Homeostasis

Question 1

What is homeostasis

Answer 1

-maintenance of a constant internal environment despite changes in external environment through regulatory processes

Question 2

What is feedback

It’s function

Answer 2

• return of information ( output change ) of a system to the control center
• maintenance of homeostasis

Question 3

Describe how homeostasis occurs

Answer 3

1 stimuli produces change to a variable

• change detected by receptor sensors
• info sent along afferent pathway to control center
• control center processes info and sends output along efferent pathway to effector
• effector carries out response and variable returned to normal

Question 4

2 types of logical feedback and describe and differentiate

Answer 4

1 negative feedback - control center acts in the opposite direction as information change. ( most common in biological systems ). It’s oscillations damp out to a stable state

2 positive feedback- control center acts in same direction as information change ( rare in biological systems). Found in mechanisms that have a definite end point

Question 5

3 components needed for homeostasis

Answer 5

1 receptor ( sensor )
2 control center
3 effector

Question 6

What does too little or too much glucose cause and the effects

Answer 6

1 hypoglycemia- coma , lethargy, death , ( body undergoes gluconeogenesis)

2 diabetes mellitus - excess excretion of water , excess thirst , death ( tries to store in cells )

Question 7

Describe homeostasis of high blood glucose levels

Answer 7

1 high glucose detected by beta cells of pancreas at islets of langerhans
2 cells secrete insulin which promotes cellular uptake of glucose
3 as glucose taken into cells , blood glucose levels decrease and cells stimulated to release less insulin
4 blood glucose retuned to normal levels

Question 8

Describe homeostasis of high body temp

Answer 8

-hypothalamus detect high body temp and pituitary stimulated to releases TSH
/TSH and iodine at thyroid made to release thyroxine
-thyroxine In body increases metabolism and more heat released
-temp increases and less TSH released
-body temp returned to normal

Question 9

4 ways in which the body can combat changes in temperature

Answer 9

1 vasoconstriction
2 vasodilation
3 piloerection
4 sweating