintains the static balance of the body.
(c) Pre-synaptic membrane is involved in the release of neurotransmitter in the chemical synapse.
The receptors sites for neurotransmitters are present on post-synaptic membrane of neuron.
(a) Xth pair of cranial nerves (vagus nerves) has a motor branch called cardiac nerve which innervate cardiac muscles.
(d) Sympathetic system prepares the body for stress or emergency conditions while parasympathetic system is associated with the period of rest.
Parasympathetic nervous system constricts the pupil to its normal condition.
(b) Afferent nerve fibres - sensory nerve fibres which carry senses from receptors to brain or spinal cord (CNS).
(c) In mammals, the sympathetic nerves arise from thoraco-lumbar nerves (autonomic nervous system).
(d) The activities of all visceral organs are coordinated through the regulation of their smooth muscles and glands by the nerve fibres of the sympathetic and parasympathetic nervous system.
These are not under the control of our will.
(d) Oligodendrocytes are neuroglial cells which produce myelin sheath in central nervous system while Schwann cell produces myelin sheath in peripheral nervous system.
(c) Neuroglia are non-nervous cells present along with and in between the neurons in central nervous system, ganglia and retina.
