Sense Organs
Keceptors or sense organs are groupsof highly specialized cells which receive stimuli and
change them in to nerve impulse which is carried to the brain for interpretation.
Receptors are found from coelenterates to chordates.
Sherrington classified receptors on the basis of position as-
i) Exteroreceptors
They respond to changes in the external environment.
They are located near the external surface
Example- Photoreceptors, Gustatoreceptors etc.
ii) Proprioreceptors -
They are located in tendons,muscles and joints.
They detect change in the position and length of the muscles
ii) Interoreceptors
Detect the changes in the internal environment.
, Example Statoreceptors ( macula and crista),
-
pain), baroreceptors (carotid bodies in heart wallVisceroreceptors (which detect
which detect pressure
change)
Skin Recepfors
Tongoecqptons
Fox teues o)Gaske Nenye ending
netwank
nehve2
Anound the Aain balb
Gnandry a) Munne sonpacle
phr Yn oleamis
beak 6inela On biea inyn trps, eai
Henben Maakel dacs
CoRpuneles . n epidomisse
inds
Mezzen conpuucle
Xnsub cutaneous
e l g i eompuucle -4ubeuanou in a
2 Aenm uepfos
acalauaptens on m
Ausins tnd 2S-usc
igidoaeeptens
End buls g knause to-20'e
LIso,00e to 25o 000
ono
*Ampulla g Lo renzinu ant hemonejptoaoA in the
3Algesi-aeaypons Scobodun
C4 mllin )
/ u nen encuin
Noaaep fan in deyen layi q, w
henunu wngal epidenmV
4Pasune-Atuphns
Pauinap (onpussle
(500, 000) dermis
shimulahd 5y
dup pacaun vibah
Rheoreupons -Fi afn cwmenngau (ahu,efra
lakene Une
N
, . Olfactory Receptors
They detect smell or odour. (Schneiderian
chamber is lined with Olfactory epithelium
Olfactory part of nasal
membrane).
I t is a pseudostratified epithelium. It has 3 types of cells
i) Olfactory or sensory cells
with a nucleus in the middle.
They are long, narrow and spindle shaped cells
They are modified bipolar neurons on the other end a nerve fibre
On the free side they have sensory stereocilia and
cells.
Life span is of 2 months, the get replaced by basal
million in humans.
Number of olfactory cells is about 20
Nerves from olfactory cells extend to olfactory bulbs.
ii) Supporting cells
They are columnar non sensory cells and provide support
to olfactory cells.
iin Basal cells
They give rise to new olfactory cells
Olfactory epithelium has Bowman's glands which secrete mucous
Olfactory cells are chemosensory; they detect the odoriferous substances in the air.
When these chemicals are inhaled, they dissolve in the mucous and stimulate the stereo
cilia of olfactory cells which initiate a nerve impulse.
Olfactory adaptation - When olfactory cells are continuously stimulated by a specific
odour, the olfaction power slowly decreases and stops that is the olfactory cells undergo
fatigue.
pon muc
Hand.
3tene6
Glia
Sylppenbig
olkackon
celu
1Basal cel
Ne <- >Mu,
1n Cin t Jland
Cnm clhecre2
neniu cOHth qe es
to oladondbulb. Bayement
mem banu.
Olfactory Membrane
Keceptors or sense organs are groupsof highly specialized cells which receive stimuli and
change them in to nerve impulse which is carried to the brain for interpretation.
Receptors are found from coelenterates to chordates.
Sherrington classified receptors on the basis of position as-
i) Exteroreceptors
They respond to changes in the external environment.
They are located near the external surface
Example- Photoreceptors, Gustatoreceptors etc.
ii) Proprioreceptors -
They are located in tendons,muscles and joints.
They detect change in the position and length of the muscles
ii) Interoreceptors
Detect the changes in the internal environment.
, Example Statoreceptors ( macula and crista),
-
pain), baroreceptors (carotid bodies in heart wallVisceroreceptors (which detect
which detect pressure
change)
Skin Recepfors
Tongoecqptons
Fox teues o)Gaske Nenye ending
netwank
nehve2
Anound the Aain balb
Gnandry a) Munne sonpacle
phr Yn oleamis
beak 6inela On biea inyn trps, eai
Henben Maakel dacs
CoRpuneles . n epidomisse
inds
Mezzen conpuucle
Xnsub cutaneous
e l g i eompuucle -4ubeuanou in a
2 Aenm uepfos
acalauaptens on m
Ausins tnd 2S-usc
igidoaeeptens
End buls g knause to-20'e
LIso,00e to 25o 000
ono
*Ampulla g Lo renzinu ant hemonejptoaoA in the
3Algesi-aeaypons Scobodun
C4 mllin )
/ u nen encuin
Noaaep fan in deyen layi q, w
henunu wngal epidenmV
4Pasune-Atuphns
Pauinap (onpussle
(500, 000) dermis
shimulahd 5y
dup pacaun vibah
Rheoreupons -Fi afn cwmenngau (ahu,efra
lakene Une
N
, . Olfactory Receptors
They detect smell or odour. (Schneiderian
chamber is lined with Olfactory epithelium
Olfactory part of nasal
membrane).
I t is a pseudostratified epithelium. It has 3 types of cells
i) Olfactory or sensory cells
with a nucleus in the middle.
They are long, narrow and spindle shaped cells
They are modified bipolar neurons on the other end a nerve fibre
On the free side they have sensory stereocilia and
cells.
Life span is of 2 months, the get replaced by basal
million in humans.
Number of olfactory cells is about 20
Nerves from olfactory cells extend to olfactory bulbs.
ii) Supporting cells
They are columnar non sensory cells and provide support
to olfactory cells.
iin Basal cells
They give rise to new olfactory cells
Olfactory epithelium has Bowman's glands which secrete mucous
Olfactory cells are chemosensory; they detect the odoriferous substances in the air.
When these chemicals are inhaled, they dissolve in the mucous and stimulate the stereo
cilia of olfactory cells which initiate a nerve impulse.
Olfactory adaptation - When olfactory cells are continuously stimulated by a specific
odour, the olfaction power slowly decreases and stops that is the olfactory cells undergo
fatigue.
pon muc
Hand.
3tene6
Glia
Sylppenbig
olkackon
celu
1Basal cel
Ne <- >Mu,
1n Cin t Jland
Cnm clhecre2
neniu cOHth qe es
to oladondbulb. Bayement
mem banu.
Olfactory Membrane
