Homeostasi Home ostasiss – Kema Kemalaran laran dinamik dinamik
Sistem kawalan tubuh badan
Cabaran senaman dalam homeostasis
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Pengenalan kepada Fisiologi Senaman
Apa itu Fisiologi? suatu bidang yang mengkaji tentang fungsi2 tisu (otot, saraf,…), organ (jantung, paru2,…) dan system (system kardiovaskular) dalam badan
Fisiologi Senaman Senaman – suatu bidang yang mengkaji/ mengkaji/ menilai kesan senaman senaman ke atas tisu, organ dan sistem badan
Sistem Fisiologi Manusia
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Homeosta Home ostasis sis – Kema Kemalaran laran dinam dinamik ik
Homeostasiss – drp perkataan Homeostasi perkataan Greek… Greek… Homeo which means ‘unchanging’ and Stasis which means ‘standing ‘standing – means ‘staying ‘staying the the same’ It is an organism’s internal environment which ‘stays the same’ providing a stable/ constant internal environment for the cells of the body
Contoh Homeostasis
The external temperature varies during the day and from season to season, sometimes by as much as 40oC, but the human body temperature stays at about 37 oC This is achieved by sweating, s weating, vasodilation, vasoconstriction, and shivering If the body temperature rises, the sweat glands in the skin are activated activated and secrete s ecrete sweat on to the surface of the skin When the sweat evaporates, it takes heat from the body and cools it down
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Section through skin
evaporation
The sweat gland extracts sweat from the blood and passes it up the duct to the skin surface where it evaporates
0.25 mm
sweat pore
epidermis
dermis
sweat duct
sweat gland
blood vessel
Sweat gland
Vasodilation
much heat lost
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If the body temperature rises, the blood vessels in the skin dilate (become wider) and allow more blood to flow near the surface. The heat loss from the blood through the skin helps cool the circulating blood
Vasoconstriction
little heat lost
If the body temperature falls. The blood vessels in the skin constrict. Less warm blood flows near the surface so less heat is lost
Vasoconstriction on& dilation
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Sistem kawalan tubuh badan manusia
Negative Negat ive feedback feedback – suap balik negatif negatif
Positive Positi ve feedback feedback – suap balik positif positif
Homeostasis
Homeostasis is the ability to maintain a relatively stable internal environment in an ever-changing outside world The internal environment of of the body is in a dynamic state of equilibrium Chemical, thermal, thermal, and neural factors interact to maintain homeostasis
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Homeostatic Homeosta tic Control Mechanisms
Some variables produces a change in the body Three interdependent interdependent components of control mechanisms are: (biological (biological control system) system )
Receptor (reseptor/ (reseptor/ penerima) – monitors the the environments and responds to changes (stimuli)
Control center (pusat kawalan) – determines the the set point at which the variable is maintained
Effector (efektor) (efektor) – provides the means to respond to the stimulus
Homeostatic Control Mechanisms 3 Input: Information sent along afferent pathway to
Control center
4 Output: Information sent along efferent pathway to
Effector
Receptor (sensor)
2 Change detected by receptor
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Stimulus: Produces change in variable
Variable (in homeostasis)
5 Response of effector feeds back to influence magnitude of stimulus and returns variable to homeostasis
Figure 1.4
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Negative Feedback (suap balik negatif)
In negative feedback systems, the output shuts off the original stimulus Example: Regulation of blood glucose levels levels
Negative Feedback
Figure 1.5
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Positive Feedbac Feedback k (suap balik positif)
In positive feedback systems, the output enhancess or enhance exaggerates the original stimulus Example: Regulation of blood clotting
Disturbance of homeostasis or the body’s normal equilibrium Overwhelming of negative feedback Overwhelming mechanisms allowing destructive positive feedback mechanisms to take over
