homeostasis

Question 1

define the term homeostasis

Answer 1

maintaining similar (not identical) internal body conditions. also prevents the disturbance of in a system

Question 2

explain the importance of maintaining constancy of the internal environment

Answer 2

failure to do so results in illness, disease and even pathology

Question 3

give examples of internal and external change that could affect homeostasis in organisms

Answer 3

external= temperature change

internal = change in energy demand

Question 4

what happens if compensation with homeostasis succeeds?

Answer 4

leads to wellness

Question 5

state the 3 main mechanisms of homeostasis

Answer 5

• negative feedback
  -feed forward
  -positive feedback

Question 6

describe the principles behind negative feedback systems

Answer 6

it is a trigger that initiates a response
that response brings homeostasis back to its normal range & removes the initial trigger

Question 7

what is one characteristic of negative feedback ( does it prevent situations from happening?)

Answer 7

no it only acts after disturbance has happened.

Question 8

what homeostasis mechanism prevents change before it happens

Answer 8

feed forward system
e.g in digestion your body has cells that are activated even before any food enters your mouth

Question 9

what are the characteristics of feed forward mechanism ?

Answer 9

prevents a situation from getting worse

Question 10

give example of positive feedback and example its mechanism

Answer 10

e.g action potential or The positive feedback mechanism of childbirth is essential for the progression of labor, as it ensures increasingly powerful contractions to facilitate the dilation of the cervix and ultimately the delivery of the baby

makes a situation worse

Question 11

what percentage of human body is water?

Answer 11

60%

Question 12

if an adult male looses 10ml of water how much does he then gain?

Answer 12

10ml
as your gain and losses are ALWAYS equally balanced

*(what we gain we must loose and what we loose we must gain)

Question 13

list the body fluid compartments in which water is located

Answer 13

• intracellular fluid (fluid inside cells)
  -intersititial fluid (fluid between cells
• plasma fluid ( fluid component of blood)

Question 14

give examples of compartments that are classified as extracellular fluids

Answer 14

intersitial fluid and plasma fluids

Question 15

what is the biggest water compartment in the body and how much does it weigh?

Answer 15

intracellular fluid (ICF) 28L

Question 16

what is the difference between the intersitial fluid and Plasma fluid & is there a barrier that separates the two?

Answer 16

there are proteins in the plasma fluid but not in intersitial fluid.

no barrier

Question 17

is the membrane that separates intracellular fluid and extracellular fluid selective?

Answer 17

yes

Question 18

what component of the extracellular fluid is known as the dynamic component

Answer 18

Plasma fluid is known as the dynamic component

Question 19

do arteries undergo exchange (nutrients and waste products) between the ISF and Plasma fluids?

Answer 19

no walls are too thick

Question 20

what does the total body water consist of ?

Answer 20

ICF, ECF(intersitial and plasma fluid)

Question 21

how would you measure body fluid volumes?

Answer 21

use dilution principle

V= M/C or C=M/V

can only measure plasma as we only have access to that

but can indirectly measure other components

Question 22

What are the dominant ions in ECF and ICF?
and what do they form?

Answer 22

ECF= Na and CL

ICF = K

this forms conc gradient

Question 23

why is the concentration gradient between the ECF and ICF important

Answer 23

important for nerve and muscle function

Question 24

If homeostasis in the ECF isnt working what does this mean?

explain how this can be resolved if the individual is healthy

Answer 24

lead to death & disrupts muscle function

kidney fixes it if ur healthy

Question 25

how much % of water does muscle contain and how much does fat contain

Answer 25

muscle 70%
fat 10%
therefore older people or obese people have a lower water content

Question 26

why is there a difference in ion composition in the ECF and the ICF ?

Answer 26

difference is due to the cell membrane which separates the two compartments

Question 27

what separates plasma fluid and ISF

Answer 27

capillary wall