• -- Structures that detect stimuli. They
monitor both external and internal
environmental conditions. Conduct
information about those stimuli to the
central nervous system.
TYPES OF RECEPTORS
• Chemoreceptors- they detect • Mechanoreptors- respond to
chemicals. touch, pressure, vibration, &
• Thermoreceptors- respond to
changes in temperature. • Baroreceptors- detect changes
in pressure within body
• Photoreceptors- detect structures.
changes in light intensity,
color, & movement. • Nocieptors- respond to pain
caused by either external or
• Gustation is our sense of taste. It
permits us to perceive the
characteristics of what we eat and
• Gustatory cells are taste receptors
housed in specialized sensory organs
termed taste buds on the tongue
THE [[external]] EAR
• A Skin covered cartilaginous structure
called the auricle or pinna.
• The Auricle is funnel shaped and serves
to protect entry into the ear.
• Directs sounds waves into the bony
tube called the external acoustic
THE [[middle]] EAR
• Contains an air ﬁlled tympanic cavity.
• Includes the the bones from lateral to
medial: Malleus, Incus, & Stapes.
• Responsible for amplifying sound
waves and transmitting them into the
THE [[inner]] EAR
• Located within the petrous part of the
• It includes the: vestibule, the semi
circular canals, & the cochlea.
• Mechanisms for equilibrium are located
within the inner ear.
Nerves Associated With Inner Ear
• VESTIBULOCOCHLEAR NERVE
& THE VAGUS NERVE
• 1) sound waves are collected and funneled by the auricle of the
• 2) the vibrations of the tympanic membrane causes movement by the
• 3) pressure waves originate within the inner ear and travel through
the perilymph in the scala vestibuli.
• 4) high-frequency and upper medium frequency pressure waves in
the scala vestibuli cause the vestibular membrane to vibrate, resulting
in pressure wave formation in the endolymph of the cochlear duct.
• 5) the remaining pressure wave vibrations in the cochlear duct are
transmitted to the perilymph of the scala tympani and they exit the
inner ear at the round window.