HOMEOSTASIS (need to finish)

Question 1

define health?

Answer 1

state in which somebody is able to adjust to and cope with various challenges he/she may encounter in daily living

Question 2

define homeostasis?

Answer 2

*ability to maintain relatively stable internal environment in an ever-changing outside world
—the maintenance of constancy of internal environment (which is in dynamic state of equilibrium)
—chemical, thermal, neuronal factors interact to maintain homeostasis

Question 3

describe the mechanisms of homeostasis?

Answer 3

-large number mechanisms exist to preserve necessary conditions for constancy in internal enviro
—controlled by specialised cells in nervous and endocrine system
-mechanisms triggered by change in extracellular fluid (ECF)
*majority act by negative feedback - restore/preserve stability by producing a change in the opposite direction
*positive feedback - rare and occur when promoting/ increasing a change is desired rather than stopping it (transient [ST] effects)

Question 4

what are the 3 independent components of control mechanisms?

Answer 4

1) receptor = monitors environment and responds to changes (stimulus)
—carries info via afferent pathway to CC
2) control centre = determines set point at which the variable is maintained
—carries info via efferent pathway to E
3) effector = provides means to respond to stimuli

Question 5

what is negative feedback? give two examples

Answer 5

*the output shuts off the original stimuli = fine tuning
—regulation blood glucose levels
—regulation body temperature

Question 6

what is positive feedback? give two examples

Answer 6

*the output enhances/ exaggerates the original stimuli = brings about change
—regulation of blood clotting
—milk production

Question 7

what is homeostatic imbalance?

Answer 7

*most diseases are considered as a homeostatic imbalance
—a disturbance to the bodies normal equilibrium
*overwhelming of negative feedback mechanisms allowing destructive positive feedback mechanisms to take over

Question 8

what are the impacts of ageing on the nervous system in terms of homeostasis?

Answer 8

• loss neurones
• loss myelin
• loss neurotransmitters
• memory loss
• reduced, reflexes
• reduced postural control

Question 9

what are the impacts of ageing on the senses in terms of homeostasis?

Answer 9

• decreased receptor sensitivity
• decline in function of lens
• decreased blood flow to cochlea (loss hearing, taste, visual acuity)

Question 10

what are the impacts of ageing on the endocrine system in terms of homeostasis?

Answer 10

*decreased synthesis, release and sensitivity to hormones