Figure 12.1
Sensory Receptors in Skin
Free nerve
endings
Thermo-,
light touch,
and pain
receptors
Modified and encapsulated
nerve endings
Merkel disks:
light touch
Hair
Free nerve
endings:
sense
changing
position
of hairs
Meissner’s
corpuscle:
light touch
Pacinian
corpuscle:
deep pressure
and high-
frequency
vibration
Ruffini endings:
pressure

Sclera
Choroid
Vitreous
humor
Retina
Fovea
Optic
disk
Optic
nerve
Figure 12.16a
Examples of Abnormal Vision
Figure 12.16b
Examples of Abnormal Vision
Figure 12.16c
Examples of Abnormal Vision
Figure 12.16d
Examples of Abnormal Vision
Figure 12.17
Structure of the Retina
•
Receptors and Sensations
A. Each receptor is more sensitive to a
specific kind of environmental
change but is less sensitive to
others.
receptor
Anatomy of the Brain
Motor and Sensory areas of the left Cerebral Cortex