Thermoregulation is the maintenance of body temperature within a range that enable cells to function efficiently Selective brain cooling has been postulated as a mechanism for animals to maintain brain temperature below thermal critical values when body temperature increases To assist this, camels have a “Rete Mirabelle By cooling the brain the animal is able to tolerate higher temperatures

1. Thermoregulation &
Osmoregulation in Camels
Presented by: Shumaila Riaz
Roll #: 0827-BH-Z-18
Semester: 6
Presented to: Dr. Muhammad Tariq
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2. Thermoregulation
 Thermoregulation is the maintenance of body
temperature within a range that enable cells to
function efficiently
 It is the ability of an organism to maintain a core
internal body temperature
 Core temperature (Tc), also referred to as core body
temperature, is the temperature of the internal organs,
such as the liver, located deep within the body.
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3.  Body temperature increases significantly above
normal, a condition known as hyperthermia occurs.
 When body temperature decreases below normal
levels, is known as hypothermia.
 Due to malfunction in homeostatic control
mechanisms
 All thermoregulation mechanisms are designed to
return your body to homeostasis. This is a state of
equilibrium
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4. Classification on basis of temperature
regulation
 Animals divided into two main categories:
 1. Pikilotherms: (cold blooded) change their body
temperature according to environment e.g. fishes,
amphibians & reptiles
 2. Homeotherms: (warm blooded) can maintain their
body temp. e.g. birds and mammals
 They loss heat by conduction, convection, radiation
and evaporation process
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5. Modern Classification of Animals
 1. Ectotherms: take heat from outside e.g. fish
amphibian & reptiles also invertebrates
 2. Endotherms: take heat from inside e.g. mammals,
birds and some fishes
 Cooling and Heating mechanisms
 3. Heterotherms: take heat from inside but body
temp. change e.g. bat, humming bird
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7. Temperature ranges in some animals
Animals Temperature Ranges
Chicken 40.3̊C – 43.0̊C
Cat 38.1̊C – 39.2̊C
Camel 34.3̊C – 40.1̊C
Human 36.1̊C – 37.2̊C
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8. Thermoregulation in Camels
 Physiological adaptation defined by biologists as
the physiological processes involved in adjustments
by the individual to climatic changes and changes in
food quality etc.
 The requirements for survival in hot arid areas are
very important . Temperature must be maintained and
water must be conserved .
 The camel losses body heat by sweating more
efficiently than other mammals
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9. 2 species of Camel
 Camel is the one of the best adapted animals to
desert conditions.
 There are two species of camels:
 1. The Arabian camel (Camelus dromedarius):
Single humped camel in the Middle East and North
Africa, it is more adapted to hot conditions.
 2. The Bactrian camel (Camelus bactrianus): Two
humped camel in central Asia, it is more adapted to
cold conditions
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Camelus
dromedarius/Arabian
Camel
Bactrian camel/
Camelus
bactrianus

11. Physiological Adaptations
 In most mammals fat is spread over the body surface
just under the skin
 In the camel the fat is concentrated in the hump
 The skin is supple, covered with short fine hairs
 The body temperature can vary over a wide range
under condition of dehydration.
 The camel can lose 25% of its body weight over a
period of time without losing its appetite for food
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12. Adaptations
 The poll glands which are situated towards the top of
the back of the neck behind ears.
 It is more active under condition of heat and fatigue
It act as modified sweat gland
 Also, the coat of the camel is fairly sparse/dispersed
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The two poll glands. They
secrete a watery yellowish
secretion with offensive odour
during breeding seasons

13. Selective Brain Cooling
 Mean temperature = 30-35°C, camels can go 10-15
days without water
 temperature exceeds 40°C, shorter periods between
watering is necessary
 Selective brain cooling has been postulated as a
mechanism for animals to maintain brain temperature
below thermal critical values when body temperature
increases
 To assist this, camels have a “Rete Mirabelle
 By cooling the brain the animal is able to tolerate
higher temperatures
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14. Selective Brain Cooling Mechanism
Body
Temper
ature
Rises
Carotid
arteries
Divided
into
smaller
blood
vessels
Connects
with the
small
veinules
of nasal
passage
Rette
Mirabel
Heat
transfer
from Warm
arterial
blood to
Cold
venous
Blood
3.98
celsius
cooler
blood
reaches
to brain
Brain
Tempera
ture
Falls
down
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This network of veins and arteries
are so close to each other that allows
the venous blood to cool the arterial
blood flowing to the brain of the
camel

16. High Temperature
 Under normal conditions the cool venous blood
travels
 However, when temperature increases in the body
the nasal and the angular veins (1 and 2) become
wider while the facial vein (3) is constricted.
 When this situation occurs the cool venous blood can
only go in one direction through the ophthalmic
veins
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17. 17
Superficial veins of the camel head under normal
conditions (A) and hot conditions (B).

