Homeostasis

Question 1

Define homeostasis

Answer 1

It is the ability of a system or living organism to adjust it’s internal environment to mantain a stable equilibrium

Question 2

What is the purpose of homeostasis?

Answer 2

To provide an optimal fluid environment for cellular function

Question 3

What is meant by extrinsic homeostatic control?

Answer 3

The control system is outside the tissue being controlled (e.g. brain controlling the homestaiss of a different organ tissue)

Question 4

What is meant by intrinsic homeostatic control?

Answer 4

The regulation occurs from within the system being regulated (autoregullation)

Question 5

What is meant by intracellular homeostatic control?

Answer 5

The regulation of homeostais in a cell by the cell itself

Question 6

What can occur if homeostasis is not maintaned?

Answer 6

If homeostasis is not mainted and conditions within the cell fall outside their normal ranges, it can lead to protein denaturation, which is a threat to the life of the cell

Question 7

What does damage in blood vessels from high glucose levels can lead to? (name 3)

Answer 7

Artherosclerosis, kidney disease, retinopathy

Question 8

What is the normal ICF Na+ concentration?

Answer 8

15mM

Question 9

Where is Na+ concentration high and K+ concentration low?

Answer 9

ECF

Question 10

What is the normal interstitial fluid Na+ concentration?

Answer 10

145mM

Question 11

What is the normal plasma a+ concentration?

Answer 11

142 mM

Question 12

Reference value of arterial pH

Answer 12

7.35 to 7.45

Question 13

Reference value of Glucose

Answer 13

75 -110mg/ 100ml – 4.4 -5.0mmol/L

Question 14

Reference value of Na+

Answer 14

135 - 145 mEq/L

Question 15

Reference value of Bicarbonate

Answer 15

24 - 28 mEq/L

Question 16

Reference value of K+ serum

Answer 16

3.5 - 5.5 mEq/L

Question 17

WHat are the steps of the feedback loop?

Answer 17

Stimulus –> Receptor –> Coordinator –> Effector –> Response

Question 18

What is the name of the receptor that monitors pressure?

Answer 18

Barorecpetors

Question 19

What do chemorecpetors monitor?

Answer 19

CHemical substances: e.g.oxygen, carbon dioxide, pH in carotid arteries, etc

Question 20

What receptors monitor osmosis?

Answer 20

Osmoreceptors

Question 21

What receptors monitor temperature?

Answer 21

Thermoreceptors

Question 22

Which is more common in the body: negative feedback or positive feedback?

Answer 22

Negative feedback

Question 23

Give one example of positive feedback

Answer 23

Lactation (secretion of milk)

Question 24

Give two examples of negative feedback

Answer 24

Temperature regulation and Glucose regulation

Question 25

What is meant by "anticipation"?

Answer 25

It is a predictive response. The reponse is activated before any changes, the body predicts those changes will occur

Question 26

What are 4 types of adaptation responses?

Answer 26

Genetic adaptation (inherited reponse), Accomodation, Acclimation, Acclimatisation (all three are acquired reponses)

Question 27

What is accomodation?

Answer 27

Immediate physiological change in sensitivity of cells to changes in extrenal environment

Question 28

What is acclimation?

Answer 28

Long term physiological changes in response to exposure to artificial or simulated changes in environment

Question 29

What is acclimatisation?

Answer 29

Long term physiological changes in response to exposure to natural changes in environment

Question 30

What are two benefits of having a fever?

Answer 30

The high temperature kiils pathogens and enhances phagocytosis

Question 31

List the steps of what happens during an infection that lead a fever to develop

Answer 31

bacteria enters the body --> causes bone marrow to produce more macrophages --> macrophages secrete endogenous pyrogens (educados piratas) --> secreted into the bloodstream --> cause the hypothalamic set point (the temp at which the hypothalamus regulates the body temp) to increase --> feedback mechanisms loops start in the body --> body temperature increases --> temperature rises above normal --> fever

Question 32

Older adults may sometimes not show fevers, what are 4 symptoms they may show of an infection?

Answer 32

Feeling hot/cold, vivid dreams, hallucinations and hedaches

Question 33

True or false: Children showcase higher temperatures than adults for relatively minor infections

Answer 33

True

Question 34

What is a reason some people feel comfortable in temperatures that are too cold for those around them?

Answer 34

Their temperature set point might be naturally lower

Question 35

What is an effector?

Answer 35

Any organ or tissue that receives information from the integrating centre and acts to bring about the changes needed for homestasis to be maintained

Question 36

Name two diseases that result from homestatic imbalance

Answer 36

Diabetes and heart failure

Question 37

True or false: Aging is a source of homeostatic imbalance as the control mechanisms of the feedback loops lose their efficiency, which can cause heart failure

Answer 37

True

Question 38

What region of the brain controls temperature, heart rate, blood pressure, satiety and circadian rythms?

Answer 38

Hypothalamus

Question 39

What is meant by sensitivity in homeostasis, give one example.

Answer 39

More than one stimulus can sensitize the loop. Low Po2 and high PCO2 both trigger increased ventilation however the response when both occur together is greater than the sum of when they occur independently

Question 40

All homeostatic control mechanisms have at leats how many interdependent components for the variable being regulated?

Answer 40

At least three