body fluid homeostasis

Question 1

ICF

Answer 1

intracellular fluid; fluid within all cells

Question 2

ECF:

Answer 2

• extracellular fluid, fluid outside of cells
• made up of plasma and interstitial fluid

Question 3

2 components of ECF

Answer 3

• plasma, also known as intravascular fluid
• interstitial fluid, which is found in the interstitial space located between cells and tissues.

Question 4

Lymph, synovial, intestinal, biliary, hepatic, pancreatic, CSF, sweat, urine, pleural, peritoneal, pericardial, and intraocular fluids are all

Answer 4

ECF

Question 5

___% of body is water

Answer 5

60

Question 6

intracellular fluid is ___% of BW

Answer 6

40

Question 7

extracellular fluid is ___% of BW

Answer 7

20
interstitial; 15% BW
intravascular (plasma); 5% BW

Question 8

Dogs have a total blood volume of ____ml/kg

Answer 8

80-90

Question 9

Cats have a total blood volume of ____ml/kg

Answer 9

60-70

Question 10

cell membranes permeable to

Answer 10

• Water and gases
• Urea
  and permeable via facilitated diffusion/active
  transport
• Ions
• Small hydrophilic molecules

Question 11

Channel proteins

Answer 11

provide a narrow channel for ions to pass through. This allows passage of ions down their
concentration and electrical gradient (passive)

Question 12

Carrier proteins

Answer 12

can physically bind to a substance on one side of the membrane, and release it on the other

Question 13

Large molecules can only cross cell membrane via

Answer 13

endocytosis, or exocytosis

Question 14

water is in osmotic _____

Answer 14

equilibrium

Question 15

Colloids

Answer 15

very large molecules such as proteins and starches

Question 16

osmotic pressure

Answer 16

amount of pressure that would have to be applied to a solution to prevent pure water - the solvent - from passing through a semi-permeable
membrane into the solution

Question 17

primary mechanism by which water is transported into and out of cells.

Answer 17

osmosis

Question 18

3 mechanisms that regulate movement of water and solutes between extracellular and intracellular fluid spaces in the body

Answer 18

1) large molecules like proteins cannot diffuse out of cell; influences osmotic pressure
2) ion transport via active and passive transport
3) positively charges attracts negatively charged ions

Question 19

Crystalloids

Answer 19

fluids with electrolytes and small molecules, can move between all 3 compartments (intravascular space, interstitial space intracellular space)

Question 20

colloids

Answer 20

fluids with large molecules
Stay in intravascular space, generating colloid osmotic pressure

Question 21

advantages and disadvantages of crystalloids

Answer 21

• Cheap
• Accessible
• Short half life
• Larger volume required for resuscitation

Question 22

advantages and disadvantages of colloids

Answer 22

• Longer half life
• Smaller volume required to expand intravascular volume
• Expensive
• Risk of allergic reaction

Question 23

how is movement between compartments controlled

Answer 23

Endothelial cells

essentially selective filters. They regulate the passage of gases, fluids, as well as various molecules across their cell membranes. Different organs have different types of endothelium, some are leaky and some are very tightly bound

Question 24

Homeostasis

Answer 24

Maintenance of relatively constant internal environment (“same state”) for optimal function

Question 25

what does homeostasis require

Answer 25

Consistent monitoring: Feedback Capacity to make changes and adjust internal environment: Integrated endocrine and neural response Defence against external environment: Microbes andTemperature

Question 26

negative feedback pathways

Answer 26

- Used to maintain a constant value = “set point” - Increase or decrease from set point detected → corrective mechanism - System controlled by negative feedback constantly oscillates about set point - An efficient homeostatic system minimises the size of oscillations

Question 27

every day water is lost from body in what ways

Answer 27

* Urine * Sweat * Faeces * Milk * Eggs * Respiration

Question 28

Factors affecting both the intake and output of water include

Answer 28

* Age * Sex * Obesity * Climate * Habits * Level of physical activity

Question 29

High fluid intake =

Answer 29

high fluid output

Question 30

Osmolality vs Osmolarity

Answer 30

Osmolality - amount of solutes in the solvent (mass) Osmolarity is per volume of solution (given in osmoles per litre (osmol/L)) – osmotic concentration

Question 31

Plasma osmolarity/osmolality is important for

Answer 31

keeping proper electrolytic balance in the blood stream

Question 32

Improper electrolyte balance can lead to

Answer 32

dehydration, alkalosis, acidosis or other life-threatening changes.

Question 33

Antidiuretic hormone (vasopressin)

Answer 33

controls the amount of water the body retains from the kidney

Question 34

Osmoregulation

Answer 34

Active regulation of the osmotic pressure of an organism's body fluids Maintains fluid balance and electrolyte concentrations

Question 35

____ play a large role in osmoregulation Controlled by _____

Answer 35

kidneys hypothalamus

Question 36

how does brain control osmoregulation

Answer 36

* Contains osmoreceptor cells which detect changes in osmolarity of blood passing through brain * Hypothalamus controls thirst and produces ADH (vasopressin)

Question 37

Osmolarity must be regulated to prevent loss of

Answer 37

water from cells

Question 38

cells need to maintain constant

Answer 38

volume

Question 39

how do cells Respond to swelling or shrinkage

Answer 39

by activating membrane transport/metabolic processes

Question 40

What is the approximate amount of intracellular fluid in a dog that weighs 20 kg?

Answer 40

8 L

Question 41

What percentage of a cat's total body weight is in the intravascular space (plasma)?

Answer 41

5%

Question 42

When a cell is immersed in a hypertonic solution, what happens to the cell volume?

Answer 42

The cell volume decreases, and the cell shrinks

Question 43

Which of the following statements is INCORRECT regarding the movement of water and solutes between the extracellular and intracellular fluid spaces? A. Ions are transported B. Large protein molecules are unable to diffuse out of the cell, which influences osmotic pressure C. The cell membrane is impermeable to water D. There is a charge difference across the cell membrane

Answer 43

C. The cell membrane is impermeable to water

Question 44

When delivering fluids to rehydrate a patient, what type of fluid will stay within the intravascular space?

Answer 44

Colloids