18. Anatomical adaptation
 The head of the camel is small with no horns
 Erected ears are present.
 Ear contains small hairs to filter and warm the air
entered the ears in sandy environment day
 Most of the fatty tissues of camel is stored in the
hump
 Skin contains short fine hairs (weber)
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20. Thermoregulation and Water
Preservation in Camel
 Camels usually maintain a body temperature of 41
Celsius during the day, and almost 34 Celsius over
the night.
 Temperature regulation in camels has a lot to do with
the water preservation,
 When they finally sweat, resulting into efficiently
cooling their body.
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21. Osmoregulation
 Osmoregulation is the process by which living
organisms control the concentration of water and
electrolytes in their bodies.
 Osmotic Stress is condition when the concentration
of dissolved substances in a cell or tissue is abnormal
 If it has more electrolytes, the concentration of water
goes down
 Osmoconformer
 Osmoregulators
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22. Osmoregulation in Camels
 The digestive and urinary tracts are well specialized
Cattle lose 20 to 40 liters of fluid daily through feces,
whereas camels lose only 1.3 liters.
 Fluid is absorbed in the end part of the intestines,
where the small fecal balls are produced
 The rumen helps maintain water balance in two
ways:
During dehydration, stored water in rumen is used
After dehydration, rumen prevents hemolysis of body
cells
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23. 23
Water cells in
stomach of camels in
rumen
Longitudinal &
Transverse

24. Role of Kidney
 The camel’s kidneys play a major role in the process
of conserving water through increasing the
osmolarity of urine.
 The kidney is characterized by a long loop of Henle,
and a well-developed medulla (the ratio medulla :
cortex is about 4:1) .
 During dehydration, the kidneys reduce water losses
both by decreasing the glomerular filtration rate
and by increasing the tubular re-absorption of
water
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26.  The long loops of Henle, which are four to six times
longer than in cattle, have the function of both
concentrating urine and reducing its flow.
 A dehydrated camel urinates only drops of
concentrated urine
 Larger release of ADH leads to a fast renal response
that causes increased re-absorption of water.
 So the water re-absorption in the collecting tube is
accompanied by that of the urea.
 The tubular re-absorption of urea would be under the
hormonal influence of the anti-diuretic hormone
(ADH).
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27. Unique feature of Blood
 Blood composition and volume remains constant
 Erythrocytes are oval shaped and non-nucleated,
stores water
 Due to the oval shape, their blood cells are able to
expand to 240% of its original volume, whereas the
red blood cells of other animals can only expand up
to 150%
 Have longer life span of about 150 days when
dehydrated (normal 90-120 days)
 Therefore extending the life span of erythrocytes
reduces energy and water expenditure
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28. 28
Oval and non-nucleated
blood cells in camels. These
cells swell when store water

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30. References
 Adem, A., Al Haj, M., Benedict, S., Yasin, J., Nagelkerke, N., Nyberg, F., ... &
Kazzam, E. (2013). ANP and BNP responses to dehydration in the one-humped
camel and effects of blocking the renin-angiotensin system. PLoS One, 8(3),
e57806.
 Goumi, M. B., Riad, F., Giry, J., De La Farge, F., Safwate, A., Davicco, M. J., &
Barlet, J. P. (1993). Hormonal control of water and sodium in plasma and urine of
camels during dehydration and rehydration. General and comparative
endocrinology, 89(3), 378-386.
 Robertshaw, D., & Zine-Filali, R. (1995). Thermoregulation and water balance in
the camel: a comparison with other ruminant species. Thermoregulation and water
balance in the camel: a comparison with other ruminant species., 563-578.
 III, J. W. C., Krausman, P. R., Rosenstock, S. S., & Turner, J. C. (2006).
Mechanisms of thermoregulation and water balance in desert ungulates. Wildlife
Society Bulletin, 34(3), 570-581.
 McKinley, M., Trevaks, D., Weissenborn, F., & McAllen, R. (2017). Interaction
between thermoregulation and osmoregulation in domestic animals. Revista
Brasileira de Zootecnia, 46(9), 783-790.
 http://seramporecollege.org/a-s-c/wp-content/uploads/2020/03/Thermoregulation_-
of_Camels_to_the_Desert_Environment.pdf
 https://www.slideshare.net/RichardBader/thermoregulation-and-osmoregulation-bd
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