Homeostasis Ch. 1

Question 1

Homeostatic regulation involves two general mechanisms

Answer 1

Autoregulation & Extrinsic regulation

Question 2

Homeostatic regulation

Answer 2

The adjustment of physiological systems to preserve homeostasis.

Question 3

Autoregulation (Intrinsic Control)

Answer 3

Control mechanism operating within a cell, tissue, or organ. Often uses chemical signals.

Question 4

Extrinsic Control

Answer 4

• Outside control
• Occurs at system or organism level
• Nervous or hormonal regulation

Question 5

Homeostasis involves regulation of:

Answer 5

• Temp
• Pco2
• Po2
• pH
• H20 balance
• Electrolyte balance
• Blood glucose

Question 6

The body _____ to maintain the variable normal ranges.

Answer 6

Self regulates

Question 7

Four Basic Components of Control Mechanism

Answer 7

1. Sensor mechanism (receives stimulus)
2. Control or integrating center (processes signal, sends instructions)
3. Effector mechanism (carries out instructions)
4. Feedback (loops back to sensor mechanism)

Question 8

Negative feedback loop (system controlled by inhibition)

Answer 8

It maintained a constant internal environment by stabilizing physiological variables

EX: Temp too high; hypothalamus inhibits body action to raise temp.

EX: Temp too low; hypothalamus inhibit systems that release heat.

Question 9

Positive feedback systems (controlled by stimulation)

Answer 9

Amplifies and/or reinforces change; inherently unstable

EX: Clotting
Sneezing
Childbirth
Immune response

Question 10

Feed-forward control (systems that plan ahead)

Answer 10

Stomach and intestines produce digestive enzymes; sight, smell, and thought of food stimulate release of enzymes.