Lesson #6: Homeostasis

Question 1

Homeostasis

Answer 1

Homeostasis is the maintenance of a
relatively stable internal environment

This is the result of conditions in every cell
remaining nearly constant

Failure to achieve and maintain homeostasis
is most often death.

“Homeo” means same, “stasis” means state.

The body’s ability to maintain “normal”
physiological conditions.

Homeostatic mechanisms must allow the
body to maintain the following conditions:

Question 2

Body Temperature

Answer 2

Body temperature is 37°C.

Maintained by the homeostatic mechanism of Thermoregulation.

Question 3

Water Balance

Answer 3

78% of the human body is composed of water

A 1% drop in fluid body mass causes thirst

A 5% drop in fluid body mass causes extreme pain and collapse

A 10% drop in fluid body mass results in death

Maintained by the homeostatic mechanism Osmoregulation

Question 4

Blood Pressure

Answer 4

Blood pressure is measured as systolic pressure over diastolic
pressure.

“normal” blood pressure is 120/80 mmHg or 160/106 kPa

Question 5

Blood pH and
Blood glucose

Answer 5

Blood pH is 7.4
Blood sugar should be maintained at 100mg/mL

Question 6

Respiratory Gases

Answer 6

Oxygen and carbon dioxide must be balanced in the bloodstream

Maintained by mechanism called Respiration

Question 7

Waste Management

Answer 7

Cellular metabolism results in the production of harmful waste.

Organs such as the liver, kidneys, lungs, stomach and skin help the
body regulate and reduce waste levels in the body.

Question 8

Immunity

Answer 8

Homeostatic mechanisms regulate the body’s response to pathogens

Question 9

Repair

Answer 9

Homeostatic mechanisms regulate the body’s ability to repair
injuries.