Cornea transplantation is outstandingly successful because
cornea is easy to preserve
cornea is not linked up with blood vascular and immune systems
the technique involved is very simple
cornea is easily available
In the chemistry of vision in mammals, the photosensitive substance is called
sclerotin
retinal
rhodopsin
melanin
In humans, visceral organs are innervated by
sympathetic nerves and are under conscious control
parasympathetic nerves and are under conscious control
Both (a) and (b)
both sympathetic and parasympathetic nerves but are not under conscious control
Light rays entering the eye are controlled by
pupil
iris
cornea
lens
Iris is part of
sclerotic
choroid/uvula
choroid and retina
sclerotic and choroid
Vagus nerve is
X
IX
VII
V
One function of parasympathetic nervous system is
contraction of hair muscles
stimulation of sweat glands
acceleration of heart beat
constriction of pupil
The sympathetic nerves, in mammals arise from
sacral nerves
cervical nerves
thoraco-lumbar nerves
III,VII,IX and X cranial nerves
CNS is mostly made of
motor neurons and sensory neurons
sensory neurons and association neurons
association neurons
motor neurons and association neurons
Afferent nerve fibres carry impulses from
effector organs to CNS
receptors to CNS
CNS to receptors
CNS to muscles
