The sympathetic nerves, in mammals arise from
sacral nerves
cervical nerves
thoraco-lumbar nerves
III,VII,IX and X cranial nerves
Iris is part of
sclerotic
choroid/uvula
choroid and retina
sclerotic and choroid
Third ventricle of brain is also known as
metacoel
rhinocoel
paracoel
diacoel
In which animal nerve cell is present but brain is absent?
Sponge
Earthworm
Cockroach
Hydra
In the chemistry of vision in mammals, the photosensitive substance is called
sclerotin
retinal
rhodopsin
melanin
Afferent nerve fibres carry impulses from
effector organs to CNS
receptors to CNS
CNS to receptors
CNS to muscles
Vagus nerve is
X
IX
VII
V
Function of iris is to
move lens forward and backward
refract light rays
bring about movements of eye lids
alter the size of pupil
The Nissl's granules of nerve cell are made on of
ribosomes
protein
DNA
RNA
Retina is most sensitive at
optic disc
periphery
macula lutea
fovea centralis
