Muzammil Siddique

Muzammil Siddique

Process Related to Homeostasis

ThermoregulationOsmoregulation

ExcretionFeedback

Mechanism

Muzammil Siddique

ThermoregulationThe process of maintaining a steady body

Temp.

System Involved:MuscularIntegument (skin)RespiratoryCirculatoryNervous SystemEndocrine

Muzammil Siddique

Muzammil Siddique

In PlantsLow Temperature:•Bring changes in solutes composition of cell (super cool without ice formation).•Increasing proportion of unsaturated fatty acid.High Temperature:•Evaporative cooling•Heat-shock proteins

Muzammil Siddique

Muzammil Siddique

OsmoregulationLand Animals: “Drying up” is the huge problem.Adaptations areWaxy exoskeletons of insectsLayers of dead Keratinized skin cellsDrinking and eating moist foodsUsing metabolic water(water produced

during cellular respiration) e.g. Kangaroo.

Muzammil Siddique

Muzammil Siddique

Muzammil Siddique

In PlantsHydrophytes: Extensive stomata present on

the upper surface.Mesophytes: Sufficient supply

Stomata openRestricted Supply Stomata close.Xerophytes: Thick and small leavesWaxy and leathery cuticleStomata are on the lower surface of leavesStem stores water

Muzammil Siddique

ExcretionElimination of waste products

In Plants through:Leaves (shedding there leaves)Old xylem (store strange chemicals in xylem

e.g. ebony)Roots (secrete waste products e.g. conifers)In Animals through:Skin ( sweat)Lungs (exhalation of Carbon dioxide)Kidney (in the form of urine)Liver (Detoxify poisons, produce ammonia,

urea, uric acid from nitrogenous waste, Recycle old RBC)

Muzammil Siddique

Muzammil Siddique

FeedbackFeedback compares current conditions to the body’s comfort levels.It has two types:Negative FeedbackPositive feedback

Muzammil Siddique

Negative FeedbackCounteracts change and brings the body back

to homeostasis.

Negative feedback loop

Muzammil Siddique

Positive FeedbackIncreases change away from the set points. Needed for rapid change in the body.e.g. Torn blood vessels stimulates the release of clotting factors to stop blood flow.

Muzammil Siddique

Muzammil Siddique

Example of Positive and Negative Feedback Loop

Muzammil Siddique